[asan] Change the way we report the alloca frame on stack-buff-overflow.

Before: the function name was stored by the compiler as a constant string
and the run-time was printing it.
Now: the PC is stored instead and the run-time prints the full symbolized frame.
This adds a couple of instructions into every function with non-empty stack frame,
but also reduces the binary size because we store less strings (I saw 2% size reduction).
This change bumps the asan ABI version to v3.

compiler-rt part, llvm part will follow.

Example of report (now):
==31711==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7fffa77cf1c5 at pc 0x41feb0 bp 0x7fffa77cefb0 sp 0x7fffa77cefa8
READ of size 1 at 0x7fffa77cf1c5 thread T0
    #0 0x41feaf in Frame0(int, char*, char*, char*) stack-oob-frames.cc:20
    #1 0x41f7ff in Frame1(int, char*, char*) stack-oob-frames.cc:24
    #2 0x41f477 in Frame2(int, char*) stack-oob-frames.cc:28
    #3 0x41f194 in Frame3(int) stack-oob-frames.cc:32
    #4 0x41eee0 in main stack-oob-frames.cc:38
    #5 0x7f0c5566f76c (/lib/x86_64-linux-gnu/libc.so.6+0x2176c)
    #6 0x41eb1c (/usr/local/google/kcc/llvm_cmake/a.out+0x41eb1c)
Address 0x7fffa77cf1c5 is located in stack of thread T0 at offset 293 in frame
    #0 0x41f87f in Frame0(int, char*, char*, char*) stack-oob-frames.cc:12  <<<<<<<<<<<<<< this is new
  This frame has 6 object(s):
    [32, 36) 'frame.addr'
    [96, 104) 'a.addr'
    [160, 168) 'b.addr'
    [224, 232) 'c.addr'
    [288, 292) 's'
    [352, 360) 'd'

llvm-svn: 177723

1 files changed, 59 insertions, 0 deletions

diff --git a/compiler-rt/lib/asan/lit_tests/stack-oob-frames.cc b/compiler-rt/lib/asan/lit_tests/stack-oob-frames.cc
new file mode 100644
index 00000000000..0395522252e
--- /dev/null
+++ b/compiler-rt/lib/asan/lit_tests/stack-oob-frames.cc
@@ -0,0 +1,59 @@
+// RUN: %clangxx_asan -m64 -O1 %s -o %t
+// RUN: %t 0 2>&1 | %symbolize | FileCheck %s --check-prefix=CHECK0
+// RUN: %t 1 2>&1 | %symbolize | FileCheck %s --check-prefix=CHECK1
+// RUN: %t 2 2>&1 | %symbolize | FileCheck %s --check-prefix=CHECK2
+// RUN: %t 3 2>&1 | %symbolize | FileCheck %s --check-prefix=CHECK3
+
+#define NOINLINE __attribute__((noinline))
+inline void break_optimization(void *arg) {
+  __asm__ __volatile__("" : : "r" (arg) : "memory");
+}
+
+NOINLINE static void Frame0(int frame, char *a, char *b, char *c) {
+  char s[4] = {0};
+  char *d = s;
+  break_optimization(&d);
+  switch (frame) {
+    case 3: a[5]++; break;
+    case 2: b[5]++; break;
+    case 1: c[5]++; break;
+    case 0: d[5]++; break;
+  }
+}
+NOINLINE static void Frame1(int frame, char *a, char *b) {
+  char c[4] = {0}; Frame0(frame, a, b, c);
+  break_optimization(0);
+}
+NOINLINE static void Frame2(int frame, char *a) {
+  char b[4] = {0}; Frame1(frame, a, b);
+  break_optimization(0);
+}
+NOINLINE static void Frame3(int frame) {
+  char a[4] = {0}; Frame2(frame, a);
+  break_optimization(0);
+}
+
+int main(int argc, char **argv) {
+  if (argc != 2) return 1;
+  Frame3(argv[1][0] - '0');
+}
+
+// CHECK0: AddressSanitizer: stack-buffer-overflow
+// CHECK0: #0{{.*}}Frame0
+// CHECK0: #1{{.*}}Frame1
+// CHECK0: #2{{.*}}Frame2
+// CHECK0: #3{{.*}}Frame3
+// CHECK0: is located in stack of thread T0 at offset
+// CHECK0-NEXT: #0{{.*}}Frame0
+//
+// CHECK1: AddressSanitizer: stack-buffer-overflow
+// CHECK1: is located in stack of thread T0 at offset
+// CHECK1-NEXT: #0{{.*}}Frame1
+//
+// CHECK2: AddressSanitizer: stack-buffer-overflow
+// CHECK2: is located in stack of thread T0 at offset
+// CHECK2-NEXT: #0{{.*}}Frame2
+//
+// CHECK3: AddressSanitizer: stack-buffer-overflow
+// CHECK3: is located in stack of thread T0 at offset
+// CHECK3-NEXT: #0{{.*}}Frame3