[compiler-rt] r202403 - tsan: work around known bug in libstdc++

[Dmitry Vyukov]

Author: dvyukov
Date: Thu Feb 27 08:43:31 2014
New Revision: 202403

URL: http://llvm.org/viewvc/llvm-project?rev=202403&view=rev
Log:
tsan: work around known bug in libstdc++
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066


Modified:
    compiler-rt/trunk/lib/sanitizer_common/sanitizer_tls_get_addr.cc

Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_tls_get_addr.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_tls_get_addr.cc?rev=202403&r1=202402&r2=202403&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_tls_get_addr.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_tls_get_addr.cc Thu Feb 27 08:43:31 2014
@@ -75,21 +75,26 @@ void DTLS_on_tls_get_addr(void *arg_void
     return;
   uptr tls_size = 0;
   uptr tls_beg = reinterpret_cast<uptr>(res) - arg->offset;
-  VPrintf(2, "__tls_get_addr: %p {%p,%p} => %p; tls_beg: %p; sp: %p\n", arg,
-          arg->dso_id, arg->offset, res, tls_beg, &tls_beg);
+  // Don't do anything fancy in this function, in particular don't print.
+  // Some versions of libstdc++ are miscompiled and call this function
+  // with mis-aligned stack:
+  // http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066
+  // Printf uses SSE instructions that crash with mis-aligned accesses.
+  // VPrintf(2, "__tls_get_addr: %p {%p,%p} => %p; tls_beg: %p; sp: %p\n", arg,
+  //        arg->dso_id, arg->offset, res, tls_beg, &tls_beg);
   if (dtls.last_memalign_ptr == tls_beg) {
     tls_size = dtls.last_memalign_size;
-    VPrintf(2, "__tls_get_addr: glibc <=2.18 suspected; tls={%p,%p}\n", tls_beg,
-            tls_size);
+    // VPrintf(2, "__tls_get_addr: glibc <=2.18 suspected; tls={%p,%p}\n",
+    //        tls_beg, tls_size);
   } else if ((tls_beg % 4096) == sizeof(Glibc_2_19_tls_header)) {
     // We may want to check gnu_get_libc_version().
     Glibc_2_19_tls_header *header = (Glibc_2_19_tls_header *)tls_beg - 1;
     tls_size = header->size;
     tls_beg = header->start;
-    VPrintf(2, "__tls_get_addr: glibc >=2.19 suspected; tls={%p %p}\n", tls_beg,
-            tls_size);
+    //VPrintf(2, "__tls_get_addr: glibc >=2.19 suspected; tls={%p %p}\n",
+    //        tls_beg, tls_size);
   } else {
-    VPrintf(2, "__tls_get_addr: Can't guess glibc version\n");
+    //VPrintf(2, "__tls_get_addr: Can't guess glibc version\n");
     // This may happen inside the DTOR of main thread, so just ignore it.
     tls_size = 0;
   }
@@ -98,7 +103,7 @@ void DTLS_on_tls_get_addr(void *arg_void
 }
 
 void DTLS_on_libc_memalign(void *ptr, uptr size) {
-  VPrintf(2, "DTLS_on_libc_memalign: %p %p\n", ptr, size);
+  // VPrintf(2, "DTLS_on_libc_memalign: %p %p\n", ptr, size);
   dtls.last_memalign_ptr = reinterpret_cast<uptr>(ptr);
   dtls.last_memalign_size = size;
 }