tequilaOS/platform_system_core
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crash_dump: use /proc/<pid> fd to check tid process membership.

Browse source 
Bug: http://b/34759490
Test: /data/nativetest/debuggerd_test/debuggerd_test32
Test: debuggerd -b `pidof system_server`
Test: debuggerd -b `pidof zygote`
Change-Id: I627692b44977335a9568cd765ad28205f0a61327
This commit is contained in:
Josh Gao 2017-02-01 16:31:43 -08:00
parent 7ae426c731
commit fe90276aee
1 changed files with 12 additions and 11 deletions
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23
debuggerd/crash_dump.cpp
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@ -51,24 +51,25 @@
using android::base::unique_fd;
using android::base::StringPrintf;
static bool pid_contains_tid(pid_t pid, pid_t tid) {
std::string task_path = StringPrintf("/proc/%d/task/%d", pid, tid);
return access(task_path.c_str(), F_OK) == 0;
static bool pid_contains_tid(int pid_proc_fd, pid_t tid) {
struct stat st;
std::string task_path = StringPrintf("task/%d", tid);
return fstatat(pid_proc_fd, task_path.c_str(), &st, 0) == 0;
}
// Attach to a thread, and verify that it's still a member of the given process
static bool ptrace_seize_thread(pid_t pid, pid_t tid, std::string* error) {
static bool ptrace_seize_thread(int pid_proc_fd, pid_t tid, std::string* error) {
if (ptrace(PTRACE_SEIZE, tid, 0, 0) != 0) {
*error = StringPrintf("failed to attach to thread %d: %s", tid, strerror(errno));
return false;
}
// Make sure that the task we attached to is actually part of the pid we're dumping.
if (!pid_contains_tid(pid, tid)) {
if (!pid_contains_tid(pid_proc_fd, tid)) {
if (ptrace(PTRACE_DETACH, tid, 0, 0) != 0) {
PLOG(FATAL) << "failed to detach from thread " << tid;
}
*error = StringPrintf("thread %d is not in process %d", tid, pid);
*error = StringPrintf("thread %d is not in process", tid);
return false;
}
@ -263,7 +264,7 @@ int main(int argc, char** argv) {
check_process(target_proc_fd, target);
std::string attach_error;
if (!ptrace_seize_thread(target, main_tid, &attach_error)) {
if (!ptrace_seize_thread(target_proc_fd, main_tid, &attach_error)) {
LOG(FATAL) << attach_error;
}
@ -304,6 +305,7 @@ int main(int argc, char** argv) {
}
int signo = siginfo.si_signo;
bool fatal_signal = signo != DEBUGGER_SIGNAL;
bool backtrace = false;
uintptr_t abort_address = 0;
@ -319,17 +321,16 @@ int main(int argc, char** argv) {
// Now that we have the signal that kicked things off, attach all of the
// sibling threads, and then proceed.
bool fatal_signal = signo != DEBUGGER_SIGNAL;
std::set<pid_t> siblings;
std::set<pid_t> attached_siblings;
if (fatal_signal || backtrace) {
{
std::set<pid_t> siblings;
if (!android::procinfo::GetProcessTids(target, &siblings)) {
PLOG(FATAL) << "failed to get process siblings";
}
siblings.erase(main_tid);
for (pid_t sibling_tid : siblings) {
if (!ptrace_seize_thread(target, sibling_tid, &attach_error)) {
if (!ptrace_seize_thread(target_proc_fd, sibling_tid, &attach_error)) {
LOG(WARNING) << attach_error;
} else {
attached_siblings.insert(sibling_tid);