[msan] Add keep_going runtime flag.

llvm-svn: 184542

7 files changed, 100 insertions, 22 deletions

diff --git a/compiler-rt/include/sanitizer/msan_interface.h b/compiler-rt/include/sanitizer/msan_interface.h
index 9eff7b597b6..52813a0b621 100644
--- a/compiler-rt/include/sanitizer/msan_interface.h
+++ b/compiler-rt/include/sanitizer/msan_interface.h
@@ -63,6 +63,11 @@ extern "C" {
      The last line will verify that a UMR happened. */
   void __msan_set_expect_umr(int expect_umr);
 
+  /* Change the value of keep_going flag. Non-zero value means don't terminate
+     program execution when an error is detected. This will not affect error in
+     modules that were compiled without the corresponding compiler flag. */
+  void __msan_set_keep_going(int keep_going);
+
   /* Print shadow and origin for the memory range to stdout in a human-readable
      format. */
   void __msan_print_shadow(const void *x, size_t size);
diff --git a/compiler-rt/lib/msan/lit_tests/keep-going-dso.cc b/compiler-rt/lib/msan/lit_tests/keep-going-dso.cc
new file mode 100644
index 00000000000..6d006756a11
--- /dev/null
+++ b/compiler-rt/lib/msan/lit_tests/keep-going-dso.cc
@@ -0,0 +1,33 @@
+// RUN: %clangxx_msan -m64 -O0 %s -o %t && not %t >%t.out 2>&1
+// FileCheck --check-prefix=CHECK-KEEP-GOING %s <%t.out
+// RUN: %clangxx_msan -m64 -O0 %s -o %t && MSAN_OPTIONS=keep_going=0 not %t >%t.out 2>&1
+// FileCheck %s <%t.out
+// RUN: %clangxx_msan -m64 -O0 %s -o %t && MSAN_OPTIONS=keep_going=1 not %t >%t.out 2>&1
+// FileCheck --check-prefix=CHECK-KEEP-GOING %s <%t.out
+
+// RUN: %clangxx_msan -m64 -mllvm -msan-keep-going=1 -O0 %s -o %t && not %t >%t.out 2>&1
+// FileCheck --check-prefix=CHECK-KEEP-GOING %s <%t.out
+// RUN: %clangxx_msan -m64 -mllvm -msan-keep-going=1 -O0 %s -o %t && MSAN_OPTIONS=keep_going=0 not %t >%t.out 2>&1
+// FileCheck %s <%t.out
+// RUN: %clangxx_msan -m64 -mllvm -msan-keep-going=1 -O0 %s -o %t && MSAN_OPTIONS=keep_going=1 not %t >%t.out 2>&1
+// FileCheck --check-prefix=CHECK-KEEP-GOING %s <%t.out
+
+// Test how -mllvm -msan-keep-going and MSAN_OPTIONS=keep_going affect reports
+// from interceptors.
+// -mllvm -msan-keep-going provides the default value of keep_going flag, but is
+// always overwritten by MSAN_OPTIONS
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int main(int argc, char **argv) {
+  char *volatile x = (char*)malloc(5 * sizeof(char));
+  x[4] = 0;
+  if (strlen(x) < 3)
+    exit(0);
+  fprintf(stderr, "Done\n");
+  // CHECK-NOT: Done
+  // CHECK-KEEP-GOING: Done
+  return 0;
+}
diff --git a/compiler-rt/lib/msan/lit_tests/keep-going.cc b/compiler-rt/lib/msan/lit_tests/keep-going.cc
new file mode 100644
index 00000000000..3cafa84b1c8
--- /dev/null
+++ b/compiler-rt/lib/msan/lit_tests/keep-going.cc
@@ -0,0 +1,30 @@
+// RUN: %clangxx_msan -m64 -O0 %s -o %t && not %t >%t.out 2>&1
+// FileCheck %s <%t.out
+// RUN: %clangxx_msan -m64 -O0 %s -o %t && MSAN_OPTIONS=keep_going=0 not %t >%t.out 2>&1
+// FileCheck %s <%t.out
+// RUN: %clangxx_msan -m64 -O0 %s -o %t && MSAN_OPTIONS=keep_going=1 not %t >%t.out 2>&1
+// FileCheck %s <%t.out
+
+// RUN: %clangxx_msan -m64 -mllvm -msan-keep-going=1 -O0 %s -o %t && not %t >%t.out 2>&1
+// FileCheck --check-prefix=CHECK-KEEP-GOING %s <%t.out
+// RUN: %clangxx_msan -m64 -mllvm -msan-keep-going=1 -O0 %s -o %t && MSAN_OPTIONS=keep_going=0 not %t >%t.out 2>&1
+// FileCheck %s <%t.out
+// RUN: %clangxx_msan -m64 -mllvm -msan-keep-going=1 -O0 %s -o %t && MSAN_OPTIONS=keep_going=1 not %t >%t.out 2>&1
+// FileCheck --check-prefix=CHECK-KEEP-GOING %s <%t.out
+
+// Test behaviour of -mllvm -msan-keep-going and MSAN_OPTIONS=keep_going.
+// -mllvm -msan-keep-going provides the default value of keep_going flag; value
+// of 1 can be overwritten by MSAN_OPTIONS, value of 0 can not.
+
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(int argc, char **argv) {
+  char *volatile x = (char*)malloc(5 * sizeof(char));
+  if (x[0])
+    exit(0);
+  fprintf(stderr, "Done\n");
+  // CHECK-NOT: Done
+  // CHECK-KEEP-GOING: Done
+  return 0;
+}
diff --git a/compiler-rt/lib/msan/msan.cc b/compiler-rt/lib/msan/msan.cc
index 0f62ef2e840..b1589669cdb 100644
--- a/compiler-rt/lib/msan/msan.cc
+++ b/compiler-rt/lib/msan/msan.cc
@@ -67,6 +67,8 @@ int __msan_get_track_origins() {
   return &__msan_track_origins ? __msan_track_origins : 0;
 }
 
