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[SYCL] Refactor SPIR implementation #8

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agozillon opened this issue Apr 15, 2019 · 0 comments
Open

[SYCL] Refactor SPIR implementation #8

agozillon opened this issue Apr 15, 2019 · 0 comments
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enhancement New feature or request

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@agozillon
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This is related to: intel/llvm#44

The current way we support SPIR builtins is as follows:

We attempt to translate any function in the cl::_spirv (after the Reflower pass this namespace looks like: spirv_ocl) namespace to its SPIR builtin mangling. This occurs in our LLVM InSPIRation pass and works by removing the namespace mangling from the builtin and altering its Z value (Z representing the number of characters in a functions mangled name excluding arguments). There is currently no check to make sure they exist or do not exist as SPIR functions at compile time, if it doesn't exist you'll get a runtime ABI exception (can't find X function) as it won't have linked properly with xocc's SPIR builtin library.

Currently id builtins (get_global_id) are defined in spirv_vars.hpp alongside the SPIRV equivalents and based on a define the compiler creates based on our -fsycl-xocc-device the SPIR builtins are swapped with their SPIRV equivalents. For the math functions we hook into the exact same math builtins as SPIRV inside builtins.hpp without any requirement to optionally swap builtins out.

Short Term Goal:

Move SPIR specific builtins from a cl::__spirv namespace to an equivalent cl::__spir namespace and separate files/folders where necessary. This will lead to something a little cleaner and easier to understand and also divorce the SPIR builtins from transformation by the Reflower making it perhaps a little more stable. As currently any changes to the Reflower's translation of the cl::__spirv namespace is felt by the InSPIRation pass.

It may be more worthwhile to ignore this short term goal and wait for the long term goal based on our priorities.

Long Term Goal:

The idea would be to transform what we currently do, to the newer builtins offloading method where the ToolChain dictates what library functions are used in place of certain placeholder builtins (as explained by Alexey briefly in the linked issue). I believe Alexey is currently looking into this, but once this has been merged into the main implementation we should consider refactoring our implementation to align with this. This may take a reasonable amount of reworking.

@agozillon agozillon added the enhancement New feature or request label Apr 15, 2019
keryell pushed a commit that referenced this issue Sep 19, 2019
Introduction
============

This patch added intial support for bpf program compile once
and run everywhere (CO-RE).

The main motivation is for bpf program which depends on
kernel headers which may vary between different kernel versions.
The initial discussion can be found at https://lwn.net/Articles/773198/.

Currently, bpf program accesses kernel internal data structure
through bpf_probe_read() helper. The idea is to capture the
kernel data structure to be accessed through bpf_probe_read()
and relocate them on different kernel versions.

On each host, right before bpf program load, the bpfloader
will look at the types of the native linux through vmlinux BTF,
calculates proper access offset and patch the instruction.

To accommodate this, three intrinsic functions
   preserve_{array,union,struct}_access_index
are introduced which in clang will preserve the base pointer,
struct/union/array access_index and struct/union debuginfo type
information. Later, bpf IR pass can reconstruct the whole gep
access chains without looking at gep itself.

This patch did the following:
  . An IR pass is added to convert preserve_*_access_index to
    global variable who name encodes the getelementptr
    access pattern. The global variable has metadata
    attached to describe the corresponding struct/union
    debuginfo type.
  . An SimplifyPatchable MachineInstruction pass is added
    to remove unnecessary loads.
  . The BTF output pass is enhanced to generate relocation
    records located in .BTF.ext section.

Typical CO-RE also needs support of global variables which can
be assigned to different values to different hosts. For example,
kernel version can be used to guard different versions of codes.
This patch added the support for patchable externals as well.

