[compiler-rt] r211585 - [msan] Fix origin copying.

[Evgeniy Stepanov]

Author: eugenis
Date: Tue Jun 24 06:50:26 2014
New Revision: 211585

URL: http://llvm.org/viewvc/llvm-project?rev=211585&view=rev
Log:
[msan] Fix origin copying.

Conditions for the first and the last origin value in range were wrong.

Modified:
    compiler-rt/trunk/lib/msan/msan_interceptors.cc
    compiler-rt/trunk/lib/msan/tests/msan_test.cc

Modified: compiler-rt/trunk/lib/msan/msan_interceptors.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/msan/msan_interceptors.cc?rev=211585&r1=211584&r2=211585&view=diff
==============================================================================
--- compiler-rt/trunk/lib/msan/msan_interceptors.cc (original)
+++ compiler-rt/trunk/lib/msan/msan_interceptors.cc Tue Jun 24 06:50:26 2014
@@ -1389,7 +1389,7 @@ void CopyOrigin(void *dst, const void *s
   uptr beg = d & ~3UL;
   // Copy left unaligned origin if that memory is poisoned.
   if (beg < d) {
-    u32 o = GetOriginIfPoisoned(beg, d - beg);
+    u32 o = GetOriginIfPoisoned((uptr)src, d - beg);
     if (o) {
       if (__msan_get_track_origins() > 1) o = ChainOrigin(o, stack);
       *(u32 *)MEM_TO_ORIGIN(beg) = o;
@@ -1397,15 +1397,14 @@ void CopyOrigin(void *dst, const void *s
     beg += 4;
   }
 
-  uptr end = (d + size + 3) & ~3UL;
+  uptr end = (d + size) & ~3UL;
   // Copy right unaligned origin if that memory is poisoned.
-  if (end > d + size) {
-    u32 o = GetOriginIfPoisoned(d + size, end - d - size);
+  if (end < d + size) {
+    u32 o = GetOriginIfPoisoned((uptr)src + (end - d), (d + size) - end);
     if (o) {
       if (__msan_get_track_origins() > 1) o = ChainOrigin(o, stack);
-      *(u32 *)MEM_TO_ORIGIN(end - 4) = o;
+      *(u32 *)MEM_TO_ORIGIN(end) = o;
     }
-    end -= 4;
   }
 
   if (beg < end) {

Modified: compiler-rt/trunk/lib/msan/tests/msan_test.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/msan/tests/msan_test.cc?rev=211585&r1=211584&r2=211585&view=diff
==============================================================================
--- compiler-rt/trunk/lib/msan/tests/msan_test.cc (original)
+++ compiler-rt/trunk/lib/msan/tests/msan_test.cc Tue Jun 24 06:50:26 2014
@@ -1291,6 +1291,7 @@ TEST(MemorySanitizer, memcpy) {
   EXPECT_POISONED(y[1]);
 }
 
+// Dst is poisoned, src is clean.
 void TestUnalignedMemcpy(int left, int right, bool src_is_aligned) {
   const int sz = 20;
   char *dst = (char *)malloc(sz);
@@ -1319,6 +1320,36 @@ TEST(MemorySanitizer, memcpy_unaligned)
     }
   }
 }
+
+// Src is poisoned, dst is clean.
+void TestUnalignedPoisonedMemcpy(int left, int right, bool src_is_aligned) {
+  const int sz = 20;
+  char *dst = (char *)malloc(sz);
+  memset(dst, 0, sz);
+
+  char *src = (char *)malloc(sz);
+  U4 origin = __msan_get_origin(src);
+
+  memcpy(dst + left, src_is_aligned ? src + left : src, sz - left - right);
+  for (int i = 0; i < left; ++i)
+    EXPECT_NOT_POISONED(dst[i]);
+  for (int i = 0; i < right; ++i)
+    EXPECT_NOT_POISONED(dst[sz - i - 1]);
+  EXPECT_POISONED_O(dst[left], origin);
+  EXPECT_POISONED_O(dst[sz - right - 1], origin);
+
+  free(dst);
+  free(src);
+}
+
+TEST(MemorySanitizer, memcpy_unaligned_poisoned) {
+  for (int i = 0; i < 10; ++i) {
+    for (int j = 0; j < 10; ++j) {
+      TestUnalignedPoisonedMemcpy(i, j, true);
+      TestUnalignedPoisonedMemcpy(i, j, false);
+    }
+  }
+}
 
 TEST(MemorySanitizer, memmove) {
   char* x = new char[2];