debuggerd_handler: use syscall(__NR_get[pt]id) instead of get[pt]id.
bionic's cached values for getpid/gettid can be invalid if the crashing
process manually invoked clone to create a thread or process, which
will lead the crash_dump refusing to do anything, because it sees the
actual values.
Use the getpid/gettid syscalls directly to ensure correct values on
this end.
Bug: http://b/37769298
Test: debuggerd_test
Change-Id: I0b1e652beb1a66e564a48b88ed7fa971d61c6ff9
diff --git a/debuggerd/debuggerd_test.cpp b/debuggerd/debuggerd_test.cpp
index 568879e..0b4bbfb 100644
--- a/debuggerd/debuggerd_test.cpp
+++ b/debuggerd/debuggerd_test.cpp
@@ -29,6 +29,7 @@
#include <android-base/file.h>
#include <android-base/logging.h>
+#include <android-base/macros.h>
#include <android-base/parseint.h>
#include <android-base/properties.h>
#include <android-base/strings.h>
@@ -149,7 +150,7 @@
// Returns -1 if we fail to read a response from tombstoned, otherwise the received return code.
void FinishIntercept(int* result);
- void StartProcess(std::function<void()> function);
+ void StartProcess(std::function<void()> function, std::function<pid_t()> forker = fork);
void StartCrasher(const std::string& crash_type);
void FinishCrasher();
void AssertDeath(int signo);
@@ -195,14 +196,14 @@
}
}
-void CrasherTest::StartProcess(std::function<void()> function) {
+void CrasherTest::StartProcess(std::function<void()> function, std::function<pid_t()> forker) {
unique_fd read_pipe;
unique_fd crasher_read_pipe;
if (!Pipe(&crasher_read_pipe, &crasher_pipe)) {
FAIL() << "failed to create pipe: " << strerror(errno);
}
- crasher_pid = fork();
+ crasher_pid = forker();
if (crasher_pid == -1) {
FAIL() << "fork failed: " << strerror(errno);
} else if (crasher_pid == 0) {
@@ -527,6 +528,37 @@
ASSERT_MATCH(result, R"(#00 pc [0-9a-f]+\s+ /system/lib)" ARCH_SUFFIX R"(/libc.so \(tgkill)");
}
+TEST_F(CrasherTest, fake_pid) {
+ int intercept_result;
+ unique_fd output_fd;
+
+ // Prime the getpid/gettid caches.
+ UNUSED(getpid());
+ UNUSED(gettid());
+
+ std::function<pid_t()> clone_fn = []() {
+ return syscall(__NR_clone, SIGCHLD, nullptr, nullptr, nullptr, nullptr);
+ };
+ StartProcess(
+ []() {
+ ASSERT_NE(getpid(), syscall(__NR_getpid));
+ ASSERT_NE(gettid(), syscall(__NR_gettid));
+ raise(SIGSEGV);
+ },
+ clone_fn);
+
+ StartIntercept(&output_fd);
+ FinishCrasher();
+ AssertDeath(SIGSEGV);
+ FinishIntercept(&intercept_result);
+
+ ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
+
+ std::string result;
+ ConsumeFd(std::move(output_fd), &result);
+ ASSERT_MATCH(result, R"(#00 pc [0-9a-f]+\s+ /system/lib)" ARCH_SUFFIX R"(/libc.so \(tgkill)");
+}
+
TEST(crash_dump, zombie) {
pid_t forkpid = fork();