PATCH: PR other/55333: libsanitizer StackTrace::FastUnwindStack wrong x32
H.J. Lu
hjl.tools@gmail.com
Thu Nov 15 17:14:00 GMT 2012
On Thu, Nov 15, 2012 at 09:05:13AM -0800, Konstantin Serebryany wrote:
> +dvyukov, +glider, +samsonov
>
> Sorry I am lagging behind e-mail, but I am sure Dmitry, Alexander or
> Alexey may submit the patch upstream.
> Please make sure to comment the reason for using a separate typedef.
Here is the patch with comments.
>
> We need our custom unwinder based on frame pointers to remain the
> default choice on x86[_64] because this is a hotspot
> and replacing it with any library call (especially if that call does
> not use frame pointers but instead uses debug info) will slow down
> the tool significantly.
> The asan docs explicitly say that you need -fno-omit-frame-pointers to
> get reasonable bug reports.
>
> Note that on ARM (and on Windows) we are using a library call.
>
Thanks.
H.J.
---
2012-11-14 H.J. Lu <hongjiu.lu@intel.com>
PR other/55333
* include/sanitizer/common_interface_defs.h (uhwptr): New type
for hardware pointer.
* sanitizer_common/sanitizer_stacktrace.cc (StackTrace::FastUnwindStack):
Replace uptr with uhwptr for frame unwind.
diff --git a/libsanitizer/include/sanitizer/common_interface_defs.h b/libsanitizer/include/sanitizer/common_interface_defs.h
index 4ac7609..d78d280 100644
--- a/libsanitizer/include/sanitizer/common_interface_defs.h
+++ b/libsanitizer/include/sanitizer/common_interface_defs.h
@@ -46,6 +46,13 @@ typedef signed long long sptr; // NOLINT
typedef unsigned long uptr; // NOLINT
typedef signed long sptr; // NOLINT
#endif // defined(_WIN64)
+#if defined(__x86_64__)
+// Since x32 uses ILP32 data model in 64-bit hardware mode, we must use
+// 64-bit pointer to unwind stack frame.
+typedef unsigned long long uhwptr; // NOLINT
+#else
+typedef uptr uhwptr; // NOLINT
+#endif
typedef unsigned char u8;
typedef unsigned short u16; // NOLINT
typedef unsigned int u32;
diff --git a/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc b/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc
index f6d7a09..915c4b8 100644
--- a/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc
@@ -120,18 +120,18 @@ void StackTrace::FastUnwindStack(uptr pc, uptr bp,
uptr stack_top, uptr stack_bottom) {
CHECK(size == 0 && trace[0] == pc);
size = 1;
- uptr *frame = (uptr*)bp;
- uptr *prev_frame = frame;
+ uhwptr *frame = (uhwptr *)bp;
+ uhwptr *prev_frame = frame;
while (frame >= prev_frame &&
- frame < (uptr*)stack_top - 2 &&
- frame > (uptr*)stack_bottom &&
+ frame < (uhwptr *)stack_top - 2 &&
+ frame > (uhwptr *)stack_bottom &&
size < max_size) {
- uptr pc1 = frame[1];
+ uhwptr pc1 = frame[1];
if (pc1 != pc) {
- trace[size++] = pc1;
+ trace[size++] = (uptr) pc1;
}
prev_frame = frame;
- frame = (uptr*)frame[0];
+ frame = (uhwptr *)frame[0];
}
}
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