<div dir="ltr">I've already fixed the failing test case in r217111 (we used fake frame pointers in a unit test setting to emulate actual stack unwinding).</div><div class="gmail_extra"><br><br><div class="gmail_quote">On Fri, Sep 5, 2014 at 4:56 AM, Maxim Ostapenko <span dir="ltr"><<a href="mailto:m.ostapenko@partner.samsung.com" target="_blank">m.ostapenko@partner.samsung.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">This looks to be mine. It seems that we loose last return address in ARM case.<br>
<br>
I suppose, something like this should fix the issue.<span class="HOEnZb"><font color="#888888"><br>
<br>
-Maxim</font></span><div class="HOEnZb"><div class="h5"><br>
On 09/05/2014 11:54 AM, Yury Gribov wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Added Max.<br>
<br>
------------------------------<u></u>-----------------<br>
From: Alexey Samsonov<br>
Sent: Thursday, September 04, 2014 3:35AM<br>
To: Chandler Carruth <<a href="mailto:chandlerc@google.com" target="_blank">chandlerc@google.com</a>><br>
Cc: llvm-commits<br>
Subject: Re: [compiler-rt] r217079 - Fix fast stack unwind on ARM to support code generated with GCC.<br>
<br>
On 09/04/2014 03:35 AM, Alexey Samsonov wrote:<br>
Indeed. Looking.<br>
<br>
<br>
On Wed, Sep 3, 2014 at 4:29 PM, Chandler Carruth <<a href="mailto:chandlerc@google.com" target="_blank">chandlerc@google.com</a>><br>
wrote:<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
I suspect this commit broke the bot:<br>
<br>
<a href="http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux/builds/12566" target="_blank">http://lab.llvm.org:8011/<u></u>builders/sanitizer-x86_64-<u></u>linux/builds/12566</a><br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
</blockquote>
On Wed, Sep 3, 2014 at 2:10 PM, Alexey Samsonov <<a href="mailto:vonosmas@gmail.com" target="_blank">vonosmas@gmail.com</a>><br>
wrote:<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Author: samsonov<br>
Date: Wed Sep 3 16:10:44 2014<br>
New Revision: 217079<br>
<br>
URL: <a href="http://llvm.org/viewvc/llvm-project?rev=217079&view=rev" target="_blank">http://llvm.org/viewvc/llvm-<u></u>project?rev=217079&view=rev</a><br>
Log:<br>
Fix fast stack unwind on ARM to support code generated with GCC.<br>
<br>
<a href="http://reviews.llvm.org/D4692" target="_blank">http://reviews.llvm.org/D4692</a><br>
<br>
Patch by Maxim Ostapenko!<br>
<br>
Added:<br>
compiler-rt/trunk/test/asan/<u></u>TestCases/Linux/clang_gcc_abi.<u></u>cc<br>
Modified:<br>
compiler-rt/trunk/lib/<u></u>sanitizer_common/sanitizer_<u></u>stacktrace.cc<br>
<br>
Modified: compiler-rt/trunk/lib/<u></u>sanitizer_common/sanitizer_<u></u>stacktrace.cc<br>
URL:<br>
<a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_stacktrace.cc?rev=217079&r1=217078&r2=217079&view=diff" target="_blank">http://llvm.org/viewvc/llvm-<u></u>project/compiler-rt/trunk/lib/<u></u>sanitizer_common/sanitizer_<u></u>stacktrace.cc?rev=217079&r1=<u></u>217078&r2=217079&view=diff</a> <br>
<br>
==============================<u></u>==============================<u></u>================== <br>
--- compiler-rt/trunk/lib/<u></u>sanitizer_common/sanitizer_<u></u>stacktrace.cc<br>
(original)<br>
+++ compiler-rt/trunk/lib/<u></u>sanitizer_common/sanitizer_<u></u>stacktrace.cc Wed<br>
Sep 3 16:10:44 2014<br>
@@ -36,19 +36,39 @@ uptr StackTrace::GetCurrentPc() {<br>
return GET_CALLER_PC();<br>
}<br>
<br>
+// Check if given pointer points into allocated stack area.<br>
+static inline bool IsValidFrame(uptr frame, uptr stack_top, uptr<br>
stack_bottom) {<br>
+ return frame > stack_bottom && frame < stack_top - 2 * sizeof (uhwptr);<br>
+}<br>
+<br>
+// In GCC on ARM bp points to saved lr, not fp, so we should check the<br>
next<br>
+// cell in stack to be a saved frame pointer. GetCanonicFrame returns the<br>
+// pointer to saved frame pointer in any case.<br>
+static inline uhwptr *GetCanonicFrame(uptr bp,<br>
+ uptr stack_top,<br>