Example
=======

The following is an example.

  struct pt_regs {
    long arg1;
    long arg2;
  };
  struct sk_buff {
    int i;
    struct net_device *dev;
  };

  #define _(x) (__builtin_preserve_access_index(x))
  static int (*bpf_probe_read)(void *dst, int size, const void *unsafe_ptr) =
          (void *) 4;
  extern __attribute__((section(".BPF.patchable_externs"))) unsigned __kernel_version;
  int bpf_prog(struct pt_regs *ctx) {
    struct net_device *dev = 0;

    // ctx->arg* does not need bpf_probe_read
    if (__kernel_version >= 41608)
      bpf_probe_read(&dev, sizeof(dev), _(&((struct sk_buff *)ctx->arg1)->dev));
    else
      bpf_probe_read(&dev, sizeof(dev), _(&((struct sk_buff *)ctx->arg2)->dev));
    return dev != 0;
  }

In the above, we want to translate the third argument of
bpf_probe_read() as relocations.

  -bash-4.4$ clang -target bpf -O2 -g -S trace.c

The compiler will generate two new subsections in .BTF.ext,
OffsetReloc and ExternReloc.
OffsetReloc is to record the structure member offset operations,
and ExternalReloc is to record the external globals where
only u8, u16, u32 and u64 are supported.

   BPFOffsetReloc Size
   struct SecLOffsetReloc for ELF section #1
   A number of struct BPFOffsetReloc for ELF section #1
   struct SecOffsetReloc for ELF section #2
   A number of struct BPFOffsetReloc for ELF section #2
   ...
   BPFExternReloc Size
   struct SecExternReloc for ELF section #1
   A number of struct BPFExternReloc for ELF section #1
   struct SecExternReloc for ELF section #2
   A number of struct BPFExternReloc for ELF section #2

  struct BPFOffsetReloc {
    uint32_t InsnOffset;    ///< Byte offset in this section
    uint32_t TypeID;        ///< TypeID for the relocation
    uint32_t OffsetNameOff; ///< The string to traverse types
  };

  struct BPFExternReloc {
    uint32_t InsnOffset;    ///< Byte offset in this section
    uint32_t ExternNameOff; ///< The string for external variable
  };

Note that only externs with attribute section ".BPF.patchable_externs"
are considered for Extern Reloc which will be patched by bpf loader
right before the load.

For the above test case, two offset records and one extern record
will be generated:
  OffsetReloc records:
        .long   .Ltmp12                 # Insn Offset
        .long   7                       # TypeId
        .long   242                     # Type Decode String
        .long   .Ltmp18                 # Insn Offset
        .long   7                       # TypeId
        .long   242                     # Type Decode String

  ExternReloc record:
        .long   .Ltmp5                  # Insn Offset
        .long   165                     # External Variable

  In string table:
        .ascii  "0:1"                   # string offset=242
        .ascii  "__kernel_version"      # string offset=165

The default member offset can be calculated as
    the 2nd member offset (0 representing the 1st member) of struct "sk_buff".

The asm code:
    .Ltmp5:
    .Ltmp6:
            r2 = 0
            r3 = 41608
    .Ltmp7:
    .Ltmp8:
            .loc    1 18 9 is_stmt 0        # t.c:18:9
    .Ltmp9:
            if r3 > r2 goto LBB0_2
    .Ltmp10:
    .Ltmp11:
            .loc    1 0 9                   # t.c:0:9
    .Ltmp12:
            r2 = 8
    .Ltmp13:
            .loc    1 19 66 is_stmt 1       # t.c:19:66
    .Ltmp14:
    .Ltmp15:
            r3 = *(u64 *)(r1 + 0)
            goto LBB0_3
    .Ltmp16:
    .Ltmp17:
    LBB0_2:
            .loc    1 0 66 is_stmt 0        # t.c:0:66
    .Ltmp18:
            r2 = 8
            .loc    1 21 66 is_stmt 1       # t.c:21:66
    .Ltmp19:
            r3 = *(u64 *)(r1 + 8)
    .Ltmp20:
    .Ltmp21:
    LBB0_3:
            .loc    1 0 66 is_stmt 0        # t.c:0:66
            r3 += r2
            r1 = r10
    .Ltmp22:
    .Ltmp23:
    .Ltmp24:
            r1 += -8
            r2 = 8
            call 4

For instruction .Ltmp12 and .Ltmp18, "r2 = 8", the number
8 is the structure offset based on the current BTF.
Loader needs to adjust it if it changes on the host.

For instruction .Ltmp5, "r2 = 0", the external variable
got a default value 0, loader needs to supply an appropriate
value for the particular host.

