Re: [libvirt] [PATCH] qemu_capabilities: Pass pointer to va_list in virQEMUCapsSetVAList

On Wed, 2019-03-27 at 10:50 +0100, Michal Privoznik wrote: > There is one specific caller (testInfoSetArgs() in > qemuxml2argvtest.c) which expect the va_list argument to change s/ / / > after returning from the virQEMUCapsSetVAList() function. > However, since we are passing plain va_list this is not > guaranteed. The man page of stdarg(3) says: > > If ap is passed to a function that uses va_arg(ap,type), then > the value of ap is undefined after the return of that function. > > (ap is a variable of type va_list) > > I've seen this in action in fact: on i686 the qemuxml2argvtest > fails on the second test case because testInfoSetArgs() sees > ARG_QEMU_CAPS and callse virQEMUCapsSetVAList to process the s/callse/calls/ > capabilities (in this case there's just one > QEMU_CAPS_SECCOMP_BLACKLIST). But since the changes are not > reflected in the caller, in the next iteration testInfoSetArgs() > sees the qemu capability and not ARG_END. s/qemu/QEMU/ > > Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; > --- > > This passed successfully on x86_64 and i686 in my testing. > > src/qemu/qemu_capabilities.c | 6 +++--- > src/qemu/qemu_capabilities.h | 2 +- > tests/qemuxml2argvtest.c | 2 +- > 3 files changed, 5 insertions(+), 5 deletions(-) The changes look okay to me, so Reviewed-by: Andrea Bolognani <abologna(a)redhat.com&gt; however I'd like to hear Eric's opinion before this gets merged.