Re: [libvirt] [PATCH v4 1/4] qemu_process.c: use g_autofree
On 12/20/19 3:34 PM, Cole Robinson wrote:
On 12/19/19 4:09 PM, Daniel Henrique Barboza wrote:
> Change all feasible strings and scalar pointers to use g_autofree.
>
> Signed-off-by: Daniel Henrique Barboza <danielhb413(a)gmail.com>
> ---
> src/qemu/qemu_process.c | 97 +++++++++++++++--------------------------
> 1 file changed, 34 insertions(+), 63 deletions(-)
[...]>>
Last one looks suspicious, either it's fixing a memory leak or something
is wrong! It's a bit of both. Later code is:
template = g_strdup_printf("%s/qmp-XXXXXX", proc->libDir);
if (!(proc->uniqDir = g_mkdtemp(template))) {
virReportSystemError(errno,
_("Failed to create unique directory with "
"template '%s' for probing QEMU"),
template);
return -1;
}
g_mkdtemp actually alters and returns the passed in string, it doesn't
return new memory. So if g_mkdtemp succeeds, we are transfering
ownership to proc->uniqDir. There's a bug though that template isn't
free'd if g_mkdtemp fails.
So if you convert to g_autofree, after g_mkdtemp succeeds, you need to
set 'template = NULL';
Thanks. I got a weird feeling about this change (this code wasn't present in
the previous version) because I thought strange that no one put a VIR_FREE()
in a string returned by g_strdup_printf(), which I know for a fact that
put stuff in the heap.
DHB
- Cole