Invalidate symbolizer module list from dlopen/dlclose interceptors

Summary:
The module list should only be invalidated by dlopen and dlclose,
so the symbolizer should only re-generate it when we've hit one of those functions.

Reviewers: kubamracek, rnk, vitalybuka

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D37268

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@314219 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 14 insertions, 4 deletions

diff --git a/lib/sanitizer_common/sanitizer_common_interceptors.inc b/lib/sanitizer_common/sanitizer_common_interceptors.inc
index b9c182e65..21a405ae4 100644
--- a/lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ b/lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -43,6 +43,7 @@
 #include "sanitizer_errno.h"
 #include "sanitizer_placement_new.h"
 #include "sanitizer_platform_interceptors.h"
+#include "sanitizer_symbolizer.h"
 #include "sanitizer_tls_get_addr.h"
 
 #include <stdarg.h>
@@ -5575,6 +5576,7 @@ INTERCEPTOR(void*, dlopen, const char *filename, int flag) {
   if (filename) COMMON_INTERCEPTOR_READ_STRING(ctx, filename, 0);
   COMMON_INTERCEPTOR_ON_DLOPEN(filename, flag);
   void *res = REAL(dlopen)(filename, flag);
+  Symbolizer::GetOrInit()->InvalidateModuleList();
   COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, res);
   return res;
 }
@@ -5583,6 +5585,7 @@ INTERCEPTOR(int, dlclose, void *handle) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER_NOIGNORE(ctx, dlclose, handle);
   int res = REAL(dlclose)(handle);
+  Symbolizer::GetOrInit()->InvalidateModuleList();
   COMMON_INTERCEPTOR_LIBRARY_UNLOADED();
   return res;
 }
diff --git a/lib/sanitizer_common/sanitizer_symbolizer.cc b/lib/sanitizer_common/sanitizer_symbolizer.cc
index 1cd5b6ee2..672c93668 100644
--- a/lib/sanitizer_common/sanitizer_symbolizer.cc
+++ b/lib/sanitizer_common/sanitizer_symbolizer.cc
@@ -71,6 +71,10 @@ Symbolizer *Symbolizer::symbolizer_;
 StaticSpinMutex Symbolizer::init_mu_;
 LowLevelAllocator Symbolizer::symbolizer_allocator_;
 
+void Symbolizer::InvalidateModuleList() {
+  modules_fresh_ = false;
+}
+
 void Symbolizer::AddHooks(Symbolizer::StartSymbolizationHook start_hook,
                           Symbolizer::EndSymbolizationHook end_hook) {
   CHECK(start_hook_ == 0 && end_hook_ == 0);
diff --git a/lib/sanitizer_common/sanitizer_symbolizer.h b/lib/sanitizer_common/sanitizer_symbolizer.h
index 4fc7742a2..543e27e39 100644
--- a/lib/sanitizer_common/sanitizer_symbolizer.h
+++ b/lib/sanitizer_common/sanitizer_symbolizer.h
@@ -121,6 +121,8 @@ class Symbolizer final {
 
   const LoadedModule *FindModuleForAddress(uptr address);
 
+  void InvalidateModuleList();
+
  private:
   // GetModuleNameAndOffsetForPC has to return a string to the caller.
   // Since the corresponding module might get unloaded later, we should create
diff --git a/lib/sanitizer_common/sanitizer_symbolizer_libcdep.cc b/lib/sanitizer_common/sanitizer_symbolizer_libcdep.cc
index 12369d709..caab4ca35 100644
--- a/lib/sanitizer_common/sanitizer_symbolizer_libcdep.cc
+++ b/lib/sanitizer_common/sanitizer_symbolizer_libcdep.cc
@@ -176,14 +176,15 @@ const LoadedModule *Symbolizer::FindModuleForAddress(uptr address) {
       return &modules_[i];
     }
   }
-  // Reload the modules and look up again, if we haven't tried it yet.
+  // dlopen/dlclose interceptors invalidate the module list, but when
+  // interception is disabled, we need to retry if the lookup fails in
+  // case the module list changed.
+#if !SANITIZER_INTERCEPT_DLOPEN_DLCLOSE
   if (!modules_were_reloaded) {
-    // FIXME: set modules_fresh_ from dlopen()/dlclose() interceptors.
-    // It's too aggressive to reload the list of modules each time we fail
-    // to find a module for a given address.
     modules_fresh_ = false;
     return FindModuleForAddress(address);
   }
+#endif
   return 0;
 }