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[Draft] Patching in BTF ID + unifying vmlinux and module BTFs acquisition #14

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@walking-machine walking-machine commented Nov 4, 2021

Now both module and vmlinux BTFs are loaded to libbpf directly
from kernel. I've decided to leave the old vmlinux loading process just
in case the new one fails.

Will push another option tomorrow.

Can't say I am fully satisfied with how this looks, so pls comment :)

mswiatko and others added 12 commits September 22, 2021 21:19
Second approach to inform driver about metadata. Let user decide if
metadata should be supported or not.

Add this flag to allow user to inform driver that metadata is used.
Set flag is sent to driver via exsisting ndo_bpf call in flag field.

Signed-off-by: Michal Swiatkowski <michal.swiatkowski@intel.com>
Definition is only a proposal. There should be free place for 8B of tx
timestamp.

Signed-off-by: Michal Swiatkowski <michal.swiatkowski@intel.com>
As starting point add vlan id and rss hash if xdp metadata is supported.

Add xd_metadata_support field in VSI to allow easy passing this value to
ring configuration.

Signed-off-by: Michal Swiatkowski <michal.swiatkowski@intel.com>
Function btf_get_type_id is needed to get correct BTF id to fill
metadata by driver. BTF id is obtained while loading XDP program and
saved in ring structure to be available in irq.

Calling btf_get_type_id with null pointer as module will result in
searching for BTF id in vmlinux.

Signed-off-by: Ederson de Souza <ederson.desouza@intel.com>
Signed-off-by: Michal Swiatkowski <michal.swiatkowski@intel.com>
Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
Example prints out BTF ID returned by a libbpf helper and received in
data_meta. It's assumed, pointer to BTF ID is data - sizeof(u32).

Possible improvements:
- print out RSS and VLAN ID, use CO-RE functions for this
(this way user can avoid defining full hints structure)
- improve user application (currently it does not )

Signed-off-by: Michal Swiatkowski <michal.swiatkowski@intel.com>
Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
Type needs to be used in the kernel in order to be present in vmlinux BTF.
Future Alex's changes to cpumap will ensure this, but for now we just declare
a variable of the required type in a random place for testing purposes.
Ensure that xdp program is detached before user program termination.
Print out trace_pipe.
This allows to run example multiple times without additional commands.
It was tested on an untagged VLAN, so VID seem to be garbage.
Hash looks fine, as well as hardcoded values.
Implementation of btf__obj_id() would probably need to change to a
separate bpf syscall case, because just before commiting I've noticed
that this implementation has problems with vmlinux BTF :(.

Furthermore, syscall implementation would be useful when we'll need to
access ids data from a userspace program that's not a libbpf loader
(for example, when using AF_XDP).

Everything aside this function should be OK and can be reviewed.

Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
As I mentioned in the previous commit, current approach has problems
with vmlinux, but works fine with kernel module BTFs.

In this sample I've checked ids of struct ice_ring.

You'd probably need to rmmod irdma in order to run the example.

Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
Previous version of patching-in BTF ID did not handle vmlinux BTF case,
because unlike kernel module BTFs it was loaded into libbpf from
an actual file, not from an anonymous file descriptor.

Unfortunately, file descriptor is the only thing that links libbpf btf
to a source kernel btf and therefore to BTF obj id.

For vmlinux BTF, there existed no way to know its BTF ID even at the
moment of creation, therefore the main part of this commit is
implementation of such functionality. I've decided to implement
getting a btf_info, because getting ID application is too limited to
create a separate syscall case. The only problem I see now with this is
that currently it reuses syscall bpf_attr struct from another syscall
case.
Refactoring this would require a lot of coding, so I'd rather not do it
until someone confirms it's neccessary.

Also, I am still not sure about how do we determine if the BTF
is vmlinux.
For  now it just assumes that every BTF without the base_btf is vmlinux,
but that could also be some local or override BTF.
For now I see 2 possible solutions:
- Just return '0' if btf is not a kernel BTF, I suppose vmlinux is
  supposed to be the only kernel BTF without base
- Add 'btf_id' field to libbpf btf struct, initialize it at the moment
  of creation for both vmlinux and module BTFs
Now both module and vmlinux BTFs are loaded to libbpf directly
from kernel. I've decided to leave the old vmlinux loading process just
in case.
btf = btf_get_vmlinux_from_kernel();
if (!IS_ERR(btf))
return btf;

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So, here we can get btf by reading vmlinux info via syscall and creating new btf, or by parsing pure elf file? It looks a little strange for me, but short comment will solve this.

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It gets it using syscall which reads built-in BTF from the vmlinux section of the same name: [1]

[1] https://elixir.bootlin.com/linux/latest/source/kernel/bpf/btf.c#L4559

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For me looks nice, with which part aren't You satisfied?

@@ -1405,13 +1387,26 @@ struct btf *btf_get_from_fd(int btf_fd, struct btf *base_btf)
}

btf = btf_new(ptr, btf_info.btf_size, base_btf);
btf->fd = btf_fd;
btf->btf_id = btf_info.id;
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Is it always 0 for vmlinux? Just curious if loading from elf file will have the same result (in btf__load_vmlinux_btf if this function fails You set id to 0).

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Nah. This says that BTF core allocates an ID dynamically for vmlinux as well, starting from 1: [0]

[0] https://elixir.bootlin.com/linux/latest/source/kernel/bpf/btf.c#L4590

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I'm curious if we can create a new anon inode for vmlinux BTF to be able to get its BTF info the existing way: [2]
It should be possible.

[2] https://elixir.bootlin.com/linux/latest/source/kernel/bpf/btf.c#L5849

struct { /* anonymous struct used by BPF_BTF_VMLINUX_INFO */
__u32 info_len;
__aligned_u64 info;
} info_vmlinux;
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Please check (using pahole) if this structure has a padding between u32 and u64. If so, it may be better to explicitly enumerate it.

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Oh, BTW, I have forgot to mention this particular problem with current version, I mean that the actual syscall does not use this structure, because internal function requires "info" structure and I kinda postponed the refactoring (hoping a little bit maybe it would not be necessary).

But I'll check the padding when structure actually gets into an object file. By enumerating you mean putting additional u32 blank space?

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Right, __u32 pad or so.

@@ -873,6 +873,7 @@ enum bpf_cmd {
BPF_ITER_CREATE,
BPF_LINK_DETACH,
BPF_PROG_BIND_MAP,
BPF_BTF_VMLINUX_INFO,
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BPF_BTF_GET_VMLINUX_INFO as we discussed previously?


res = btf_mod->btf;

break;
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No empty line needed here.

@@ -6152,6 +6152,43 @@ struct module *btf_try_get_module(const struct btf *btf)
return res;
}

struct btf *btf_get_from_module(const struct module *module)
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It doesn't get exposed anywhere. static?

return res;
}

s32 btf_get_type_id(const struct module *mod, char *name, u32 kind)
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'name' can (and should) be const as well.

@@ -4430,6 +4455,10 @@ struct btf *btf__load_vmlinux_btf(void)
struct btf *btf;
int i, err;

btf = btf_get_vmlinux_from_kernel();
if (!IS_ERR(btf))
return btf;
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I think you can goto line 4475 from here (don't forget to initialize err to 0 then) instead of an immediate return. This way we'll unify the output. For now, if btf_get_vmlinux_from_kernel() returned a valid BTF, no pr_debug() occurs.


err = sys_bpf(BPF_BTF_VMLINUX_INFO, &attr, sizeof(attr));

if (!err)
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No empty line needed here.

@@ -4447,6 +4476,7 @@ struct btf *btf__load_vmlinux_btf(void)
if (err)
continue;

btf->btf_id = 0;
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Is this on purpose to distinguish if it's a vmlinux BTF or a module's one?

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It's just to signify that in case we were not able to get info from kernel, BTF ID is invalid. I have to see if getting vmlinux the new way works without module btf info enabled and if btf_id is '0' by default. Maybe I could get rid of all the stuff after the first return altogether.

@@ -1025,7 +1029,8 @@ static int bpf_core_patch_insn(const char *prog_name, struct bpf_insn *insn,
}

insn[0].imm = new_val;
insn[1].imm = 0; /* currently only 32-bit values are supported */
insn[1].imm = relo->kind == BPF_TYPE_ID_TARGET ?
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You always initialize btf_obj_id to 0 in bpf_core_calc_relo() and rewrite it only in case of !err && relo->kind == BPF_TYPE_ID_TARGET, is this condition check needed?

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Well, my thought behind that is that in the future these more significant 32 bits could be used for something else (if some other cmake builtin gets u64 return type), so this just shows that there is a possibility for such extension.

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So it's really pointless from the logical point of view, but adds some consistency in my opinion, but what do you think?

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I think one simple comment will solve potential questions. Like:

insn[1].imm = res->btf_obj_id; /* BTF ID for BPF_TYPE_ID_TARGET, 0 otherwise */

We (or any other folks) can expand this later to ifs or a switch-case later when needed.

@@ -4430,6 +4455,10 @@ struct btf *btf__load_vmlinux_btf(void)
struct btf *btf;
int i, err;

btf = btf_get_vmlinux_from_kernel();
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In the OP you said both module and vmlinux BTFs are now being loaded directly, but is it so? Seems like you call the new functionality only here, so only for vmlinux.

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I'm curious if we can create a new anon inode for vmlinux BTF to be able to get its BTF info the existing way: [2] It should be possible.

[2] https://elixir.bootlin.com/linux/latest/source/kernel/bpf/btf.c#L5849

I looks like we probably could, but I do not know if it makes sense. As far as I remember, fds are required by non-vmlinux BTFs just to prevent unloading BTFs that are used by some user processes. I guess vmlinux is not unloadable by nature.

  • we would still need to get an fd for vmlinux. Currently, the only way to do this that would not require additional syscalls like get_vmlinux_info is stumbling upon vmlinux while iterating over ids. As I've mentioned earlier, we can't load vmlinux together with other kernel BTFs (or we could after a ton of refactoring), so we are left with iterating over ids separately for vmlinux, which would work and probably won't go beyond the first iteration, but doesn't seem like a clean solution.

Therefore using inode approach would still require some separate syscall for vmlinux, just for getting the fd instead of btf_info

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You're right I think, it doesn't make sense to overcomplicate things only to avoid introducing new BPF syscall action.

alobakin pushed a commit that referenced this pull request Nov 23, 2021
The exit function fixes a memory leak with the src field as detected by
leak sanitizer. An example of which is:

Indirect leak of 25133184 byte(s) in 207 object(s) allocated from:
    #0 0x7f199ecfe987 in __interceptor_calloc libsanitizer/asan/asan_malloc_linux.cpp:154
    #1 0x55defe638224 in annotated_source__alloc_histograms util/annotate.c:803
    #2 0x55defe6397e4 in symbol__hists util/annotate.c:952
    #3 0x55defe639908 in symbol__inc_addr_samples util/annotate.c:968
    #4 0x55defe63aa29 in hist_entry__inc_addr_samples util/annotate.c:1119
    #5 0x55defe499a79 in hist_iter__report_callback tools/perf/builtin-report.c:182
    #6 0x55defe7a859d in hist_entry_iter__add util/hist.c:1236
    #7 0x55defe49aa63 in process_sample_event tools/perf/builtin-report.c:315
    #8 0x55defe731bc8 in evlist__deliver_sample util/session.c:1473
    #9 0x55defe731e38 in machines__deliver_event util/session.c:1510
    #10 0x55defe732a23 in perf_session__deliver_event util/session.c:1590
    #11 0x55defe72951e in ordered_events__deliver_event util/session.c:183
    #12 0x55defe740082 in do_flush util/ordered-events.c:244
    #13 0x55defe7407cb in __ordered_events__flush util/ordered-events.c:323
    #14 0x55defe740a61 in ordered_events__flush util/ordered-events.c:341
    #15 0x55defe73837f in __perf_session__process_events util/session.c:2390
    #16 0x55defe7385ff in perf_session__process_events util/session.c:2420
    ...

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin Liška <mliska@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20211112035124.94327-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
alobakin pushed a commit that referenced this pull request Dec 22, 2021
In `igbvf_probe`, if register_netdev() fails, the program will go to
label err_hw_init, and then to label err_ioremap. In free_netdev() which
is just below label err_ioremap, there is `list_for_each_entry_safe` and
`netif_napi_del` which aims to delete all entries in `dev->napi_list`.
The program has added an entry `adapter->rx_ring->napi` which is added by
`netif_napi_add` in igbvf_alloc_queues(). However, adapter->rx_ring has
been freed below label err_hw_init. So this a UAF.

In terms of how to patch the problem, we can refer to igbvf_remove() and
delete the entry before `adapter->rx_ring`.

The KASAN logs are as follows:

[   35.126075] BUG: KASAN: use-after-free in free_netdev+0x1fd/0x450
[   35.127170] Read of size 8 at addr ffff88810126d990 by task modprobe/366
[   35.128360]
[   35.128643] CPU: 1 PID: 366 Comm: modprobe Not tainted 5.15.0-rc2+ #14
[   35.129789] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
[   35.131749] Call Trace:
[   35.132199]  dump_stack_lvl+0x59/0x7b
[   35.132865]  print_address_description+0x7c/0x3b0
[   35.133707]  ? free_netdev+0x1fd/0x450
[   35.134378]  __kasan_report+0x160/0x1c0
[   35.135063]  ? free_netdev+0x1fd/0x450
[   35.135738]  kasan_report+0x4b/0x70
[   35.136367]  free_netdev+0x1fd/0x450
[   35.137006]  igbvf_probe+0x121d/0x1a10 [igbvf]
[   35.137808]  ? igbvf_vlan_rx_add_vid+0x100/0x100 [igbvf]
[   35.138751]  local_pci_probe+0x13c/0x1f0
[   35.139461]  pci_device_probe+0x37e/0x6c0
[   35.165526]
[   35.165806] Allocated by task 366:
[   35.166414]  ____kasan_kmalloc+0xc4/0xf0
[   35.167117]  foo_kmem_cache_alloc_trace+0x3c/0x50 [igbvf]
[   35.168078]  igbvf_probe+0x9c5/0x1a10 [igbvf]
[   35.168866]  local_pci_probe+0x13c/0x1f0
[   35.169565]  pci_device_probe+0x37e/0x6c0
[   35.179713]
[   35.179993] Freed by task 366:
[   35.180539]  kasan_set_track+0x4c/0x80
[   35.181211]  kasan_set_free_info+0x1f/0x40
[   35.181942]  ____kasan_slab_free+0x103/0x140
[   35.182703]  kfree+0xe3/0x250
[   35.183239]  igbvf_probe+0x1173/0x1a10 [igbvf]
[   35.184040]  local_pci_probe+0x13c/0x1f0

Fixes: d4e0fe0 (igbvf: add new driver to support 82576 virtual functions)
Reported-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Letu Ren <fantasquex@gmail.com>
Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
walking-machine pushed a commit that referenced this pull request Mar 10, 2022
Ido Schimmel says:

====================
HW counters for soft devices

Petr says:

Offloading switch device drivers may be able to collect statistics of the
traffic taking place in the HW datapath that pertains to a certain soft
netdevice, such as a VLAN. In this patch set, add the necessary
infrastructure to allow exposing these statistics to the offloaded
netdevice in question, and add mlxsw offload.

Across HW platforms, the counter itself very likely constitutes a limited
resource, and the act of counting may have a performance impact. Therefore
this patch set makes the HW statistics collection opt-in and togglable from
userspace on a per-netdevice basis.

Additionally, HW devices may have various limiting conditions under which
they can realize the counter. Therefore it is also possible to query
whether the requested counter is realized by any driver. In TC parlance,
which is to a degree reused in this patch set, two values are recognized:
"request" tracks whether the user enabled collecting HW statistics, and
"used" tracks whether any HW statistics are actually collected.

In the past, this author has expressed the opinion that `a typical user
doing "ip -s l sh", including various scripts, wants to see the full
picture and not worry what's going on where'. While that would be nice,
unfortunately it cannot work:

- Packets that trap from the HW datapath to the SW datapath would be
  double counted.

  For a given netdevice, some traffic can be purely a SW artifact, and some
  may flow through the HW object corresponding to the netdevice. But some
  traffic can also get trapped to the SW datapath after bumping the HW
  counter. It is not clear how to make sure double-counting does not occur
  in the SW datapath in that case, while still making sure that possibly
  divergent SW forwarding path gets bumped as appropriate.

  So simply adding HW and SW stats may work roughly, most of the time, but
  there are scenarios where the result is nonsensical.

- HW devices will have limitations as to what type of traffic they can
  count.

  In case of mlxsw, which is part of this patch set, there is no reasonable
  way to count all traffic going through a certain netdevice, such as a
  VLAN netdevice enslaved to a bridge. It is however very simple to count
  traffic flowing through an L3 object, such as a VLAN netdevice with an IP
  address.

  Similarly for physical netdevices, the L3 object at which the counter is
  installed is the subport carrying untagged traffic.

  These are not "just counters". It is important that the user understands
  what is being counted. It would be incorrect to conflate these statistics
  with another existing statistics suite.

To that end, this patch set introduces a statistics suite called "L3
stats". This label should make it easy to understand what is being counted,
and to decide whether a given device can or cannot implement this suite for
some type of netdevice. At the same time, the code is written to make
future extensions easy, should a device pop up that can implement a
different flavor of statistics suite (say L2, or an address-family-specific
suite).

For example, using a work-in-progress iproute2[1], to turn on and then list
the counters on a VLAN netdevice:

    # ip stats set dev swp1.200 l3_stats on
    # ip stats show dev swp1.200 group offload subgroup l3_stats
    56: swp1.200: group offload subgroup l3_stats on used on
	RX:  bytes packets errors dropped  missed   mcast
		0       0      0       0       0       0
	TX:  bytes packets errors dropped carrier collsns
		0       0      0       0       0       0

The patchset progresses as follows:

- Patch #1 is a cleanup.

- In patch #2, remove the assumption that all LINK_OFFLOAD_XSTATS are
  dev-backed.

  The only attribute defined under the nest is currently
  IFLA_OFFLOAD_XSTATS_CPU_HIT. L3_STATS differs from CPU_HIT in that the
  driver that supplies the statistics is not the same as the driver that
  implements the netdevice. Make the code compatible with this in patch #2.

- In patch #3, add the possibility to filter inside nests.

  The filter_mask field of RTM_GETSTATS header determines which
  top-level attributes should be included in the netlink response. This
  saves processing time by only including the bits that the user cares
  about instead of always dumping everything. This is doubly important
  for HW-backed statistics that would typically require a trip to the
  device to fetch the stats. In this patch, the UAPI is extended to
  allow filtering inside IFLA_STATS_LINK_OFFLOAD_XSTATS in particular,
  but the scheme is easily extensible to other nests as well.

- In patch #4, propagate extack where we need it.
  In patch #5, make it possible to propagate errors from drivers to the
  user.

- In patch #6, add the in-kernel APIs for keeping track of the new stats
  suite, and the notifiers that the core uses to communicate with the
  drivers.

- In patch #7, add UAPI for obtaining the new stats suite.

- In patch #8, add a new UAPI message, RTM_SETSTATS, which will carry
  the message to toggle the newly-added stats suite.
  In patch #9, add the toggle itself.

At this point the core is ready for drivers to add support for the new
stats suite.

- In patches #10, #11 and #12, apply small tweaks to mlxsw code.

- In patch #13, add support for L3 stats, which are realized as RIF
  counters.

- Finally in patch #14, a selftest is added to the net/forwarding
  directory. Technically this is a HW-specific test, in that without a HW
  implementing the counters, it just will not pass. But devices that
  support L3 statistics at all are likely to be able to reuse this
  selftest, so it seems appropriate to put it in the general forwarding
  directory.

We also have a netdevsim implementation, and a corresponding selftest that
verifies specifically some of the core code. We intend to contribute these
later. Interested parties can take a look at the raw code at [2].

[1] https://github.com/pmachata/iproute2/commits/soft_counters
[2] https://github.com/pmachata/linux_mlxsw/commits/petrm_soft_counters_2

v2:
- Patch #3:
    - Do not declare strict_start_type at the new policies, since they are
      used with nla_parse_nested() (sans _deprecated).
    - Use NLA_POLICY_NESTED to declare what the nest contents should be
    - Use NLA_POLICY_MASK instead of BITFIELD32 for the filtering
      attribute.
- Patch #6:
    - s/monotonous/monotonic/ in commit message
    - Use a newly-added struct rtnl_hw_stats64 for stats transfer
- Patch #7:
    - Use a newly-added struct rtnl_hw_stats64 for stats transfer
- Patch #8:
    - Do not declare strict_start_type at the new policies, since they are
      used with nla_parse_nested() (sans _deprecated).
- Patch #13:
    - Use a newly-added struct rtnl_hw_stats64 for stats transfer
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
alobakin pushed a commit that referenced this pull request Apr 11, 2022
Ido Schimmel says:

====================
net/sched: Better error reporting for offload failures

This patchset improves error reporting to user space when offload fails
during the flow action setup phase. That is, when failures occur in the
actions themselves, even before calling device drivers. Requested /
reported in [1].

