[SanitizeCoverage] Enable stack-depth coverage for -fsanitize=fuzzer

Summary:
- Don't sanitize __sancov_lowest_stack.
- Don't instrument leaf functions.
- Add CoverageStackDepth to Fuzzer and FuzzerNoLink.
- Only enable on Linux.

Reviewers: vitalybuka, kcc, george.karpenkov

Reviewed By: kcc

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

Differential Revision: https://reviews.llvm.org/D37156

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@312185 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 17 insertions, 1 deletions

diff --git a/lib/sanitizer_common/sanitizer_coverage_libcdep_new.cc b/lib/sanitizer_common/sanitizer_coverage_libcdep_new.cc
index 469656766..3c5f29b28 100644
--- a/lib/sanitizer_common/sanitizer_coverage_libcdep_new.cc
+++ b/lib/sanitizer_common/sanitizer_coverage_libcdep_new.cc
@@ -211,5 +211,10 @@ SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_indir, void) {}
 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_8bit_counters_init, void) {}
 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_pcs_init, void) {}
 }  // extern "C"
+// Weak definition for code instrumented with -fsanitize-coverage=stack-depth
+// and later linked with code containing a strong definition.
+// E.g., -fsanitize=fuzzer-no-link
+SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+SANITIZER_TLS_INITIAL_EXEC_ATTRIBUTE uptr __sancov_lowest_stack;
 
 #endif  // !SANITIZER_FUCHSIA
diff --git a/lib/sanitizer_common/sanitizer_internal_defs.h b/lib/sanitizer_common/sanitizer_internal_defs.h
index 4b780917f..e7230e43b 100644
--- a/lib/sanitizer_common/sanitizer_internal_defs.h
+++ b/lib/sanitizer_common/sanitizer_internal_defs.h
@@ -35,6 +35,14 @@
 # define SANITIZER_WEAK_ATTRIBUTE  __attribute__((weak))
 #endif
 
+// TLS is handled differently on different platforms
+#if SANITIZER_LINUX
+# define SANITIZER_TLS_INITIAL_EXEC_ATTRIBUTE \
+    __attribute__((tls_model("initial-exec"))) thread_local
+#else
+# define SANITIZER_TLS_INITIAL_EXEC_ATTRIBUTE
+#endif
+
 //--------------------------- WEAK FUNCTIONS ---------------------------------//
 // When working with weak functions, to simplify the code and make it more
 // portable, when possible define a default implementation using this macro:
diff --git a/test/asan/TestCases/Darwin/interface_symbols_darwin.c b/test/asan/TestCases/Darwin/interface_symbols_darwin.c
index 09af1ece5..431de435f 100644
--- a/test/asan/TestCases/Darwin/interface_symbols_darwin.c
+++ b/test/asan/TestCases/Darwin/interface_symbols_darwin.c
@@ -12,6 +12,7 @@
 // RUN:  | grep -v "__sanitizer_weak_hook"                                     \
 // RUN:  | grep -v "__sanitizer_mz"                                            \
 // RUN:  | grep -v "__ubsan_handle_dynamic_type_cache_miss"                    \
+// RUN:  | grep -v "__sancov_lowest_stack"                                     \
 // RUN:  | sed -e "s/__asan_version_mismatch_check_v[0-9]+/__asan_version_mismatch_check/" \
 // RUN:  > %t.exports
 //
diff --git a/test/asan/TestCases/Linux/interface_symbols_linux.c b/test/asan/TestCases/Linux/interface_symbols_linux.c
index 33fdd5ca1..a8b9d37cc 100644
--- a/test/asan/TestCases/Linux/interface_symbols_linux.c
+++ b/test/asan/TestCases/Linux/interface_symbols_linux.c
@@ -6,6 +6,7 @@
 // RUN:  | grep -v "__sanitizer_syscall"                                       \
 // RUN:  | grep -v "__sanitizer_weak_hook"                                     \
 // RUN:  | grep -v "__ubsan_handle_dynamic_type_cache_miss"                    \
+// RUN:  | grep -v "__sancov_lowest_stack"                                     \
 // RUN:  | sed -e "s/__asan_version_mismatch_check_v[0-9]+/__asan_version_mismatch_check/" \
 // RUN:  > %t.exports
 //
diff --git a/test/asan/TestCases/Windows/interface_symbols_windows.c b/test/asan/TestCases/Windows/interface_symbols_windows.c
index a08f35872..bc2f3e883 100644
--- a/test/asan/TestCases/Windows/interface_symbols_windows.c
+++ b/test/asan/TestCases/Windows/interface_symbols_windows.c
@@ -38,6 +38,7 @@
 // IMPORT: __asan_set_seh_filter
 // IMPORT: __asan_unhandled_exception_filter
 // IMPORT: __asan_test_only_reported_buggy_pointer
+// IMPORT: __sancov_lowest_stack
 //
 // RUN: cat %t.imports1 %t.imports2 %t.imports3 | sort | uniq > %t.imports-sorted
 // RUN: cat %t.exports | sort | uniq > %t.exports-sorted
diff --git a/test/fuzzer/deep-recursion.test b/test/fuzzer/deep-recursion.test
index b99bad4c6..22475f912 100644
--- a/test/fuzzer/deep-recursion.test
+++ b/test/fuzzer/deep-recursion.test
@@ -1,5 +1,5 @@
 # Test that we can find a stack overflow
 REQUIRES: linux
-RUN: %cpp_compiler -fsanitize-coverage=stack-depth %S/DeepRecursionTest.cpp -o %t
+RUN: %cpp_compiler %S/DeepRecursionTest.cpp -o %t
 RUN: not %t -seed=1 -runs=100000000 2>&1 | FileCheck %s
 CHECK: ERROR: libFuzzer: deadly signal