Compiling to generate object code and disassemble:
   0000000000000000 bpf_prog:
           0:       b7 02 00 00 00 00 00 00         r2 = 0
           1:       7b 2a f8 ff 00 00 00 00         *(u64 *)(r10 - 8) = r2
           2:       b7 02 00 00 00 00 00 00         r2 = 0
           3:       b7 03 00 00 88 a2 00 00         r3 = 41608
           4:       2d 23 03 00 00 00 00 00         if r3 > r2 goto +3 <LBB0_2>
           5:       b7 02 00 00 08 00 00 00         r2 = 8
           6:       79 13 00 00 00 00 00 00         r3 = *(u64 *)(r1 + 0)
           7:       05 00 02 00 00 00 00 00         goto +2 <LBB0_3>

    0000000000000040 LBB0_2:
           8:       b7 02 00 00 08 00 00 00         r2 = 8
           9:       79 13 08 00 00 00 00 00         r3 = *(u64 *)(r1 + 8)

    0000000000000050 LBB0_3:
          10:       0f 23 00 00 00 00 00 00         r3 += r2
          11:       bf a1 00 00 00 00 00 00         r1 = r10
          12:       07 01 00 00 f8 ff ff ff         r1 += -8
          13:       b7 02 00 00 08 00 00 00         r2 = 8
          14:       85 00 00 00 04 00 00 00         call 4

Instructions #2, #5 and #8 need relocation resoutions from the loader.

Signed-off-by: Yonghong Song <yhs@fb.com>

Differential Revision: https://reviews.llvm.org/D61524

llvm-svn: 365503
Ralender pushed a commit to Ralender/sycl that referenced this issue Jul 1, 2020
  CONFLICT (content): Merge conflict in clang/test/SemaOpenCL/address-spaces.cl
Ralender pushed a commit to Ralender/sycl that referenced this issue Jul 1, 2020
  CONFLICT (content): Merge conflict in clang/include/clang/Basic/DiagnosticSemaKinds.td
Ralender pushed a commit to Ralender/sycl that referenced this issue Jul 6, 2020
  CONFLICT (content): Merge conflict in clang/include/clang/Driver/Driver.h
keryell pushed a commit that referenced this issue Oct 1, 2020
A couple of AArch64 tests were failing on Solaris, both sparc and x86:

  LLVM :: MC/AArch64/SVE/add-diagnostics.s
  LLVM :: MC/AArch64/SVE/cpy-diagnostics.s
  LLVM :: MC/AArch64/SVE/cpy.s
  LLVM :: MC/AArch64/SVE/dup-diagnostics.s
  LLVM :: MC/AArch64/SVE/dup.s
  LLVM :: MC/AArch64/SVE/mov-diagnostics.s
  LLVM :: MC/AArch64/SVE/mov.s
  LLVM :: MC/AArch64/SVE/sqadd-diagnostics.s
  LLVM :: MC/AArch64/SVE/sqsub-diagnostics.s
  LLVM :: MC/AArch64/SVE/sub-diagnostics.s
  LLVM :: MC/AArch64/SVE/subr-diagnostics.s
  LLVM :: MC/AArch64/SVE/uqadd-diagnostics.s
  LLVM :: MC/AArch64/SVE/uqsub-diagnostics.s

For example, reduced from `MC/AArch64/SVE/add-diagnostics.s`:

  add     z0.b, z0.b, #0, lsl #8

missed the expected diagnostics

  $ ./bin/llvm-mc -triple=aarch64 -show-encoding -mattr=+sve add.s
  add.s:1:21: error: immediate must be an integer in range [0, 255] with a shift amount of 0
  add     z0.b, z0.b, #0, lsl #8
                      ^

The message is `Match_InvalidSVEAddSubImm8`, emitted in the generated
`lib/Target/AArch64/AArch64GenAsmMatcher.inc` for `MCK_SVEAddSubImm8`.
When comparing the call to `::AArch64Operand::isSVEAddSubImm<char>` on both
Linux/x86_64 and Solaris, I find

  875	    bool IsByte = std::is_same<int8_t, std::make_signed_t<T>>::value;

is `false` on Solaris, unlike Linux.