This is done by passing extack to the offload_act_setup() callback and
making use of it in the various actions.

Patches #1-#2 change matchall and flower to log error messages to user
space in accordance with the verbose flag.

Patch #3 passes extack to the offload_act_setup() callback from the
various call sites, including matchall and flower.

Patches #4-#11 make use of extack in the various actions to report
offload failures.

Patch #12 adds an error message when the action does not support offload
at all.

Patches #13-#14 change matchall and flower to stop overwriting more
specific error messages.

[1] https://lore.kernel.org/netdev/20220317185249.5mff5u2x624pjewv@skbuf/
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
@alobakin alobakin closed this Sep 28, 2022
@alobakin alobakin deleted the generic-metadata-btf-id-unify branch September 28, 2022 10:57
alobakin pushed a commit that referenced this pull request Oct 18, 2022
ASAN reports an use-after-free in btf_dump_name_dups:

ERROR: AddressSanitizer: heap-use-after-free on address 0xffff927006db at pc 0xaaaab5dfb618 bp 0xffffdd89b890 sp 0xffffdd89b928
READ of size 2 at 0xffff927006db thread T0
    #0 0xaaaab5dfb614 in __interceptor_strcmp.part.0 (test_progs+0x21b614)
    #1 0xaaaab635f144 in str_equal_fn tools/lib/bpf/btf_dump.c:127
    #2 0xaaaab635e3e0 in hashmap_find_entry tools/lib/bpf/hashmap.c:143
    #3 0xaaaab635e72c in hashmap__find tools/lib/bpf/hashmap.c:212
    #4 0xaaaab6362258 in btf_dump_name_dups tools/lib/bpf/btf_dump.c:1525
    #5 0xaaaab636240c in btf_dump_resolve_name tools/lib/bpf/btf_dump.c:1552
    #6 0xaaaab6362598 in btf_dump_type_name tools/lib/bpf/btf_dump.c:1567
    #7 0xaaaab6360b48 in btf_dump_emit_struct_def tools/lib/bpf/btf_dump.c:912
    #8 0xaaaab6360630 in btf_dump_emit_type tools/lib/bpf/btf_dump.c:798
    #9 0xaaaab635f720 in btf_dump__dump_type tools/lib/bpf/btf_dump.c:282
    #10 0xaaaab608523c in test_btf_dump_incremental tools/testing/selftests/bpf/prog_tests/btf_dump.c:236
    #11 0xaaaab6097530 in test_btf_dump tools/testing/selftests/bpf/prog_tests/btf_dump.c:875
    #12 0xaaaab6314ed0 in run_one_test tools/testing/selftests/bpf/test_progs.c:1062
    #13 0xaaaab631a0a8 in main tools/testing/selftests/bpf/test_progs.c:1697
    #14 0xffff9676d214 in __libc_start_main ../csu/libc-start.c:308
    #15 0xaaaab5d65990  (test_progs+0x185990)

0xffff927006db is located 11 bytes inside of 16-byte region [0xffff927006d0,0xffff927006e0)
freed by thread T0 here:
    #0 0xaaaab5e2c7c4 in realloc (test_progs+0x24c7c4)
    #1 0xaaaab634f4a0 in libbpf_reallocarray tools/lib/bpf/libbpf_internal.h:191
    #2 0xaaaab634f840 in libbpf_add_mem tools/lib/bpf/btf.c:163
    #3 0xaaaab636643c in strset_add_str_mem tools/lib/bpf/strset.c:106
    #4 0xaaaab6366560 in strset__add_str tools/lib/bpf/strset.c:157
    #5 0xaaaab6352d70 in btf__add_str tools/lib/bpf/btf.c:1519
    #6 0xaaaab6353e10 in btf__add_field tools/lib/bpf/btf.c:2032
    #7 0xaaaab6084fcc in test_btf_dump_incremental tools/testing/selftests/bpf/prog_tests/btf_dump.c:232
    #8 0xaaaab6097530 in test_btf_dump tools/testing/selftests/bpf/prog_tests/btf_dump.c:875
    #9 0xaaaab6314ed0 in run_one_test tools/testing/selftests/bpf/test_progs.c:1062
    #10 0xaaaab631a0a8 in main tools/testing/selftests/bpf/test_progs.c:1697
    #11 0xffff9676d214 in __libc_start_main ../csu/libc-start.c:308
    #12 0xaaaab5d65990  (test_progs+0x185990)

previously allocated by thread T0 here:
    #0 0xaaaab5e2c7c4 in realloc (test_progs+0x24c7c4)
    #1 0xaaaab634f4a0 in libbpf_reallocarray tools/lib/bpf/libbpf_internal.h:191
    #2 0xaaaab634f840 in libbpf_add_mem tools/lib/bpf/btf.c:163
    #3 0xaaaab636643c in strset_add_str_mem tools/lib/bpf/strset.c:106
    #4 0xaaaab6366560 in strset__add_str tools/lib/bpf/strset.c:157
    #5 0xaaaab6352d70 in btf__add_str tools/lib/bpf/btf.c:1519
    #6 0xaaaab6353ff0 in btf_add_enum_common tools/lib/bpf/btf.c:2070
    #7 0xaaaab6354080 in btf__add_enum tools/lib/bpf/btf.c:2102
    #8 0xaaaab6082f50 in test_btf_dump_incremental tools/testing/selftests/bpf/prog_tests/btf_dump.c:162
    #9 0xaaaab6097530 in test_btf_dump tools/testing/selftests/bpf/prog_tests/btf_dump.c:875
    #10 0xaaaab6314ed0 in run_one_test tools/testing/selftests/bpf/test_progs.c:1062
    #11 0xaaaab631a0a8 in main tools/testing/selftests/bpf/test_progs.c:1697
    #12 0xffff9676d214 in __libc_start_main ../csu/libc-start.c:308
    #13 0xaaaab5d65990  (test_progs+0x185990)

The reason is that the key stored in hash table name_map is a string
address, and the string memory is allocated by realloc() function, when
the memory is resized by realloc() later, the old memory may be freed,
so the address stored in name_map references to a freed memory, causing
use-after-free.

Fix it by storing duplicated string address in name_map.

Fixes: 919d2b1 ("libbpf: Allow modification of BTF and add btf__add_str API")
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/bpf/20221011120108.782373-2-xukuohai@huaweicloud.com
alobakin pushed a commit that referenced this pull request Feb 21, 2023
Petr Machata says:

====================
bridge: Limit number of MDB entries per port, port-vlan

The MDB maintained by the bridge is limited. When the bridge is configured
for IGMP / MLD snooping, a buggy or malicious client can easily exhaust its
capacity. In SW datapath, the capacity is configurable through the
IFLA_BR_MCAST_HASH_MAX parameter, but ultimately is finite. Obviously a
similar limit exists in the HW datapath for purposes of offloading.

In order to prevent the issue of unilateral exhaustion of MDB resources,
introduce two parameters in each of two contexts:

- Per-port and (when BROPT_MCAST_VLAN_SNOOPING_ENABLED is enabled)
  per-port-VLAN number of MDB entries that the port is member in.

- Per-port and (when BROPT_MCAST_VLAN_SNOOPING_ENABLED is enabled)
  per-port-VLAN maximum permitted number of MDB entries, or 0 for
  no limit.

Per-port number of entries keeps track of the total number of MDB entries
configured on a given port. The per-port-VLAN value then keeps track of the
subset of MDB entries configured specifically for the given VLAN, on that
port. The number is adjusted as port_groups are created and deleted, and
therefore under multicast lock.

A maximum value, if non-zero, then places a limit on the number of entries
that can be configured in a given context. Attempts to add entries above
the maximum are rejected.

Rejection reason of netlink-based requests to add MDB entries is
communicated through extack. This channel is unavailable for rejections
triggered from the control path. To address this lack of visibility, the
patchset adds a tracepoint, bridge:br_mdb_full:

	# perf record -e bridge:br_mdb_full &
	# [...]
	# perf script | cut -d: -f4-
	 dev v2 af 2 src ::ffff:0.0.0.0 grp ::ffff:239.1.1.112/00:00:00:00:00:00 vid 0
	 dev v2 af 10 src :: grp ff0e::112/00:00:00:00:00:00 vid 0
	 dev v2 af 2 src ::ffff:0.0.0.0 grp ::ffff:239.1.1.112/00:00:00:00:00:00 vid 10
	 dev v2 af 10 src 2001:db8:1::1 grp ff0e::1/00:00:00:00:00:00 vid 10
	 dev v2 af 2 src ::ffff:192.0.2.1 grp ::ffff:239.1.1.1/00:00:00:00:00:00 vid 10

Another option to consume the tracepoint is e.g. through the bpftrace tool:

	# bpftrace -e ' tracepoint:bridge:br_mdb_full /args->af != 0/ {
			    printf("dev %s src %s grp %s vid %u\n",
				   str(args->dev), ntop(args->src),
				   ntop(args->grp), args->vid);
			}
			tracepoint:bridge:br_mdb_full /args->af == 0/ {
			    printf("dev %s grp %s vid %u\n",
				   str(args->dev),
				   macaddr(args->grpmac), args->vid);
			}'

This tracepoint is triggered for mcast_hash_max exhaustions as well.

The following is an example of how the feature is used. A more extensive
example is available in patch #8:

	# bridge vlan set dev v1 vid 1 mcast_max_groups 1
	# bridge mdb add dev br port v1 grp 230.1.2.3 temp vid 1
	# bridge mdb add dev br port v1 grp 230.1.2.4 temp vid 1
	Error: bridge: Port-VLAN is already in 1 groups, and mcast_max_groups=1.

The patchset progresses as follows:

- In patch #1, set strict_start_type at two bridge-related policies. The
  reason is we are adding a new attribute to one of these, and want the new
  attribute to be parsed strictly. The other was adjusted for completeness'
  sake.

- In patches #2 to #5, br_mdb and br_multicast code is adjusted to make the
  following additions smoother.

- In patch #6, add the tracepoint.

- In patch #7, the code to maintain number of MDB entries is added as
  struct net_bridge_mcast_port::mdb_n_entries. The maximum is added, too,
  as struct net_bridge_mcast_port::mdb_max_entries, however at this point
  there is no way to set the value yet, and since 0 is treated as "no
  limit", the functionality doesn't change at this point. Note however,
  that mcast_hash_max violations already do trigger at this point.

- In patch #8, netlink plumbing is added: reading of number of entries, and
  reading and writing of maximum.

  The per-port values are passed through RTM_NEWLINK / RTM_GETLINK messages
  in IFLA_BRPORT_MCAST_N_GROUPS and _MAX_GROUPS, inside IFLA_PROTINFO nest.

  The per-port-vlan values are passed through RTM_GETVLAN / RTM_NEWVLAN
  messages in BRIDGE_VLANDB_ENTRY_MCAST_N_GROUPS, _MAX_GROUPS, inside
  BRIDGE_VLANDB_ENTRY.

The following patches deal with the selftest:

- Patches #9 and #10 clean up and move around some selftest code.

- Patches #11 to #14 add helpers and generalize the existing IGMP / MLD
  support to allow generating packets with configurable group addresses and
  varying source lists for (S,G) memberships.

- Patch #15 adds code to generate IGMP leave and MLD done packets.

- Patch #16 finally adds the selftest itself.

v3:
- Patch #7:
    - Access mdb_max_/_n_entries through READ_/WRITE_ONCE
    - Move extack setting to br_multicast_port_ngroups_inc_one().
      Since we use NL_SET_ERR_MSG_FMT_MOD, the correct context
      (port / port-vlan) can be passed through an argument.
      This also removes the need for more READ/WRITE_ONCE's
      at the extack-setting site.
- Patch #8:
    - Move the br_multicast_port_ctx_vlan_disabled() check
      out to the _vlan_ helpers callers. Thus these helpers
      cannot fail, which makes them very similar to the
      _port_ helpers. Have them take the MC context directly
      and unify them.

v2:
- Cover letter:
    - Add an example of a bpftrace-based probe script
- Patch #6:
    - Report IPv4 as an IPv6-mapped address through the IPv6 buffer
      as well, to save ring buffer space.
- Patch #7:
    - In br_multicast_port_ngroups_inc_one(), bounce
      if n>=max, not if n==max
    - Adjust extack messages to mention ngroups, now
      that the bounces appear when n>=max, not n==max
    - In __br_multicast_enable_port_ctx(), do not reset
      max to 0. Also do not count number of entries by
      going through _inc, as that would end up incorrectly
      bouncing the entries.
- Patch #8:
    - Drop locks around accesses in
      br_multicast_{port,vlan}_ngroups_{get,set_max}(),
    - Drop bounces due to max<n in
      br_multicast_{port,vlan}_ngroups_set_max().
- Patch #12:
    - In the comment at payload_template_calc_checksum(),
      s/%#02x/%02x/, that's the mausezahn payload format.
- Patch #16:
    - Adjust the tests that check setting max below n and
      reset of max on VLAN snooping enablement
    - Make test naming uniform
    - Enable testing of control path (IGMP/MLD) in
      mcast_vlan_snooping bridge
    - Reorganize the code so that test instances (per bridge
      type and configuration type) always come right after
      the test, in order of {d,q,qvs}{4,6}{cfg,ctl}.
      Then groups of selftests are at the end of the file.
      Similarly adjust invocation order of the tests.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
alobakin pushed a commit that referenced this pull request May 8, 2023
Add support precision backtracking in the presence of subprogram frames in
jump history.

This means supporting a few different kinds of subprogram invocation
situations, all requiring a slightly different handling in precision
backtracking handling logic:
  - static subprogram calls;
  - global subprogram calls;
  - callback-calling helpers/kfuncs.

For each of those we need to handle a few precision propagation cases:
  - what to do with precision of subprog returns (r0);
  - what to do with precision of input arguments;
  - for all of them callee-saved registers in caller function should be
    propagated ignoring subprog/callback part of jump history.

N.B. Async callback-calling helpers (currently only
bpf_timer_set_callback()) are transparent to all this because they set
a separate async callback environment and thus callback's history is not
shared with main program's history. So as far as all the changes in this
commit goes, such helper is just a regular helper.

Let's look at all these situation in more details. Let's start with
static subprogram being called, using an exxerpt of a simple main
program and its static subprog, indenting subprog's frame slightly to
make everything clear.

frame 0				frame 1			precision set
=======				=======			=============

 9: r6 = 456;
10: r1 = 123;						fr0: r6
11: call pc+10;						fr0: r1, r6
				22: r0 = r1;		fr0: r6;     fr1: r1
				23: exit		fr0: r6;     fr1: r0
12: r1 = <map_pointer>					fr0: r0, r6
13: r1 += r0;						fr0: r0, r6
14: r1 += r6;						fr0: r6
15: exit

As can be seen above main function is passing 123 as single argument to
an identity (`return x;`) subprog. Returned value is used to adjust map
pointer offset, which forces r0 to be marked as precise. Then
instruction #14 does the same for callee-saved r6, which will have to be
backtracked all the way to instruction #9. For brevity, precision sets
for instruction #13 and #14 are combined in the diagram above.

First, for subprog calls, r0 returned from subprog (in frame 0) has to
go into subprog's frame 1, and should be cleared from frame 0. So we go
back into subprog's frame knowing we need to mark r0 precise. We then
see that insn #22 sets r0 from r1, so now we care about marking r1
precise.  When we pop up from subprog's frame back into caller at
insn #11 we keep r1, as it's an argument-passing register, so we eventually
find `10: r1 = 123;` and satify precision propagation chain for insn #13.

This example demonstrates two sets of rules:
  - r0 returned after subprog call has to be moved into subprog's r0 set;
  - *static* subprog arguments (r1-r5) are moved back to caller precision set.

Let's look at what happens with callee-saved precision propagation. Insn #14
mark r6 as precise. When we get into subprog's frame, we keep r6 in
frame 0's precision set *only*. Subprog itself has its own set of
independent r6-r10 registers and is not affected. When we eventually
made our way out of subprog frame we keep r6 in precision set until we
reach `9: r6 = 456;`, satisfying propagation. r6-r10 propagation is
perhaps the simplest aspect, it always stays in its original frame.

That's pretty much all we have to do to support precision propagation
across *static subprog* invocation.

Let's look at what happens when we have global subprog invocation.

frame 0				frame 1			precision set
=======				=======			=============

 9: r6 = 456;
10: r1 = 123;						fr0: r6
11: call pc+10; # global subprog			fr0: r6
12: r1 = <map_pointer>					fr0: r0, r6
13: r1 += r0;						fr0: r0, r6
14: r1 += r6;						fr0: r6;
15: exit

Starting from insn #13, r0 has to be precise. We backtrack all the way
to insn #11 (call pc+10) and see that subprog is global, so was already
validated in isolation. As opposed to static subprog, global subprog
always returns unknown scalar r0, so that satisfies precision
propagation and we drop r0 from precision set. We are done for insns #13.

Now for insn #14. r6 is in precision set, we backtrack to `call pc+10;`.
Here we need to recognize that this is effectively both exit and entry
to global subprog, which means we stay in caller's frame. So we carry on
with r6 still in precision set, until we satisfy it at insn #9. The only
hard part with global subprogs is just knowing when it's a global func.

Lastly, callback-calling helpers and kfuncs do simulate subprog calls,
so jump history will have subprog instructions in between caller
program's instructions, but the rules of propagating r0 and r1-r5
differ, because we don't actually directly call callback. We actually
call helper/kfunc, which at runtime will call subprog, so the only
difference between normal helper/kfunc handling is that we need to make
sure to skip callback simulatinog part of jump history.
Let's look at an example to make this clearer.

frame 0				frame 1			precision set
=======				=======			=============

 8: r6 = 456;
 9: r1 = 123;						fr0: r6
10: r2 = &callback;					fr0: r6
11: call bpf_loop;					fr0: r6
				22: r0 = r1;		fr0: r6      fr1:
				23: exit		fr0: r6      fr1:
12: r1 = <map_pointer>					fr0: r0, r6
13: r1 += r0;						fr0: r0, r6
14: r1 += r6;						fr0: r6;
15: exit

Again, insn #13 forces r0 to be precise. As soon as we get to `23: exit`
we see that this isn't actually a static subprog call (it's `call
bpf_loop;` helper call instead). So we clear r0 from precision set.

For callee-saved register, there is no difference: it stays in frame 0's
precision set, we go through insn #22 and #23, ignoring them until we
get back to caller frame 0, eventually satisfying precision backtrack
logic at insn #8 (`r6 = 456;`).

Assuming callback needed to set r0 as precise at insn #23, we'd
backtrack to insn #22, switching from r0 to r1, and then at the point
when we pop back to frame 0 at insn #11, we'll clear r1-r5 from
precision set, as we don't really do a subprog call directly, so there
is no input argument precision propagation.

That's pretty much it. With these changes, it seems like the only still
unsupported situation for precision backpropagation is the case when
program is accessing stack through registers other than r10. This is
still left as unsupported (though rare) case for now.

As for results. For selftests, few positive changes for bigger programs,
cls_redirect in dynptr variant benefitting the most:

[vmuser@archvm bpf]$ ./veristat -C ~/subprog-precise-before-results.csv ~/subprog-precise-after-results.csv -f @veristat.cfg -e file,prog,insns -f 'insns_diff!=0'
File                                      Program        Insns (A)  Insns (B)  Insns     (DIFF)
----------------------------------------  -------------  ---------  ---------  ----------------
pyperf600_bpf_loop.bpf.linked1.o          on_event            2060       2002      -58 (-2.82%)
test_cls_redirect_dynptr.bpf.linked1.o    cls_redirect       15660       2914  -12746 (-81.39%)
test_cls_redirect_subprogs.bpf.linked1.o  cls_redirect       61620      59088    -2532 (-4.11%)
xdp_synproxy_kern.bpf.linked1.o           syncookie_tc      109980      86278  -23702 (-21.55%)
xdp_synproxy_kern.bpf.linked1.o           syncookie_xdp      97716      85147  -12569 (-12.86%)

Cilium progress don't really regress. They don't use subprogs and are
mostly unaffected, but some other fixes and improvements could have
changed something. This doesn't appear to be the case:

[vmuser@archvm bpf]$ ./veristat -C ~/subprog-precise-before-results-cilium.csv ~/subprog-precise-after-results-cilium.csv -e file,prog,insns -f 'insns_diff!=0'
File           Program                         Insns (A)  Insns (B)  Insns (DIFF)
-------------  ------------------------------  ---------  ---------  ------------
bpf_host.o     tail_nodeport_nat_ingress_ipv6       4983       5003  +20 (+0.40%)
bpf_lxc.o      tail_nodeport_nat_ingress_ipv6       4983       5003  +20 (+0.40%)
bpf_overlay.o  tail_nodeport_nat_ingress_ipv6       4983       5003  +20 (+0.40%)
bpf_xdp.o      tail_handle_nat_fwd_ipv6            12475      12504  +29 (+0.23%)
bpf_xdp.o      tail_nodeport_nat_ingress_ipv6       6363       6371   +8 (+0.13%)

Looking at (somewhat anonymized) Meta production programs, we see mostly
insignificant variation in number of instructions, with one program
(syar_bind6_protect6) benefitting the most at -17%.

