tsan: switch libignore from /proc/self/maps to dl_iterate_phdr

/proc/self/maps can't be read atomically, this leads to episodic
crashes in libignore as it thinks that a module is loaded twice.
See the new test for an example.
dl_iterate_phdr does not have this problem.
Switch libignore to dl_iterate_phdr.



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@287632 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 16 insertions, 15 deletions

diff --git a/lib/sanitizer_common/sanitizer_libignore.cc b/lib/sanitizer_common/sanitizer_libignore.cc
index 545393966..33a1763d2 100644
--- a/lib/sanitizer_common/sanitizer_libignore.cc
+++ b/lib/sanitizer_common/sanitizer_libignore.cc
@@ -50,23 +50,23 @@ void LibIgnore::OnLibraryLoaded(const char *name) {
   }
 
   // Scan suppressions list and find newly loaded and unloaded libraries.
-  MemoryMappingLayout proc_maps(/*cache_enabled*/false);
-  InternalScopedString module(kMaxPathLength);
+  ListOfModules modules;
+  modules.init();
   for (uptr i = 0; i < count_; i++) {
     Lib *lib = &libs_[i];
     bool loaded = false;
-    proc_maps.Reset();
-    uptr b, e, off, prot;
-    while (proc_maps.Next(&b, &e, &off, module.data(), module.size(), &prot)) {
-      if ((prot & MemoryMappingLayout::kProtectionExecute) == 0)
-        continue;
-      if (TemplateMatch(lib->templ, module.data()) ||
-          (lib->real_name &&
-          internal_strcmp(lib->real_name, module.data()) == 0)) {
+    for (const auto &mod : modules) {
+      for (const auto &range : mod.ranges()) {
+        if (!range.executable)
+          continue;
+        if (!TemplateMatch(lib->templ, mod.full_name()) &&
+            !(lib->real_name &&
+            internal_strcmp(lib->real_name, mod.full_name()) == 0))
+          continue;
         if (loaded) {
           Report("%s: called_from_lib suppression '%s' is matched against"
                  " 2 libraries: '%s' and '%s'\n",
-                 SanitizerToolName, lib->templ, lib->name, module.data());
+                 SanitizerToolName, lib->templ, lib->name, mod.full_name());
           Die();
         }
         loaded = true;
@@ -75,13 +75,14 @@ void LibIgnore::OnLibraryLoaded(const char *name) {
         VReport(1,
                 "Matched called_from_lib suppression '%s' against library"
                 " '%s'\n",
-                lib->templ, module.data());
+                lib->templ, mod.full_name());
         lib->loaded = true;
-        lib->name = internal_strdup(module.data());
+        lib->name = internal_strdup(mod.full_name());
         const uptr idx = atomic_load(&loaded_count_, memory_order_relaxed);
-        code_ranges_[idx].begin = b;
-        code_ranges_[idx].end = e;
+        code_ranges_[idx].begin = range.beg;
+        code_ranges_[idx].end = range.end;
         atomic_store(&loaded_count_, idx + 1, memory_order_release);
+        break;
       }
     }
     if (lib->loaded && !loaded) {