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Fix fast stack unwind on ARM to support code generated with GCC. 

http://reviews.llvm.org/D4692

Patch by Maxim Ostapenko!

llvm-svn: 217079
This commit is contained in:
Alexey Samsonov 2014-09-03 21:10:44 +00:00
parent 0e3e6155fe
commit c8d8ca0bd6
2 changed files with 68 additions and 5 deletions
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30
compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.cc
View File

@ -36,19 +36,39 @@ uptr StackTrace::GetCurrentPc() {
return GET_CALLER_PC(); return GET_CALLER_PC();
} }
// Check if given pointer points into allocated stack area.
static inline bool IsValidFrame(uptr frame, uptr stack_top, uptr stack_bottom) {
return frame > stack_bottom && frame < stack_top - 2 * sizeof (uhwptr);
}
// In GCC on ARM bp points to saved lr, not fp, so we should check the next
// cell in stack to be a saved frame pointer. GetCanonicFrame returns the
// pointer to saved frame pointer in any case.
static inline uhwptr *GetCanonicFrame(uptr bp,
uptr stack_top,
uptr stack_bottom) {
#ifdef __arm__
if (!IsValidFrame(bp, stack_top, stack_bottom)) return 0;
uhwptr *bp_prev = (uhwptr *)bp;
if (IsValidFrame((uptr)bp_prev[0], stack_top, stack_bottom)) return bp_prev;
return bp_prev - 1;
#else
return (uhwptr*)bp;
#endif
}
void StackTrace::FastUnwindStack(uptr pc, uptr bp, void StackTrace::FastUnwindStack(uptr pc, uptr bp,
uptr stack_top, uptr stack_bottom, uptr stack_top, uptr stack_bottom,
uptr max_depth) { uptr max_depth) {
CHECK_GE(max_depth, 2); CHECK_GE(max_depth, 2);
trace[0] = pc; trace[0] = pc;
size = 1; size = 1;
uhwptr *frame = (uhwptr *)bp;
uhwptr *prev_frame = frame - 1;
if (stack_top < 4096) return; // Sanity check for stack top. if (stack_top < 4096) return; // Sanity check for stack top.
uhwptr *frame = GetCanonicFrame(bp, stack_top, stack_bottom);
uhwptr *prev_frame = 0;
// Avoid infinite loop when frame == frame[0] by using frame > prev_frame. // Avoid infinite loop when frame == frame[0] by using frame > prev_frame.
while (frame > prev_frame && while (frame > prev_frame &&
frame < (uhwptr *)stack_top - 2 && IsValidFrame((uptr)frame, stack_top, stack_bottom) &&
frame > (uhwptr *)stack_bottom &&
IsAligned((uptr)frame, sizeof(*frame)) && IsAligned((uptr)frame, sizeof(*frame)) &&
size < max_depth) { size < max_depth) {
uhwptr pc1 = frame[1]; uhwptr pc1 = frame[1];
@ -56,7 +76,7 @@ void StackTrace::FastUnwindStack(uptr pc, uptr bp,
trace[size++] = (uptr) pc1; trace[size++] = (uptr) pc1;
} }
prev_frame = frame; prev_frame = frame;
frame = (uhwptr *)frame[0]; frame = GetCanonicFrame((uptr)frame[0], stack_top, stack_bottom);
} }
} }

43
compiler-rt/test/asan/TestCases/Linux/clang_gcc_abi.cc Normal file
View File

@ -0,0 +1,43 @@
// RUN: %clangxx_asan -O0 -x c %s -o %t && not %run %t 2>&1 | FileCheck %s
// RUN: %clangxx_asan -O1 -x c %s -o %t && not %run %t 2>&1 | FileCheck %s
// RUN: %clangxx_asan -O2 -x c %s -o %t && not %run %t 2>&1 | FileCheck %s
// RUN: %clangxx_asan -O3 -x c %s -o %t && not %run %t 2>&1 | FileCheck %s
// REQUIRES: arm-supported-target
#include <stdlib.h>
int boom() {
volatile int three = 3;
char *s = (char *)malloc(three);
// CHECK: #1 0x{{.*}} in boom {{.*}}clang_gcc_abi.cc:[[@LINE-1]]
return s[three]; //BOOM
}
__attribute__((naked, noinline)) void gcc_abi() {
// CHECK: #2 0x{{.*}} in gcc_abi {{.*}}clang_gcc_abi.cc:[[@LINE+1]]
asm volatile("str fp, [sp, #-8]!\n\t"
"str lr, [sp, #4]\n\t"
"add fp, sp, #4\n\t"
"bl boom\n\t"
"sub sp, fp, #4\n\t"
"ldr fp, [sp]\n\t"
"add sp, sp, #4\n\t"
"ldr pc, [sp], #4\n\t"
);
}
__attribute__((naked, noinline)) void clang_abi() {
// CHECK: #3 0x{{.*}} in clang_abi {{.*}}clang_gcc_abi.cc:[[@LINE+1]]
asm volatile("push {r11, lr}\n\t"
"mov r11, sp\n\t"
"bl gcc_abi\n\t"
"add r0, r0, #1\n\t"
"pop {r11, pc}\n\t"
);
}
int main() {
clang_abi();
// CHECK: #4 0x{{.*}} in main {{.*}}clang_gcc_abi.cc:[[@LINE-1]]
}