The problem boils down to the fact that `int8_t` is plain `char` on
Solaris: both the sparc and i386 psABIs have `char` as signed.  However,
with

  9887	    DiagnosticPredicate DP(Operand.isSVEAddSubImm<int8_t>());

in `lib/Target/AArch64/AArch64GenAsmMatcher.inc`, `std::make_signed_t<int8_t>`
above yieds `signed char`, so `std::is_same<int8_t, signed char>` is `false`.

This can easily be fixed by also allowing for `int8_t` here and in a few
similar places.

Tested on `amd64-pc-solaris2.11`, `sparcv9-sun-solaris2.11`, and
`x86_64-pc-linux-gnu`.

Differential Revision: https://reviews.llvm.org/D85225
keryell pushed a commit that referenced this issue Apr 28, 2021
  CONFLICT (content): Merge conflict in clang/lib/Frontend/CompilerInvocation.cpp
keryell pushed a commit that referenced this issue Feb 21, 2022
…he parser"

This reverts commit b0e8667.

ASAN/UBSAN bot is broken with this trace:

[ RUN      ] FlatAffineConstraintsTest.FindSampleTest
llvm-project/mlir/include/mlir/Support/MathExtras.h:27:15: runtime error: signed integer overflow: 1229996100002 * 809999700000 cannot be represented in type 'long'
    #0 0x7f63ace960e4 in mlir::ceilDiv(long, long) llvm-project/mlir/include/mlir/Support/MathExtras.h:27:15
    #1 0x7f63ace8587e in ceil llvm-project/mlir/include/mlir/Analysis/Presburger/Fraction.h:57:42
    #2 0x7f63ace8587e in operator* llvm-project/llvm/include/llvm/ADT/STLExtras.h:347:42
    #3 0x7f63ace8587e in uninitialized_copy<llvm::mapped_iterator<mlir::Fraction *, long (*)(mlir::Fraction), long>, long *> include/c++/v1/__memory/uninitialized_algorithms.h:36:62
    #4 0x7f63ace8587e in uninitialized_copy<llvm::mapped_iterator<mlir::Fraction *, long (*)(mlir::Fraction), long>, long *> llvm-project/llvm/include/llvm/ADT/SmallVector.h:490:5
    #5 0x7f63ace8587e in append<llvm::mapped_iterator<mlir::Fraction *, long (*)(mlir::Fraction), long>, void> llvm-project/llvm/include/llvm/ADT/SmallVector.h:662:5
    #6 0x7f63ace8587e in SmallVector<llvm::mapped_iterator<mlir::Fraction *, long (*)(mlir::Fraction), long> > llvm-project/llvm/include/llvm/ADT/SmallVector.h:1204:11
    #7 0x7f63ace8587e in mlir::FlatAffineConstraints::findIntegerSample() const llvm-project/mlir/lib/Analysis/AffineStructures.cpp:1171:27
    #8 0x7f63ae95a84d in mlir::checkSample(bool, mlir::FlatAffineConstraints const&, mlir::TestFunction) llvm-project/mlir/unittests/Analysis/AffineStructuresTest.cpp:37:23
    #9 0x7f63ae957545 in mlir::FlatAffineConstraintsTest_FindSampleTest_Test::TestBody() llvm-project/mlir/unittests/Analysis/AffineStructuresTest.cpp:222:3
keryell pushed a commit that referenced this issue Oct 6, 2022
…ned form

The DWARF spec says:

 Any debugging information entry representing the declaration of an object,
 module, subprogram or type may have DW_AT_decl_file, DW_AT_decl_line and
 DW_AT_decl_column attributes, each of whose value is an unsigned integer
							 ^^^^^^^^
 constant.

