[msan] Add store_context_size= flag.

A new flag to control stack trace size for store event (in
track-origins=2 mode) independently of malloc_context_size.

llvm-svn: 211896

diff --git a/compiler-rt/lib/msan/msan.cc b/compiler-rt/lib/msan/msan.cc
index 58a5af4..6d681b1 100644 (file)
--- a/compiler-rt/lib/msan/msan.cc
+++ b/compiler-rt/lib/msan/msan.cc
@@ -145,6 +145,8 @@ static void ParseFlagsFromString(Flags *f, const char *str) {
   ParseFlag(str, &f->wrap_signals, "wrap_signals", "");
   ParseFlag(str, &f->print_stats, "print_stats", "");
   ParseFlag(str, &f->atexit, "atexit", "");
+  ParseFlag(str, &f->store_context_size, "store_context_size", "");
+  if (f->store_context_size < 1) f->store_context_size = 1;
 
   // keep_going is an old name for halt_on_error,
   // and it has inverse meaning.
@@ -177,6 +179,7 @@ static void InitializeFlags(Flags *f, const char *options) {
   f->print_stats = false;
   f->atexit = false;
   f->halt_on_error = !&__msan_keep_going;
+  f->store_context_size = 20;
 
   // Override from user-specified string.
   if (__msan_default_options)

diff --git a/compiler-rt/lib/msan/msan.h b/compiler-rt/lib/msan/msan.h
index 2105791..f8b79a7 100644 (file)
--- a/compiler-rt/lib/msan/msan.h
+++ b/compiler-rt/lib/msan/msan.h
@@ -104,12 +104,12 @@ u32 ChainOrigin(u32 id, StackTrace *stack);
         StackTrace::GetCurrentPc(), GET_CURRENT_FRAME(),           \
         common_flags()->fast_unwind_on_malloc)
 
-#define GET_STORE_STACK_TRACE_PC_BP(pc, bp)                            \
-  StackTrace stack;                                                    \
-  stack.size = 0;                                                      \
-  if (__msan_get_track_origins() > 1 && msan_inited)                   \
-    GetStackTrace(&stack, common_flags()->malloc_context_size, pc, bp, \
-                  common_flags()->fast_unwind_on_malloc)
+#define GET_STORE_STACK_TRACE_PC_BP(pc, bp)                  \
+  StackTrace stack;                                          \
+  stack.size = 0;                                            \
+  if (__msan_get_track_origins() > 1 && msan_inited)         \
+  GetStackTrace(&stack, flags()->store_context_size, pc, bp, \
+                common_flags()->fast_unwind_on_malloc)
 
 #define GET_FATAL_STACK_TRACE_PC_BP(pc, bp)       \
   StackTrace stack;                               \

diff --git a/compiler-rt/lib/msan/msan_flags.h b/compiler-rt/lib/msan/msan_flags.h
index e9ea32b..9b93f11 100644 (file)
--- a/compiler-rt/lib/msan/msan_flags.h
+++ b/compiler-rt/lib/msan/msan_flags.h
@@ -30,6 +30,7 @@ struct Flags {
   bool print_stats;
   bool halt_on_error;
   bool atexit;
+  int store_context_size; // like malloc_context_size, but for uninit stores
 };
 
 Flags *flags();

diff --git a/compiler-rt/test/msan/chained_origin_empty_stack.cc b/compiler-rt/test/msan/chained_origin_empty_stack.cc
index d4c1bc5..36727e3 100644 (file)
--- a/compiler-rt/test/msan/chained_origin_empty_stack.cc
+++ b/compiler-rt/test/msan/chained_origin_empty_stack.cc
@@ -1,5 +1,5 @@
 // RUN: %clangxx_msan -fsanitize-memory-track-origins=2 -m64 -O3 %s -o %t && \
-// RUN:     MSAN_OPTIONS=malloc_context_size=1 not %run %t 2>&1 | FileCheck %s
+// RUN:     MSAN_OPTIONS=store_context_size=1 not %run %t 2>&1 | FileCheck %s
 
 // Test that stack trace for the intermediate store is not empty.
 
@@ -8,6 +8,7 @@
 
 // CHECK: Uninitialized value was stored to memory at
 // CHECK:   #0 {{.*}} in fn_g
+// CHECK-NOT: #1
 
 // CHECK: Uninitialized value was created by an allocation of 'z' in the stack frame of function 'main'
 // CHECK:   #0 {{.*}} in main