Fix false positive in sys_clone on amd64 when optional args are not given (e.g. child_tidptr)
rev 10493 fixed bug 117564 in syswrap-x86-linux.c.
This commit fixes the same problem in syswrap-amd64-linux.c.
The problem makes memcheck/tests/linux/stack_switch fails (at least on gcc20)
with unexpected
==802== Syscall param clone(child_tidptr) contains uninitialised byte(s)
The problem originates from always checking 3 optional args PRE_read,
while these should be checked only if the corresponding flags are set.
syswrap-{arm,ppc32,ppc64}-linux.c seems to have the same problem
(but no visible effect) : VKI_CLONE_PARENT_SETTID,VKI_CLONE_CHILD_SETTID
and VKI_CLONE_SETTLS not properly handled in the PRE part.
syswrap-s390x-linux.c seems to have the VKI_CLONE_SETTLS part wrong,
but VKI_CLONE_PARENT_SETTID and VKI_CLONE_CHILD_SETTID correct.
Commiting a fix just for amd64 for now.
We probably better make some common code in syswrap-generic.c
to regroup all similar platforms.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@12586 a5019735-40e9-0310-863c-91ae7b9d1cf9
2 files changed
