From 83868b8c46ace8a3a5df069be84e4f4f3c4ad872 Mon Sep 17 00:00:00 2001
From: Max Rottenkolber <max@mr.gy>
Date: Thu, 17 Dec 2015 17:35:06 +0100
Subject: [PATCH 1/3] core.shm: Assert return value of `mkdir(2)' when creating
 shm root.

---
 src/core/shm.lua | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/core/shm.lua b/src/core/shm.lua
index 47f0c7cf9c..429f204a5e 100644
--- a/src/core/shm.lua
+++ b/src/core/shm.lua
@@ -103,10 +103,15 @@ end
 -- Make directories needed for a named object.
 -- Given the name "foo/bar/baz" create /var/run/foo and /var/run/foo/bar.
 function mkdir (name)
-   -- Create root with mode "rwxrwxrwt" (R/W for all and sticky)
-   local mask = S.umask(0)
-   S.mkdir(root, "01777")
-   S.umask(mask)
+   -- Create root with mode "rwxrwxrwt" (R/W for all and sticky) if it
+   -- does not exist yet.
+   if not S.stat(root) then
+      local mask = S.umask(0)
+      local status, err = S.mkdir(root, "01777")
+      assert(status, ("Unable to create %s: %s"):format(
+                root, tostring(err or "unspecified error")))
+      S.umask(mask)
+   end
    -- Create sub directories
    local dir = root
    name:gsub("([^/]+)",

From d32aef5b17d4979eafcfc578b78174d7d370efef Mon Sep 17 00:00:00 2001
From: Max Rottenkolber <max@mr.gy>
Date: Thu, 17 Dec 2015 17:53:29 +0100
Subject: [PATCH 2/3] lib.hardware.pci: Make device_info throw error when
 device by pciaddress does not exist.

---
 src/lib/hardware/pci.lua | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/lib/hardware/pci.lua b/src/lib/hardware/pci.lua
index 00d0fd1d35..db24465642 100644
--- a/src/lib/hardware/pci.lua
+++ b/src/lib/hardware/pci.lua
@@ -2,6 +2,7 @@ module(...,package.seeall)
 
 local ffi = require("ffi")
 local C = ffi.C
+local S = require("syscall")
 
 local lib = require("core.lib")
 
@@ -34,6 +35,7 @@ end
 function device_info (pciaddress)
    local info = {}
    local p = path(pciaddress)
+   assert(S.stat(p), ("No such device: %s"):format(pciaddress))
    info.pciaddress = canonical(pciaddress)
    info.vendor = lib.firstline(p.."/vendor")
    info.device = lib.firstline(p.."/device")

From e880a1b332be8cc29d47dceab95d88c961b09127 Mon Sep 17 00:00:00 2001
From: Max Rottenkolber <max@mr.gy>
Date: Thu, 17 Dec 2015 17:57:57 +0100
Subject: [PATCH 3/3] packetblaster: Bail out when no suitable PCI devices were
 selected.

---
 src/program/packetblaster/packetblaster.lua | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/program/packetblaster/packetblaster.lua b/src/program/packetblaster/packetblaster.lua
index 37af858960..4deb70d3f9 100644
--- a/src/program/packetblaster/packetblaster.lua
+++ b/src/program/packetblaster/packetblaster.lua
@@ -46,6 +46,7 @@ function run (args)
          config.link(c, "tee."..tostring(nics).."->"..name..".input")
       end
    end
+   assert(nics > 0, "<PCI> matches no suitable devices.")
    engine.busywait = true
    intel10g.num_descriptors = 32*1024
    engine.configure(c)