+extern "C" SANITIZER_WEAK_ATTRIBUTE const int __msan_keep_going;
+
 namespace __msan {
 
 static bool IsRunningUnderDr() {
@@ -128,6 +130,7 @@ static void ParseFlagsFromString(Flags *f, const char *str) {
   ParseFlag(str, &f->report_umrs, "report_umrs");
   ParseFlag(str, &f->verbosity, "verbosity");
   ParseFlag(str, &f->wrap_signals, "wrap_signals");
+  ParseFlag(str, &f->keep_going, "keep_going");
 }
 
 static void InitializeFlags(Flags *f, const char *options) {
@@ -147,6 +150,7 @@ static void InitializeFlags(Flags *f, const char *options) {
   f->report_umrs = true;
   f->verbosity = 0;
   f->wrap_signals = true;
+  f->keep_going = !!&__msan_keep_going;
 
   // Override from user-specified string.
   if (__msan_default_options)
@@ -226,6 +230,10 @@ void __msan_warning() {
   GET_CALLER_PC_BP_SP;
   (void)sp;
   PrintWarning(pc, bp);
+  if (!__msan::flags()->keep_going) {
+    Printf("Exiting\n");
+    Die();
+  }
 }
 
 void __msan_warning_noreturn() {
@@ -296,6 +304,10 @@ void __msan_set_exit_code(int exit_code) {
   flags()->exit_code = exit_code;
 }
 
+void __msan_set_keep_going(int keep_going) {
+  flags()->keep_going = keep_going;
+}
+
 void __msan_set_expect_umr(int expect_umr) {
   if (expect_umr) {
     msan_expected_umr_found = 0;
diff --git a/compiler-rt/lib/msan/msan_flags.h b/compiler-rt/lib/msan/msan_flags.h
index 64ef8450988..e046617d2b6 100644
--- a/compiler-rt/lib/msan/msan_flags.h
+++ b/compiler-rt/lib/msan/msan_flags.h
@@ -25,6 +25,7 @@ struct Flags {
   bool poison_in_malloc;  // default: true
   bool report_umrs;
   bool wrap_signals;
+  bool keep_going;
 };
 
