Commit 68b1eddd authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

static_call: Fix static_call_set_init() 



It turns out that static_call_set_init() does not preserve the other
flags; IOW. it clears TAIL if it was set.

Fixes: 9183c3f9 ("static_call: Add inline static call infrastructure")
Reported-by: default avatarSumit Garg <sumit.garg@linaro.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
Tested-by: default avatarSumit Garg <sumit.garg@linaro.org>
Link: https://lkml.kernel.org/r/20210318113610.519406371@infradead.org
parent bee64578

kernel/static_call.c

+10 −7
Original line number Diff line number Diff line
@@ -35,27 +35,30 @@ static inline void *static_call_addr(struct static_call_site *site) 
	return (void *)((long)site->addr + (long)&site->addr);

}



static inline unsigned long __static_call_key(const struct static_call_site *site)

{

	return (long)site->key + (long)&site->key;

}



static inline struct static_call_key *static_call_key(const struct static_call_site *site)

{

	return (struct static_call_key *)

		(((long)site->key + (long)&site->key) & ~STATIC_CALL_SITE_FLAGS);

	return (void *)(__static_call_key(site) & ~STATIC_CALL_SITE_FLAGS);

}



/* These assume the key is word-aligned. */

static inline bool static_call_is_init(struct static_call_site *site)

{

	return ((long)site->key + (long)&site->key) & STATIC_CALL_SITE_INIT;

	return __static_call_key(site) & STATIC_CALL_SITE_INIT;

}



static inline bool static_call_is_tail(struct static_call_site *site)

{

	return ((long)site->key + (long)&site->key) & STATIC_CALL_SITE_TAIL;

	return __static_call_key(site) & STATIC_CALL_SITE_TAIL;

}



static inline void static_call_set_init(struct static_call_site *site)

{

	site->key = ((long)static_call_key(site) | STATIC_CALL_SITE_INIT) -

	site->key = (__static_call_key(site) | STATIC_CALL_SITE_INIT) -

		    (long)&site->key;

}
@@ -349,7 +352,7 @@ static int static_call_add_module(struct module *mod) 
	struct static_call_site *site;



	for (site = start; site != stop; site++) {

		unsigned long s_key = (long)site->key + (long)&site->key;

		unsigned long s_key = __static_call_key(site);

		unsigned long addr = s_key & ~STATIC_CALL_SITE_FLAGS;

		unsigned long key;