[compiler-rt] [nsan] Add nsan_preinit.cpp and make it static library only (PR #98564)
via llvm-commits
llvm-commits at lists.llvm.org
Thu Jul 11 15:53:36 PDT 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-compiler-rt-sanitizer
Author: Fangrui Song (MaskRay)
<details>
<summary>Changes</summary>
#<!-- -->94322 defines .preinit_array to initialize nsan early.
DT_PREINIT_ARRAY can only be used with the main executable. GNU ld would
complain when a DSO has .preinit_array. Therefore,
nsan_preinit.cpp cannot be linked into `libclang_rt.nsan.so`.
Working with @<!-- -->alexander-shaposhnikov, we noticed that `Nsan-x86_64-Test
--gtest_output=json` without `.preinit_array` will sigsegv.
This is because googletest calls timing functions, which call `free` (intercepted).
`__nsan_init` needs to be called early (.preinit_array) to make the
`free` interceptor work.
The robust way to ensure `nsan_preinit.cpp.o` is used is to link the
unittest executable with `-fsanitize=numerical` and remove
`NSAN_TEST_RUNTIME_OBJECTS`.
---
Full diff: https://github.com/llvm/llvm-project/pull/98564.diff
5 Files Affected:
- (modified) compiler-rt/lib/nsan/CMakeLists.txt (+10-1)
- (modified) compiler-rt/lib/nsan/nsan.cpp (-5)
- (modified) compiler-rt/lib/nsan/nsan.h (+2)
- (added) compiler-rt/lib/nsan/nsan_preinit.cpp (+21)
- (modified) compiler-rt/lib/nsan/tests/CMakeLists.txt (+3-18)
``````````diff
diff --git a/compiler-rt/lib/nsan/CMakeLists.txt b/compiler-rt/lib/nsan/CMakeLists.txt
index d67c3ac434d3a..1e138d4560c89 100644
--- a/compiler-rt/lib/nsan/CMakeLists.txt
+++ b/compiler-rt/lib/nsan/CMakeLists.txt
@@ -11,6 +11,9 @@ set(NSAN_SOURCES
nsan_suppressions.cpp
)
+set(NSAN_PREINIT_SOURCES
+ nsan_preinit.cpp)
+
set(NSAN_HEADERS
nsan.h
nsan_flags.h
@@ -61,6 +64,12 @@ if(NOT APPLE)
ADDITIONAL_HEADERS ${NSAN_HEADERS}
CFLAGS ${NSAN_CFLAGS})
+ add_compiler_rt_object_libraries(RTNsan_preinit
+ ARCHS ${NSAN_SUPPORTED_ARCH}
+ SOURCES ${NSAN_PREINIT_SOURCES}
+ ADDITIONAL_HEADERS ${NSAN_HEADERS}
+ CFLAGS ${NSAN_CFLAGS})
+
file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/dummy.cpp "")
add_compiler_rt_object_libraries(RTNsan_dynamic_version_script_dummy
ARCHS ${NSAN_SUPPORTED_ARCH}
@@ -72,7 +81,7 @@ add_compiler_rt_runtime(
clang_rt.nsan
STATIC
ARCHS ${NSAN_SUPPORTED_ARCH}
- OBJECT_LIBS RTNsan
+ OBJECT_LIBS RTNsan_preinit RTNsan
${NSAN_COMMON_RUNTIME_OBJECT_LIBS}
CFLAGS ${NSAN_CFLAGS}
PARENT_TARGET nsan)
diff --git a/compiler-rt/lib/nsan/nsan.cpp b/compiler-rt/lib/nsan/nsan.cpp
index f7b2ce2048290..7a5f013579dfb 100644
--- a/compiler-rt/lib/nsan/nsan.cpp
+++ b/compiler-rt/lib/nsan/nsan.cpp
@@ -801,8 +801,3 @@ extern "C" SANITIZER_INTERFACE_ATTRIBUTE void __nsan_init() {
nsan_init_is_running = false;
nsan_initialized = true;
}
-
-#if SANITIZER_CAN_USE_PREINIT_ARRAY
-__attribute__((section(".preinit_array"),
- used)) static void (*nsan_init_ptr)() = __nsan_init;
-#endif
diff --git a/compiler-rt/lib/nsan/nsan.h b/compiler-rt/lib/nsan/nsan.h
index 0fb998b049854..8277e3d778047 100644
--- a/compiler-rt/lib/nsan/nsan.h
+++ b/compiler-rt/lib/nsan/nsan.h
@@ -32,6 +32,8 @@ using __sanitizer::uptr;
// Private nsan interface. Used e.g. by interceptors.
extern "C" {
+void __nsan_init();
+
// This marks the shadow type of the given block of application memory as
// unknown.