If however, a producer happens to emit DW_AT_decl_file /
DW_AT_decl_line using a signed integer form, llvm-dwarfdump crashes,
like so:

     (... snip ...)
     0x000000b4:   DW_TAG_structure_type
                     DW_AT_name      ("test_struct")
                     DW_AT_byte_size (136)
                     DW_AT_decl_file (llvm-dwarfdump: (... snip ...)/llvm/include/llvm/ADT/Optional.h:197: T& llvm::optional_detail::OptionalStorage<T, true>::getValue() &
 [with T = long unsigned int]: Assertion `hasVal' failed.
     PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
     Stack dump:
     0.      Program arguments: /opt/rocm/llvm/bin/llvm-dwarfdump ./testsuite/outputs/gdb.rocm/lane-pc-vega20/lane-pc-vega20-kernel.so
      #0 0x000055cc8e78315f PrintStackTraceSignalHandler(void*) Signals.cpp:0:0
      #1 0x000055cc8e780d3d SignalHandler(int) Signals.cpp:0:0
      #2 0x00007f8f2cae8420 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x14420)
      #3 0x00007f8f2c58d00b raise /build/glibc-SzIz7B/glibc-2.31/signal/../sysdeps/unix/sysv/linux/raise.c:51:1
      #4 0x00007f8f2c56c859 abort /build/glibc-SzIz7B/glibc-2.31/stdlib/abort.c:81:7
      #5 0x00007f8f2c56c729 get_sysdep_segment_value /build/glibc-SzIz7B/glibc-2.31/intl/loadmsgcat.c:509:8
      #6 0x00007f8f2c56c729 _nl_load_domain /build/glibc-SzIz7B/glibc-2.31/intl/loadmsgcat.c:970:34
      #7 0x00007f8f2c57dfd6 (/lib/x86_64-linux-gnu/libc.so.6+0x33fd6)
      #8 0x000055cc8e58ceb9 llvm::DWARFDie::dump(llvm::raw_ostream&, unsigned int, llvm::DIDumpOptions) const (/opt/rocm/llvm/bin/llvm-dwarfdump+0x2e0eb9)
      #9 0x000055cc8e58bec3 llvm::DWARFDie::dump(llvm::raw_ostream&, unsigned int, llvm::DIDumpOptions) const (/opt/rocm/llvm/bin/llvm-dwarfdump+0x2dfec3)
     #10 0x000055cc8e5b28a3 llvm::DWARFCompileUnit::dump(llvm::raw_ostream&, llvm::DIDumpOptions) (.part.21) DWARFCompileUnit.cpp:0:0

Likewise with DW_AT_call_file / DW_AT_call_line.

The problem is that the code in llvm/lib/DebugInfo/DWARF/DWARFDie.cpp
dumping these attributes assumes that
FormValue.getAsUnsignedConstant() returns an armed optional.  If in
debug mode, we get an assertion line the above.  If in release mode,
and asserts are compiled out, then we proceed as if the optional had a
value, running into undefined behavior, printing whatever random
value.

Fix this by checking whether the optional returned by
FormValue.getAsUnsignedConstant() has a value, like done in other
places.

In addition, DWARFVerifier.cpp is validating DW_AT_call_file /
DW_AT_decl_file, but not AT_call_line / DW_AT_decl_line.  This commit
fixes that too.

The llvm-dwarfdump/X86/verify_file_encoding.yaml testcase is extended
to cover these cases.  Current llvm-dwarfdump crashes running the
newly-extended test.

"make check-llvm-tools-llvm-dwarfdump" shows no regressions, on x86-64
GNU/Linux.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D129392
keryell pushed a commit that referenced this issue Jan 4, 2023
Found by msan -fsanitize-memory-use-after-dtor.

