Re: [libvirt] [PATCH] nodeinfo: avoid uninitialized variable on error

[Michal Privoznik]

On 11.06.2014 00:27, Eric Blake wrote:

Commit 8ba0a58 introduced a compiler warning that I hit during
a run of ./autobuild.sh:

../../src/nodeinfo.c: In function 'nodeCapsInitNUMA':
../../src/nodeinfo.c:1853:43: error: 'nsiblings' may be used uninitialized in 
this function [-Werror=maybe-uninitialized]
  if (virCapabilitiesAddHostNUMACell(caps, n, memory,
^

Sure enough, nsiblings starts uninitialized, and is set by a call
to virNodeCapsGetSiblingInfo, but that function fails to assign
through the pointer if virNumaGetDistances fails.


If that's the case, virNodeCapsGetSiblingInfo() fails too so at the 
incriminated lines we jump at cleanup label directly. But maybe the 
compiler you've used fails to do analysis this deep.


Michal

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[libvirt] [PATCH] nodeinfo: avoid uninitialized variable on error

[Eric Blake]

Commit 8ba0a58 introduced a compiler warning that I hit during
a run of ./autobuild.sh:

../../src/nodeinfo.c: In function 'nodeCapsInitNUMA':
../../src/nodeinfo.c:1853:43: error: 'nsiblings' may be used uninitialized in 
this function [-Werror=maybe-uninitialized]
 if (virCapabilitiesAddHostNUMACell(caps, n, memory,
   ^

Sure enough, nsiblings starts uninitialized, and is set by a call
to virNodeCapsGetSiblingInfo, but that function fails to assign
through the pointer if virNumaGetDistances fails.

* src/nodeinfo.c (nodeCapsInitNUMA): Initialize nsiblings.

Signed-off-by: Eric Blake ebl...@redhat.com
---

Pushing under the build-breaker rule.

 src/nodeinfo.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/nodeinfo.c b/src/nodeinfo.c
index 5eef42e..5332ede 100644
--- a/src/nodeinfo.c
+++ b/src/nodeinfo.c
@@ -1803,7 +1803,7 @@ nodeCapsInitNUMA(virCapsPtr caps)
 virCapsHostNUMACellCPUPtr cpus = NULL;
 virBitmapPtr cpumap = NULL;
 virCapsHostNUMACellSiblingInfoPtr siblings = NULL;
-int nsiblings;
+int nsiblings = 0;
 int ret = -1;
 int ncpus = 0;
 int cpu;
-- 
1.9.3

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