mirrors/ladybird
1
0
Fork 0
mirror of https://github.com/LadybirdBrowser/ladybird.git synced 2025-01-23 01:32:14 -05:00
Code Issues Projects Releases Packages Wiki Activity

Kernel: Briefly resume stopped threads when being killed

Browse source 
We need to briefly put Stopped threads back into Running state
so that the kernel stacks can get cleaned up when they're being
killed.

Fixes #3130
This commit is contained in:
Tom 2020-08-14 10:24:31 -06:00 committed by Andreas Kling
parent 2614ef550c
commit 72960fedc6
Notes: sideshowbarker 2024-07-19 03:38:01 +09:00 
Author: https://github.com/tomuta
Commit: https://github.com/SerenityOS/serenity/commit/72960fedc60
Pull-request: https://github.com/SerenityOS/serenity/pull/3143
Issue: https://github.com/SerenityOS/serenity/issues/3130
2 changed files with 33 additions and 13 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

44
Kernel/Thread.cpp
View file

@ -136,7 +136,21 @@ void Thread::set_should_die()
// Remember that we should die instead of returning to
// the userspace.
m_should_die = true;
{
ScopedSpinLock lock(g_scheduler_lock);
m_should_die = true;
// NOTE: Even the current thread can technically be in "Stopped"
// state! This is the case when another thread sent a SIGSTOP to
// it while it was running and it calls e.g. exit() before
// the scheduler gets involved again.
if (is_stopped()) {
// If we were stopped, we need to briefly resume so that
// the kernel stacks can clean up. We won't ever return back
// to user mode, though
resume_from_stopped();
}
}
if (is_blocked()) {
ScopedSpinLock lock(m_lock);
@ -428,6 +442,20 @@ static void push_value_on_user_stack(u32* stack, u32 data)
copy_to_user((u32*)*stack, &data);
}
void Thread::resume_from_stopped()
{
ASSERT(is_stopped());
ASSERT(m_stop_state != State::Invalid);
set_state(m_stop_state);
m_stop_state = State::Invalid;
// make sure SemiPermanentBlocker is unblocked
if (m_state != Thread::Runnable && m_state != Thread::Running) {
ScopedSpinLock lock(m_lock);
if (m_blocker && m_blocker->is_reason_signal())
unblock();
}
}
ShouldUnblockThread Thread::dispatch_signal(u8 signal)
{
ASSERT_INTERRUPTS_DISABLED();
@ -455,18 +483,8 @@ ShouldUnblockThread Thread::dispatch_signal(u8 signal)
}
if (signal == SIGCONT && is_stopped()) {
ASSERT(m_stop_state != State::Invalid);
set_state(m_stop_state);
m_stop_state = State::Invalid;
// make sure SemiPermanentBlocker is unblocked
if (m_state != Thread::Runnable && m_state != Thread::Running) {
ScopedSpinLock lock(m_lock);
if (m_blocker && m_blocker->is_reason_signal())
unblock();
}
}
else {
resume_from_stopped();
} else {
auto* thread_tracer = tracer();
if (thread_tracer != nullptr) {
// when a thread is traced, it should be stopped whenever it receives a signal

2
Kernel/Thread.h
View file

@ -270,6 +270,8 @@ public:
void did_schedule() { ++m_times_scheduled; }
u32 times_scheduled() const { return m_times_scheduled; }
void resume_from_stopped();
bool is_stopped() const { return m_state == Stopped; }
bool is_blocked() const { return m_state == Blocked; }
bool has_blocker() const