[compiler-rt] r263551 - [sanitizer] On OS X, verify that interceptors work and abort if not

Kuba Brecka via llvm-commits llvm-commits at lists.llvm.org
Tue Mar 15 07:30:29 PDT 2016


Author: kuba.brecka
Date: Tue Mar 15 09:30:28 2016
New Revision: 263551

URL: http://llvm.org/viewvc/llvm-project?rev=263551&view=rev
Log:
[sanitizer] On OS X, verify that interceptors work and abort if not

On OS X 10.11+, we have "automatic interceptors", so we don't need to use DYLD_INSERT_LIBRARIES when launching instrumented programs. However, non-instrumented programs that load TSan late (e.g. via dlopen) are currently broken, as TSan will still try to initialize, but the program will crash/hang at random places (because the interceptors don't work). This patch adds an explicit check that interceptors are working, and if not, it aborts and prints out an error message suggesting to explicitly use DYLD_INSERT_LIBRARIES.

Differential Revision: http://reviews.llvm.org/D18121


Added:
    compiler-rt/trunk/test/tsan/Darwin/dlopen.cc
Modified:
    compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.cc
    compiler-rt/trunk/test/lit.common.cfg

Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.cc?rev=263551&r1=263550&r2=263551&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.cc Tue Mar 15 09:30:28 2016
@@ -627,6 +627,21 @@ void MaybeReexec() {
     CHECK("execv failed" && 0);
   }
 
+  // Verify that interceptors really work.  We'll use dlsym to locate
+  // "pthread_create", if interceptors are working, it should really point to
+  // "wrap_pthread_create" within our own dylib.
+  Dl_info info_pthread_create;
+  void *dlopen_addr = dlsym(RTLD_DEFAULT, "pthread_create");
+  CHECK(dladdr(dlopen_addr, &info_pthread_create));
+  if (internal_strcmp(info.dli_fname, info_pthread_create.dli_fname) != 0) {
+    Report(
+        "ERROR: Interceptors are not working. This may be because %s is "
+        "loaded too late (e.g. via dlopen). Please launch the executable "
+        "with:\n%s=%s\n",
+        SanitizerToolName, kDyldInsertLibraries, info.dli_fname);
+    CHECK("interceptors not installed" && 0);
+  }
+
   if (!lib_is_in_env)
     return;
 

Modified: compiler-rt/trunk/test/lit.common.cfg
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/lit.common.cfg?rev=263551&r1=263550&r2=263551&view=diff
==============================================================================
--- compiler-rt/trunk/test/lit.common.cfg (original)
+++ compiler-rt/trunk/test/lit.common.cfg Tue Mar 15 09:30:28 2016
@@ -118,6 +118,14 @@ if config.can_symbolize:
 
 lit.util.usePlatformSdkOnDarwin(config, lit_config)
 
+if config.host_os == 'Darwin':
+  ld_cmd = subprocess.Popen(["bash", "-c", "sw_vers -productVersion | awk -F '.' '{print $1 \".\" $2}'"], stdout = subprocess.PIPE)
+  ld_out = ld_cmd.stdout.read().decode()
+  ld_cmd.wait()
+  osx_version = float(ld_out)
+  if osx_version >= 10.11:
+    config.available_features.add('osx-autointerception')
+
 sancovcc_path = os.path.join(llvm_tools_dir, "sancov") 
 if os.path.exists(sancovcc_path):
   config.available_features.add("has_sancovcc")

Added: compiler-rt/trunk/test/tsan/Darwin/dlopen.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/tsan/Darwin/dlopen.cc?rev=263551&view=auto
==============================================================================
--- compiler-rt/trunk/test/tsan/Darwin/dlopen.cc (added)
+++ compiler-rt/trunk/test/tsan/Darwin/dlopen.cc Tue Mar 15 09:30:28 2016
@@ -0,0 +1,41 @@
+// Checks that on OS X 10.11+ (where we do not re-exec anymore, because
+// interceptors work automatically), dlopen'ing a TSanified library from a
+// non-instrumented program exits with a user-friendly message.
+
+// REQUIRES: osx-autointerception
+
+// RUN: %clangxx_tsan %s -o %t.so -shared -DSHARED_LIB
+// RUN: %clangxx_tsan -fno-sanitize=thread %s -o %t
+
+// RUN: TSAN_DYLIB_PATH=`%clangxx_tsan %s -### 2>&1 \
+// RUN:   | grep "libclang_rt.tsan_osx_dynamic.dylib" \
+// RUN:   | sed -e 's/.*"\(.*libclang_rt.tsan_osx_dynamic.dylib\)".*/\1/'`
+
+// Launching a non-instrumented binary that dlopen's an instrumented library should fail.
+// RUN: not %run %t-noninstr %t.so 2>&1 | FileCheck %s --check-prefix=CHECK-FAIL
+// Launching a non-instrumented binary with an explicit DYLD_INSERT_LIBRARIES should work.
+// RUN: DYLD_INSERT_LIBRARIES=$TSAN_DYLIB_PATH %run %t-noninstr %t.so 2>&1 | FileCheck %s
+
+#include <dlfcn.h>
+#include <pthread.h>
+#include <stdio.h>
+
+#if defined(SHARED_LIB)
+void foo() {
+  fprintf(stderr, "Hello world.\n");
+}
+#else  // defined(SHARED_LIB)
+int main(int argc, char *argv[]) {
+  void *handle = dlopen(argv[1], RTLD_NOW);
+  fprintf(stderr, "handle = %p\n", handle);
+  void (*foo)() = (void (*)())dlsym(handle, "foo");
+  fprintf(stderr, "foo = %p\n", foo);
+  foo();
+}
+#endif  // defined(SHARED_LIB)
+
+// CHECK: Hello world.
+// CHECK-NOT: ERROR: Interceptors are not working.
+
+// CHECK-FAIL-NOT: Hello world.
+// CHECK-FAIL: ERROR: Interceptors are not working.




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