On Tue, Jul 07, 2026 at 07:33:16AM +0000, [email protected] wrote:
> Thank you for your contribution! Sashiko AI review found 2 potential issue(s)
> to consider:
> - [Medium] The `sdt_might_sleep_end()` macro is bypassed when
> `___wait_var_event` is interrupted, leaving the DEPT tracker in an
> inconsistent state.
> - [Medium] The `sdt_might_sleep_end()` macro is bypassed when `___wait_event`
> is interrupted, leaving the DEPT tracker in an inconsistent state.
> --
>
> commit 0bd2d42866fa6b852ee5317edcaf6890a90c3c65
> Author: Byungchul Park <[email protected]>
>
> dept: apply sdt_might_sleep_{start,end}() to hashed-waitqueue wait
>
> Make dept able to track dependencies by hashed-waitqueue waits.
>
> > diff --git a/include/linux/wait_bit.h b/include/linux/wait_bit.h
> > index 9e29d79fc790a..179a616ad245a 100644
> > --- a/include/linux/wait_bit.h
> > +++ b/include/linux/wait_bit.h
> [ ... ]
> > @@ -257,6 +258,7 @@ extern wait_queue_head_t *__var_waitqueue(void *p);
> > struct wait_bit_queue_entry __wbq_entry; \
> > long __ret = ret; /* explicit shadow */ \
> > \
> > + sdt_might_sleep_start(NULL); \
> > init_wait_var_entry(&__wbq_entry, var, \
> > exclusive ? WQ_FLAG_EXCLUSIVE : 0); \
> > for (;;) { \
> > @@ -274,6 +276,7 @@ extern wait_queue_head_t *__var_waitqueue(void *p);
> > cmd; \
> > } \
> > finish_wait(__wq_head, &__wbq_entry.wq_entry); \
> > + sdt_might_sleep_end(); \
> > __out: __ret;
> > \
> > })
>
> [Severity: Medium]
> If this wait is interrupted by a signal, the loop executes a goto __out
> which bypasses sdt_might_sleep_end(). Does this leave the dept tracker
> in an inconsistent state where the task's stage remains permanently armed?
>
> This could cause false positive dependency tracking splats on subsequent
> waits, or fail to record new dependencies because the tracker is blinded by
> the stale stage.
>
> I noticed the exact same issue is present in ___wait_event():
>
> include/linux/wait.h:___wait_event() {
> ...
> if (___wait_is_interruptible(state) && __int) {
> __ret = __int;
> goto __out;
> }
> ...
> sdt_might_sleep_end();
> __out: __ret;
> })
I will fix it.
> [Severity: Medium]
> Does ___wait_event() also skip sdt_might_sleep_end() when interrupted?
> By missing the paired cleanup call, the task's stage could remain
> permanently armed here as well.
>
> Would it make sense to move the __out label above sdt_might_sleep_end(),
> or otherwise ensure the state is cleaned up on the interrupted paths for
> both of these macros?
Right. I will fix it.
Byungchul
> --
> Sashiko AI review ยท
> https://sashiko.dev/#/patchset/[email protected]?part=13
