[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'




git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@177723 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 2 deletions

diff --git a/lib/asan/asan_interface_internal.h b/lib/asan/asan_interface_internal.h
index 8288d0cb2..d0f3ba958 100644
--- a/lib/asan/asan_interface_internal.h
+++ b/lib/asan/asan_interface_internal.h
@@ -25,8 +25,13 @@ extern "C" {
   // Everytime the asan ABI changes we also change the version number in this
   // name. Objects build with incompatible asan ABI version
   // will not link with run-time.
-  void __asan_init_v2() SANITIZER_INTERFACE_ATTRIBUTE;
-  #define __asan_init __asan_init_v2
+  // Changes between ABI versions:
+  // v1=>v2: added 'module_name' to __asan_global
+  // v2=>v3: stack frame description (created by the compiler)
+  //         contains the function PC as the 3-rd field (see
+  //         DescribeAddressIfStack).
+  void __asan_init_v3() SANITIZER_INTERFACE_ATTRIBUTE;
+  #define __asan_init __asan_init_v3
 
   // This structure describes an instrumented global variable.
   struct __asan_global {