[PATCH] x86-64: work around gcc4 issue with -Os in Dwarf2 stack unwind
This fixes a problem with gcc4 mis-compiling the stack unwind code under
-Os, which resulted in 'stuck' messages whenever an assembly routine was
encountered.
(The second hunk is trivial cleanup.)
Signed-off-by: Jan Beulich <jbeulich@novell.com>
diff --git a/kernel/unwind.c b/kernel/unwind.c
index f7e50d1..ed0a21d 100644
--- a/kernel/unwind.c
+++ b/kernel/unwind.c
@@ -938,8 +938,11 @@
else {
retAddrReg = state.version <= 1 ? *ptr++ : get_uleb128(&ptr, end);
/* skip augmentation */
- if (((const char *)(cie + 2))[1] == 'z')
- ptr += get_uleb128(&ptr, end);
+ if (((const char *)(cie + 2))[1] == 'z') {
+ uleb128_t augSize = get_uleb128(&ptr, end);
+
+ ptr += augSize;
+ }
if (ptr > end
|| retAddrReg >= ARRAY_SIZE(reg_info)
|| REG_INVALID(retAddrReg)
@@ -963,9 +966,7 @@
if (cie == NULL || fde == NULL) {
#ifdef CONFIG_FRAME_POINTER
unsigned long top, bottom;
-#endif
-#ifdef CONFIG_FRAME_POINTER
top = STACK_TOP(frame->task);
bottom = STACK_BOTTOM(frame->task);
# if FRAME_RETADDR_OFFSET < 0