[vmuser@archvm bpf]$ ./veristat -C ~/subprog-precise-before-results-fbcode.csv ~/subprog-precise-after-results-fbcode.csv -e prog,insns -f 'insns_diff!=0'
Program                   Insns (A)  Insns (B)  Insns     (DIFF)
------------------------  ---------  ---------  ----------------
on_request_context_event        597        585      -12 (-2.01%)
read_async_py_stack           43789      43657     -132 (-0.30%)
read_sync_py_stack            35041      37599    +2558 (+7.30%)
rrm_usdt                        946        940       -6 (-0.63%)
sysarmor_inet6_bind           28863      28249     -614 (-2.13%)
sysarmor_inet_bind            28845      28240     -605 (-2.10%)
syar_bind4_protect4          154145     147640    -6505 (-4.22%)
syar_bind6_protect6          165242     137088  -28154 (-17.04%)
syar_task_exit_setgid         21289      19720    -1569 (-7.37%)
syar_task_exit_setuid         21290      19721    -1569 (-7.37%)
do_uprobe                     19967      19413     -554 (-2.77%)
tw_twfw_ingress              215877     204833   -11044 (-5.12%)
tw_twfw_tc_in                215877     204833   -11044 (-5.12%)

But checking duration (wall clock) differences, that is the actual time taken
by verifier to validate programs, we see a sometimes dramatic improvements, all
the way to about 16x improvements:

[vmuser@archvm bpf]$ ./veristat -C ~/subprog-precise-before-results-meta.csv ~/subprog-precise-after-results-meta.csv -e prog,duration -s duration_diff^ | head -n20
Program                                   Duration (us) (A)  Duration (us) (B)  Duration (us) (DIFF)
----------------------------------------  -----------------  -----------------  --------------------
tw_twfw_ingress                                     4488374             272836    -4215538 (-93.92%)
tw_twfw_tc_in                                       4339111             268175    -4070936 (-93.82%)
tw_twfw_egress                                      3521816             270751    -3251065 (-92.31%)
tw_twfw_tc_eg                                       3472878             284294    -3188584 (-91.81%)
balancer_ingress                                     343119             291391      -51728 (-15.08%)
syar_bind6_protect6                                   78992              64782      -14210 (-17.99%)
ttls_tc_ingress                                       11739               8176       -3563 (-30.35%)
kprobe__security_inode_link                           13864              11341       -2523 (-18.20%)
read_sync_py_stack                                    21927              19442       -2485 (-11.33%)
read_async_py_stack                                   30444              28136        -2308 (-7.58%)
syar_task_exit_setuid                                 10256               8440       -1816 (-17.71%)

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230505043317.3629845-9-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
alobakin pushed a commit that referenced this pull request Jun 13, 2023
The cited commit adds a compeletion to remove dependency on rtnl
lock. But it causes a deadlock for multiple encapsulations:

 crash> bt ffff8aece8a64000
 PID: 1514557  TASK: ffff8aece8a64000  CPU: 3    COMMAND: "tc"
  #0 [ffffa6d14183f368] __schedule at ffffffffb8ba7f45
  #1 [ffffa6d14183f3f8] schedule at ffffffffb8ba8418
  #2 [ffffa6d14183f418] schedule_preempt_disabled at ffffffffb8ba8898
  #3 [ffffa6d14183f428] __mutex_lock at ffffffffb8baa7f8
  #4 [ffffa6d14183f4d0] mutex_lock_nested at ffffffffb8baabeb
  #5 [ffffa6d14183f4e0] mlx5e_attach_encap at ffffffffc0f48c17 [mlx5_core]
  #6 [ffffa6d14183f628] mlx5e_tc_add_fdb_flow at ffffffffc0f39680 [mlx5_core]
  #7 [ffffa6d14183f688] __mlx5e_add_fdb_flow at ffffffffc0f3b636 [mlx5_core]
  #8 [ffffa6d14183f6f0] mlx5e_tc_add_flow at ffffffffc0f3bcdf [mlx5_core]
  #9 [ffffa6d14183f728] mlx5e_configure_flower at ffffffffc0f3c1d1 [mlx5_core]
 #10 [ffffa6d14183f790] mlx5e_rep_setup_tc_cls_flower at ffffffffc0f3d529 [mlx5_core]
 #11 [ffffa6d14183f7a0] mlx5e_rep_setup_tc_cb at ffffffffc0f3d714 [mlx5_core]
 #12 [ffffa6d14183f7b0] tc_setup_cb_add at ffffffffb8931bb8
 #13 [ffffa6d14183f810] fl_hw_replace_filter at ffffffffc0dae901 [cls_flower]
 #14 [ffffa6d14183f8d8] fl_change at ffffffffc0db5c57 [cls_flower]
 #15 [ffffa6d14183f970] tc_new_tfilter at ffffffffb8936047
 #16 [ffffa6d14183fac8] rtnetlink_rcv_msg at ffffffffb88c7c31
 #17 [ffffa6d14183fb50] netlink_rcv_skb at ffffffffb8942853
 #18 [ffffa6d14183fbc0] rtnetlink_rcv at ffffffffb88c1835
 #19 [ffffa6d14183fbd0] netlink_unicast at ffffffffb8941f27
 #20 [ffffa6d14183fc18] netlink_sendmsg at ffffffffb8942245
 #21 [ffffa6d14183fc98] sock_sendmsg at ffffffffb887d482
 #22 [ffffa6d14183fcb8] ____sys_sendmsg at ffffffffb887d81a
 #23 [ffffa6d14183fd38] ___sys_sendmsg at ffffffffb88806e2
 #24 [ffffa6d14183fe90] __sys_sendmsg at ffffffffb88807a2
 #25 [ffffa6d14183ff28] __x64_sys_sendmsg at ffffffffb888080f
 #26 [ffffa6d14183ff38] do_syscall_64 at ffffffffb8b9b6a8
 #27 [ffffa6d14183ff50] entry_SYSCALL_64_after_hwframe at ffffffffb8c0007c
 crash> bt 0xffff8aeb07544000
 PID: 1110766  TASK: ffff8aeb07544000  CPU: 0    COMMAND: "kworker/u20:9"
  #0 [ffffa6d14e6b7bd8] __schedule at ffffffffb8ba7f45
  #1 [ffffa6d14e6b7c68] schedule at ffffffffb8ba8418
  #2 [ffffa6d14e6b7c88] schedule_timeout at ffffffffb8baef88
  #3 [ffffa6d14e6b7d10] wait_for_completion at ffffffffb8ba968b
  #4 [ffffa6d14e6b7d60] mlx5e_take_all_encap_flows at ffffffffc0f47ec4 [mlx5_core]
  #5 [ffffa6d14e6b7da0] mlx5e_rep_update_flows at ffffffffc0f3e734 [mlx5_core]
  #6 [ffffa6d14e6b7df8] mlx5e_rep_neigh_update at ffffffffc0f400bb [mlx5_core]
  #7 [ffffa6d14e6b7e50] process_one_work at ffffffffb80acc9c
  #8 [ffffa6d14e6b7ed0] worker_thread at ffffffffb80ad012
  #9 [ffffa6d14e6b7f10] kthread at ffffffffb80b615d
 #10 [ffffa6d14e6b7f50] ret_from_fork at ffffffffb8001b2f

After the first encap is attached, flow will be added to encap
entry's flows list. If neigh update is running at this time, the
following encaps of the flow can't hold the encap_tbl_lock and
sleep. If neigh update thread is waiting for that flow's init_done,
deadlock happens.

Fix it by holding lock outside of the for loop. If neigh update is
running, prevent encap flows from offloading. Since the lock is held
outside of the for loop, concurrent creation of encap entries is not
allowed. So remove unnecessary wait_for_completion call for res_ready.

Fixes: 95435ad ("net/mlx5e: Only access fully initialized flows in neigh update")
Signed-off-by: Chris Mi <cmi@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
alobakin pushed a commit that referenced this pull request Jun 13, 2023
Currently, the per cpu upcall counters are allocated after the vport is
created and inserted into the system. This could lead to the datapath
accessing the counters before they are allocated resulting in a kernel
Oops.

Here is an example:

  PID: 59693    TASK: ffff0005f4f51500  CPU: 0    COMMAND: "ovs-vswitchd"
   #0 [ffff80000a39b5b0] __switch_to at ffffb70f0629f2f4
   #1 [ffff80000a39b5d0] __schedule at ffffb70f0629f5cc
   #2 [ffff80000a39b650] preempt_schedule_common at ffffb70f0629fa60
   #3 [ffff80000a39b670] dynamic_might_resched at ffffb70f0629fb58
   #4 [ffff80000a39b680] mutex_lock_killable at ffffb70f062a1388
   #5 [ffff80000a39b6a0] pcpu_alloc at ffffb70f0594460c
   #6 [ffff80000a39b750] __alloc_percpu_gfp at ffffb70f05944e68
   #7 [ffff80000a39b760] ovs_vport_cmd_new at ffffb70ee6961b90 [openvswitch]
   ...

  PID: 58682    TASK: ffff0005b2f0bf00  CPU: 0    COMMAND: "kworker/0:3"
   #0 [ffff80000a5d2f40] machine_kexec at ffffb70f056a0758
   #1 [ffff80000a5d2f70] __crash_kexec at ffffb70f057e2994
   #2 [ffff80000a5d3100] crash_kexec at ffffb70f057e2ad8
   #3 [ffff80000a5d3120] die at ffffb70f0628234c
   #4 [ffff80000a5d31e0] die_kernel_fault at ffffb70f062828a8
   #5 [ffff80000a5d3210] __do_kernel_fault at ffffb70f056a31f4
   #6 [ffff80000a5d3240] do_bad_area at ffffb70f056a32a4
   #7 [ffff80000a5d3260] do_translation_fault at ffffb70f062a9710
   #8 [ffff80000a5d3270] do_mem_abort at ffffb70f056a2f74
   #9 [ffff80000a5d32a0] el1_abort at ffffb70f06297dac
  #10 [ffff80000a5d32d0] el1h_64_sync_handler at ffffb70f06299b24
  #11 [ffff80000a5d3410] el1h_64_sync at ffffb70f056812dc
  #12 [ffff80000a5d3430] ovs_dp_upcall at ffffb70ee6963c84 [openvswitch]
  #13 [ffff80000a5d3470] ovs_dp_process_packet at ffffb70ee6963fdc [openvswitch]
  #14 [ffff80000a5d34f0] ovs_vport_receive at ffffb70ee6972c78 [openvswitch]
  #15 [ffff80000a5d36f0] netdev_port_receive at ffffb70ee6973948 [openvswitch]
  #16 [ffff80000a5d3720] netdev_frame_hook at ffffb70ee6973a28 [openvswitch]
  #17 [ffff80000a5d3730] __netif_receive_skb_core.constprop.0 at ffffb70f06079f90

We moved the per cpu upcall counter allocation to the existing vport
alloc and free functions to solve this.

Fixes: 95637d9 ("net: openvswitch: release vport resources on failure")
Fixes: 1933ea3 ("net: openvswitch: Add support to count upcall packets")
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Acked-by: Aaron Conole <aconole@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
alobakin pushed a commit that referenced this pull request Jul 10, 2023
The buffer is used to save register mapping in a sample.  Normally
perf samples don't have any register so the string should be empty.
But it missed to initialize the buffer when the size is 0.  And it's
passed to PyUnicode_FromString() with a garbage data.

So it returns NULL due to invalid input (instead of an empty unicode
string object) which causes a segfault like below:

  Thread 2.1 "perf" received signal SIGSEGV, Segmentation fault.
  [Switching to Thread 0x7ffff7c83780 (LWP 193775)]
  0x00007ffff6dbca2e in PyDict_SetItem () from /lib/x86_64-linux-gnu/libpython3.11.so.1.0
  (gdb) bt
  #0  0x00007ffff6dbca2e in PyDict_SetItem () from /lib/x86_64-linux-gnu/libpython3.11.so.1.0
  #1  0x00007ffff6dbf848 in PyDict_SetItemString () from /lib/x86_64-linux-gnu/libpython3.11.so.1.0
  #2  0x000055555575824d in pydict_set_item_string_decref (val=0x0, key=0x5555557f96e3 "iregs", dict=0x7ffff5f7f780)
      at util/scripting-engines/trace-event-python.c:145
  #3  set_regs_in_dict (evsel=0x555555efc370, sample=0x7fffffffb870, dict=0x7ffff5f7f780)
      at util/scripting-engines/trace-event-python.c:776
  #4  get_perf_sample_dict (sample=sample@entry=0x7fffffffb870, evsel=evsel@entry=0x555555efc370, al=al@entry=0x7fffffffb2e0,
      addr_al=addr_al@entry=0x0, callchain=callchain@entry=0x7ffff63ef440) at util/scripting-engines/trace-event-python.c:923
  #5  0x0000555555758ec1 in python_process_tracepoint (sample=0x7fffffffb870, evsel=0x555555efc370, al=0x7fffffffb2e0, addr_al=0x0)
      at util/scripting-engines/trace-event-python.c:1044
  #6  0x00005555555c5db8 in process_sample_event (tool=<optimized out>, event=<optimized out>, sample=<optimized out>,
      evsel=0x555555efc370, machine=0x555555ef4d68) at builtin-script.c:2421
  #7  0x00005555556b7793 in perf_session__deliver_event (session=0x555555ef4b60, event=0x7ffff62ff7d0, tool=0x7fffffffc150,
      file_offset=30672, file_path=0x555555efb8a0 "perf.data") at util/session.c:1639
  #8  0x00005555556bc864 in do_flush (show_progress=true, oe=0x555555efb700) at util/ordered-events.c:245
  #9  __ordered_events__flush (oe=oe@entry=0x555555efb700, how=how@entry=OE_FLUSH__FINAL, timestamp=timestamp@entry=0)
      at util/ordered-events.c:324
  #10 0x00005555556bd06e in ordered_events__flush (oe=oe@entry=0x555555efb700, how=how@entry=OE_FLUSH__FINAL)
      at util/ordered-events.c:342
  #11 0x00005555556b9d63 in __perf_session__process_events (session=0x555555ef4b60) at util/session.c:2465
  #12 perf_session__process_events (session=0x555555ef4b60) at util/session.c:2627
  #13 0x00005555555cb1d0 in __cmd_script (script=0x7fffffffc150) at builtin-script.c:2839
  #14 cmd_script (argc=<optimized out>, argv=<optimized out>) at builtin-script.c:4365
  #15 0x0000555555650811 in run_builtin (p=p@entry=0x555555ed8948 <commands+456>, argc=argc@entry=4, argv=argv@entry=0x7fffffffe240)
      at perf.c:323
  #16 0x0000555555597eb3 in handle_internal_command (argv=0x7fffffffe240, argc=4) at perf.c:377
  #17 run_argv (argv=<synthetic pointer>, argcp=<synthetic pointer>) at perf.c:421
  #18 main (argc=4, argv=0x7fffffffe240) at perf.c:537

Fixes: 51cfe7a ("perf python: Avoid 2 leak sanitizer issues")
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
alobakin pushed a commit that referenced this pull request Jul 24, 2023
Petr Machata says:

====================
mlxsw: Permit enslavement to netdevices with uppers

The mlxsw driver currently makes the assumption that the user applies
configuration in a bottom-up manner. Thus netdevices need to be added to
the bridge before IP addresses are configured on that bridge or SVI added
on top of it. Enslaving a netdevice to another netdevice that already has
uppers is in fact forbidden by mlxsw for this reason. Despite this safety,
it is rather easy to get into situations where the offloaded configuration
is just plain wrong.

As an example, take a front panel port, configure an IP address: it gets a
RIF. Now enslave the port to the bridge, and the RIF is gone. Remove the
port from the bridge again, but the RIF never comes back. There is a number
of similar situations, where changing the configuration there and back
utterly breaks the offload.

Similarly, detaching a front panel port from a configured topology means
unoffloading of this whole topology -- VLAN uppers, next hops, etc.
Attaching the port back is then not permitted at all. If it were, it would
not result in a working configuration, because much of mlxsw is written to
react to changes in immediate configuration. There is nothing that would go
visit netdevices in the attached-to topology and offload existing routes
and VLAN memberships, for example.

In this patchset, introduce a number of replays to be invoked so that this
sort of post-hoc offload is supported. Then remove the vetoes that
disallowed enslavement of front panel ports to other netdevices with
uppers.

The patchset progresses as follows:

- In patch #1, fix an issue in the bridge driver. To my knowledge, the
  issue could not have resulted in a buggy behavior previously, and thus is
  packaged with this patchset instead of being sent separately to net.

- In patch #2, add a new helper to the switchdev code.

- In patch #3, drop mlxsw selftests that will not be relevant after this
  patchset anymore.

- Patches #4, #5, #6, #7 and #8 prepare the codebase for smoother
  introduction of the rest of the code.

- Patches #9, #10, #11, #12, #13 and #14 replay various aspects of upper
  configuration when a front panel port is introduced into a topology.
  Individual patches take care of bridge and LAG RIF memberships, switchdev
  replay, nexthop and neighbors replay, and MACVLAN offload.

- Patches #15 and #16 introduce RIFs for newly-relevant netdevices when a
  front panel port is enslaved (in which case all uppers are newly
  relevant), or, respectively, deslaved (in which case the newly-relevant
  netdevice is the one being deslaved).

- Up until this point, the introduced scaffolding was not really used,
  because mlxsw still forbids enslavement of mlxsw netdevices to uppers
  with uppers. In patch #17, this condition is finally relaxed.

A sizable selftest suite is available to test all this new code. That will
be sent in a separate patchset.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
alobakin pushed a commit that referenced this pull request Aug 4, 2023
The cited commit holds encap tbl lock unconditionally when setting
up dests. But it may cause the following deadlock:

 PID: 1063722  TASK: ffffa062ca5d0000  CPU: 13   COMMAND: "handler8"
  #0 [ffffb14de05b7368] __schedule at ffffffffa1d5aa91
  #1 [ffffb14de05b7410] schedule at ffffffffa1d5afdb
  #2 [ffffb14de05b7430] schedule_preempt_disabled at ffffffffa1d5b528
  #3 [ffffb14de05b7440] __mutex_lock at ffffffffa1d5d6cb
  #4 [ffffb14de05b74e8] mutex_lock_nested at ffffffffa1d5ddeb
  #5 [ffffb14de05b74f8] mlx5e_tc_tun_encap_dests_set at ffffffffc12f2096 [mlx5_core]
  #6 [ffffb14de05b7568] post_process_attr at ffffffffc12d9fc5 [mlx5_core]
  #7 [ffffb14de05b75a0] mlx5e_tc_add_fdb_flow at ffffffffc12de877 [mlx5_core]
  #8 [ffffb14de05b75f0] __mlx5e_add_fdb_flow at ffffffffc12e0eef [mlx5_core]
  #9 [ffffb14de05b7660] mlx5e_tc_add_flow at ffffffffc12e12f7 [mlx5_core]
 #10 [ffffb14de05b76b8] mlx5e_configure_flower at ffffffffc12e1686 [mlx5_core]
 #11 [ffffb14de05b7720] mlx5e_rep_indr_offload at ffffffffc12e3817 [mlx5_core]
 #12 [ffffb14de05b7730] mlx5e_rep_indr_setup_tc_cb at ffffffffc12e388a [mlx5_core]
 #13 [ffffb14de05b7740] tc_setup_cb_add at ffffffffa1ab2ba8
 #14 [ffffb14de05b77a0] fl_hw_replace_filter at ffffffffc0bdec2f [cls_flower]
 #15 [ffffb14de05b7868] fl_change at ffffffffc0be6caa [cls_flower]
 #16 [ffffb14de05b7908] tc_new_tfilter at ffffffffa1ab71f0

[1031218.028143]  wait_for_completion+0x24/0x30
[1031218.028589]  mlx5e_update_route_decap_flows+0x9a/0x1e0 [mlx5_core]
[1031218.029256]  mlx5e_tc_fib_event_work+0x1ad/0x300 [mlx5_core]
[1031218.029885]  process_one_work+0x24e/0x510

Actually no need to hold encap tbl lock if there is no encap action.
Fix it by checking if encap action exists or not before holding
encap tbl lock.

Fixes: 37c3b9f ("net/mlx5e: Prevent encap offload when neigh update is running")
Signed-off-by: Chris Mi <cmi@nvidia.com>
Reviewed-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
alobakin pushed a commit that referenced this pull request Aug 24, 2023
…inux/kernel/git/saeed/linux

Saeed Mahameed says:

====================
mlx5-updates-2023-08-22

1) Patches #1..#13 From Jiri:

The goal of this patchset is to make the SF code cleaner.

Benefit from previously introduced devlink_port struct containerization
to avoid unnecessary lookups in devlink port ops.

Also, benefit from the devlink locking changes and avoid unnecessary
reference counting.

2) Patches #14,#15:

Add ability to configure proto both UDP and TCP selectors in RX and TX
directions.

