Re: [PATCH 34/40] lib: code tagging context capture support

Dave Hansen
2023-05-03T15:26:50Z

On 5/3/23 08:18, Suren Baghdasaryan wrote:
>>> +static inline void rem_ctx(struct codetag_ctx *ctx,
>>> + void (*free_ctx)(struct kref *refcount))
>>> +{
>>> + struct codetag_with_ctx *ctc = ctx->ctc;
>>> +
>>> + spin_lock(&ctc->ctx_lock);
>> This could deadlock when allocator is called from the IRQ context.
> I see. spin_lock_irqsave() then?

Yes. But, even better, please turn on lockdep when you are testing. It
will find these for you. If you're on x86, we have a set of handy-dandy
debug options that you can add to an existing config with:

make x86_debug.config

That said, I'm as concerned as everyone else that this is all "new" code
and doesn't lean on existing tracing or things like PAGE_OWNER enough.