[x86,x86_64] Fix libgcc unwinding through signal
This change provides __restore/__restore_rt on x86 and __restore_rt on
x86_64 with unwinding information to be able to unwind through signal
frame via libgcc provided unwinding interface. See comments inlined for
more details.
Also remove the test that had a dependency on
__attribute__((cleanup(foo_cleanup))). It doesn't provide us with any
better test coverage than we have from the newer tests, and it doesn't
work well across a variety architectures (presumably because no one uses
this attribute in the real world).
Tested this on host via bionic-unit-tests-run-on-host on both x86 and
x86-64.
Bug: 17436734
Change-Id: I2f06814e82c8faa732cb4f5648868dc0fd2e5fe4
Signed-off-by: Pavel Chupin <pavel.v.chupin@intel.com>
diff --git a/tests/Android.mk b/tests/Android.mk
index f61f175..c0345e4 100644
--- a/tests/Android.mk
+++ b/tests/Android.mk
@@ -91,6 +91,7 @@
semaphore_test.cpp \
signal_test.cpp \
stack_protector_test.cpp \
+ stack_unwinding_test.cpp \
stdatomic_test.cpp \
stdint_test.cpp \
stdio_test.cpp \
@@ -234,8 +235,6 @@
atexit_test.cpp \
dlext_test.cpp \
dlfcn_test.cpp \
- stack_unwinding_test.cpp \
- stack_unwinding_test_impl.c \
bionic-unit-tests_cflags := $(test_cflags)
diff --git a/tests/ScopedSignalHandler.h b/tests/ScopedSignalHandler.h
index 89a14a6..3ec23b0 100644
--- a/tests/ScopedSignalHandler.h
+++ b/tests/ScopedSignalHandler.h
@@ -21,9 +21,10 @@
class ScopedSignalHandler {
public:
- ScopedSignalHandler(int signal_number, void (*handler)(int)) : signal_number_(signal_number) {
+ ScopedSignalHandler(int signal_number, void (*handler)(int), int sa_flags = 0)
+ : signal_number_(signal_number) {
sigemptyset(&action_.sa_mask);
- action_.sa_flags = 0;
+ action_.sa_flags = sa_flags;
action_.sa_handler = handler;
sigaction(signal_number_, &action_, &old_action_);
}
diff --git a/tests/stack_unwinding_test.cpp b/tests/stack_unwinding_test.cpp
index 017a5f2..3fc45c5 100644
--- a/tests/stack_unwinding_test.cpp
+++ b/tests/stack_unwinding_test.cpp
@@ -31,7 +31,8 @@
#include "ScopedSignalHandler.h"
-#define noinline __attribute__((noinline))
+#define noinline __attribute__((__noinline__))
+#define __unused __attribute__((__unused__))
static _Unwind_Reason_Code FrameCounter(_Unwind_Context* ctx __unused, void* arg) {
int* count_ptr = reinterpret_cast<int*>(arg);
@@ -85,6 +86,7 @@
}
TEST(stack_unwinding, unwind_through_signal_frame) {
+ killer_count = handler_count = handler_one_deeper_count = 0;
ScopedSignalHandler ssh(SIGUSR1, UnwindSignalHandler);
_Unwind_Backtrace(FrameCounter, &killer_count);
@@ -92,11 +94,12 @@
ASSERT_EQ(0, kill(getpid(), SIGUSR1));
}
-extern "C" void unwind_through_frame_with_cleanup_function();
+// On LP32, the SA_SIGINFO flag gets you __restore_rt instead of __restore.
+TEST(stack_unwinding, unwind_through_signal_frame_SA_SIGINFO) {
+ killer_count = handler_count = handler_one_deeper_count = 0;
+ ScopedSignalHandler ssh(SIGUSR1, UnwindSignalHandler, SA_SIGINFO);
-// We have to say "DeathTest" here so gtest knows to run this test (which exits)
-// in its own process.
-TEST(stack_unwinding_DeathTest, unwind_through_frame_with_cleanup_function) {
- ::testing::FLAGS_gtest_death_test_style = "threadsafe";
- ASSERT_EXIT(unwind_through_frame_with_cleanup_function(), ::testing::ExitedWithCode(42), "");
+ _Unwind_Backtrace(FrameCounter, &killer_count);
+
+ ASSERT_EQ(0, kill(getpid(), SIGUSR1));
}
diff --git a/tests/stack_unwinding_test_impl.c b/tests/stack_unwinding_test_impl.c
deleted file mode 100644
index 2e03938..0000000
--- a/tests/stack_unwinding_test_impl.c
+++ /dev/null
@@ -1,64 +0,0 @@
-/*
- * Copyright (C) 2013 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-/*
- * Contributed by: Intel Corporation
- */
-
-#include <dlfcn.h>
-#include <signal.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <unwind.h>
-
-#define noinline __attribute__((__noinline__))
-
-#ifndef __unused
-#define __unused __attribute__((__unused__))
-#endif
-
-static noinline _Unwind_Reason_Code cleanup_unwind_fn(int a __unused,
- _Unwind_Action action,
- _Unwind_Exception_Class b __unused,
- struct _Unwind_Exception* c __unused,
- struct _Unwind_Context* ctx __unused,
- void* e __unused) {
- if ((action & _UA_END_OF_STACK) != 0) {
- abort(); // We reached the end of the stack without executing foo_cleanup (which would have exited). Test failed.
- }
- return _URC_NO_REASON;
-}
-
-static void noinline foo_cleanup(char* param __unused) {
- exit(42);
-}
-
-static void noinline function_with_cleanup_function() {
- char c __attribute__((cleanup(foo_cleanup))) __unused;
- *((int*) 1) = 0;
-}
-
-static void noinline cleanup_sigsegv_handler(int param __unused) {
- struct _Unwind_Exception* exception = (struct _Unwind_Exception*) calloc(1, sizeof(*exception));
- _Unwind_ForcedUnwind(exception, cleanup_unwind_fn, 0);
-}
-
-void unwind_through_frame_with_cleanup_function() {
- signal(SIGSEGV, &cleanup_sigsegv_handler);
- function_with_cleanup_function();
-}