* tag 'mlx5-updates-2023-08-22' of git://git.kernel.org/pub/scm/linux/kernel/git/saeed/linux:
  net/mlx5e: Support IPsec upper TCP protocol selector
  net/mlx5e: Support IPsec upper protocol selector field offload for RX
  net/mlx5: Store vport in struct mlx5_devlink_port and use it in port ops
  net/mlx5: Check vhca_resource_manager capability in each op and add extack msg
  net/mlx5: Relax mlx5_devlink_eswitch_get() return value checking
  net/mlx5: Return -EOPNOTSUPP in mlx5_devlink_port_fn_migratable_set() directly
  net/mlx5: Reduce number of vport lookups passing vport pointer instead of index
  net/mlx5: Embed struct devlink_port into driver structure
  net/mlx5: Don't register ops for non-PF/VF/SF port and avoid checks in ops
  net/mlx5: Remove no longer used mlx5_esw_offloads_sf_vport_enable/disable()
  net/mlx5: Introduce mlx5_eswitch_load/unload_sf_vport() and use it from SF code
  net/mlx5: Allow mlx5_esw_offloads_devlink_port_register() to register SFs
  net/mlx5: Push devlink port PF/VF init/cleanup calls out of devlink_port_register/unregister()
  net/mlx5: Push out SF devlink port init and cleanup code to separate helpers
  net/mlx5: Rework devlink port alloc/free into init/cleanup
====================

Link: https://lore.kernel.org/all/20230823051012.162483-1-saeed@kernel.org/
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
alobakin pushed a commit that referenced this pull request Sep 11, 2023
Noticed with:

  make EXTRA_CFLAGS="-fsanitize=address" BUILD_BPF_SKEL=1 CORESIGHT=1 O=/tmp/build/perf-tools-next -C tools/perf install-bin

Direct leak of 45 byte(s) in 1 object(s) allocated from:
    #0 0x7f213f87243b in strdup (/lib64/libasan.so.8+0x7243b)
    #1 0x63d15f in evsel__set_filter util/evsel.c:1371
    #2 0x63d15f in evsel__append_filter util/evsel.c:1387
    #3 0x63d15f in evsel__append_tp_filter util/evsel.c:1400
    #4 0x62cd52 in evlist__append_tp_filter util/evlist.c:1145
    #5 0x62cd52 in evlist__append_tp_filter_pids util/evlist.c:1196
    #6 0x541e49 in trace__set_filter_loop_pids /home/acme/git/perf-tools/tools/perf/builtin-trace.c:3646
    #7 0x541e49 in trace__set_filter_pids /home/acme/git/perf-tools/tools/perf/builtin-trace.c:3670
    #8 0x541e49 in trace__run /home/acme/git/perf-tools/tools/perf/builtin-trace.c:3970
    #9 0x541e49 in cmd_trace /home/acme/git/perf-tools/tools/perf/builtin-trace.c:5141
    #10 0x5ef1a2 in run_builtin /home/acme/git/perf-tools/tools/perf/perf.c:323
    #11 0x4196da in handle_internal_command /home/acme/git/perf-tools/tools/perf/perf.c:377
    #12 0x4196da in run_argv /home/acme/git/perf-tools/tools/perf/perf.c:421
    #13 0x4196da in main /home/acme/git/perf-tools/tools/perf/perf.c:537
    #14 0x7f213e84a50f in __libc_start_call_main (/lib64/libc.so.6+0x2750f)

Free it on evsel__exit().

Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/20230719202951.534582-2-acme@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
alobakin pushed a commit that referenced this pull request Sep 11, 2023
To plug these leaks detected with:

  $ make EXTRA_CFLAGS="-fsanitize=address" BUILD_BPF_SKEL=1 CORESIGHT=1 O=/tmp/build/perf-tools-next -C tools/perf install-bin

  =================================================================
  ==473890==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 112 byte(s) in 1 object(s) allocated from:
    #0 0x7fdf19aba097 in calloc (/lib64/libasan.so.8+0xba097)
    #1 0x987836 in zalloc (/home/acme/bin/perf+0x987836)
    #2 0x5367ae in thread_trace__new /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:1289
    #3 0x5367ae in thread__trace /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:1307
    #4 0x5367ae in trace__sys_exit /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:2468
    #5 0x52bf34 in trace__handle_event /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3177
    #6 0x52bf34 in __trace__deliver_event /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3685
    #7 0x542927 in trace__deliver_event /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3712
    #8 0x542927 in trace__run /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:4055
    #9 0x542927 in cmd_trace /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:5141
    #10 0x5ef1a2 in run_builtin /home/acme/git/perf-tools-next/tools/perf/perf.c:323
    #11 0x4196da in handle_internal_command /home/acme/git/perf-tools-next/tools/perf/perf.c:377
    #12 0x4196da in run_argv /home/acme/git/perf-tools-next/tools/perf/perf.c:421
    #13 0x4196da in main /home/acme/git/perf-tools-next/tools/perf/perf.c:537
    #14 0x7fdf18a4a50f in __libc_start_call_main (/lib64/libc.so.6+0x2750f)

  Direct leak of 2048 byte(s) in 1 object(s) allocated from:
    #0 0x7f788fcba6af in __interceptor_malloc (/lib64/libasan.so.8+0xba6af)
    #1 0x5337c0 in trace__sys_enter /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:2342
    #2 0x52bfb4 in trace__handle_event /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3191
    #3 0x52bfb4 in __trace__deliver_event /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3699
    #4 0x542883 in trace__deliver_event /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3726
    #5 0x542883 in trace__run /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:4069
    #6 0x542883 in cmd_trace /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:5155
    #7 0x5ef232 in run_builtin /home/acme/git/perf-tools-next/tools/perf/perf.c:323
    #8 0x4196da in handle_internal_command /home/acme/git/perf-tools-next/tools/perf/perf.c:377
    #9 0x4196da in run_argv /home/acme/git/perf-tools-next/tools/perf/perf.c:421
    #10 0x4196da in main /home/acme/git/perf-tools-next/tools/perf/perf.c:537
    #11 0x7f788ec4a50f in __libc_start_call_main (/lib64/libc.so.6+0x2750f)

  Indirect leak of 48 byte(s) in 1 object(s) allocated from:
    #0 0x7fdf19aba6af in __interceptor_malloc (/lib64/libasan.so.8+0xba6af)
    #1 0x77b335 in intlist__new util/intlist.c:116
    #2 0x5367fd in thread_trace__new /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:1293
    #3 0x5367fd in thread__trace /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:1307
    #4 0x5367fd in trace__sys_exit /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:2468
    #5 0x52bf34 in trace__handle_event /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3177
    #6 0x52bf34 in __trace__deliver_event /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3685
    #7 0x542927 in trace__deliver_event /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3712
    #8 0x542927 in trace__run /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:4055
    #9 0x542927 in cmd_trace /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:5141
    #10 0x5ef1a2 in run_builtin /home/acme/git/perf-tools-next/tools/perf/perf.c:323
    #11 0x4196da in handle_internal_command /home/acme/git/perf-tools-next/tools/perf/perf.c:377
    #12 0x4196da in run_argv /home/acme/git/perf-tools-next/tools/perf/perf.c:421
    #13 0x4196da in main /home/acme/git/perf-tools-next/tools/perf/perf.c:537
    #14 0x7fdf18a4a50f in __libc_start_call_main (/lib64/libc.so.6+0x2750f)

Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/20230719202951.534582-4-acme@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
alobakin pushed a commit that referenced this pull request Sep 11, 2023
…failure to add a probe

Building perf with EXTRA_CFLAGS="-fsanitize=address" a leak is detect
when trying to add a probe to a non-existent function:

  # perf probe -x ~/bin/perf dso__neW
  Probe point 'dso__neW' not found.
    Error: Failed to add events.

  =================================================================
  ==296634==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 128 byte(s) in 1 object(s) allocated from:
      #0 0x7f67642ba097 in calloc (/lib64/libasan.so.8+0xba097)
      #1 0x7f67641a76f1 in allocate_cfi (/lib64/libdw.so.1+0x3f6f1)

  Direct leak of 65 byte(s) in 1 object(s) allocated from:
      #0 0x7f67642b95b5 in __interceptor_realloc.part.0 (/lib64/libasan.so.8+0xb95b5)
      #1 0x6cac75 in strbuf_grow util/strbuf.c:64
      #2 0x6ca934 in strbuf_init util/strbuf.c:25
      #3 0x9337d2 in synthesize_perf_probe_point util/probe-event.c:2018
      #4 0x92be51 in try_to_find_probe_trace_events util/probe-event.c:964
      #5 0x93d5c6 in convert_to_probe_trace_events util/probe-event.c:3512
      #6 0x93d6d5 in convert_perf_probe_events util/probe-event.c:3529
      #7 0x56f37f in perf_add_probe_events /var/home/acme/git/perf-tools-next/tools/perf/builtin-probe.c:354
      #8 0x572fbc in __cmd_probe /var/home/acme/git/perf-tools-next/tools/perf/builtin-probe.c:738
      #9 0x5730f2 in cmd_probe /var/home/acme/git/perf-tools-next/tools/perf/builtin-probe.c:766
      #10 0x635d81 in run_builtin /var/home/acme/git/perf-tools-next/tools/perf/perf.c:323
      #11 0x6362c1 in handle_internal_command /var/home/acme/git/perf-tools-next/tools/perf/perf.c:377
      #12 0x63667a in run_argv /var/home/acme/git/perf-tools-next/tools/perf/perf.c:421
      #13 0x636b8d in main /var/home/acme/git/perf-tools-next/tools/perf/perf.c:537
      #14 0x7f676302950f in __libc_start_call_main (/lib64/libc.so.6+0x2950f)

  SUMMARY: AddressSanitizer: 193 byte(s) leaked in 2 allocation(s).
  #

synthesize_perf_probe_point() returns a "detachec" strbuf, i.e. a
malloc'ed string that needs to be free'd.

An audit will be performed to find other such cases.

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/ZM0l1Oxamr4SVjfY@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
alobakin pushed a commit that referenced this pull request Oct 4, 2023
The following processes run into a deadlock. CPU 41 was waiting for CPU 29
to handle a CSD request while holding spinlock "crashdump_lock", but CPU 29
was hung by that spinlock with IRQs disabled.

  PID: 17360    TASK: ffff95c1090c5c40  CPU: 41  COMMAND: "mrdiagd"
  !# 0 [ffffb80edbf37b58] __read_once_size at ffffffff9b871a40 include/linux/compiler.h:185:0
  !# 1 [ffffb80edbf37b58] atomic_read at ffffffff9b871a40 arch/x86/include/asm/atomic.h:27:0
  !# 2 [ffffb80edbf37b58] dump_stack at ffffffff9b871a40 lib/dump_stack.c:54:0
   # 3 [ffffb80edbf37b78] csd_lock_wait_toolong at ffffffff9b131ad5 kernel/smp.c:364:0
   # 4 [ffffb80edbf37b78] __csd_lock_wait at ffffffff9b131ad5 kernel/smp.c:384:0
   # 5 [ffffb80edbf37bf8] csd_lock_wait at ffffffff9b13267a kernel/smp.c:394:0
   # 6 [ffffb80edbf37bf8] smp_call_function_many at ffffffff9b13267a kernel/smp.c:843:0
   # 7 [ffffb80edbf37c50] smp_call_function at ffffffff9b13279d kernel/smp.c:867:0
   # 8 [ffffb80edbf37c50] on_each_cpu at ffffffff9b13279d kernel/smp.c:976:0
   # 9 [ffffb80edbf37c78] flush_tlb_kernel_range at ffffffff9b085c4b arch/x86/mm/tlb.c:742:0
   #10 [ffffb80edbf37cb8] __purge_vmap_area_lazy at ffffffff9b23a1e0 mm/vmalloc.c:701:0
   #11 [ffffb80edbf37ce0] try_purge_vmap_area_lazy at ffffffff9b23a2cc mm/vmalloc.c:722:0
   #12 [ffffb80edbf37ce0] free_vmap_area_noflush at ffffffff9b23a2cc mm/vmalloc.c:754:0
   #13 [ffffb80edbf37cf8] free_unmap_vmap_area at ffffffff9b23bb3b mm/vmalloc.c:764:0
   #14 [ffffb80edbf37cf8] remove_vm_area at ffffffff9b23bb3b mm/vmalloc.c:1509:0
   #15 [ffffb80edbf37d18] __vunmap at ffffffff9b23bb8a mm/vmalloc.c:1537:0
   #16 [ffffb80edbf37d40] vfree at ffffffff9b23bc85 mm/vmalloc.c:1612:0
   #17 [ffffb80edbf37d58] megasas_free_host_crash_buffer [megaraid_sas] at ffffffffc020b7f2 drivers/scsi/megaraid/megaraid_sas_fusion.c:3932:0
   #18 [ffffb80edbf37d80] fw_crash_state_store [megaraid_sas] at ffffffffc01f804d drivers/scsi/megaraid/megaraid_sas_base.c:3291:0
   #19 [ffffb80edbf37dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0
   #20 [ffffb80edbf37dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0
   #21 [ffffb80edbf37de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0
   #22 [ffffb80edbf37e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0
   #23 [ffffb80edbf37ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0
   #24 [ffffb80edbf37ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0
   #25 [ffffb80edbf37ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0
   #26 [ffffb80edbf37f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0
   #27 [ffffb80edbf37f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0

  PID: 17355    TASK: ffff95c1090c3d80  CPU: 29  COMMAND: "mrdiagd"
  !# 0 [ffffb80f2d3c7d30] __read_once_size at ffffffff9b0f2ab0 include/linux/compiler.h:185:0
  !# 1 [ffffb80f2d3c7d30] native_queued_spin_lock_slowpath at ffffffff9b0f2ab0 kernel/locking/qspinlock.c:368:0
   # 2 [ffffb80f2d3c7d58] pv_queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/paravirt.h:674:0
   # 3 [ffffb80f2d3c7d58] queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/qspinlock.h:53:0
   # 4 [ffffb80f2d3c7d68] queued_spin_lock at ffffffff9b8961a6 include/asm-generic/qspinlock.h:90:0
   # 5 [ffffb80f2d3c7d68] do_raw_spin_lock_flags at ffffffff9b8961a6 include/linux/spinlock.h:173:0
   # 6 [ffffb80f2d3c7d68] __raw_spin_lock_irqsave at ffffffff9b8961a6 include/linux/spinlock_api_smp.h:122:0
   # 7 [ffffb80f2d3c7d68] _raw_spin_lock_irqsave at ffffffff9b8961a6 kernel/locking/spinlock.c:160:0
   # 8 [ffffb80f2d3c7d88] fw_crash_buffer_store [megaraid_sas] at ffffffffc01f8129 drivers/scsi/megaraid/megaraid_sas_base.c:3205:0
   # 9 [ffffb80f2d3c7dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0
   #10 [ffffb80f2d3c7dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0
   #11 [ffffb80f2d3c7de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0
   #12 [ffffb80f2d3c7e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0
   #13 [ffffb80f2d3c7ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0
   #14 [ffffb80f2d3c7ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0
   #15 [ffffb80f2d3c7ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0
   #16 [ffffb80f2d3c7f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0
   #17 [ffffb80f2d3c7f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0

The lock is used to synchronize different sysfs operations, it doesn't
protect any resource that will be touched by an interrupt. Consequently
it's not required to disable IRQs. Replace the spinlock with a mutex to fix
the deadlock.

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Link: https://lore.kernel.org/r/20230828221018.19471-1-junxiao.bi@oracle.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
alobakin pushed a commit that referenced this pull request Oct 4, 2023
Fix an error detected by memory sanitizer:
```
==4033==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x55fb0fbedfc7 in read_alias_info tools/perf/util/pmu.c:457:6
    #1 0x55fb0fbea339 in check_info_data tools/perf/util/pmu.c:1434:2
    #2 0x55fb0fbea339 in perf_pmu__check_alias tools/perf/util/pmu.c:1504:9
    #3 0x55fb0fbdca85 in parse_events_add_pmu tools/perf/util/parse-events.c:1429:32
    #4 0x55fb0f965230 in parse_events_parse tools/perf/util/parse-events.y:299:6
    #5 0x55fb0fbdf6b2 in parse_events__scanner tools/perf/util/parse-events.c:1822:8
    #6 0x55fb0fbdf8c1 in __parse_events tools/perf/util/parse-events.c:2094:8
    #7 0x55fb0fa8ffa9 in parse_events tools/perf/util/parse-events.h:41:9
    #8 0x55fb0fa8ffa9 in test_event tools/perf/tests/parse-events.c:2393:8
    #9 0x55fb0fa8f458 in test__pmu_events tools/perf/tests/parse-events.c:2551:15
    #10 0x55fb0fa6d93f in run_test tools/perf/tests/builtin-test.c:242:9
    #11 0x55fb0fa6d93f in test_and_print tools/perf/tests/builtin-test.c:271:8
    #12 0x55fb0fa6d082 in __cmd_test tools/perf/tests/builtin-test.c:442:5
    #13 0x55fb0fa6d082 in cmd_test tools/perf/tests/builtin-test.c:564:9
    #14 0x55fb0f942720 in run_builtin tools/perf/perf.c:322:11
    #15 0x55fb0f942486 in handle_internal_command tools/perf/perf.c:375:8
    #16 0x55fb0f941dab in run_argv tools/perf/perf.c:419:2
    #17 0x55fb0f941dab in main tools/perf/perf.c:535:3
```

Fixes: 7b723db ("perf pmu: Be lazy about loading event info files from sysfs")
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@arm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Link: https://lore.kernel.org/r/20230914022425.1489035-1-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
alobakin pushed a commit that referenced this pull request Oct 4, 2023
The following call trace shows a deadlock issue due to recursive locking of
mutex "device_mutex". First lock acquire is in target_for_each_device() and
second in target_free_device().

 PID: 148266   TASK: ffff8be21ffb5d00  CPU: 10   COMMAND: "iscsi_ttx"
  #0 [ffffa2bfc9ec3b18] __schedule at ffffffffa8060e7f
  #1 [ffffa2bfc9ec3ba0] schedule at ffffffffa8061224
  #2 [ffffa2bfc9ec3bb8] schedule_preempt_disabled at ffffffffa80615ee
  #3 [ffffa2bfc9ec3bc8] __mutex_lock at ffffffffa8062fd7
  #4 [ffffa2bfc9ec3c40] __mutex_lock_slowpath at ffffffffa80631d3
  #5 [ffffa2bfc9ec3c50] mutex_lock at ffffffffa806320c
  #6 [ffffa2bfc9ec3c68] target_free_device at ffffffffc0935998 [target_core_mod]
  #7 [ffffa2bfc9ec3c90] target_core_dev_release at ffffffffc092f975 [target_core_mod]
  #8 [ffffa2bfc9ec3ca0] config_item_put at ffffffffa79d250f
  #9 [ffffa2bfc9ec3cd0] config_item_put at ffffffffa79d2583
 #10 [ffffa2bfc9ec3ce0] target_devices_idr_iter at ffffffffc0933f3a [target_core_mod]
 #11 [ffffa2bfc9ec3d00] idr_for_each at ffffffffa803f6fc
 #12 [ffffa2bfc9ec3d60] target_for_each_device at ffffffffc0935670 [target_core_mod]
 #13 [ffffa2bfc9ec3d98] transport_deregister_session at ffffffffc0946408 [target_core_mod]
 #14 [ffffa2bfc9ec3dc8] iscsit_close_session at ffffffffc09a44a6 [iscsi_target_mod]
 #15 [ffffa2bfc9ec3df0] iscsit_close_connection at ffffffffc09a4a88 [iscsi_target_mod]
 #16 [ffffa2bfc9ec3df8] finish_task_switch at ffffffffa76e5d07
 #17 [ffffa2bfc9ec3e78] iscsit_take_action_for_connection_exit at ffffffffc0991c23 [iscsi_target_mod]
 #18 [ffffa2bfc9ec3ea0] iscsi_target_tx_thread at ffffffffc09a403b [iscsi_target_mod]
 #19 [ffffa2bfc9ec3f08] kthread at ffffffffa76d8080
 #20 [ffffa2bfc9ec3f50] ret_from_fork at ffffffffa8200364

Fixes: 36d4cb4 ("scsi: target: Avoid that EXTENDED COPY commands trigger lock inversion")
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Link: https://lore.kernel.org/r/20230918225848.66463-1-junxiao.bi@oracle.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
alobakin pushed a commit that referenced this pull request Nov 15, 2023
The top syzbot report for networking (#14 for the entire kernel)
is the queue timeout splat. We kept it around for a long time,
because in real life it provides pretty strong signal that
something is wrong with the driver or the device.

Removing it is also likely to break monitoring for those who
track it as a kernel warning.

Nevertheless, WARN()ings are best suited for catching kernel
programming bugs. If a Tx queue gets starved due to a pause
storm, priority configuration, or other weirdness - that's
obviously a problem, but not a problem we can fix at
the kernel level.

Bite the bullet and convert the WARN() to a print.

Before:

  NETDEV WATCHDOG: eni1np1 (netdevsim): transmit queue 0 timed out 1975 ms
  WARNING: CPU: 0 PID: 0 at net/sched/sch_generic.c:525 dev_watchdog+0x39e/0x3b0
  [... completely pointless stack trace of a timer follows ...]

