2 files changed, 17 insertions, 13 deletions
diff --git a/lib/sanitizer_common/sanitizer_posix.cc b/lib/sanitizer_common/sanitizer_posix.cc
index 65ff16566..a9b9d77f7 100644
--- a/lib/sanitizer_common/sanitizer_posix.cc
+++ b/lib/sanitizer_common/sanitizer_posix.cc
@@ -64,7 +64,8 @@ void *MmapOrDie(uptr size, const char *mem_type) {
       Die();
     }
     recursion_count++;
-    Report("ERROR: %s failed to allocate 0x%zx (%zd) bytes of %s: %d\n",
+    Report("ERROR: %s failed to "
+           "allocate 0x%zx (%zd) bytes of %s (errno: %d)\n",
            SanitizerToolName, size, size, mem_type, reserrno);
     DumpProcessMap();
     CHECK("unable to mmap" && 0);
@@ -91,8 +92,8 @@ void *MmapNoReserveOrDie(uptr size, const char *mem_type) {
       -1, 0);
   int reserrno;
   if (internal_iserror(p, &reserrno)) {
-    Report("ERROR: "
-           "%s failed to allocate noreserve 0x%zx (%zd) bytes for '%s' (%d)\n",
+    Report("ERROR: %s failed to "
+           "allocate noreserve 0x%zx (%zd) bytes for '%s' (errno: %d)\n",
            SanitizerToolName, size, size, mem_type, reserrno);
     CHECK("unable to mmap" && 0);
   }
@@ -108,8 +109,8 @@ void *MmapFixedNoReserve(uptr fixed_addr, uptr size) {
       -1, 0);
   int reserrno;
   if (internal_iserror(p, &reserrno))
-    Report("ERROR: "
-           "%s failed to allocate 0x%zx (%zd) bytes at address %zu (%d)\n",
+    Report("ERROR: %s failed to "
+           "allocate 0x%zx (%zd) bytes at address %zu (errno: %d)\n",
            SanitizerToolName, size, size, fixed_addr, reserrno);
   return (void *)p;
 }
@@ -123,8 +124,8 @@ void *MmapFixedOrDie(uptr fixed_addr, uptr size) {
       -1, 0);
   int reserrno;
   if (internal_iserror(p, &reserrno)) {
-    Report("ERROR:"
-           " %s failed to allocate 0x%zx (%zd) bytes at address %zu (%d)\n",
+    Report("ERROR: %s failed to "
+           "allocate 0x%zx (%zd) bytes at address %zu (errno: %d)\n",
            SanitizerToolName, size, size, fixed_addr, reserrno);
     CHECK("unable to mmap" && 0);
   }
diff --git a/lib/sanitizer_common/sanitizer_win.cc b/lib/sanitizer_common/sanitizer_win.cc
index 21f92b3b6..d7d1c36ea 100644
--- a/lib/sanitizer_common/sanitizer_win.cc
+++ b/lib/sanitizer_common/sanitizer_win.cc
@@ -80,8 +80,9 @@ void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
 void *MmapOrDie(uptr size, const char *mem_type) {
   void *rv = VirtualAlloc(0, size, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
   if (rv == 0) {
-    Report("ERROR: Failed to allocate 0x%zx (%zd) bytes of %s\n",
-           size, size, mem_type);
+    Report("ERROR: %s failed to "
+           "allocate 0x%zx (%zd) bytes of %s (error code: %d)\n",
+           SanitizerToolName, size, size, mem_type, GetLastError());
     CHECK("unable to mmap" && 0);
   }
   return rv;
@@ -89,8 +90,9 @@ void *MmapOrDie(uptr size, const char *mem_type) {
 
 void UnmapOrDie(void *addr, uptr size) {
   if (VirtualFree(addr, size, MEM_DECOMMIT) == 0) {
-    Report("ERROR: Failed to deallocate 0x%zx (%zd) bytes at address %p\n",
-           size, size, addr);
+    Report("ERROR: %s failed to "
+           "deallocate 0x%zx (%zd) bytes at address %p (error code: %d)\n",
+           SanitizerToolName, size, size, addr, GetLastError());
     CHECK("unable to unmap" && 0);
   }
 }
@@ -101,8 +103,9 @@ void *MmapFixedNoReserve(uptr fixed_addr, uptr size) {
   void *p = VirtualAlloc((LPVOID)fixed_addr, size,
       MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
   if (p == 0)
-    Report("ERROR: Failed to allocate 0x%zx (%zd) bytes at %p (%d)\n",
-           size, size, fixed_addr, GetLastError());
+    Report("ERROR: %s failed to "
+           "allocate %p (%zd) bytes at %p (error code: %d)\n",
+           SanitizerToolName, size, size, fixed_addr, GetLastError());
   return p;
 }