x86-darwin: _start: keep the stack 16-aligned. Fixes #295428.

(Jack Howarth, howarth@nitro.med.uc.edu)

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@12424

diff --git a/coregrind/m_main.c b/coregrind/m_main.c
index bb0b096e938845efa59fdb13438a056d104b0eee..85bec7bc14673216bd260e6680ca957b72680584 100644 (file)
--- a/coregrind/m_main.c
+++ b/coregrind/m_main.c
@@ -2840,6 +2840,7 @@ asm("\n"
     "\taddl  $"VG_STRINGIFY(VG_STACK_ACTIVE_SZB)", %eax\n"
     "\tsubl  $16, %eax\n"
     "\tandl  $~15, %eax\n"
+    "\tsubl  $12, %esp\n"  // keep stack 16 aligned; see #295428
     /* install it, and collect the original one */
     "\txchgl %eax, %esp\n"
     /* call _start_in_C_darwin, passing it the startup %esp */