[compiler-rt] r311186 - [SanitizerCoverage] Add stack depth tracing instrumentation.

[Matt Morehouse via llvm-commits]

Author: morehouse
Date: Fri Aug 18 11:43:30 2017
New Revision: 311186

URL: http://llvm.org/viewvc/llvm-project?rev=311186&view=rev
Log:
[SanitizerCoverage] Add stack depth tracing instrumentation.

Summary:
Augment SanitizerCoverage to insert maximum stack depth tracing for
use by libFuzzer.  The new instrumentation is enabled by the flag
-fsanitize-coverage=stack-depth and is compatible with the existing
trace-pc-guard coverage.  The user must also declare the following
global variable in their code:
  thread_local uintptr_t __sancov_lowest_stack

https://bugs.llvm.org/show_bug.cgi?id=33857

Reviewers: vitalybuka, kcc

Reviewed By: vitalybuka

Subscribers: kubamracek, hiraditya, cfe-commits, llvm-commits

Differential Revision: https://reviews.llvm.org/D36839

Added:
    compiler-rt/trunk/test/sanitizer_common/TestCases/sanitizer_coverage_stack_depth.cc

Added: compiler-rt/trunk/test/sanitizer_common/TestCases/sanitizer_coverage_stack_depth.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/sanitizer_common/TestCases/sanitizer_coverage_stack_depth.cc?rev=311186&view=auto
==============================================================================
--- compiler-rt/trunk/test/sanitizer_common/TestCases/sanitizer_coverage_stack_depth.cc (added)
+++ compiler-rt/trunk/test/sanitizer_common/TestCases/sanitizer_coverage_stack_depth.cc Fri Aug 18 11:43:30 2017
@@ -0,0 +1,32 @@
+// Tests -fsanitize-coverage=stack-depth
+//
+// XFAIL: tsan
+//
+// RUN: %clangxx -O0 -std=c++11 -fsanitize-coverage=stack-depth %s -o %t
+// RUN: %run %t 2>&1 | FileCheck %s --implicit-check-not Assertion{{.*}}failed
+// RUN: %clangxx -O0 -std=c++11 -fsanitize-coverage=trace-pc-guard,stack-depth \
+// RUN:     %s -o %t
+// RUN: %run %t 2>&1 | FileCheck %s --implicit-check-not Assertion{{.*}}failed
+
+#include <cstdint>
+#include <cstdio>
+#include <cassert>
+
+thread_local uintptr_t __sancov_lowest_stack;
+uintptr_t last_stack;
+
+void foo(int recurse) {
+  assert(__sancov_lowest_stack < last_stack);
+  last_stack = __sancov_lowest_stack;
+  if (recurse <= 0) return;
+  foo(recurse - 1);
+}
+
+int main() {
+  last_stack = __sancov_lowest_stack;
+  foo(100);
+  printf("Success!\n");
+  return 0;
+}
+
+// CHECK: Success!