[compiler-rt] r289063 - [compiler-rt][asan] Fix overlaping parameters for memmove/memcpy on windows.

[Etienne Bergeron via llvm-commits]

Author: etienneb
Date: Thu Dec  8 09:53:33 2016
New Revision: 289063

URL: http://llvm.org/viewvc/llvm-project?rev=289063&view=rev
Log:
[compiler-rt][asan] Fix overlaping parameters for memmove/memcpy on windows.

Summary:
On windows, memmove and memcpy may be the same functions (on 64-bits).

```
-- f:\dd\vctools\crt\vcruntime\src\string\amd64\memcpy.asm --------------------

        OPTION PROLOGUE:NONE, EPILOGUE:NONE

        memmove = memcpy
        mov     r11, rcx                ; save destination address
```


This is causing ASAN to report overlaping parameters when instrumenting chromium.

```
D:\src\chromium\src>out\asan64\chrome.exe --no-sandbox
[8956:6208:1121/162511:ERROR:entry.cc(167)] Entry::Deserialize: dictionary has no interface_provider_specs key
[8956:11560:1121/162511:ERROR:external_registry_loader_win.cc(130)] Missing value path for key Software\Google\Chrome\Ex
tensions\doeiiacdhfmpdeckdaifnjaemmkkdlkf.
=================================================================
==5132==ERROR: AddressSanitizer: memcpy-param-overlap: memory ranges [0x000000237ee8,0x000000237eea) and [0x000000237ee9
, 0x000000237eeb) overlap
```

The error triggered on chromium:
```
Child-SP          RetAddr           Call Site
00000000`00166520 00000001`400a4886 chrome!__asan::ReportStringFunctionMemoryRangesOverlap+0x23 [d:\src\llvm\llvm\projects\compiler-rt\lib\asan\asan_report.cc @ 305]
*** WARNING: Unable to verify checksum for D:\src\chromium\src\out\asan64dynamic\libglesv2.dll
00000000`001672a0 000007fe`e1859607 chrome!__asan_wrap_memcpy+0xf6 [d:\src\llvm\llvm\projects\compiler-rt\lib\asan\asan_interceptors.cc @ 458]
00000000`00167b30 000007fe`e184bcbc libglesv2!__acrt_fp_strflt_to_string+0xb7 [d:\th\minkernel\crts\ucrt\src\appcrt\convert\_fptostr.cpp @ 86]
(Inline Function) --------`-------- libglesv2!fp_format_f+0x57 [d:\th\minkernel\crts\ucrt\src\appcrt\convert\cvt.cpp @ 578]
00000000`00167b60 000007fe`e182e2a2 libglesv2!__acrt_fp_format+0x180 [d:\th\minkernel\crts\ucrt\src\appcrt\convert\cvt.cpp @ 722]
00000000`00167bf0 000007fe`e182ce80 libglesv2!__crt_stdio_output::output_processor<char,__crt_stdio_output::stream_output_adapter<char>,__crt_stdio_output::format_validation_
```


This bug is similar to: https://llvm.org/bugs/show_bug.cgi?id=16362

Reviewers: rnk, zaks.anna, filcab

Subscribers: filcab, kubabrecka, chrisha, llvm-commits, dberris

Differential Revision: https://reviews.llvm.org/D27052

Modified:
    compiler-rt/trunk/lib/asan/asan_interceptors.cc

Modified: compiler-rt/trunk/lib/asan/asan_interceptors.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_interceptors.cc?rev=289063&r1=289062&r2=289063&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_interceptors.cc (original)
+++ compiler-rt/trunk/lib/asan/asan_interceptors.cc Thu Dec  8 09:53:33 2016
@@ -454,17 +454,17 @@ INTERCEPTOR(void*, memmove, void *to, co
 INTERCEPTOR(void*, memcpy, void *to, const void *from, uptr size) {
   void *ctx;
   ASAN_INTERCEPTOR_ENTER(ctx, memcpy);
-#if !SANITIZER_MAC
-  ASAN_MEMCPY_IMPL(ctx, to, from, size);
-#else
-  // At least on 10.7 and 10.8 both memcpy() and memmove() are being replaced
-  // with WRAP(memcpy). As a result, false positives are reported for memmove()
-  // calls. If we just disable error reporting with
-  // ASAN_OPTIONS=replace_intrin=0, memmove() is still replaced with
-  // internal_memcpy(), which may lead to crashes, see
-  // http://llvm.org/bugs/show_bug.cgi?id=16362.
-  ASAN_MEMMOVE_IMPL(ctx, to, from, size);
-#endif  // !SANITIZER_MAC
+  if (PLATFORM_HAS_DIFFERENT_MEMCPY_AND_MEMMOVE) {
+    ASAN_MEMCPY_IMPL(ctx, to, from, size);
+  } else {
+    // At least on 10.7 and 10.8 both memcpy() and memmove() are being replaced
+    // with WRAP(memcpy). As a result, false positives are reported for
+    // memmove() calls. If we just disable error reporting with
+    // ASAN_OPTIONS=replace_intrin=0, memmove() is still replaced with
+    // internal_memcpy(), which may lead to crashes, see
+    // http://llvm.org/bugs/show_bug.cgi?id=16362.
+    ASAN_MEMMOVE_IMPL(ctx, to, from, size);
+  }
 }
 
 INTERCEPTOR(void*, memset, void *block, int c, uptr size) {