On 04/12/2012 04:37 PM, Daniel P. Berrange wrote:

On Thu, Apr 12, 2012 at 03:24:08PM +0800, Alex Jia wrote:

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Detected by valgrind. Leaks are introduced in commit 6e6e9be.

* daemon/libvirtd-config.c (macro GET_CONF_STR): fix memory leaks.

How to reproduce?

% make&& make -C tests check TESTS=libvirtdconftest % cd tests&& valgrind -v --leak-check=full ./libvirtdconftest

actual result:

==11008== 185 bytes in 5 blocks are definitely lost in loss record 3 of 5 ==11008== at 0x4A05FDE: malloc (vg_replace_malloc.c:236) ==11008== by 0x39CF07F6E1: strdup (strdup.c:43) ==11008== by 0x406626: daemonConfigLoadOptions (libvirtd-config.c:438) ==11008== by 0x406800: daemonConfigLoadData (libvirtd-config.c:492) ==11008== by 0x403CCF: testCorrupt (libvirtdconftest.c:110) ==11008== by 0x404FAD: virtTestRun (testutils.c:145) ==11008== by 0x403A34: mymain (libvirtdconftest.c:219) ==11008== by 0x404687: virtTestMain (testutils.c:700) ==11008== by 0x39CF01ECDC: (below main) (libc-start.c:226) ==11008== ==11008== LEAK SUMMARY: ==11008== definitely lost: 185 bytes in 5 blocks

Signed-off-by: Alex Jia<ajia@redhat.com> --- daemon/libvirtd-config.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/daemon/libvirtd-config.c b/daemon/libvirtd-config.c index 4d041f0..0a4323a 100644 --- a/daemon/libvirtd-config.c +++ b/daemon/libvirtd-config.c @@ -152,6 +152,7 @@ checkType (virConfValuePtr p, const char *filename, virReportOOMError(); \ goto error; \ } \ + VIR_FREE(data->var_name); \ } \ } while (0) Errr, no. Please look at the context of what's going on, rather than just blindly adding code to free a block at the point where valgrind shows the allocation.

The full context to this diff

#define GET_CONF_STR(conf, filename, var_name) \ do { \ virConfValuePtr p = virConfGetValue (conf, #var_name); \ if (p) { \ if (checkType (p, filename, #var_name, VIR_CONF_STRING)< 0) \ goto error; \ VIR_FREE(data->var_name); \ if (!(data->var_name = strdup (p->str))) { \ virReportOOMError(); \ goto error; \ } \ } \ } while (0)

Your suggested change means we would be free'ing the config file before we have even used it.

If you look at this line: Yeah.

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==11008== by 0x406626: daemonConfigLoadOptions (libvirtd-config.c:438) You'll see it matches:

GET_CONF_STR (conf, filename, host_uuid);

There are no leak reports for other uses of GET_CONF_STR, so this suggests that 'host_uuid' is not being freed. Check daemonConfigFree and you'll see this is indeed missing Yeah, it's a little weird, the previous codes also haven't free 'host_uuid', but valgrind hasn't complains memory leak.

Thanks for your review, Alex

Daniel