Fixed bug 3495487.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@4004 35acf78f-673a-0410-8e92-d51de3d6d3f4

1 files changed, 10 insertions, 1 deletions

diff --git a/os/ports/GCC/SIMIA32/chcore.h b/os/ports/GCC/SIMIA32/chcore.h
index d7fe957a1..1dcab09d1 100644
--- a/os/ports/GCC/SIMIA32/chcore.h
+++ b/os/ports/GCC/SIMIA32/chcore.h
@@ -98,6 +98,12 @@ struct context {
 

 #define APUSH(p, a) (p) -= sizeof(void *), *(void **)(p) = (void*)(a)

 

+/* Darwin requires the stack to be aligned to a 16-byte boundary at

+ * the time of a call instruction (in case the called function needs

+ * to save MMX registers). This aligns to 'mod' module 16, so that we'll end

+ * up with the right alignment after pushing the args. */

+#define AALIGN(p, mask, mod) p = (void *)((((uintptr_t)(p) - mod) & ~mask) + mod)

+

 /**

  * Platform dependent part of the @p chThdCreateI() API.

  * This code usually setup the context switching frame represented by a

@@ -105,6 +111,9 @@ struct context {
  */

 #define SETUP_CONTEXT(workspace, wsize, pf, arg) {                      \

   uint8_t *esp = (uint8_t *)workspace + wsize;                          \

+  APUSH(esp, 0);                                                        \

+  uint8_t *savebp = esp;                                                \

+  AALIGN(esp, 15, 8);                                                   \

   APUSH(esp, arg);                                                      \

   APUSH(esp, pf);                                                       \

   APUSH(esp, 0);                                                        \

@@ -113,7 +122,7 @@ struct context {
   ((struct intctx *)esp)->ebx = 0;                                      \

   ((struct intctx *)esp)->edi = 0;                                      \

   ((struct intctx *)esp)->esi = 0;                                      \

-  ((struct intctx *)esp)->ebp = 0;                                      \

+  ((struct intctx *)esp)->ebp = savebp;                                 \

   tp->p_ctx.esp = (struct intctx *)esp;                                 \

 }