+ uptr stack_bottom) {<br>
+#ifdef __arm__<br>
+ if (!IsValidFrame(bp, stack_top, stack_bottom)) return 0;<br>
+ uhwptr *bp_prev = (uhwptr *)bp;<br>
+ if (IsValidFrame((uptr)bp_prev[0]<u></u>, stack_top, stack_bottom)) return<br>
bp_prev;<br>
+ return bp_prev - 1;<br>
+#else<br>
+ return (uhwptr*)bp;<br>
+#endif<br>
+}<br>
+<br>
void StackTrace::FastUnwindStack(<u></u>uptr pc, uptr bp,<br>
uptr stack_top, uptr stack_bottom,<br>
uptr max_depth) {<br>
CHECK_GE(max_depth, 2);<br>
trace[0] = pc;<br>
size = 1;<br>
- uhwptr *frame = (uhwptr *)bp;<br>
- uhwptr *prev_frame = frame - 1;<br>
if (stack_top < 4096) return; // Sanity check for stack top.<br>
+ uhwptr *frame = GetCanonicFrame(bp, stack_top, stack_bottom);<br>
+ uhwptr *prev_frame = 0;<br>
// Avoid infinite loop when frame == frame[0] by using frame ><br>
prev_frame.<br>
while (frame > prev_frame &&<br>
- frame < (uhwptr *)stack_top - 2 &&<br>
- frame > (uhwptr *)stack_bottom &&<br>
+ IsValidFrame((uptr)frame, stack_top, stack_bottom) &&<br>
IsAligned((uptr)frame, sizeof(*frame)) &&<br>
size < max_depth) {<br>
uhwptr pc1 = frame[1];<br>
@@ -56,7 +76,7 @@ void StackTrace::FastUnwindStack(<u></u>uptr pc<br>
trace[size++] = (uptr) pc1;<br>
}<br>
prev_frame = frame;<br>
- frame = (uhwptr *)frame[0];<br>
+ frame = GetCanonicFrame((uptr)frame[0]<u></u>, stack_top, stack_bottom);<br>
}<br>
}<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
</blockquote>
Added: compiler-rt/trunk/test/asan/<u></u>TestCases/Linux/clang_gcc_abi.<u></u>cc<br>
URL:<br>
<a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/asan/TestCases/Linux/clang_gcc_abi.cc?rev=217079&view=auto" target="_blank">http://llvm.org/viewvc/llvm-<u></u>project/compiler-rt/trunk/<u></u>test/asan/TestCases/Linux/<u></u>clang_gcc_abi.cc?rev=217079&<u></u>view=auto</a> <br>
<br>
==============================<u></u>==============================<u></u>================== <br>
--- compiler-rt/trunk/test/asan/<u></u>TestCases/Linux/clang_gcc_abi.<u></u>cc (added)<br>
+++ compiler-rt/trunk/test/asan/<u></u>TestCases/Linux/clang_gcc_abi.<u></u>cc Wed Sep<br>
3 16:10:44 2014<br>
@@ -0,0 +1,43 @@<br>
+// RUN: %clangxx_asan -O0 -x c %s -o %t && not %run %t 2>&1 | FileCheck<br>
%s<br>
+// RUN: %clangxx_asan -O1 -x c %s -o %t && not %run %t 2>&1 | FileCheck<br>
%s<br>
+// RUN: %clangxx_asan -O2 -x c %s -o %t && not %run %t 2>&1 | FileCheck<br>
%s<br>
+// RUN: %clangxx_asan -O3 -x c %s -o %t && not %run %t 2>&1 | FileCheck<br>
%s<br>
+<br>
+// REQUIRES: arm-supported-target<br>
+<br>
+#include <stdlib.h><br>
+<br>
+int boom() {<br>
+ volatile int three = 3;<br>
+ char *s = (char *)malloc(three);<br>
+// CHECK: #1 0x{{.*}} in boom {{.*}}clang_gcc_abi.cc:[[@<u></u>LINE-1]]<br>
+ return s[three]; //BOOM<br>
+}<br>
+<br>
+__attribute__((naked, noinline)) void gcc_abi() {<br>
+// CHECK: #2 0x{{.*}} in gcc_abi {{.*}}clang_gcc_abi.cc:[[@<u></u>LINE+1]]<br>
+ asm volatile("str fp, [sp, #-8]!\n\t"<br>
+ "str lr, [sp, #4]\n\t"<br>
+ "add fp, sp, #4\n\t"<br>
+ "bl boom\n\t"<br>
+ "sub sp, fp, #4\n\t"<br>
+ "ldr fp, [sp]\n\t"<br>
+ "add sp, sp, #4\n\t"<br>
+ "ldr pc, [sp], #4\n\t"<br>
+ );<br>
+}<br>
+<br>
+__attribute__((naked, noinline)) void clang_abi() {<br>
+// CHECK: #3 0x{{.*}} in clang_abi {{.*}}clang_gcc_abi.cc:[[@<u></u>LINE+1]]<br>
+ asm volatile("push {r11, lr}\n\t"<br>
+ "mov r11, sp\n\t"<br>
+ "bl gcc_abi\n\t"<br>
+ "add r0, r0, #1\n\t"<br>
+ "pop {r11, pc}\n\t"<br>
+ );<br>
+}<br>
+<br>
+int main() {<br>
+ clang_abi();<br>
+// CHECK: #4 0x{{.*}} in main {{.*}}clang_gcc_abi.cc:[[@<u></u>LINE-1]]<br>
+}<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
</blockquote>
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</blockquote>
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<br>
</div></div></blockquote></div><br><br clear="all"><div><br></div>-- <br><div dir="ltr">Alexey Samsonov<br><a href="mailto:vonosmas@gmail.com" target="_blank">vonosmas@gmail.com</a></div>
</div>