From: Arnaud Giersch <arnaud.giersch@iut-bm.univ-fcomte.fr>
Date: Thu, 13 Mar 2014 21:45:38 +0000 (+0100)
Subject: Align stack on a 16 bytes boundary in raw_makecontext.
X-Git-Tag: v3_11~216^2~1
X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/commitdiff_plain/0c5f183849112970e4ce7f7af4df4d2267cda7e1?hp=ca7e44eedb71bed5a09556bdd8e3fa13be21c9ce

Align stack on a 16 bytes boundary in raw_makecontext.

A wrongly aligned stack may lead to segfaults.
---

diff --git a/src/simix/smx_context_raw.c b/src/simix/smx_context_raw.c
index df733cda81..f380e90843 100644
--- a/src/simix/smx_context_raw.c
+++ b/src/simix/smx_context_raw.c
@@ -62,6 +62,7 @@ __asm__ (
 #endif
    "   mov %rdi,%rax\n"      /* stack */
    "   add %rsi,%rax\n"      /* size  */
+   "   andq $-16, %rax\n"    /* align stack */
    "   movq $0,   -8(%rax)\n" /* @return for func */
    "   mov %rdx,-16(%rax)\n" /* func */
    "   mov %rcx,-24(%rax)\n" /* arg/rdi */
@@ -137,6 +138,7 @@ __asm__ (
 #endif
    "   movl 4(%esp),%eax\n"   /* stack */
    "   addl 8(%esp),%eax\n"   /* size  */
+   "   andl $-16, %eax\n"     /* align stack */
    "   movl 12(%esp),%ecx\n"  /* func  */
    "   movl 16(%esp),%edx\n"  /* arg   */
    "   movl %edx, -4(%eax)\n"