==8259==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x55dbec54d2b8 in dtorRecord(clang::interp::Block*, char*, clang::interp::Descriptor*) clang/lib/AST/Interp/Descriptor.cpp:150:22
    #1 0x55dbec54bfcf in dtorArrayDesc(clang::interp::Block*, char*, clang::interp::Descriptor*) clang/lib/AST/Interp/Descriptor.cpp:97:7
    #2 0x55dbec508578 in invokeDtor clang/lib/AST/Interp/InterpBlock.h:79:7
    #3 0x55dbec508578 in clang::interp::Program::~Program() clang/lib/AST/Interp/Program.h:55:19
    #4 0x55dbec50657a in operator() third_party/crosstool/v18/stable/toolchain/bin/../include/c++/v1/__memory/unique_ptr.h:55:5
    #5 0x55dbec50657a in std::__msan::unique_ptr<clang::interp::Program, std::__msan::default_delete<clang::interp::Program>>::~unique_ptr() third_party/crosstool/v18/stable/toolchain/bin/../include/c++/v1/__memory/unique_ptr.h:261:7
    #6 0x55dbec5035a1 in clang::interp::Context::~Context() clang/lib/AST/Interp/Context.cpp:27:22
    #7 0x55dbebec1daa in operator() third_party/crosstool/v18/stable/toolchain/bin/../include/c++/v1/__memory/unique_ptr.h:55:5
    #8 0x55dbebec1daa in std::__msan::unique_ptr<clang::interp::Context, std::__msan::default_delete<clang::interp::Context>>::~unique_ptr() third_party/crosstool/v18/stable/toolchain/bin/../include/c++/v1/__memory/unique_ptr.h:261:7
    #9 0x55dbebe285f9 in clang::ASTContext::~ASTContext() clang/lib/AST/ASTContext.cpp:1038:40
    #10 0x55dbe941ff13 in llvm::RefCountedBase<clang::ASTContext>::Release() const llvm/include/llvm/ADT/IntrusiveRefCntPtr.h:101:7
    #11 0x55dbe94353ef in release llvm/include/llvm/ADT/IntrusiveRefCntPtr.h:159:38
    #12 0x55dbe94353ef in release llvm/include/llvm/ADT/IntrusiveRefCntPtr.h:224:7
    #13 0x55dbe94353ef in ~IntrusiveRefCntPtr llvm/include/llvm/ADT/IntrusiveRefCntPtr.h:191:27
    #14 0x55dbe94353ef in clang::CompilerInstance::setASTContext(clang::ASTContext*) clang/lib/Frontend/CompilerInstance.cpp:178:3
    #15 0x55dbe95ad0ad in clang::FrontendAction::EndSourceFile() clang/lib/Frontend/FrontendAction.cpp:1100:8
    #16 0x55dbe9445fcf in clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) clang/lib/Frontend/CompilerInstance.cpp:1047:11
    #17 0x55dbe6b3afef in clang::ExecuteCompilerInvocation(clang::CompilerInstance*) clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp:266:25
    #18 0x55dbe6b13288 in cc1_main(llvm::ArrayRef<char const*>, char const*, void*) clang/tools/driver/cc1_main.cpp:250:15
    #19 0x55dbe6b0095f in ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) clang/tools/driver/driver.cpp:319:12
    #20 0x55dbe6aff41c in clang_main(int, char**) clang/tools/driver/driver.cpp:395:12
    #21 0x7f9be07fa632 in __libc_start_main
    #22 0x55dbe6a702e9 in _start

