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Kernel: Convert Processor::in_irq() to static current_in_irq()

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This closes the race window between Processor::current() and a context
switch happening before in_irq().
This commit is contained in:
Andreas Kling 2021-08-22 12:21:31 +02:00
parent 3e3f760808
commit d60635cb9d
14 changed files with 37 additions and 39 deletions
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16
Kernel/Scheduler.cpp
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@ -252,16 +252,15 @@ bool Scheduler::pick_next()
bool Scheduler::yield()
{
InterruptDisabler disabler;
auto& proc = Processor::current();
auto current_thread = Thread::current();
dbgln_if(SCHEDULER_DEBUG, "Scheduler[{}]: yielding thread {} in_irq={}", proc.get_id(), *current_thread, proc.in_irq());
dbgln_if(SCHEDULER_DEBUG, "Scheduler[{}]: yielding thread {} in_irq={}", Processor::id(), *current_thread, Processor::current_in_irq());
VERIFY(current_thread != nullptr);
if (proc.in_irq() || Processor::in_critical()) {
if (Processor::current_in_irq() || Processor::in_critical()) {
// If we're handling an IRQ we can't switch context, or we're in
// a critical section where we don't want to switch contexts, then
// delay until exiting the trap or critical section
proc.invoke_scheduler_async();
Processor::current().invoke_scheduler_async();
return false;
}
@ -269,7 +268,7 @@ bool Scheduler::yield()
return false;
if constexpr (SCHEDULER_DEBUG)
dbgln("Scheduler[{}]: yield returns to thread {} in_irq={}", Processor::id(), *current_thread, Processor::current().in_irq());
dbgln("Scheduler[{}]: yield returns to thread {} in_irq={}", Processor::id(), *current_thread, Processor::current_in_irq());
return true;
}
@ -462,7 +461,7 @@ void Scheduler::add_time_scheduled(u64 time_to_add, bool is_kernel)
void Scheduler::timer_tick(const RegisterState& regs)
{
VERIFY_INTERRUPTS_DISABLED();
VERIFY(Processor::current().in_irq());
VERIFY(Processor::current_in_irq());
auto current_thread = Processor::current_thread();
if (!current_thread)
@ -506,15 +505,14 @@ void Scheduler::timer_tick(const RegisterState& regs)
}
VERIFY_INTERRUPTS_DISABLED();
VERIFY(Processor::current().in_irq());
VERIFY(Processor::current_in_irq());
Processor::current().invoke_scheduler_async();
}
void Scheduler::invoke_async()
{
VERIFY_INTERRUPTS_DISABLED();
auto& processor = Processor::current();
VERIFY(!processor.in_irq());
VERIFY(!Processor::current_in_irq());
// Since this function is called when leaving critical sections (such
// as a Spinlock), we need to check if we're not already doing this