Now:

  netdevsim netdevsim1 eni1np1: NETDEV WATCHDOG: CPU: 0: transmit queue 0 timed out 1769 ms

Alternatively we could mark the drivers which syzbot has
learned to abuse as "print-instead-of-WARN" selectively.

Reported-by: syzbot+d55372214aff0faa1f1f@syzkaller.appspotmail.com
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
alobakin pushed a commit that referenced this pull request Nov 20, 2023
Petr Machata says:

====================
mlxsw: Add support for new reset flow

Ido Schimmel writes:

This patchset changes mlxsw to issue a PCI reset during probe and
devlink reload so that the PCI firmware could be upgraded without a
reboot.

Unlike the old version of this patchset [1], in this version the driver
no longer tries to issue a PCI reset by triggering a PCI link toggle on
its own, but instead calls the PCI core to issue the reset.

The PCI APIs require the device lock to be held which is why patches

Patches #7 adds reset method quirk for NVIDIA Spectrum devices.

Patch #8 adds a debug level print in PCI core so that device ready delay
will be printed even if it is shorter than one second.

Patches #9-#11 are straightforward preparations in mlxsw.

Patch #12 finally implements the new reset flow in mlxsw.

Patch #13 adds PCI reset handlers in mlxsw to avoid user space from
resetting the device from underneath an unaware driver. Instead, the
driver is gracefully de-initialized before the PCI reset and then
initialized again after it.

Patch #14 adds a PCI reset selftest to make sure this code path does not
regress.

[1] https://lore.kernel.org/netdev/cover.1679502371.git.petrm@nvidia.com/
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
alobakin pushed a commit that referenced this pull request Nov 23, 2023
Petr Machata says:

====================
mlxsw: Preparations for support of CFF flood mode

PGT is an in-HW table that maps addresses to sets of ports. Then when some
HW process needs a set of ports as an argument, instead of embedding the
actual set in the dynamic configuration, what gets configured is the
address referencing the set. The HW then works with the appropriate PGT
entry.

Among other allocations, the PGT currently contains two large blocks for
bridge flooding: one for 802.1q and one for 802.1d. Within each of these
blocks are three tables, for unknown-unicast, multicast and broadcast
flooding:

      . . . |    802.1q    |    802.1d    | . . .
            | UC | MC | BC | UC | MC | BC |
             \______ _____/ \_____ ______/
                    v             v
                   FID flood vectors

Thus each FID (which corresponds to an 802.1d bridge or one VLAN in an
802.1q bridge) uses three flood vectors spread across a fairly large region
of PGT.

This way of organizing the flood table (called "controlled") is not very
flexible. E.g. to decrease a bridge scale and store more IP MC vectors, one
would need to completely rewrite the bridge PGT blocks, or resort to hacks
such as storing individual MC flood vectors into unused part of the bridge
table.

In order to address these shortcomings, Spectrum-2 and above support what
is called CFF flood mode, for Compressed FID Flooding. In CFF flood mode,
each FID has a little table of its own, with three entries adjacent to each
other, one for unknown-UC, one for MC, one for BC. This allows for a much
more fine-grained approach to PGT management, where bits of it are
allocated on demand.

      . . . | FID | FID | FID | FID | FID | . . .
            |U|M|B|U|M|B|U|M|B|U|M|B|U|M|B|
             \_____________ _____________/
                           v
                   FID flood vectors

Besides the FID table organization, the CFF flood mode also impacts Router
Subport (RSP) table. This table contains flood vectors for rFIDs, which are
FIDs that reference front panel ports or LAGs. The RSP table contains two
entries per front panel port and LAG, one for unknown-UC traffic, and one
for everything else. Currently, the FW allocates and manages the table in
its own part of PGT. rFIDs are marked with flood_rsp bit and managed
specially. In CFF mode, rFIDs are managed as all other FIDs. The driver
therefore has to allocate and maintain the flood vectors. Like with bridge
FIDs, this is more work, but increases flexibility of the system.

The FW currently supports both the controlled and CFF flood modes. To shed
complexity, in the future it should only support CFF flood mode. Hence this
patchset, which is the first in series of two to add CFF flood mode support
to mlxsw.

There are FW versions out there that do not support CFF flood mode, and on
Spectrum-1 in particular, there is no plan to support it at all. mlxsw will
therefore have to support both controlled flood mode as well as CFF.

Another aspect is that at least on Spectrum-1, there are FW versions out
there that claim to support CFF flood mode, but then reject or ignore
configurations enabling the same. The driver thus has to have a say in
whether an attempt to configure CFF flood mode should even be made.

Much like with the LAG mode, the feature is therefore expressed in terms of
"does the driver prefer CFF flood mode?", and "what flood mode the PCI
module managed to configure the FW with". This gives to the driver a chance
to determine whether CFF flood mode configuration should be attempted.

In this patchset, we lay the ground with new definitions, registers and
their fields, and some minor code shaping. The next patchset will be more
focused on introducing necessary abstractions and implementation.

- Patches #1 and #2 add CFF-related items to the command interface.

- Patch #3 adds a new resource, for maximum number of flood profiles
  supported. (A flood profile is a mapping between traffic type and offset
  in the per-FID flood vector table.)

- Patches #4 to #8 adjust reg.h. The SFFP register is added, which is used
  for configuring the abovementioned traffic-type-to-offset mapping. The
  SFMR, register, which serves for FID configuration, is extended with
  fields specific to CFF mode. And other minor adjustments.

- Patches #9 and #10 add the plumbing for CFF mode: a way to request that
  CFF flood mode be configured, and a way to query the flood mode that was
  actually configured.

- Patch #11 removes dead code.

- Patches #12 and #13 add helpers that the next patchset will make use of.
  Patch #14 moves RIF setup ahead so that FID code can make use of it.
====================

Link: https://lore.kernel.org/r/cover.1700503643.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
alobakin pushed a commit that referenced this pull request Nov 30, 2023
Petr Machata says:

====================
mlxsw: Support CFF flood mode

The registers to configure to initialize a flood table differ between the
controlled and CFF flood modes. In therefore needs to be an op. Add it,
hook up the current init to the existing families, and invoke the op.

PGT is an in-HW table that maps addresses to sets of ports. Then when some
HW process needs a set of ports as an argument, instead of embedding the
actual set in the dynamic configuration, what gets configured is the
address referencing the set. The HW then works with the appropriate PGT
entry.

Among other allocations, the PGT currently contains two large blocks for
bridge flooding: one for 802.1q and one for 802.1d. Within each of these
blocks are three tables, for unknown-unicast, multicast and broadcast
flooding:

      . . . |    802.1q    |    802.1d    | . . .
            | UC | MC | BC | UC | MC | BC |
             \______ _____/ \_____ ______/
                    v             v
                   FID flood vectors

Thus each FID (which corresponds to an 802.1d bridge or one VLAN in an
802.1q bridge) uses three flood vectors spread across a fairly large region
of PGT.

This way of organizing the flood table (called "controlled") is not very
flexible. E.g. to decrease a bridge scale and store more IP MC vectors, one
would need to completely rewrite the bridge PGT blocks, or resort to hacks
such as storing individual MC flood vectors into unused part of the bridge
table.

In order to address these shortcomings, Spectrum-2 and above support what
is called CFF flood mode, for Compressed FID Flooding. In CFF flood mode,
each FID has a little table of its own, with three entries adjacent to each
other, one for unknown-UC, one for MC, one for BC. This allows for a much
more fine-grained approach to PGT management, where bits of it are
allocated on demand.

      . . . | FID | FID | FID | FID | FID | . . .
            |U|M|B|U|M|B|U|M|B|U|M|B|U|M|B|
             \_____________ _____________/
                           v
                   FID flood vectors

Besides the FID table organization, the CFF flood mode also impacts Router
Subport (RSP) table. This table contains flood vectors for rFIDs, which are
FIDs that reference front panel ports or LAGs. The RSP table contains two
entries per front panel port and LAG, one for unknown-UC traffic, and one
for everything else. Currently, the FW allocates and manages the table in
its own part of PGT. rFIDs are marked with flood_rsp bit and managed
specially. In CFF mode, rFIDs are managed as all other FIDs. The driver
therefore has to allocate and maintain the flood vectors. Like with bridge
FIDs, this is more work, but increases flexibility of the system.

The FW currently supports both the controlled and CFF flood modes. To shed
complexity, in the future it should only support CFF flood mode. Hence this
patchset, which adds CFF flood mode support to mlxsw.

Since mlxsw needs to maintain both the controlled mode as well as CFF mode
support, we will keep the layout as compatible as possible. The bridge
tables will stay in the same overall shape, just their inner organization
will change from flood mode -> FID to FID -> flood mode. Likewise will RSP
be kept as a contiguous block of PGT memory, as was the case when the FW
maintained it.

- The way FIDs get configured under the CFF flood mode differs from the
  currently used controlled mode. The simple approach of having several
  globally visible arrays for spectrum.c to statically choose from no
  longer works.

  Patch #1 thus privatizes all FID initialization and finalization logic,
  and exposes it as ops instead.

- Patch #2 renames the ops that are specific to the controlled mode, to
  make room in the namespace for the CFF variants.

  Patch #3 extracts a helper to compute flood table base out of
  mlxsw_sp_fid_flood_table_mid().

- The op fid_setup configured fid_offset, i.e. the number of this FID
  within its family. For rFIDs in CFF mode, to determine this number, the
  driver will need to do fallible queries.

  Thus in patch #4, make the FID setup operation fallible as well.

- Flood mode initialization routine differs between the controlled and CFF
  flood modes. The controlled mode needs to configure flood table layout,
  which the CFF mode does not need to do.

  In patch #5, move mlxsw_sp_fid_flood_table_init() up so that the
  following patch can make use of it.

  In patch #6, add an op to be invoked per table (if defined).

- The current way of determining PGT allocation size depends on the number
  of FIDs and number of flood tables. RFIDs however have PGT footprint
  depending not on number of FIDs, but on number of ports and LAGs, because
  which ports an rFID should flood to does not depend on the FID itself,
  but on the port or LAG that it references.

  Therefore in patch #7, add FID family ops for determining PGT allocation
  size.

- As elaborated above, layout of PGT will differ between controlled and CFF
  flood modes. In CFF mode, it will further differ between rFIDs and other
  FIDs (as described at previous patch). The way to pack the SFMR register
  to configure a FID will likewise differ from controlled to CFF.

  Thus in patches #8 and #9 add FID family ops to determine PGT base
  address for a FID and to pack SFMR.

- Patches #10 and #11 add more bits for RSP support. In patch #10, add a
  new traffic type enumerator, for non-UC traffic. This is a combination of
  BC and MC traffic, but the way that mlxsw maps these mnemonic names to
  actual traffic type configurations requires that we have a new name to
  describe this class of traffic.

  Patch #11 then adds hooks necessary for RSP table maintenance. As ports
  come and go, and join and leave LAGs, it is necessary to update flood
  vectors that the rFIDs use. These new hooks will make that possible.

- Patches #12, #13 and #14 introduce flood profiles. These have been
  implicit so far, but the way that CFF flood mode works with profile IDs
  requires that we make them explicit.

  Thus in patch #12, introduce flood profile objects as a set of flood
  tables that FID families then refer to. The FID code currently only
  uses a single flood profile.

  In patch #13, add a flood profile ID to flood profile objects.

  In patch #14, when in CFF mode, configure SFFP according to the existing
  flood profiles (or the one that exists as of that point).

- Patches #15 and #16 add code to implement, respectively, bridge FIDs and
  RSP FIDs in CFF mode.

- In patch #17, toggle flood_mode_prefer_cff on Spectrum-2 and above, which
  makes the newly-added code live.
====================

Link: https://lore.kernel.org/r/cover.1701183891.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
alobakin pushed a commit that referenced this pull request Dec 18, 2023
When creating ceq_0 during probing irdma, cqp.sc_cqp will be sent as a
cqp_request to cqp->sc_cqp.sq_ring. If the request is pending when
removing the irdma driver or unplugging its aux device, cqp.sc_cqp will be
dereferenced as wrong struct in irdma_free_pending_cqp_request().

  PID: 3669   TASK: ffff88aef892c000  CPU: 28  COMMAND: "kworker/28:0"
   #0 [fffffe0000549e38] crash_nmi_callback at ffffffff810e3a34
   #1 [fffffe0000549e40] nmi_handle at ffffffff810788b2
   #2 [fffffe0000549ea0] default_do_nmi at ffffffff8107938f
   #3 [fffffe0000549eb8] do_nmi at ffffffff81079582
   #4 [fffffe0000549ef0] end_repeat_nmi at ffffffff82e016b4
      [exception RIP: native_queued_spin_lock_slowpath+1291]
      RIP: ffffffff8127e72b  RSP: ffff88aa841ef778  RFLAGS: 00000046
      RAX: 0000000000000000  RBX: ffff88b01f849700  RCX: ffffffff8127e47e
      RDX: 0000000000000000  RSI: 0000000000000004  RDI: ffffffff83857ec0
      RBP: ffff88afe3e4efc8   R8: ffffed15fc7c9dfa   R9: ffffed15fc7c9dfa
      R10: 0000000000000001  R11: ffffed15fc7c9df9  R12: 0000000000740000
      R13: ffff88b01f849708  R14: 0000000000000003  R15: ffffed1603f092e1
      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0000
  -- <NMI exception stack> --
   #5 [ffff88aa841ef778] native_queued_spin_lock_slowpath at ffffffff8127e72b
   #6 [ffff88aa841ef7b0] _raw_spin_lock_irqsave at ffffffff82c22aa4
   #7 [ffff88aa841ef7c8] __wake_up_common_lock at ffffffff81257363
   #8 [ffff88aa841ef888] irdma_free_pending_cqp_request at ffffffffa0ba12cc [irdma]
   #9 [ffff88aa841ef958] irdma_cleanup_pending_cqp_op at ffffffffa0ba1469 [irdma]
   #10 [ffff88aa841ef9c0] irdma_ctrl_deinit_hw at ffffffffa0b2989f [irdma]
   #11 [ffff88aa841efa28] irdma_remove at ffffffffa0b252df [irdma]
   #12 [ffff88aa841efae8] auxiliary_bus_remove at ffffffff8219afdb
   #13 [ffff88aa841efb00] device_release_driver_internal at ffffffff821882e6
   #14 [ffff88aa841efb38] bus_remove_device at ffffffff82184278
   #15 [ffff88aa841efb88] device_del at ffffffff82179d23
   #16 [ffff88aa841efc48] ice_unplug_aux_dev at ffffffffa0eb1c14 [ice]
   #17 [ffff88aa841efc68] ice_service_task at ffffffffa0d88201 [ice]
   #18 [ffff88aa841efde8] process_one_work at ffffffff811c589a
   #19 [ffff88aa841efe60] worker_thread at ffffffff811c71ff
   #20 [ffff88aa841eff10] kthread at ffffffff811d87a0
   #21 [ffff88aa841eff50] ret_from_fork at ffffffff82e0022f

Fixes: 44d9e52 ("RDMA/irdma: Implement device initialization definitions")
Link: https://lore.kernel.org/r/20231130081415.891006-1-lishifeng@sangfor.com.cn
Suggested-by: "Ismail, Mustafa" <mustafa.ismail@intel.com>
Signed-off-by: Shifeng Li <lishifeng@sangfor.com.cn>
Reviewed-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
alobakin pushed a commit that referenced this pull request Feb 5, 2024
Maxim Mikityanskiy says:

====================
Improvements for tracking scalars in the BPF verifier

From: Maxim Mikityanskiy <maxim@isovalent.com>

The goal of this series is to extend the verifier's capabilities of
tracking scalars when they are spilled to stack, especially when the
spill or fill is narrowing. It also contains a fix by Eduard for
infinite loop detection and a state pruning optimization by Eduard that
compensates for a verification complexity regression introduced by
tracking unbounded scalars. These improvements reduce the surface of
false rejections that I saw while working on Cilium codebase.

Patches 1-9 of the original series were previously applied in v2.

Patches 1-2 (Maxim): Support the case when boundary checks are first
performed after the register was spilled to the stack.

Patches 3-4 (Maxim): Support narrowing fills.

Patches 5-6 (Eduard): Optimization for state pruning in stacksafe() to
mitigate the verification complexity regression.

veristat -e file,prog,states -f '!states_diff<50' -f '!states_pct<10' -f '!states_a<10' -f '!states_b<10' -C ...

 * Without patch 5:

File                  Program   States (A)  States (B)  States    (DIFF)
--------------------  --------  ----------  ----------  ----------------
pyperf100.bpf.o       on_event        4878        6528   +1650 (+33.83%)
pyperf180.bpf.o       on_event        6936       11032   +4096 (+59.05%)
pyperf600.bpf.o       on_event       22271       39455  +17184 (+77.16%)
pyperf600_iter.bpf.o  on_event         400         490     +90 (+22.50%)
strobemeta.bpf.o      on_event        4895       14028  +9133 (+186.58%)

 * With patch 5:

File                     Program        States (A)  States (B)  States   (DIFF)
-----------------------  -------------  ----------  ----------  ---------------
bpf_xdp.o                tail_lb_ipv4         2770        2224   -546 (-19.71%)
pyperf100.bpf.o          on_event             4878        5848   +970 (+19.89%)
pyperf180.bpf.o          on_event             6936        8868  +1932 (+27.85%)
pyperf600.bpf.o          on_event            22271       29656  +7385 (+33.16%)
pyperf600_iter.bpf.o     on_event              400         450    +50 (+12.50%)
xdp_synproxy_kern.bpf.o  syncookie_tc          280         226    -54 (-19.29%)
xdp_synproxy_kern.bpf.o  syncookie_xdp         302         228    -74 (-24.50%)

v2 changes:

Fixed comments in patch 1, moved endianness checks to header files in
patch 12 where possible, added Eduard's ACKs.

v3 changes:

Maxim: Removed __is_scalar_unbounded altogether, addressed Andrii's
comments.

Eduard: Patch #5 (#14 in v2) changed significantly:
- Logical changes:
  - Handling of STACK_{MISC,ZERO} mix turned out to be incorrect:
    a mix of MISC and ZERO in old state is not equivalent to e.g.
    just MISC is current state, because verifier could have deduced
    zero scalars from ZERO slots in old state for some loads.
  - There is no reason to limit the change only to cases when
    old or current stack is a spill of unbounded scalar,
    it is valid to compare any 64-bit scalar spill with fake
    register impersonating MISC.
  - STACK_ZERO vs spilled zero case was dropped,
    after recent changes for zero handling by Andrii and Yonghong
    it is hard (impossible?) to conjure all ZERO slots for an spi.
    => the case does not make any difference in veristat results.
- Use global static variable for unbound_reg (Andrii)
- Code shuffling to remove duplication in stacksafe() (Andrii)
====================

Link: https://lore.kernel.org/r/20240127175237.526726-1-maxtram95@gmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
alobakin pushed a commit that referenced this pull request Mar 12, 2024
…-maps'

Eduard Zingerman says:

====================
libbpf: type suffixes and autocreate flag for struct_ops maps

Tweak struct_ops related APIs to allow the following features:
- specify version suffixes for stuct_ops map types;
- share same BPF program between several map definitions with
  different local BTF types, assuming only maps with same
  kernel BTF type would be selected for load;
- toggle autocreate flag for struct_ops maps;
- automatically toggle autoload for struct_ops programs referenced
  from struct_ops maps, depending on autocreate status of the
  corresponding map;
- use SEC("?.struct_ops") and SEC("?.struct_ops.link")
  to define struct_ops maps with autocreate == false after object open.

This would allow loading programs like below:

    SEC("struct_ops/foo") int BPF_PROG(foo) { ... }
    SEC("struct_ops/bar") int BPF_PROG(bar) { ... }

    struct bpf_testmod_ops___v1 {
        int (*foo)(void);
    };

    struct bpf_testmod_ops___v2 {
        int (*foo)(void);
        int (*bar)(void);
    };

    /* Assume kernel type name to be 'test_ops' */
    SEC(".struct_ops.link")
    struct test_ops___v1 map_v1 = {
        /* Program 'foo' shared by maps with
         * different local BTF type
         */
        .foo = (void *)foo
    };

    SEC(".struct_ops.link")
    struct test_ops___v2 map_v2 = {
        .foo = (void *)foo,
        .bar = (void *)bar
    };

Assuming the following tweaks are done before loading:

    /* to load v1 */
    bpf_map__set_autocreate(skel->maps.map_v1, true);
    bpf_map__set_autocreate(skel->maps.map_v2, false);

    /* to load v2 */
    bpf_map__set_autocreate(skel->maps.map_v1, false);
    bpf_map__set_autocreate(skel->maps.map_v2, true);

Patch #8 ties autocreate and autoload flags for struct_ops maps and
programs.