 Flags *flags();
diff --git a/compiler-rt/lib/msan/msan_interceptors.cc b/compiler-rt/lib/msan/msan_interceptors.cc
index 99e65467926..ea868c73c64 100644
--- a/compiler-rt/lib/msan/msan_interceptors.cc
+++ b/compiler-rt/lib/msan/msan_interceptors.cc
@@ -28,12 +28,6 @@
 // ACHTUNG! No other system header includes in this file.
 // Ideally, we should get rid of stdarg.h as well.
 
-extern "C" SANITIZER_WEAK_ATTRIBUTE const int __msan_keep_going;
-
-int __msan_get_keep_going() {
-  return &__msan_keep_going ? __msan_keep_going : 0;
-}
-
 using namespace __msan;
 
 // True if this is a nested interceptor.
@@ -56,22 +50,22 @@ bool IsInInterceptorScope() {
 } while (0)
 
 // Check that [x, x+n) range is unpoisoned.
-#define CHECK_UNPOISONED_0(x, n)                                              \
-  do {                                                                        \
-    sptr offset = __msan_test_shadow(x, n);                                   \
-    if (__msan::IsInSymbolizer()) break;                                      \
-    if (offset >= 0 && __msan::flags()->report_umrs) {                        \
-      GET_CALLER_PC_BP_SP;                                                    \
-      (void) sp;                                                              \
-      Printf("UMR in %s at offset %d inside [%p, +%d) \n", __FUNCTION__,      \
-             offset, x, n);                                                   \
-      __msan::PrintWarningWithOrigin(pc, bp,                                  \
-                                     __msan_get_origin((char *) x + offset)); \
-      if (!__msan_get_keep_going()) {                                         \
-        Printf("Exiting\n");                                                  \
-        Die();                                                                \
-      }                                                                       \
-    }                                                                         \
+#define CHECK_UNPOISONED_0(x, n)                                             \
+  do {                                                                       \
+    sptr offset = __msan_test_shadow(x, n);                                  \
+    if (__msan::IsInSymbolizer()) break;                                     \
+    if (offset >= 0 && __msan::flags()->report_umrs) {                       \
+      GET_CALLER_PC_BP_SP;                                                   \
+      (void) sp;                                                             \
+      Printf("UMR in %s at offset %d inside [%p, +%d) \n", __FUNCTION__,     \
+             offset, x, n);                                                  \
+      __msan::PrintWarningWithOrigin(pc, bp,                                 \
+                                     __msan_get_origin((char *)x + offset)); \
+      if (!__msan::flags()->keep_going) {                                    \
+        Printf("Exiting\n");                                                 \
+        Die();                                                               \
+      }                                                                      \
+    }                                                                        \
   } while (0)
 
 // Check that [x, x+n) range is unpoisoned unless we are in a nested
diff --git a/compiler-rt/lib/msan/msan_interface_internal.h b/compiler-rt/lib/msan/msan_interface_internal.h
index f3d8ee3efde..098e6f3b353 100644
--- a/compiler-rt/lib/msan/msan_interface_internal.h
+++ b/compiler-rt/lib/msan/msan_interface_internal.h
@@ -83,6 +83,9 @@ SANITIZER_INTERFACE_ATTRIBUTE
 void __msan_set_exit_code(int exit_code);
 
 SANITIZER_INTERFACE_ATTRIBUTE
+void __msan_set_keep_going(int keep_going);
+
+SANITIZER_INTERFACE_ATTRIBUTE
 int __msan_set_poison_in_malloc(int do_poison);
 
 SANITIZER_WEAK_ATTRIBUTE SANITIZER_INTERFACE_ATTRIBUTE