  Member fields were destroyed
    #0 0x55dbe6a7da5d in __sanitizer_dtor_callback_fields compiler-rt/lib/msan/msan_interceptors.cpp:949:5
    #1 0x55dbec5094ac in ~SmallVectorImpl llvm/include/llvm/ADT/SmallVector.h:479:7
    #2 0x55dbec5094ac in ~SmallVectorImpl llvm/include/llvm/ADT/SmallVector.h:612:3
    #3 0x55dbec5094ac in llvm::SmallVector<clang::interp::Record::Base, 8u>::~SmallVector() llvm/include/llvm/ADT/SmallVector.h:1207:3
    #4 0x55dbec508e79 in clang::interp::Record::~Record() clang/lib/AST/Interp/Record.h:24:7
    #5 0x55dbec508612 in clang::interp::Program::~Program() clang/lib/AST/Interp/Program.h:49:26
    #6 0x55dbec50657a in operator() third_party/crosstool/v18/stable/toolchain/bin/../include/c++/v1/__memory/unique_ptr.h:55:5
    #7 0x55dbec50657a in std::__msan::unique_ptr<clang::interp::Program, std::__msan::default_delete<clang::interp::Program>>::~unique_ptr() third_party/crosstool/v18/stable/toolchain/bin/../include/c++/v1/__memory/unique_ptr.h:261:7
    #8 0x55dbec5035a1 in clang::interp::Context::~Context() clang/lib/AST/Interp/Context.cpp:27:22
    #9 0x55dbebec1daa in operator() third_party/crosstool/v18/stable/toolchain/bin/../include/c++/v1/__memory/unique_ptr.h:55:5
    #10 0x55dbebec1daa in std::__msan::unique_ptr<clang::interp::Context, std::__msan::default_delete<clang::interp::Context>>::~unique_ptr() third_party/crosstool/v18/stable/toolchain/bin/../include/c++/v1/__memory/unique_ptr.h:261:7
    #11 0x55dbebe285f9 in clang::ASTContext::~ASTContext() clang/lib/AST/ASTContext.cpp:1038:40
    #12 0x55dbe941ff13 in llvm::RefCountedBase<clang::ASTContext>::Release() const llvm/include/llvm/ADT/IntrusiveRefCntPtr.h:101:7
    #13 0x55dbe94353ef in release llvm/include/llvm/ADT/IntrusiveRefCntPtr.h:159:38
    #14 0x55dbe94353ef in release llvm/include/llvm/ADT/IntrusiveRefCntPtr.h:224:7
    #15 0x55dbe94353ef in ~IntrusiveRefCntPtr llvm/include/llvm/ADT/IntrusiveRefCntPtr.h:191:27
    #16 0x55dbe94353ef in clang::CompilerInstance::setASTContext(clang::ASTContext*) clang/lib/Frontend/CompilerInstance.cpp:178:3
    #17 0x55dbe95ad0ad in clang::FrontendAction::EndSourceFile() clang/lib/Frontend/FrontendAction.cpp:1100:8
    #18 0x55dbe9445fcf in clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) clang/lib/Frontend/CompilerInstance.cpp:1047:11
    #19 0x55dbe6b3afef in clang::ExecuteCompilerInvocation(clang::CompilerInstance*) clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp:266:25
    #20 0x55dbe6b13288 in cc1_main(llvm::ArrayRef<char const*>, char const*, void*) clang/tools/driver/cc1_main.cpp:250:15
    #21 0x55dbe6b0095f in ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) clang/tools/driver/driver.cpp:319:12
    #22 0x55dbe6aff41c in clang_main(int, char**) clang/tools/driver/driver.cpp:395:12
    #23 0x7f9be07fa632 in __libc_start_main
    #24 0x55dbe6a702e9 in _start
keryell pushed a commit that referenced this issue Jan 4, 2023
For the following program,
  $ cat t.c
  struct t {
   int (__attribute__((btf_type_tag("rcu"))) *f)();
   int a;
  };
  int foo(struct t *arg) {
    return arg->a;
  }
Compiling with 'clang -g -O2 -S t.c' will cause a failure like below:
  clang: /home/yhs/work/llvm-project/clang/lib/Sema/SemaType.cpp:6391: void {anonymous}::DeclaratorLocFiller::VisitParenTypeLoc(clang::ParenTypeLoc):
         Assertion `Chunk.Kind == DeclaratorChunk::Paren' failed.
  PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
  Stack dump:
  ......
  #5 0x00007f89e4280ea5 abort (/lib64/libc.so.6+0x21ea5)
  #6 0x00007f89e4280d79 _nl_load_domain.cold.0 (/lib64/libc.so.6+0x21d79)
  #7 0x00007f89e42a6456 (/lib64/libc.so.6+0x47456)
  #8 0x00000000045c2596 GetTypeSourceInfoForDeclarator((anonymous namespace)::TypeProcessingState&, clang::QualType, clang::TypeSourceInfo*) SemaType.cpp:0:0
  #9 0x00000000045ccfa5 GetFullTypeForDeclarator((anonymous namespace)::TypeProcessingState&, clang::QualType, clang::TypeSourceInfo*) SemaType.cpp:0:0
  ......

The reason of the failure is due to the mismatch of TypeLoc and D.getTypeObject().Kind. For example,
the TypeLoc is
  BTFTagAttributedType 0x88614e0 'int  btf_type_tag(rcu)()' sugar
  |-ParenType 0x8861480 'int ()' sugar
  | `-FunctionNoProtoType 0x8861450 'int ()' cdecl
  |   `-BuiltinType 0x87fd500 'int'
while corresponding D.getTypeObject().Kind points to DeclaratorChunk::Paren, and
this will cause later assertion.

