[libsanitizer] Replace ReadBinaryName() with ReadBinaryNameCached(),

which caches the executable name upon the first invocation.
This is necessary because Google Chrome (and potentially other programs)
restrict the access to /proc/self/exe on linux.
This change should fix https://code.google.com/p/chromium/issues/detail?id=502974

4 files changed, 16 insertions, 3 deletions

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common.cc b/compiler-rt/lib/sanitizer_common/sanitizer_common.cc
index 5bbd31ed6d1..d14e98824d9 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common.cc
@@ -353,11 +353,23 @@ const char *GetBinaryBasename() {
 
 // Call once to make sure that binary_name_cache_str is initialized
 void CacheBinaryName() {
-  CHECK_EQ('\0', binary_name_cache_str[0]);
+  if (binary_name_cache_str[0] != '\0')
+    return;
   ReadBinaryName(binary_name_cache_str, sizeof(binary_name_cache_str));
   binary_basename_cache_str = StripModuleName(binary_name_cache_str);
 }
 
+uptr ReadBinaryNameCached(/*out*/char *buf, uptr buf_len) {
+  CacheBinaryName();
+  uptr name_len = internal_strlen(binary_name_cache_str);
+  name_len = (name_len < buf_len - 1) ? name_len : buf_len - 1;
+  if (buf_len == 0)
+    return 0;
+  internal_memcpy(buf, binary_name_cache_str, name_len);
+  buf[name_len] = '\0';
+  return name_len;
+}
+
 }  // namespace __sanitizer
 
 using namespace __sanitizer;  // NOLINT
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common.h b/compiler-rt/lib/sanitizer_common/sanitizer_common.h
index 3cd04450396..e697eb5359c 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common.h
@@ -243,6 +243,7 @@ const char *StripModuleName(const char *module);
 
 // OS
 uptr ReadBinaryName(/*out*/char *buf, uptr buf_len);
+uptr ReadBinaryNameCached(/*out*/char *buf, uptr buf_len);
 const char *GetBinaryBasename();
 void CacheBinaryName();
 void DisableCoreDumperIfNecessary();
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cc b/compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cc
index ba844be1b3b..04ecbb81e80 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cc
@@ -425,7 +425,7 @@ static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) {
   if (data->first) {
     data->first = false;
     // First module is the binary itself.
-    ReadBinaryName(module_name.data(), module_name.size());
+    ReadBinaryNameCached(module_name.data(), module_name.size());
   } else if (info->dlpi_name) {
     module_name.append("%s", info->dlpi_name);
   }
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_suppressions.cc b/compiler-rt/lib/sanitizer_common/sanitizer_suppressions.cc
index 8009b4d6aad..08cb497269b 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_suppressions.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_suppressions.cc
@@ -34,7 +34,7 @@ static bool GetPathAssumingFileIsRelativeToExec(const char *file_path,
                                                 /*out*/char *new_file_path,
                                                 uptr new_file_path_size) {
   InternalScopedString exec(kMaxPathLength);
-  if (ReadBinaryName(exec.data(), exec.size())) {
+  if (ReadBinaryNameCached(exec.data(), exec.size())) {
     const char *file_name_pos = StripModuleName(exec.data());
     uptr path_to_exec_len = file_name_pos - exec.data();
     internal_strncat(new_file_path, exec.data(),