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SubjectRe: [PATCH 1/4] context_tracking: Protect against recursion

* Frederic Weisbecker <fweisbec@gmail.com> wrote:

> @@ -75,6 +94,11 @@ void context_tracking_enter(enum ctx_state state)
> WARN_ON_ONCE(!current->mm);
>
> local_irq_save(flags);
> + if (!context_tracking_recursion_enter()) {
> + local_irq_restore(flags);
> + return;
> + }
> +
> if ( __this_cpu_read(context_tracking.state) != state) {
> if (__this_cpu_read(context_tracking.active)) {
> /*
> @@ -105,6 +129,7 @@ void context_tracking_enter(enum ctx_state state)
> */
> __this_cpu_write(context_tracking.state, state);
> }
> + context_tracking_recursion_exit();

> local_irq_restore(flags);
> }

So why not add an 'out_irq_restore:' label and use goto instead of
duplicating the return path in the recursion check?

> NOKPROBE_SYMBOL(context_tracking_enter);
> @@ -139,6 +164,10 @@ void context_tracking_exit(enum ctx_state state)
> return;
>
> local_irq_save(flags);
> + if (!context_tracking_recursion_enter()) {
> + local_irq_restore(flags);
> + return;

Ditto.

No need to resend, I fixed this up in the patch.

Thanks,

Ingo


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