// printf-free (see comment in nsan_interceptors.cc).
diff --git a/compiler-rt/lib/nsan/nsan_preinit.cpp b/compiler-rt/lib/nsan/nsan_preinit.cpp
new file mode 100644
index 0000000000000..5d869bbdf9668
--- /dev/null
+++ b/compiler-rt/lib/nsan/nsan_preinit.cpp
@@ -0,0 +1,21 @@
+//===- nsan_preinit.cpp ---------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Call __nsan_init early using ELF DT_PREINIT_ARRAY.
+//
+//===----------------------------------------------------------------------===//
+
+#include "nsan/nsan.h"
+#include "sanitizer_common/sanitizer_internal_defs.h"
+
+#if SANITIZER_CAN_USE_PREINIT_ARRAY
+
+__attribute__((section(".preinit_array"), used)) static auto nsan_preinit =
+ __nsan_init;
+
+#endif
diff --git a/compiler-rt/lib/nsan/tests/CMakeLists.txt b/compiler-rt/lib/nsan/tests/CMakeLists.txt
index e472fc5c06f90..ecb1aa9c56cf2 100644
--- a/compiler-rt/lib/nsan/tests/CMakeLists.txt
+++ b/compiler-rt/lib/nsan/tests/CMakeLists.txt
@@ -15,6 +15,8 @@ set(NSAN_UNITTEST_LINK_FLAGS
${COMPILER_RT_UNITTEST_LINK_FLAGS}
${COMPILER_RT_UNWINDER_LINK_LIBS}
${SANITIZER_TEST_CXX_LIBRARIES})
+set(NSAN_UNITTEST_INSTRUMENTED_LINK_FLAGS ${NSAN_UNITTEST_LINK_FLAGS})
+list(APPEND NSAN_UNITTEST_INSTRUMENTED_LINK_FLAGS -fsanitize=numerical)
file(GLOB NSAN_HEADERS ../*.h)
set(NSAN_UNITTESTS
@@ -27,30 +29,13 @@ if(COMPILER_RT_DEFAULT_TARGET_ARCH IN_LIST NSAN_SUPPORTED_ARCH)
# NSan unit tests are only run on the host machine.
set(arch ${COMPILER_RT_DEFAULT_TARGET_ARCH})
- set(NSAN_TEST_RUNTIME RTNsanTest.${arch})
-
- set(NSAN_TEST_RUNTIME_OBJECTS
- $<TARGET_OBJECTS:RTNsan.${arch}>
- $<TARGET_OBJECTS:RTInterception.${arch}>
- $<TARGET_OBJECTS:RTSanitizerCommon.${arch}>
- $<TARGET_OBJECTS:RTSanitizerCommonLibc.${arch}>
- $<TARGET_OBJECTS:RTSanitizerCommonSymbolizer.${arch}>)
-
- add_library(${NSAN_TEST_RUNTIME} STATIC
- ${NSAN_TEST_RUNTIME_OBJECTS})
-
- set_target_properties(${NSAN_TEST_RUNTIME} PROPERTIES
- ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
- FOLDER "Compiler-RT Runtime tests")
-
set(NsanTestObjects)
generate_compiler_rt_tests(NsanTestObjects
NsanUnitTests "Nsan-${arch}-Test" ${arch}
SOURCES ${NSAN_UNITTESTS} ${COMPILER_RT_GTEST_SOURCE}
- RUNTIME ${NSAN_TEST_RUNTIME}
DEPS ${NSAN_UNIT_TEST_HEADERS}
CFLAGS ${NSAN_UNITTEST_CFLAGS}
- LINK_FLAGS ${NSAN_UNITTEST_LINK_FLAGS})
+ LINK_FLAGS ${NSAN_UNITTEST_INSTRUMENTED_LINK_FLAGS})
set_target_properties(NsanUnitTests PROPERTIES
RUNTIME_OUTPUT_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
endif()
``````````
</details>
https://github.com/llvm/llvm-project/pull/98564
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