To fix the issue, similar to AttributedTypeLoc, let us skip BTFTagAttributedTypeLoc in
GetTypeSourceInfoForDeclarator().

Differential Revision: https://reviews.llvm.org/D136807
Ralender pushed a commit to Ralender/sycl that referenced this issue Jun 9, 2023
When building/testing ASan inside the GCC tree on Solaris while using GNU
`ld` instead of Solaris `ld`, a large number of tests SEGVs on both sparc
and x86 like this:

  Thread 2 received signal SIGSEGV, Segmentation fault.
  [Switching to Thread 1 (LWP 1)]
  0xfe014cfc in __sanitizer::atomic_load<__sanitizer::atomic_uintptr_t>
(a=0xfc602a58, mo=__sanitizer::memory_order_acquire) at
sanitizer_common/sanitizer_atomic_clang_x86.h:46
  46	      v = a->val_dont_use;
  1: x/i $pc
  => 0xfe014cfc
<_ZN11__sanitizer11atomic_loadINS_16atomic_uintptr_tEEENT_4TypeEPVKS2_NS_12memory_orderE+62>:
mov (%eax),%eax
  (gdb) bt
  #0 0xfe014cfc in __sanitizer::atomic_load<__sanitizer::atomic_uintptr_t>
(a=0xfc602a58, mo=__sanitizer::memory_order_acquire) at
sanitizer_common/sanitizer_atomic_clang_x86.h:46
  #1 0xfe0bd1d7 in __sanitizer::DTLS_NextBlock (cur=0xfc602a58) at
sanitizer_common/sanitizer_tls_get_addr.cpp:53
  triSYCL#2 0xfe0bd319 in __sanitizer::DTLS_Find (id=1) at
sanitizer_common/sanitizer_tls_get_addr.cpp:77
  triSYCL#3 0xfe0bd466 in __sanitizer::DTLS_on_tls_get_addr (arg_void=0xfeffd068,
res=0xfe602a18, static_tls_begin=0, static_tls_end=0) at
sanitizer_common/sanitizer_tls_get_addr.cpp:116
  triSYCL#4 0xfe063f81 in __interceptor___tls_get_addr (arg=0xfeffd068) at
sanitizer_common/sanitizer_common_interceptors.inc:5501
  triSYCL#5 0xfe0a3054 in __sanitizer::CollectStaticTlsBlocks (info=0xfeffd108,
size=40, data=0xfeffd16c) at
sanitizer_common/sanitizer_linux_libcdep.cpp:366
  triSYCL#6  0xfe6ba9fa in dl_iterate_phdr () from /usr/lib/ld.so.1
  triSYCL#7 0xfe0a3132 in __sanitizer::GetStaticTlsBoundary (addr=0xfe608020,
size=0xfeffd244, align=0xfeffd1b0) at
sanitizer_common/sanitizer_linux_libcdep.cpp:382
  triSYCL#8 0xfe0a33f7 in __sanitizer::GetTls (addr=0xfe608020, size=0xfeffd244)
at sanitizer_common/sanitizer_linux_libcdep.cpp:482
  triSYCL#9 0xfe0a34b1 in __sanitizer::GetThreadStackAndTls (main=true,
stk_addr=0xfe608010, stk_size=0xfeffd240, tls_addr=0xfe608020,
tls_size=0xfeffd244) at sanitizer_common/sanitizer_linux_libcdep.cpp:565

The address being accessed is unmapped.  However, even when the tests
`PASS` with Solaris `ld`, `ASAN_OPTIONS=verbosity=2` shows

  ==6582==__tls_get_addr: Can't guess glibc version

Given that that the code is stricly `glibc`-specific according to
`sanitizer_tls_get_addr.h`, there seems little point in using the
interceptor on non-`glibc` targets.

That's what this patch does.  Tested on `i386-pc-solaris2.11` and
`sparc-sun-solaris2.11` inside the GCC tree.

Differential Revision: https://reviews.llvm.org/D141385
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