Changelog:
- v3 [3] -> v4:
  - changes for multiple styling suggestions from Andrii;
  - patch #5: libbpf log capture now happens for LIBBPF_INFO and
    LIBBPF_WARN messages and does not depend on verbosity flags
    (Andrii);
  - patch #6: fixed runtime crash caused by conflict with newly added
    test case struct_ops_multi_pages;
  - patch #7: fixed free of possibly uninitialized pointer (Daniel)
  - patch #8: simpler algorithm to detect which programs to autoload
    (Andrii);
  - patch #9: added assertions for autoload flag after object load
    (Andrii);
  - patch #12: DATASEC name rewrite in libbpf is now done inplace, no
    new strings added to BTF (Andrii);
  - patch #14: allow any printable characters in DATASEC names when
    kernel validates BTF (Andrii)
- v2 [2] -> v3:
  - moved patch #8 logic to be fully done on load
    (requested by Andrii in offlist discussion);
  - in patch #9 added test case for shadow vars and
    autocreate/autoload interaction.
- v1 [1] -> v2:
  - fixed memory leak in patch #1 (Kui-Feng);
  - improved error messages in patch #2 (Martin, Andrii);
  - in bad_struct_ops selftest from patch #6 added .test_2
    map member setup (David);
  - added utility functions to capture libbpf log from selftests (David)
  - in selftests replaced usage of ...__open_and_load by separate
    calls to ..._open() and ..._load() (Andrii);
  - removed serial_... in selftest definitions (Andrii);
  - improved comments in selftest struct_ops_autocreate
    from patch #7 (David);
  - removed autoload toggling logic incompatible with shadow variables
    from bpf_map__set_autocreate(), instead struct_ops programs
    autoload property is computed at struct_ops maps load phase,
    see patch #8 (Kui-Feng, Martin, Andrii);
  - added support for SEC("?.struct_ops") and SEC("?.struct_ops.link")
    (Andrii).

[1] https://lore.kernel.org/bpf/20240227204556.17524-1-eddyz87@gmail.com/
[2] https://lore.kernel.org/bpf/20240302011920.15302-1-eddyz87@gmail.com/
[3] https://lore.kernel.org/bpf/20240304225156.24765-1-eddyz87@gmail.com/
====================

Link: https://lore.kernel.org/r/20240306104529.6453-1-eddyz87@gmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
alobakin pushed a commit that referenced this pull request Mar 12, 2024
Make arch_kunwind_consume_entry() as __always_inline otherwise the
compiler might not inline it and allow attaching probes to it.

Without this, just probing arch_kunwind_consume_entry() via
<tracefs>/kprobe_events will crash the kernel on arm64.

The crash can be reproduced using the following compiler and kernel
combination:
clang version 19.0.0git (https://github.com/llvm/llvm-project.git d68d29516102252f6bf6dc23fb22cef144ca1cb3)
commit 87adede ("Merge tag 'net-6.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net")

 [root@localhost ~]# echo 'p arch_kunwind_consume_entry' > /sys/kernel/debug/tracing/kprobe_events
 [root@localhost ~]# echo 1 > /sys/kernel/debug/tracing/events/kprobes/enable

 Modules linked in: aes_ce_blk aes_ce_cipher ghash_ce sha2_ce virtio_net sha256_arm64 sha1_ce arm_smccc_trng net_failover failover virtio_mmio uio_pdrv_genirq uio sch_fq_codel dm_mod dax configfs
 CPU: 3 PID: 1405 Comm: bash Not tainted 6.8.0-rc6+ #14
 Hardware name: linux,dummy-virt (DT)
 pstate: 604003c5 (nZCv DAIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : kprobe_breakpoint_handler+0x17c/0x258
 lr : kprobe_breakpoint_handler+0x17c/0x258
 sp : ffff800085d6ab60
 x29: ffff800085d6ab60 x28: ffff0000066f0040 x27: ffff0000066f0b20
 x26: ffff800081fa7b0c x25: 0000000000000002 x24: ffff00000b29bd18
 x23: ffff00007904c590 x22: ffff800081fa6590 x21: ffff800081fa6588
 x20: ffff00000b29bd18 x19: ffff800085d6ac40 x18: 0000000000000079
 x17: 0000000000000001 x16: ffffffffffffffff x15: 0000000000000004
 x14: ffff80008277a940 x13: 0000000000000003 x12: 0000000000000003
 x11: 00000000fffeffff x10: c0000000fffeffff x9 : aa95616fdf80cc00
 x8 : aa95616fdf80cc00 x7 : 205d343137373231 x6 : ffff800080fb48ec
 x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
 x2 : 0000000000000000 x1 : ffff800085d6a910 x0 : 0000000000000079
 Call trace:
 kprobes: Failed to recover from reentered kprobes.
 kprobes: Dump kprobe:
 .symbol_name = arch_kunwind_consume_entry, .offset = 0, .addr = arch_kunwind_consume_entry+0x0/0x40
 ------------[ cut here ]------------
 kernel BUG at arch/arm64/kernel/probes/kprobes.c:241!
 kprobes: Failed to recover from reentered kprobes.
 kprobes: Dump kprobe:
 .symbol_name = arch_kunwind_consume_entry, .offset = 0, .addr = arch_kunwind_consume_entry+0x0/0x40

Fixes: 1aba06e ("arm64: stacktrace: factor out kunwind_stack_walk()")
Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20240229231620.24846-1-puranjay12@gmail.com
Signed-off-by: Will Deacon <will@kernel.org>
alobakin pushed a commit that referenced this pull request Mar 29, 2024
Petr Machata says:

====================
selftests: Fixes for kernel CI

As discussed on the bi-weekly call on Jan 30, and in mailing around
kernel CI effort, some changes are desirable in the suite of forwarding
selftests the better to work with the CI tooling. Namely:

- The forwarding selftests use a configuration file where names of
  interfaces are defined and various variables can be overridden. There
  is also forwarding.config.sample that users can use as a template to
  refer to when creating the config file. What happens a fair bit is
  that users either do not know about this at all, or simply forget, and
  are confused by cryptic failures about interfaces that cannot be
  created.

  In patches #1 - #3 have lib.sh just be the single source of truth with
  regards to which variables exist. That includes the topology variables
  which were previously only in the sample file, and any "tweak
  variables", such as what tools to use, sleep times, etc.

  forwarding.config.sample then becomes just a placeholder with a couple
  examples. Unless specific HW should be exercised, or specific tools
  used, the defaults are usually just fine.

- Several net/forwarding/ selftests (and one net/ one) cannot be run on
  veth pairs, they need an actual HW interface to run on. They are
  generic in the sense that any capable HW should pass them, which is
  why they have been put to net/forwarding/ as opposed to drivers/net/,
  but they do not generalize to veth. The fact that these tests are in
  net/forwarding/, but still complaining when run, is confusing.

  In patches #4 - #6 move these tests to a new directory
  drivers/net/hw.

- The following patches extend the codebase to handle well test results
  other than pass and fail.

  Patch #7 is preparatory. It converts several log_test_skip to XFAIL,
  so that tests do not spuriously end up returning non-0 when they
  are not supposed to.

  In patches #8 - #10, introduce some missing ksft constants, then support
  having those constants in RET, and then finally in EXIT_STATUS.

- The traffic scheduler tests generate a large amount of network traffic
  to test the behavior of the scheduler. This demands a relatively
  high-performance computer. On slow machines, such as with a debugging
  kernel, the test would spuriously fail.

  It can still be useful to "go through the motions" though, to possibly
  catch bugs in setup of the scheduler graph and passing packets around.
  Thus we still want to run the tests, just with lowered demands.

  To that end, in patches #11 - #12, introduce an environment variable
  KSFT_MACHINE_SLOW, with obvious meaning. Tests can then make checks
  more lenient, such as mark failures as XFAIL. A helper, xfail_on_slow,
  is provided to mark performance-sensitive parts of the selftest.

- In patch #13, use a similar mechanism to mark a NH group stats
  selftest to XFAIL HW stats tests when run on VETH pairs.

- All these changes complicate the hitherto straightforward logging and
  checking logic, so in patch #14, add a selftest that checks this
  functionality in lib.sh.

v1 (vs. an RFC circulated through linux-kselftest):
- Patch #9:
    - Clarify intended usage by s/set_ret/ret_set_ksft_status/,
      s/nret/ksft_status/
====================

Link: https://lore.kernel.org/r/cover.1711464583.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
alobakin pushed a commit that referenced this pull request Apr 4, 2024
Petr Machata says:

====================
mlxsw: Preparations for improving performance

Amit Cohen writes:

mlxsw driver will use NAPI for event processing in a next patch set.
Some additional improvements will be added later. This patch set
prepares the code for NAPI usage and refactor some relevant areas. See
more details in commit messages.

Patch Set overview:
Patches #1-#2 are preparations for patch #3
Patch #3 setups tasklets as part of queue initializtion
Patch #4 removes handling of unlikely scenario
Patch #5 removes unused counters
Patch #6 makes style change in mlxsw_pci_eq_tasklet()
Patch #7-#10 poll command interface instead of EQ0 usage
Patches #11-#12 make style change and break the function
mlxsw_pci_cq_tasklet()
Patches #13-#14 remove functions which can be replaced by a stored value
Patch #15 improves accessing to descriptor queue instance
====================

Link: https://lore.kernel.org/r/cover.1712062203.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
alobakin pushed a commit that referenced this pull request Apr 15, 2024
Although ipv6_get_ifaddr walks inet6_addr_lst under the RCU lock, it
still means hlist_for_each_entry_rcu can return an item that got removed
from the list. The memory itself of such item is not freed thanks to RCU
but nothing guarantees the actual content of the memory is sane.

In particular, the reference count can be zero. This can happen if
ipv6_del_addr is called in parallel. ipv6_del_addr removes the entry
from inet6_addr_lst (hlist_del_init_rcu(&ifp->addr_lst)) and drops all
references (__in6_ifa_put(ifp) + in6_ifa_put(ifp)). With bad enough
timing, this can happen:

1. In ipv6_get_ifaddr, hlist_for_each_entry_rcu returns an entry.

2. Then, the whole ipv6_del_addr is executed for the given entry. The
   reference count drops to zero and kfree_rcu is scheduled.

3. ipv6_get_ifaddr continues and tries to increments the reference count
   (in6_ifa_hold).

4. The rcu is unlocked and the entry is freed.

5. The freed entry is returned.

Prevent increasing of the reference count in such case. The name
in6_ifa_hold_safe is chosen to mimic the existing fib6_info_hold_safe.

[   41.506330] refcount_t: addition on 0; use-after-free.
[   41.506760] WARNING: CPU: 0 PID: 595 at lib/refcount.c:25 refcount_warn_saturate+0xa5/0x130
[   41.507413] Modules linked in: veth bridge stp llc
[   41.507821] CPU: 0 PID: 595 Comm: python3 Not tainted 6.9.0-rc2.main-00208-g49563be82afa #14
[   41.508479] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
[   41.509163] RIP: 0010:refcount_warn_saturate+0xa5/0x130
[   41.509586] Code: ad ff 90 0f 0b 90 90 c3 cc cc cc cc 80 3d c0 30 ad 01 00 75 a0 c6 05 b7 30 ad 01 01 90 48 c7 c7 38 cc 7a 8c e8 cc 18 ad ff 90 <0f> 0b 90 90 c3 cc cc cc cc 80 3d 98 30 ad 01 00 0f 85 75 ff ff ff
[   41.510956] RSP: 0018:ffffbda3c026baf0 EFLAGS: 00010282
[   41.511368] RAX: 0000000000000000 RBX: ffff9e9c46914800 RCX: 0000000000000000
[   41.511910] RDX: ffff9e9c7ec29c00 RSI: ffff9e9c7ec1c900 RDI: ffff9e9c7ec1c900
[   41.512445] RBP: ffff9e9c43660c9c R08: 0000000000009ffb R09: 00000000ffffdfff
[   41.512998] R10: 00000000ffffdfff R11: ffffffff8ca58a40 R12: ffff9e9c4339a000
[   41.513534] R13: 0000000000000001 R14: ffff9e9c438a0000 R15: ffffbda3c026bb48
[   41.514086] FS:  00007fbc4cda1740(0000) GS:ffff9e9c7ec00000(0000) knlGS:0000000000000000
[   41.514726] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   41.515176] CR2: 000056233b337d88 CR3: 000000000376e006 CR4: 0000000000370ef0
[   41.515713] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   41.516252] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   41.516799] Call Trace:
[   41.517037]  <TASK>
[   41.517249]  ? __warn+0x7b/0x120
[   41.517535]  ? refcount_warn_saturate+0xa5/0x130
[   41.517923]  ? report_bug+0x164/0x190
[   41.518240]  ? handle_bug+0x3d/0x70
[   41.518541]  ? exc_invalid_op+0x17/0x70
[   41.520972]  ? asm_exc_invalid_op+0x1a/0x20
[   41.521325]  ? refcount_warn_saturate+0xa5/0x130
[   41.521708]  ipv6_get_ifaddr+0xda/0xe0
[   41.522035]  inet6_rtm_getaddr+0x342/0x3f0
[   41.522376]  ? __pfx_inet6_rtm_getaddr+0x10/0x10
[   41.522758]  rtnetlink_rcv_msg+0x334/0x3d0
[   41.523102]  ? netlink_unicast+0x30f/0x390
[   41.523445]  ? __pfx_rtnetlink_rcv_msg+0x10/0x10
[   41.523832]  netlink_rcv_skb+0x53/0x100
[   41.524157]  netlink_unicast+0x23b/0x390
[   41.524484]  netlink_sendmsg+0x1f2/0x440
[   41.524826]  __sys_sendto+0x1d8/0x1f0
[   41.525145]  __x64_sys_sendto+0x1f/0x30
[   41.525467]  do_syscall_64+0xa5/0x1b0
[   41.525794]  entry_SYSCALL_64_after_hwframe+0x72/0x7a
[   41.526213] RIP: 0033:0x7fbc4cfcea9a
[   41.526528] Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 15 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 7e c3 0f 1f 44 00 00 41 54 48 83 ec 30 44 89
[   41.527942] RSP: 002b:00007ffcf54012a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
[   41.528593] RAX: ffffffffffffffda RBX: 00007ffcf5401368 RCX: 00007fbc4cfcea9a
[   41.529173] RDX: 000000000000002c RSI: 00007fbc4b9d9bd0 RDI: 0000000000000005
[   41.529786] RBP: 00007fbc4bafb040 R08: 00007ffcf54013e0 R09: 000000000000000c
[   41.530375] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
[   41.530977] R13: ffffffffc4653600 R14: 0000000000000001 R15: 00007fbc4ca85d1b
[   41.531573]  </TASK>

Fixes: 5c578ae ("IPv6: convert addrconf hash list to RCU")
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Link: https://lore.kernel.org/r/8ab821e36073a4a406c50ec83c9e8dc586c539e4.1712585809.git.jbenc@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
alobakin pushed a commit that referenced this pull request Apr 19, 2024
vhost_worker will call tun call backs to receive packets. If too many
illegal packets arrives, tun_do_read will keep dumping packet contents.
When console is enabled, it will costs much more cpu time to dump
packet and soft lockup will be detected.

net_ratelimit mechanism can be used to limit the dumping rate.

PID: 33036    TASK: ffff949da6f20000  CPU: 23   COMMAND: "vhost-32980"
 #0 [fffffe00003fce50] crash_nmi_callback at ffffffff89249253
 #1 [fffffe00003fce58] nmi_handle at ffffffff89225fa3
 #2 [fffffe00003fceb0] default_do_nmi at ffffffff8922642e
 #3 [fffffe00003fced0] do_nmi at ffffffff8922660d
 #4 [fffffe00003fcef0] end_repeat_nmi at ffffffff89c01663
    [exception RIP: io_serial_in+20]
    RIP: ffffffff89792594  RSP: ffffa655314979e8  RFLAGS: 00000002
    RAX: ffffffff89792500  RBX: ffffffff8af428a0  RCX: 0000000000000000
    RDX: 00000000000003fd  RSI: 0000000000000005  RDI: ffffffff8af428a0
    RBP: 0000000000002710   R8: 0000000000000004   R9: 000000000000000f
    R10: 0000000000000000  R11: ffffffff8acbf64f  R12: 0000000000000020
    R13: ffffffff8acbf698  R14: 0000000000000058  R15: 0000000000000000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #5 [ffffa655314979e8] io_serial_in at ffffffff89792594
 #6 [ffffa655314979e8] wait_for_xmitr at ffffffff89793470
 #7 [ffffa65531497a08] serial8250_console_putchar at ffffffff897934f6
 #8 [ffffa65531497a20] uart_console_write at ffffffff8978b605
 #9 [ffffa65531497a48] serial8250_console_write at ffffffff89796558
 #10 [ffffa65531497ac8] console_unlock at ffffffff89316124
 #11 [ffffa65531497b10] vprintk_emit at ffffffff89317c07
 #12 [ffffa65531497b68] printk at ffffffff89318306
 #13 [ffffa65531497bc8] print_hex_dump at ffffffff89650765
 #14 [ffffa65531497ca8] tun_do_read at ffffffffc0b06c27 [tun]
 #15 [ffffa65531497d38] tun_recvmsg at ffffffffc0b06e34 [tun]
 #16 [ffffa65531497d68] handle_rx at ffffffffc0c5d682 [vhost_net]
 #17 [ffffa65531497ed0] vhost_worker at ffffffffc0c644dc [vhost]
 #18 [ffffa65531497f10] kthread at ffffffff892d2e72
 #19 [ffffa65531497f50] ret_from_fork at ffffffff89c0022f

Fixes: ef3db4a ("tun: avoid BUG, dump packet on GSO errors")
Signed-off-by: Lei Chen <lei.chen@smartx.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20240415020247.2207781-1-lei.chen@smartx.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
alobakin pushed a commit that referenced this pull request Apr 26, 2024
The rehash delayed work migrates filters from one region to another.
This is done by iterating over all chunks (all the filters with the same
priority) in the region and in each chunk iterating over all the
filters.

If the migration fails, the code tries to migrate the filters back to
the old region. However, the rollback itself can also fail in which case
another migration will be erroneously performed. Besides the fact that
this ping pong is not a very good idea, it also creates a problem.

Each virtual chunk references two chunks: The currently used one
('vchunk->chunk') and a backup ('vchunk->chunk2'). During migration the
first holds the chunk we want to migrate filters to and the second holds
the chunk we are migrating filters from.

The code currently assumes - but does not verify - that the backup chunk
does not exist (NULL) if the currently used chunk does not reference the
target region. This assumption breaks when we are trying to rollback a
rollback, resulting in the backup chunk being overwritten and leaked
[1].

Fix by not rolling back a failed rollback and add a warning to avoid
future cases.

[1]
WARNING: CPU: 5 PID: 1063 at lib/parman.c:291 parman_destroy+0x17/0x20
Modules linked in:
CPU: 5 PID: 1063 Comm: kworker/5:11 Tainted: G        W          6.9.0-rc2-custom-00784-gc6a05c468a0b #14
Hardware name: Mellanox Technologies Ltd. MSN3700/VMOD0005, BIOS 5.11 01/06/2019
Workqueue: mlxsw_core mlxsw_sp_acl_tcam_vregion_rehash_work
RIP: 0010:parman_destroy+0x17/0x20
[...]
Call Trace:
 <TASK>
 mlxsw_sp_acl_atcam_region_fini+0x19/0x60
 mlxsw_sp_acl_tcam_region_destroy+0x49/0xf0
 mlxsw_sp_acl_tcam_vregion_rehash_work+0x1f1/0x470
 process_one_work+0x151/0x370
 worker_thread+0x2cb/0x3e0
 kthread+0xd0/0x100
 ret_from_fork+0x34/0x50
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Fixes: 8435005 ("mlxsw: spectrum_acl: Do rollback as another call to mlxsw_sp_acl_tcam_vchunk_migrate_all()")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Alexander Zubkov <green@qrator.net>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/d5edd4f4503934186ae5cfe268503b16345b4e0f.1713797103.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
alobakin pushed a commit that referenced this pull request May 6, 2024
Wen Gu says:

====================
net/smc: SMC intra-OS shortcut with loopback-ism

This patch set acts as the second part of the new version of [1] (The first
part can be referred from [2]), the updated things of this version are listed
at the end.

- Background

SMC-D is now used in IBM z with ISM function to optimize network interconnect
for intra-CPC communications. Inspired by this, we try to make SMC-D available
on the non-s390 architecture through a software-implemented Emulated-ISM device,
that is the loopback-ism device here, to accelerate inter-process or
inter-containers communication within the same OS instance.

- Design

This patch set includes 3 parts:

 - Patch #1: some prepare work for loopback-ism.
 - Patch #2-#7: implement loopback-ism device and adapt SMC-D for it.
   loopback-ism now serves only SMC and no userspace interfaces exposed.
 - Patch #8-#11: memory copy optimization for intra-OS scenario.

The loopback-ism device is designed as an ISMv2 device and not be limited to
a specific net namespace, ends of both inter-process connection (1/1' in diagram
below) or inter-container connection (2/2' in diagram below) can find the same
available loopback-ism and choose it during the CLC handshake.

