Messages in this thread | | | Date | Wed, 23 Nov 2022 11:07:19 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH v5 1/5] jump_label: Prevent key->enabled int overflow |
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On Tue, Nov 22, 2022 at 06:55:30PM +0000, Dmitry Safonov wrote:
> key->enabled is indeed a ref-counter as it's documented in multiple > places: top comment in jump_label.h, Documentation/staging/static-keys.rst, > etc.
> +/*** > + * static_key_fast_inc_not_negative - adds a user for a static key > + * @key: static key that must be already enabled > + * > + * The caller must make sure that the static key can't get disabled while > + * in this function. It doesn't patch jump labels, only adds a user to > + * an already enabled static key. > + * > + * Returns true if the increment was done. > + */
One more thing; it might be useful to point out that unlike refcount_t this thing does not saturate but will fail to increment on overflow.
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