On Tue, 2012-11-20 at 23:19 -0500, David Miller wrote:
> The address violation detection seems to work properly and the only
> thing that seems to be left are some backtrace/unwind issues. These
> are perhaps similar to the unwind bits that the powerpc folks ran
> into.
David, does the following patch (will have some fuzz since I removed
one ppc only hunk from the patch) fix your backtrace issue? I'll note
you'll have to add "|| defined(__sparc__)" to the #if ... or as
it's probably going to turn out, just replace the whole thing
with a "#if !defined(__i386__) && !defined(__x86_64__)".
Peter
Index: libsanitizer/asan/asan_linux.cc
===================================================================
--- libsanitizer/asan/asan_linux.cc (revision 193678)
+++ libsanitizer/asan/asan_linux.cc (working copy)
@@ -134,11 +141,27 @@
#endif
}
+uptr Unwind_GetBP(struct _Unwind_Context *ctx) {
+ return _Unwind_GetCFA(ctx);
+}
+
+struct Unwind_Trace_Info {
+ StackTrace *stack;
+ uptr bp;
+};
+
_Unwind_Reason_Code Unwind_Trace(struct _Unwind_Context *ctx,
void *param) {
- StackTrace *b = (StackTrace*)param;
+ Unwind_Trace_Info *p = (Unwind_Trace_Info *)param;
+ StackTrace *b = p->stack;
+ uptr pc = Unwind_GetIP(ctx);
+ if (Unwind_GetBP(ctx) == p->bp) {
+ // We just encountered the frame pointer we want to start
+ // our backtrace with, so empty the backtrace before adding
+ // this frame to the backtrace.
+ b->size = 0;
+ }
CHECK(b->size < b->max_size);
- uptr pc = Unwind_GetIP(ctx);
b->trace[b->size++] = pc;
if (b->size == b->max_size) return UNWIND_STOP;
return UNWIND_CONTINUE;
@@ -149,8 +172,11 @@
stack->trace[0] = pc;
if ((max_s) > 1) {
stack->max_size = max_s;
-#ifdef __arm__
- _Unwind_Backtrace(Unwind_Trace, stack);
+#if defined(__arm__) || defined(__powerpc__) || defined(__powerpc64__)
+ Unwind_Trace_Info param;
+ param.stack = stack;
+ param.bp = bp;
+ _Unwind_Backtrace(Unwind_Trace, ¶m);
#else
if (!asan_inited) return;
if (AsanThread *t = asanThreadRegistry().GetCurrent())