 Container 1 (ns1)                              Container 2 (ns2)
 +-----------------------------------------+    +-------------------------+
 | +-------+      +-------+      +-------+ |    |        +-------+        |
 | | App A |      | App B |      | App C | |    |        | App D |<-+     |
 | +-------+      +---^---+      +-------+ |    |        +-------+  |(2') |
 |     |127.0.0.1 (1')|             |192.168.0.11       192.168.0.12|     |
 |  (1)|   +--------+ | +--------+  |(2)   |    | +--------+   +--------+ |
 |     `-->|   lo   |-` |  eth0  |<-`      |    | |   lo   |   |  eth0  | |
 +---------+--|---^-+---+-----|--+---------+    +-+--------+---+-^------+-+
              |   |           |                                  |
 Kernel       |   |           |                                  |
 +----+-------v---+-----------v----------------------------------+---+----+
 |    |                            TCP                               |    |
 |    |                                                              |    |
 |    +--------------------------------------------------------------+    |
 |                                                                        |
 |                           +--------------+                             |
 |                           | smc loopback |                             |
 +---------------------------+--------------+-----------------------------+

loopback-ism device creates DMBs (shared memory) for each connection peer.
Since data transfer occurs within the same kernel, the sndbuf of each peer
is only a descriptor and point to the same memory region as peer DMB, so that
the data copy from sndbuf to peer DMB can be avoided in loopback-ism case.

 Container 1 (ns1)                              Container 2 (ns2)
 +-----------------------------------------+    +-------------------------+
 | +-------+                               |    |        +-------+        |
 | | App C |-----+                         |    |        | App D |        |
 | +-------+     |                         |    |        +-^-----+        |
 |               |                         |    |          |              |
 |           (2) |                         |    |     (2') |              |
 |               |                         |    |          |              |
 +---------------|-------------------------+    +----------|--------------+
                 |                                         |
 Kernel          |                                         |
 +---------------|-----------------------------------------|--------------+
 | +--------+ +--v-----+                           +--------+ +--------+  |
 | |dmb_desc| |snd_desc|                           |dmb_desc| |snd_desc|  |
 | +-----|--+ +--|-----+                           +-----|--+ +--------+  |
 | +-----|--+    |                                 +-----|--+             |
 | | DMB C  |    +---------------------------------| DMB D  |             |
 | +--------+                                      +--------+             |
 |                                                                        |
 |                           +--------------+                             |
 |                           | smc loopback |                             |
 +---------------------------+--------------+-----------------------------+

- Benchmark Test

 * Test environments:
      - VM with Intel Xeon Platinum 8 core 2.50GHz, 16 GiB mem.
      - SMC sndbuf/DMB size 1MB.

 * Test object:
      - TCP: run on TCP loopback.
      - SMC lo: run on SMC loopback-ism.

1. ipc-benchmark (see [3])

 - ./<foo> -c 1000000 -s 100

                            TCP                  SMC-lo
Message
rate (msg/s)              84991                  151293(+78.01%)

2. sockperf

 - serv: <smc_run> sockperf sr --tcp
 - clnt: <smc_run> sockperf { tp | pp } --tcp --msg-size={ 64000 for tp | 14 for pp } -i 127.0.0.1 -t 30

                            TCP                  SMC-lo
Bandwidth(MBps)        5033.569                7987.732(+58.69%)
Latency(us)               5.986                   3.398(-43.23%)

3. nginx/wrk

 - serv: <smc_run> nginx
 - clnt: <smc_run> wrk -t 8 -c 1000 -d 30 http://127.0.0.1:80

                           TCP                   SMC-lo
Requests/s           187951.76                267107.90(+42.12%)

4. redis-benchmark

 - serv: <smc_run> redis-server
 - clnt: <smc_run> redis-benchmark -h 127.0.0.1 -q -t set,get -n 400000 -c 200 -d 1024

                           TCP                   SMC-lo
GET(Requests/s)       86132.64                118133.49(+37.15%)
SET(Requests/s)       87374.40                122887.86(+40.65%)

Change log:
v7->v6
- Patch #2: minor: remove unnecessary 'return' of inline smc_loopback_exit().
- Patch #10: minor: directly return 0 instead of 'rc' in smcd_cdc_msg_send().
- all: collect the Reviewed-by tags.

v6->RFC v5
Link: https://lore.kernel.org/netdev/20240414040304.54255-1-guwen@linux.alibaba.com/
- Patch #2: make the use of CONFIG_SMC_LO cleaner.
- Patch #5: mark some smcd_ops that loopback-ism doesn't support as
  optional and check for the support when they are called.
- Patch #7: keep loopback-ism at the beginning of the SMC-D device list.
- Some expression changes in commit logs and comments.

RFC v5->RFC v4:
Link: https://lore.kernel.org/netdev/20240324135522.108564-1-guwen@linux.alibaba.com/
- Patch #2: minor changes in description of config SMC_LO and comments.
- Patch #10: minor changes in comments and if(smc_ism_support_dmb_nocopy())
  check in smcd_cdc_msg_send().
- Patch #3: change smc_lo_generate_id() to smc_lo_generate_ids() and SMC_LO_CHID
  to SMC_LO_RESERVED_CHID.
- Patch #5: memcpy while holding the ldev->dmb_ht_lock.
- Some expression changes in commit logs.

RFC v4->v3:
Link: https://lore.kernel.org/netdev/20240317100545.96663-1-guwen@linux.alibaba.com/
- The merge window of v6.9 is open, so post this series as an RFC.
- Patch #6: since some information fed back by smc_nl_handle_smcd_dev() dose
  not apply to Emulated-ISM (including loopback-ism here), loopback-ism is
  not exposed through smc netlink for the time being. we may refactor this
  part when smc netlink interface is updated.

v3->v2:
Link: https://lore.kernel.org/netdev/20240312142743.41406-1-guwen@linux.alibaba.com/
- Patch #11: use tasklet_schedule(&conn->rx_tsklet) instead of smcd_cdc_rx_handler()
  to avoid possible recursive locking of conn->send_lock and use {read|write}_lock_bh()
  to acquire dmb_ht_lock.

v2->v1:
Link: https://lore.kernel.org/netdev/20240307095536.29648-1-guwen@linux.alibaba.com/
- All the patches: changed the term virtual-ISM to Emulated-ISM as defined by SMCv2.1.
- Patch #3: optimized the description of SMC_LO config. Avoid exposing loopback-ism
  to sysfs and remove all the knobs until future definition clear.
- Patch #3: try to make lockdep happy by using read_lock_bh() in smc_lo_move_data().
- Patch #6: defaultly use physical contiguous DMB buffers.
- Patch #11: defaultly enable DMB no-copy for loopback-ism and free the DMB in
  unregister_dmb or detach_dmb when dmb_node->refcnt reaches 0, instead of using
  wait_event to keep waiting in unregister_dmb.

v1->RFC:
Link: https://lore.kernel.org/netdev/20240111120036.109903-1-guwen@linux.alibaba.com/
- Patch #9: merge rx_bytes and tx_bytes as xfer_bytes statistics:
  /sys/devices/virtual/smc/loopback-ism/xfer_bytes
- Patch #10: add support_dmb_nocopy operation to check if SMC-D device supports
  merging sndbuf with peer DMB.
- Patch #13 & #14: introduce loopback-ism device control of DMB memory type and
  control of whether to merge sndbuf and DMB. They can be respectively set by:
  /sys/devices/virtual/smc/loopback-ism/dmb_type
  /sys/devices/virtual/smc/loopback-ism/dmb_copy
  The motivation for these two control is that a performance bottleneck was
  found when using vzalloced DMB and sndbuf is merged with DMB, and there are
  many CPUs and CONFIG_HARDENED_USERCOPY is set [4]. The bottleneck is caused
  by the lock contention in vmap_area_lock [5] which is involved in memcpy_from_msg()
  or memcpy_to_msg(). Currently, Uladzislau Rezki is working on mitigating the
  vmap lock contention [6]. It has significant effects, but using virtual memory
  still has additional overhead compared to using physical memory.
  So this new version provides controls of dmb_type and dmb_copy to suit
  different scenarios.
- Some minor changes and comments improvements.

RFC->old version([1]):
Link: https://lore.kernel.org/netdev/1702214654-32069-1-git-send-email-guwen@linux.alibaba.com/
- Patch #1: improve the loopback-ism dump, it shows as follows now:
  # smcd d
  FID  Type  PCI-ID        PCHID  InUse  #LGs  PNET-ID
  0000 0     loopback-ism  ffff   No        0
- Patch #3: introduce the smc_ism_set_v2_capable() helper and set
  smc_ism_v2_capable when ISMv2 or virtual ISM is registered,
  regardless of whether there is already a device in smcd device list.
- Patch #3: loopback-ism will be added into /sys/devices/virtual/smc/loopback-ism/.
- Patch #8: introduce the runtime switch /sys/devices/virtual/smc/loopback-ism/active
  to activate or deactivate the loopback-ism.
- Patch #9: introduce the statistics of loopback-ism by
  /sys/devices/virtual/smc/loopback-ism/{{tx|rx}_tytes|dmbs_cnt}.
- Some minor changes and comments improvements.

[1] https://lore.kernel.org/netdev/1695568613-125057-1-git-send-email-guwen@linux.alibaba.com/
[2] https://lore.kernel.org/netdev/20231219142616.80697-1-guwen@linux.alibaba.com/
[3] https://github.com/goldsborough/ipc-bench
[4] https://lore.kernel.org/all/3189e342-c38f-6076-b730-19a6efd732a5@linux.alibaba.com/
[5] https://lore.kernel.org/all/238e63cd-e0e8-4fbf-852f-bc4d5bc35d5a@linux.alibaba.com/
[6] https://lore.kernel.org/all/20240102184633.748113-1-urezki@gmail.com/
====================

Link: https://lore.kernel.org/r/20240428060738.60843-1-guwen@linux.alibaba.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
alobakin pushed a commit that referenced this pull request May 22, 2024
ui_browser__show() is capturing the input title that is stack allocated
memory in hist_browser__run().

Avoid a use after return by strdup-ing the string.

Committer notes:

Further explanation from Ian Rogers:

My command line using tui is:
$ sudo bash -c 'rm /tmp/asan.log*; export
ASAN_OPTIONS="log_path=/tmp/asan.log"; /tmp/perf/perf mem record -a
sleep 1; /tmp/perf/perf mem report'
I then go to the perf annotate view and quit. This triggers the asan
error (from the log file):
```
==1254591==ERROR: AddressSanitizer: stack-use-after-return on address
0x7f2813331920 at pc 0x7f28180
65991 bp 0x7fff0a21c750 sp 0x7fff0a21bf10
READ of size 80 at 0x7f2813331920 thread T0
    #0 0x7f2818065990 in __interceptor_strlen
../../../../src/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:461
    #1 0x7f2817698251 in SLsmg_write_wrapped_string
(/lib/x86_64-linux-gnu/libslang.so.2+0x98251)
    #2 0x7f28176984b9 in SLsmg_write_nstring
(/lib/x86_64-linux-gnu/libslang.so.2+0x984b9)
    #3 0x55c94045b365 in ui_browser__write_nstring ui/browser.c:60
    #4 0x55c94045c558 in __ui_browser__show_title ui/browser.c:266
    #5 0x55c94045c776 in ui_browser__show ui/browser.c:288
    #6 0x55c94045c06d in ui_browser__handle_resize ui/browser.c:206
    #7 0x55c94047979b in do_annotate ui/browsers/hists.c:2458
    #8 0x55c94047fb17 in evsel__hists_browse ui/browsers/hists.c:3412
    #9 0x55c940480a0c in perf_evsel_menu__run ui/browsers/hists.c:3527
    #10 0x55c940481108 in __evlist__tui_browse_hists ui/browsers/hists.c:3613
    #11 0x55c9404813f7 in evlist__tui_browse_hists ui/browsers/hists.c:3661
    #12 0x55c93ffa253f in report__browse_hists tools/perf/builtin-report.c:671
    #13 0x55c93ffa58ca in __cmd_report tools/perf/builtin-report.c:1141
    #14 0x55c93ffaf159 in cmd_report tools/perf/builtin-report.c:1805
    #15 0x55c94000c05c in report_events tools/perf/builtin-mem.c:374
    #16 0x55c94000d96d in cmd_mem tools/perf/builtin-mem.c:516
    #17 0x55c9400e44ee in run_builtin tools/perf/perf.c:350
    #18 0x55c9400e4a5a in handle_internal_command tools/perf/perf.c:403
    #19 0x55c9400e4e22 in run_argv tools/perf/perf.c:447
    #20 0x55c9400e53ad in main tools/perf/perf.c:561
    #21 0x7f28170456c9 in __libc_start_call_main
../sysdeps/nptl/libc_start_call_main.h:58
    #22 0x7f2817045784 in __libc_start_main_impl ../csu/libc-start.c:360
    #23 0x55c93ff544c0 in _start (/tmp/perf/perf+0x19a4c0) (BuildId:
84899b0e8c7d3a3eaa67b2eb35e3d8b2f8cd4c93)

Address 0x7f2813331920 is located in stack of thread T0 at offset 32 in frame
    #0 0x55c94046e85e in hist_browser__run ui/browsers/hists.c:746

  This frame has 1 object(s):
    [32, 192) 'title' (line 747) <== Memory access at offset 32 is
inside this variable
HINT: this may be a false positive if your program uses some custom
stack unwind mechanism, swapcontext or vfork
```
hist_browser__run isn't on the stack so the asan error looks legit.
There's no clean init/exit on struct ui_browser so I may be trading a
use-after-return for a memory leak, but that seems look a good trade
anyway.

Fixes: 05e8b08 ("perf ui browser: Stop using 'self'")
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Ben Gainey <ben.gainey@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Li Dong <lidong@vivo.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Paran Lee <p4ranlee@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Sun Haiyong <sunhaiyong@loongson.cn>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Cc: Yicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/20240507183545.1236093-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
alobakin pushed a commit that referenced this pull request May 27, 2024
When I did memory failure tests recently, below panic occurs:

 kernel BUG at include/linux/mm.h:1135!
 invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
 CPU: 9 PID: 137 Comm: kswapd1 Not tainted 6.9.0-rc4-00491-gd5ce28f156fe-dirty #14
 RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0
 RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246
 RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8
 RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0
 RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492
 R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000
 R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00
 FS:  0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0
 Call Trace:
  <TASK>
  do_shrink_slab+0x14f/0x6a0
  shrink_slab+0xca/0x8c0
  shrink_node+0x2d0/0x7d0
  balance_pgdat+0x33a/0x720
  kswapd+0x1f3/0x410
  kthread+0xd5/0x100
  ret_from_fork+0x2f/0x50
  ret_from_fork_asm+0x1a/0x30
  </TASK>
 Modules linked in: mce_inject hwpoison_inject
 ---[ end trace 0000000000000000 ]---
 RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0
 RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246
 RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8
 RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0
 RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492
 R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000
 R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00
 FS:  0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0

The root cause is that HWPoison flag will be set for huge_zero_folio
without increasing the folio refcnt.  But then unpoison_memory() will
decrease the folio refcnt unexpectedly as it appears like a successfully
hwpoisoned folio leading to VM_BUG_ON_PAGE(page_ref_count(page) == 0) when
releasing huge_zero_folio.

Skip unpoisoning huge_zero_folio in unpoison_memory() to fix this issue. 
We're not prepared to unpoison huge_zero_folio yet.

Link: https://lkml.kernel.org/r/20240516122608.22610-1-linmiaohe@huawei.com
Fixes: 478d134 ("mm/huge_memory: do not overkill when splitting huge_zero_page")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Xu Yu <xuyu@linux.alibaba.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
alobakin pushed a commit that referenced this pull request Jun 14, 2024
We have been seeing crashes on duplicate keys in
btrfs_set_item_key_safe():

  BTRFS critical (device vdb): slot 4 key (450 108 8192) new key (450 108 8192)
  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/ctree.c:2620!
  invalid opcode: 0000 [#1] PREEMPT SMP PTI
  CPU: 0 PID: 3139 Comm: xfs_io Kdump: loaded Not tainted 6.9.0 #6
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014
  RIP: 0010:btrfs_set_item_key_safe+0x11f/0x290 [btrfs]

With the following stack trace:

  #0  btrfs_set_item_key_safe (fs/btrfs/ctree.c:2620:4)
  #1  btrfs_drop_extents (fs/btrfs/file.c:411:4)
  #2  log_one_extent (fs/btrfs/tree-log.c:4732:9)
  #3  btrfs_log_changed_extents (fs/btrfs/tree-log.c:4955:9)
  #4  btrfs_log_inode (fs/btrfs/tree-log.c:6626:9)
  #5  btrfs_log_inode_parent (fs/btrfs/tree-log.c:7070:8)
  #6  btrfs_log_dentry_safe (fs/btrfs/tree-log.c:7171:8)
  #7  btrfs_sync_file (fs/btrfs/file.c:1933:8)
  #8  vfs_fsync_range (fs/sync.c:188:9)
  #9  vfs_fsync (fs/sync.c:202:9)
  #10 do_fsync (fs/sync.c:212:9)
  #11 __do_sys_fdatasync (fs/sync.c:225:9)
  #12 __se_sys_fdatasync (fs/sync.c:223:1)
  #13 __x64_sys_fdatasync (fs/sync.c:223:1)
  #14 do_syscall_x64 (arch/x86/entry/common.c:52:14)
  #15 do_syscall_64 (arch/x86/entry/common.c:83:7)
  #16 entry_SYSCALL_64+0xaf/0x14c (arch/x86/entry/entry_64.S:121)

So we're logging a changed extent from fsync, which is splitting an
extent in the log tree. But this split part already exists in the tree,
triggering the BUG().

This is the state of the log tree at the time of the crash, dumped with
drgn (https://github.com/osandov/drgn/blob/main/contrib/btrfs_tree.py)
to get more details than btrfs_print_leaf() gives us:

  >>> print_extent_buffer(prog.crashed_thread().stack_trace()[0]["eb"])
  leaf 33439744 level 0 items 72 generation 9 owner 18446744073709551610
  leaf 33439744 flags 0x100000000000000
  fs uuid e5bd3946-400c-4223-8923-190ef1f18677
  chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da
          item 0 key (450 INODE_ITEM 0) itemoff 16123 itemsize 160
                  generation 7 transid 9 size 8192 nbytes 8473563889606862198
                  block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0
                  sequence 204 flags 0x10(PREALLOC)
                  atime 1716417703.220000000 (2024-05-22 15:41:43)
                  ctime 1716417704.983333333 (2024-05-22 15:41:44)
                  mtime 1716417704.983333333 (2024-05-22 15:41:44)
                  otime 17592186044416.000000000 (559444-03-08 01:40:16)
          item 1 key (450 INODE_REF 256) itemoff 16110 itemsize 13
                  index 195 namelen 3 name: 193
          item 2 key (450 XATTR_ITEM 1640047104) itemoff 16073 itemsize 37
                  location key (0 UNKNOWN.0 0) type XATTR
                  transid 7 data_len 1 name_len 6
                  name: user.a
                  data a
          item 3 key (450 EXTENT_DATA 0) itemoff 16020 itemsize 53
                  generation 9 type 1 (regular)
                  extent data disk byte 303144960 nr 12288
                  extent data offset 0 nr 4096 ram 12288
                  extent compression 0 (none)
          item 4 key (450 EXTENT_DATA 4096) itemoff 15967 itemsize 53
                  generation 9 type 2 (prealloc)
                  prealloc data disk byte 303144960 nr 12288
                  prealloc data offset 4096 nr 8192
          item 5 key (450 EXTENT_DATA 8192) itemoff 15914 itemsize 53
                  generation 9 type 2 (prealloc)
                  prealloc data disk byte 303144960 nr 12288
                  prealloc data offset 8192 nr 4096
  ...

So the real problem happened earlier: notice that items 4 (4k-12k) and 5
(8k-12k) overlap. Both are prealloc extents. Item 4 straddles i_size and
item 5 starts at i_size.

Here is the state of the filesystem tree at the time of the crash:

  >>> root = prog.crashed_thread().stack_trace()[2]["inode"].root
  >>> ret, nodes, slots = btrfs_search_slot(root, BtrfsKey(450, 0, 0))
  >>> print_extent_buffer(nodes[0])
  leaf 30425088 level 0 items 184 generation 9 owner 5
  leaf 30425088 flags 0x100000000000000
  fs uuid e5bd3946-400c-4223-8923-190ef1f18677
  chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da
  	...
          item 179 key (450 INODE_ITEM 0) itemoff 4907 itemsize 160
                  generation 7 transid 7 size 4096 nbytes 12288
                  block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0
                  sequence 6 flags 0x10(PREALLOC)
                  atime 1716417703.220000000 (2024-05-22 15:41:43)
                  ctime 1716417703.220000000 (2024-05-22 15:41:43)
                  mtime 1716417703.220000000 (2024-05-22 15:41:43)
                  otime 1716417703.220000000 (2024-05-22 15:41:43)
          item 180 key (450 INODE_REF 256) itemoff 4894 itemsize 13
                  index 195 namelen 3 name: 193
          item 181 key (450 XATTR_ITEM 1640047104) itemoff 4857 itemsize 37
                  location key (0 UNKNOWN.0 0) type XATTR
                  transid 7 data_len 1 name_len 6
                  name: user.a
                  data a
          item 182 key (450 EXTENT_DATA 0) itemoff 4804 itemsize 53
                  generation 9 type 1 (regular)
                  extent data disk byte 303144960 nr 12288
                  extent data offset 0 nr 8192 ram 12288
                  extent compression 0 (none)
          item 183 key (450 EXTENT_DATA 8192) itemoff 4751 itemsize 53
                  generation 9 type 2 (prealloc)
                  prealloc data disk byte 303144960 nr 12288
                  prealloc data offset 8192 nr 4096

Item 5 in the log tree corresponds to item 183 in the filesystem tree,
but nothing matches item 4. Furthermore, item 183 is the last item in
the leaf.

btrfs_log_prealloc_extents() is responsible for logging prealloc extents
beyond i_size. It first truncates any previously logged prealloc extents
that start beyond i_size. Then, it walks the filesystem tree and copies
the prealloc extent items to the log tree.

