[compiler-rt] r255287 - [TSan] Try harder to avoid compiler-generated memcpy calls.

[Alexey Samsonov via llvm-commits]

Author: samsonov
Date: Thu Dec 10 13:24:27 2015
New Revision: 255287

URL: http://llvm.org/viewvc/llvm-project?rev=255287&view=rev
Log:
[TSan] Try harder to avoid compiler-generated memcpy calls.

check_memcpy test added in r254959 fails on some configurations due to
memcpy() calls inserted by Clang. Try harder to avoid them by using
internal_memcpy() where applicable.

Modified:
    compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc
    compiler-rt/trunk/lib/tsan/rtl/tsan_interceptors.cc
    compiler-rt/trunk/lib/tsan/rtl/tsan_symbolize.cc

Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc?rev=255287&r1=255286&r2=255287&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc Thu Dec 10 13:24:27 2015
@@ -1691,16 +1691,19 @@ static int wrapped_gl_stat(const char *s
   return pglob_copy->gl_stat(s, st);
 }
 
+static const __sanitizer_glob_t kGlobCopy = {
+      0,                  0,                   0,
+      0,                  wrapped_gl_closedir, wrapped_gl_readdir,
+      wrapped_gl_opendir, wrapped_gl_lstat,    wrapped_gl_stat};
+
 INTERCEPTOR(int, glob, const char *pattern, int flags,
             int (*errfunc)(const char *epath, int eerrno),
             __sanitizer_glob_t *pglob) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, glob, pattern, flags, errfunc, pglob);
   COMMON_INTERCEPTOR_READ_STRING(ctx, pattern, 0);
-  __sanitizer_glob_t glob_copy = {
-      0,                  0,                   0,
-      0,                  wrapped_gl_closedir, wrapped_gl_readdir,
-      wrapped_gl_opendir, wrapped_gl_lstat,    wrapped_gl_stat};
+  __sanitizer_glob_t glob_copy;
+  internal_memcpy(&glob_copy, &kGlobCopy, sizeof(glob_copy));
   if (flags & glob_altdirfunc) {
     Swap(pglob->gl_closedir, glob_copy.gl_closedir);
     Swap(pglob->gl_readdir, glob_copy.gl_readdir);
@@ -1728,10 +1731,8 @@ INTERCEPTOR(int, glob64, const char *pat
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, glob64, pattern, flags, errfunc, pglob);
   COMMON_INTERCEPTOR_READ_STRING(ctx, pattern, 0);
-  __sanitizer_glob_t glob_copy = {
-      0,                  0,                   0,
-      0,                  wrapped_gl_closedir, wrapped_gl_readdir,
-      wrapped_gl_opendir, wrapped_gl_lstat,    wrapped_gl_stat};
+  __sanitizer_glob_t glob_copy;
+  internal_memcpy(&glob_copy, &kGlobCopy, sizeof(glob_copy));
   if (flags & glob_altdirfunc) {
     Swap(pglob->gl_closedir, glob_copy.gl_closedir);
     Swap(pglob->gl_readdir, glob_copy.gl_readdir);

Modified: compiler-rt/trunk/lib/tsan/rtl/tsan_interceptors.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_interceptors.cc?rev=255287&r1=255286&r2=255287&view=diff
==============================================================================
--- compiler-rt/trunk/lib/tsan/rtl/tsan_interceptors.cc (original)
+++ compiler-rt/trunk/lib/tsan/rtl/tsan_interceptors.cc Thu Dec 10 13:24:27 2015
@@ -444,7 +444,7 @@ static void JmpBufGarbageCollect(ThreadS
     JmpBuf *buf = &thr->jmp_bufs[i];
     if (buf->sp <= sp) {
       uptr sz = thr->jmp_bufs.Size();
-      thr->jmp_bufs[i] = thr->jmp_bufs[sz - 1];
+      internal_memcpy(buf, &thr->jmp_bufs[sz - 1], sizeof(*buf));
       thr->jmp_bufs.PopBack();
       i--;
     }

Modified: compiler-rt/trunk/lib/tsan/rtl/tsan_symbolize.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_symbolize.cc?rev=255287&r1=255286&r2=255287&view=diff
==============================================================================
--- compiler-rt/trunk/lib/tsan/rtl/tsan_symbolize.cc (original)
+++ compiler-rt/trunk/lib/tsan/rtl/tsan_symbolize.cc Thu Dec 10 13:24:27 2015
@@ -71,7 +71,7 @@ ReportLocation *SymbolizeData(uptr addr)
   if (!Symbolizer::GetOrInit()->SymbolizeData(addr, &info))
     return 0;
   ReportLocation *ent = ReportLocation::New(ReportLocationGlobal);
-  ent->global = info;
+  internal_memcpy(&ent->global, &info, sizeof(info));
   return ent;
 }