On Fri, 18 Nov 2022 18:00:11 +0800 Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx> wrote:
> When we specify __GFP_NOWARN, we only expect that no warnings
> will be issued for current caller. But in the __should_failslab()
> and __should_fail_alloc_page(), the local GFP flags alter the
> global {failslab|fail_page_alloc}.attr, which is persistent and
> shared by all tasks. This is not what we expected, let's fix it.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 3f913fc5f974 ("mm: fix missing handler for __GFP_NOWARN")
> Reported-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
> Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
> Reviewed-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
>
> ...
>
> -bool should_fail(struct fault_attr *attr, ssize_t size)
> +bool should_fail_ex(struct fault_attr *attr, ssize_t size, int flags)
> {
> bool stack_checked = false;
>
> @@ -152,13 +149,20 @@ bool should_fail(struct fault_attr *attr, ssize_t size)
> return false;
>
> fail:
> - fail_dump(attr);
> + if (!(flags & FAULT_NOWARN))
> + fail_dump(attr);
>
> if (atomic_read(&attr->times) != -1)
> atomic_dec_not_zero(&attr->times);
>
> return true;
> }
> +EXPORT_SYMBOL_GPL(should_fail_ex);
I don't see a need to export this?