If it hits the end of a leaf, then it calls btrfs_next_leaf(), which
unlocks the tree and does another search. However, while the filesystem
tree is unlocked, an ordered extent completion may modify the tree. In
particular, it may insert an extent item that overlaps with an extent
item that was already copied to the log tree.

This may manifest in several ways depending on the exact scenario,
including an EEXIST error that is silently translated to a full sync,
overlapping items in the log tree, or this crash. This particular crash
is triggered by the following sequence of events:

- Initially, the file has i_size=4k, a regular extent from 0-4k, and a
  prealloc extent beyond i_size from 4k-12k. The prealloc extent item is
  the last item in its B-tree leaf.
- The file is fsync'd, which copies its inode item and both extent items
  to the log tree.
- An xattr is set on the file, which sets the
  BTRFS_INODE_COPY_EVERYTHING flag.
- The range 4k-8k in the file is written using direct I/O. i_size is
  extended to 8k, but the ordered extent is still in flight.
- The file is fsync'd. Since BTRFS_INODE_COPY_EVERYTHING is set, this
  calls copy_inode_items_to_log(), which calls
  btrfs_log_prealloc_extents().
- btrfs_log_prealloc_extents() finds the 4k-12k prealloc extent in the
  filesystem tree. Since it starts before i_size, it skips it. Since it
  is the last item in its B-tree leaf, it calls btrfs_next_leaf().
- btrfs_next_leaf() unlocks the path.
- The ordered extent completion runs, which converts the 4k-8k part of
  the prealloc extent to written and inserts the remaining prealloc part
  from 8k-12k.
- btrfs_next_leaf() does a search and finds the new prealloc extent
  8k-12k.
- btrfs_log_prealloc_extents() copies the 8k-12k prealloc extent into
  the log tree. Note that it overlaps with the 4k-12k prealloc extent
  that was copied to the log tree by the first fsync.
- fsync calls btrfs_log_changed_extents(), which tries to log the 4k-8k
  extent that was written.
- This tries to drop the range 4k-8k in the log tree, which requires
  adjusting the start of the 4k-12k prealloc extent in the log tree to
  8k.
- btrfs_set_item_key_safe() sees that there is already an extent
  starting at 8k in the log tree and calls BUG().

Fix this by detecting when we're about to insert an overlapping file
extent item in the log tree and truncating the part that would overlap.

CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
alobakin pushed a commit that referenced this pull request Jun 21, 2024
The kprobes and synth event generation test modules add events and lock
(get a reference) those event file reference in module init function,
and unlock and delete it in module exit function. This is because those
are designed for playing as modules.

If we make those modules as built-in, those events are left locked in the
kernel, and never be removed. This causes kprobe event self-test failure
as below.

[   97.349708] ------------[ cut here ]------------
[   97.353453] WARNING: CPU: 3 PID: 1 at kernel/trace/trace_kprobe.c:2133 kprobe_trace_self_tests_init+0x3f1/0x480
[   97.357106] Modules linked in:
[   97.358488] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 6.9.0-g699646734ab5-dirty #14
[   97.361556] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
[   97.363880] RIP: 0010:kprobe_trace_self_tests_init+0x3f1/0x480
[   97.365538] Code: a8 24 08 82 e9 ae fd ff ff 90 0f 0b 90 48 c7 c7 e5 aa 0b 82 e9 ee fc ff ff 90 0f 0b 90 48 c7 c7 2d 61 06 82 e9 8e fd ff ff 90 <0f> 0b 90 48 c7 c7 33 0b 0c 82 89 c6 e8 6e 03 1f ff 41 ff c7 e9 90
[   97.370429] RSP: 0000:ffffc90000013b50 EFLAGS: 00010286
[   97.371852] RAX: 00000000fffffff0 RBX: ffff888005919c00 RCX: 0000000000000000
[   97.373829] RDX: ffff888003f40000 RSI: ffffffff8236a598 RDI: ffff888003f40a68
[   97.375715] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
[   97.377675] R10: ffffffff811c9ae5 R11: ffffffff8120c4e0 R12: 0000000000000000
[   97.379591] R13: 0000000000000001 R14: 0000000000000015 R15: 0000000000000000
[   97.381536] FS:  0000000000000000(0000) GS:ffff88807dcc0000(0000) knlGS:0000000000000000
[   97.383813] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   97.385449] CR2: 0000000000000000 CR3: 0000000002244000 CR4: 00000000000006b0
[   97.387347] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   97.389277] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   97.391196] Call Trace:
[   97.391967]  <TASK>
[   97.392647]  ? __warn+0xcc/0x180
[   97.393640]  ? kprobe_trace_self_tests_init+0x3f1/0x480
[   97.395181]  ? report_bug+0xbd/0x150
[   97.396234]  ? handle_bug+0x3e/0x60
[   97.397311]  ? exc_invalid_op+0x1a/0x50
[   97.398434]  ? asm_exc_invalid_op+0x1a/0x20
[   97.399652]  ? trace_kprobe_is_busy+0x20/0x20
[   97.400904]  ? tracing_reset_all_online_cpus+0x15/0x90
[   97.402304]  ? kprobe_trace_self_tests_init+0x3f1/0x480
[   97.403773]  ? init_kprobe_trace+0x50/0x50
[   97.404972]  do_one_initcall+0x112/0x240
[   97.406113]  do_initcall_level+0x95/0xb0
[   97.407286]  ? kernel_init+0x1a/0x1a0
[   97.408401]  do_initcalls+0x3f/0x70
[   97.409452]  kernel_init_freeable+0x16f/0x1e0
[   97.410662]  ? rest_init+0x1f0/0x1f0
[   97.411738]  kernel_init+0x1a/0x1a0
[   97.412788]  ret_from_fork+0x39/0x50
[   97.413817]  ? rest_init+0x1f0/0x1f0
[   97.414844]  ret_from_fork_asm+0x11/0x20
[   97.416285]  </TASK>
[   97.417134] irq event stamp: 13437323
[   97.418376] hardirqs last  enabled at (13437337): [<ffffffff8110bc0c>] console_unlock+0x11c/0x150
[   97.421285] hardirqs last disabled at (13437370): [<ffffffff8110bbf1>] console_unlock+0x101/0x150
[   97.423838] softirqs last  enabled at (13437366): [<ffffffff8108e17f>] handle_softirqs+0x23f/0x2a0
[   97.426450] softirqs last disabled at (13437393): [<ffffffff8108e346>] __irq_exit_rcu+0x66/0xd0
[   97.428850] ---[ end trace 0000000000000000 ]---

And also, since we can not cleanup dynamic_event file, ftracetest are
failed too.

To avoid these issues, build these tests only as modules.

Link: https://lore.kernel.org/all/171811263754.85078.5877446624311852525.stgit@devnote2/

Fixes: 9fe41ef ("tracing: Add synth event generation test module")
Fixes: 6483624 ("tracing: Add kprobe event command generation test module")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
alobakin pushed a commit that referenced this pull request Jun 28, 2024
The code in ocfs2_dio_end_io_write() estimates number of necessary
transaction credits using ocfs2_calc_extend_credits().  This however does
not take into account that the IO could be arbitrarily large and can
contain arbitrary number of extents.

Extent tree manipulations do often extend the current transaction but not
in all of the cases.  For example if we have only single block extents in
the tree, ocfs2_mark_extent_written() will end up calling
ocfs2_replace_extent_rec() all the time and we will never extend the
current transaction and eventually exhaust all the transaction credits if
the IO contains many single block extents.  Once that happens a
WARN_ON(jbd2_handle_buffer_credits(handle) <= 0) is triggered in
jbd2_journal_dirty_metadata() and subsequently OCFS2 aborts in response to
this error.  This was actually triggered by one of our customers on a
heavily fragmented OCFS2 filesystem.

To fix the issue make sure the transaction always has enough credits for
one extent insert before each call of ocfs2_mark_extent_written().

Heming Zhao said:

------
PANIC: "Kernel panic - not syncing: OCFS2: (device dm-1): panic forced after error"

PID: xxx  TASK: xxxx  CPU: 5  COMMAND: "SubmitThread-CA"
  #0 machine_kexec at ffffffff8c069932
  #1 __crash_kexec at ffffffff8c1338fa
  #2 panic at ffffffff8c1d69b9
  #3 ocfs2_handle_error at ffffffffc0c86c0c [ocfs2]
  #4 __ocfs2_abort at ffffffffc0c88387 [ocfs2]
  #5 ocfs2_journal_dirty at ffffffffc0c51e98 [ocfs2]
  #6 ocfs2_split_extent at ffffffffc0c27ea3 [ocfs2]
  #7 ocfs2_change_extent_flag at ffffffffc0c28053 [ocfs2]
  #8 ocfs2_mark_extent_written at ffffffffc0c28347 [ocfs2]
  #9 ocfs2_dio_end_io_write at ffffffffc0c2bef9 [ocfs2]
#10 ocfs2_dio_end_io at ffffffffc0c2c0f5 [ocfs2]
#11 dio_complete at ffffffff8c2b9fa7
#12 do_blockdev_direct_IO at ffffffff8c2bc09f
#13 ocfs2_direct_IO at ffffffffc0c2b653 [ocfs2]
#14 generic_file_direct_write at ffffffff8c1dcf14
#15 __generic_file_write_iter at ffffffff8c1dd07b
#16 ocfs2_file_write_iter at ffffffffc0c49f1f [ocfs2]
#17 aio_write at ffffffff8c2cc72e
#18 kmem_cache_alloc at ffffffff8c248dde
#19 do_io_submit at ffffffff8c2ccada
#20 do_syscall_64 at ffffffff8c004984
#21 entry_SYSCALL_64_after_hwframe at ffffffff8c8000ba

Link: https://lkml.kernel.org/r/20240617095543.6971-1-jack@suse.cz
Link: https://lkml.kernel.org/r/20240614145243.8837-1-jack@suse.cz
Fixes: c15471f ("ocfs2: fix sparse file & data ordering issue in direct io")
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Heming Zhao <heming.zhao@suse.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
alobakin pushed a commit that referenced this pull request Jul 1, 2024
…rnel/git/netfilter/nf-next into main

Pablo Neira Ayuso says:

====================
Netfilter/IPVS updates for net-next

The following patchset contains Netfilter/IPVS updates for net-next:

Patch #1 to #11 to shrink memory consumption for transaction objects:

  struct nft_trans_chain { /* size: 120 (-32), cachelines: 2, members: 10 */
  struct nft_trans_elem { /* size: 72 (-40), cachelines: 2, members: 4 */
  struct nft_trans_flowtable { /* size: 80 (-48), cachelines: 2, members: 5 */
  struct nft_trans_obj { /* size: 72 (-40), cachelines: 2, members: 4 */
  struct nft_trans_rule { /* size: 80 (-32), cachelines: 2, members: 6 */
  struct nft_trans_set { /* size: 96 (-24), cachelines: 2, members: 8 */
  struct nft_trans_table { /* size: 56 (-40), cachelines: 1, members: 2 */

  struct nft_trans_elem can now be allocated from kmalloc-96 instead of
  kmalloc-128 slab.

  Series from Florian Westphal. For the record, I have mangled patch #1
  to add nft_trans_container_*() and use if for every transaction object.
   I have also added BUILD_BUG_ON to ensure struct nft_trans always comes
  at the beginning of the container transaction object. And few minor
  cleanups, any new bugs are of my own.

Patch #12 simplify check for SCTP GSO in IPVS, from Ismael Luceno.

Patch #13 nf_conncount key length remains in the u32 bound, from Yunjian Wang.

Patch #14 removes unnecessary check for CTA_TIMEOUT_L3PROTO when setting
          default conntrack timeouts via nfnetlink_cttimeout API, from
          Lin Ma.

Patch #15 updates NFT_SECMARK_CTX_MAXLEN to 4096, SELinux could use
          larger secctx names than the existing 256 bytes length.

Patch #16 adds a selftest to exercise nfnetlink_queue listeners leaving
          nfnetlink_queue, from Florian Westphal.

Patch #17 increases hitcount from 255 to 65535 in xt_recent, from Phil Sutter.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
alobakin pushed a commit that referenced this pull request Jul 24, 2024
With latest llvm19, the selftest iters/iter_arr_with_actual_elem_count
failed with -mcpu=v4.

The following are the details:
  0: R1=ctx() R10=fp0
  ; int iter_arr_with_actual_elem_count(const void *ctx) @ iters.c:1420
  0: (b4) w7 = 0                        ; R7_w=0
  ; int i, n = loop_data.n, sum = 0; @ iters.c:1422
  1: (18) r1 = 0xffffc90000191478       ; R1_w=map_value(map=iters.bss,ks=4,vs=1280,off=1144)
  3: (61) r6 = *(u32 *)(r1 +128)        ; R1_w=map_value(map=iters.bss,ks=4,vs=1280,off=1144) R6_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
  ; if (n > ARRAY_SIZE(loop_data.data)) @ iters.c:1424
  4: (26) if w6 > 0x20 goto pc+27       ; R6_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=32,var_off=(0x0; 0x3f))
  5: (bf) r8 = r10                      ; R8_w=fp0 R10=fp0
  6: (07) r8 += -8                      ; R8_w=fp-8
  ; bpf_for(i, 0, n) { @ iters.c:1427
  7: (bf) r1 = r8                       ; R1_w=fp-8 R8_w=fp-8
  8: (b4) w2 = 0                        ; R2_w=0
  9: (bc) w3 = w6                       ; R3_w=scalar(id=1,smin=smin32=0,smax=umax=smax32=umax32=32,var_off=(0x0; 0x3f)) R6_w=scalar(id=1,smin=smin32=0,smax=umax=smax32=umax32=32,var_off=(0x0; 0x3f))
  10: (85) call bpf_iter_num_new#45179          ; R0=scalar() fp-8=iter_num(ref_id=2,state=active,depth=0) refs=2
  11: (bf) r1 = r8                      ; R1=fp-8 R8=fp-8 refs=2
  12: (85) call bpf_iter_num_next#45181 13: R0=rdonly_mem(id=3,ref_obj_id=2,sz=4) R6=scalar(id=1,smin=smin32=0,smax=umax=smax32=umax32=32,var_off=(0x0; 0x3f)) R7=0 R8=fp-8 R10=fp0 fp-8=iter_num(ref_id=2,state=active,depth=1) refs=2
  ; bpf_for(i, 0, n) { @ iters.c:1427
  13: (15) if r0 == 0x0 goto pc+2       ; R0=rdonly_mem(id=3,ref_obj_id=2,sz=4) refs=2
  14: (81) r1 = *(s32 *)(r0 +0)         ; R0=rdonly_mem(id=3,ref_obj_id=2,sz=4) R1_w=scalar(smin=0xffffffff80000000,smax=0x7fffffff) refs=2
  15: (ae) if w1 < w6 goto pc+4 20: R0=rdonly_mem(id=3,ref_obj_id=2,sz=4) R1=scalar(smin=0xffffffff80000000,smax=smax32=umax32=31,umax=0xffffffff0000001f,smin32=0,var_off=(0x0; 0xffffffff0000001f)) R6=scalar(id=1,smin=umin=smin32=umin32=1,smax=umax=smax32=umax32=32,var_off=(0x0; 0x3f)) R7=0 R8=fp-8 R10=fp0 fp-8=iter_num(ref_id=2,state=active,depth=1) refs=2
  ; sum += loop_data.data[i]; @ iters.c:1429
  20: (67) r1 <<= 2                     ; R1_w=scalar(smax=0x7ffffffc0000007c,umax=0xfffffffc0000007c,smin32=0,smax32=umax32=124,var_off=(0x0; 0xfffffffc0000007c)) refs=2
  21: (18) r2 = 0xffffc90000191478      ; R2_w=map_value(map=iters.bss,ks=4,vs=1280,off=1144) refs=2
  23: (0f) r2 += r1
  math between map_value pointer and register with unbounded min value is not allowed

The source code:
  int iter_arr_with_actual_elem_count(const void *ctx)
  {
        int i, n = loop_data.n, sum = 0;

        if (n > ARRAY_SIZE(loop_data.data))
                return 0;

        bpf_for(i, 0, n) {
                /* no rechecking of i against ARRAY_SIZE(loop_data.n) */
                sum += loop_data.data[i];
        }

        return sum;
  }

The insn #14 is a sign-extenstion load which is related to 'int i'.
The insn #15 did a subreg comparision. Note that smin=0xffffffff80000000 and this caused later
insn #23 failed verification due to unbounded min value.

Actually insn #15 R1 smin range can be better. Before insn #15, we have
  R1_w=scalar(smin=0xffffffff80000000,smax=0x7fffffff)
With the above range, we know for R1, upper 32bit can only be 0xffffffff or 0.
Otherwise, the value range for R1 could be beyond [smin=0xffffffff80000000,smax=0x7fffffff].

After insn #15, for the true patch, we know smin32=0 and smax32=32. With the upper 32bit 0xffffffff,
then the corresponding value is [0xffffffff00000000, 0xffffffff00000020]. The range is
obviously beyond the original range [smin=0xffffffff80000000,smax=0x7fffffff] and the
range is not possible. So the upper 32bit must be 0, which implies smin = smin32 and
smax = smax32.

This patch fixed the issue by adding additional register deduction after 32-bit compare
insn. If the signed 32-bit register range is non-negative then 64-bit smin is
in range of [S32_MIN, S32_MAX], then the actual 64-bit smin/smax should be the same
as 32-bit smin32/smax32.

With this patch, iters/iter_arr_with_actual_elem_count succeeded with better register range:

from 15 to 20: R0=rdonly_mem(id=7,ref_obj_id=2,sz=4) R1_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=31,var_off=(0x0; 0x1f)) R6=scalar(id=1,smin=umin=smin32=umin32=1,smax=umax=smax32=umax32=32,var_off=(0x0; 0x3f)) R7=scalar(id=9,smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R8=scalar(id=9,smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R10=fp0 fp-8=iter_num(ref_id=2,state=active,depth=3) refs=2

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240723162933.2731620-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
alobakin pushed a commit that referenced this pull request Aug 30, 2024
A sysfs reader can race with a device reset or removal, attempting to
read device state when the device is not actually present. eg:

     [exception RIP: qed_get_current_link+17]
  #8 [ffffb9e4f2907c48] qede_get_link_ksettings at ffffffffc07a994a [qede]
  #9 [ffffb9e4f2907cd8] __rh_call_get_link_ksettings at ffffffff992b01a3
 #10 [ffffb9e4f2907d38] __ethtool_get_link_ksettings at ffffffff992b04e4
 #11 [ffffb9e4f2907d90] duplex_show at ffffffff99260300
 #12 [ffffb9e4f2907e38] dev_attr_show at ffffffff9905a01c
 #13 [ffffb9e4f2907e50] sysfs_kf_seq_show at ffffffff98e0145b
 #14 [ffffb9e4f2907e68] seq_read at ffffffff98d902e3
 #15 [ffffb9e4f2907ec8] vfs_read at ffffffff98d657d1
 #16 [ffffb9e4f2907f00] ksys_read at ffffffff98d65c3f
 #17 [ffffb9e4f2907f38] do_syscall_64 at ffffffff98a052fb

 crash> struct net_device.state ffff9a9d21336000
    state = 5,

state 5 is __LINK_STATE_START (0b1) and __LINK_STATE_NOCARRIER (0b100).
The device is not present, note lack of __LINK_STATE_PRESENT (0b10).

This is the same sort of panic as observed in commit 4224cfd
("net-sysfs: add check for netdevice being present to speed_show").

There are many other callers of __ethtool_get_link_ksettings() which
don't have a device presence check.

Move this check into ethtool to protect all callers.

Fixes: d519e17 ("net: export device speed and duplex via sysfs")
Fixes: 4224cfd ("net-sysfs: add check for netdevice being present to speed_show")
Signed-off-by: Jamie Bainbridge <jamie.bainbridge@gmail.com>
Link: https://patch.msgid.link/8bae218864beaa44ed01628140475b9bf641c5b0.1724393671.git.jamie.bainbridge@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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