Commit 28fb7909 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

x86/alternatives: Rename 'bp_refs' to 'text_poke_array_refs' 



Make it clear that these reference counts lock access
to text_poke_array.

Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250411054105.2341982-5-mingo@kernel.org
parent 84e5ba94

arch/x86/kernel/alternative.c

+7 −7
Original line number Diff line number Diff line
@@ -2476,14 +2476,14 @@ struct text_poke_int3_vec { 
	int nr_entries;

};



static DEFINE_PER_CPU(atomic_t, bp_refs);

static DEFINE_PER_CPU(atomic_t, text_poke_array_refs);



static struct text_poke_int3_vec bp_desc;



static __always_inline

struct text_poke_int3_vec *try_get_desc(void)

{

	atomic_t *refs = this_cpu_ptr(&bp_refs);

	atomic_t *refs = this_cpu_ptr(&text_poke_array_refs);



	if (!raw_atomic_inc_not_zero(refs))

		return NULL;
@@ -2493,7 +2493,7 @@ struct text_poke_int3_vec *try_get_desc(void) 


static __always_inline void put_desc(void)

{

	atomic_t *refs = this_cpu_ptr(&bp_refs);

	atomic_t *refs = this_cpu_ptr(&text_poke_array_refs);



	smp_mb__before_atomic();

	raw_atomic_dec(refs);
@@ -2529,9 +2529,9 @@ noinstr int poke_int3_handler(struct pt_regs *regs) 
	 * Having observed our INT3 instruction, we now must observe

	 * bp_desc with non-zero refcount:

	 *

	 *	bp_refs = 1		INT3

	 *	text_poke_array_refs = 1		INT3

	 *	WMB			RMB

	 *	write INT3		if (bp_refs != 0)

	 *	write INT3		if (text_poke_array_refs != 0)

	 */

	smp_rmb();
@@ -2638,7 +2638,7 @@ static void text_poke_bp_batch(struct text_poke_loc *tp, unsigned int nr_entries 
	 * ensure reading a non-zero refcount provides up to date bp_desc data.

	 */

	for_each_possible_cpu(i)

		atomic_set_release(per_cpu_ptr(&bp_refs, i), 1);

		atomic_set_release(per_cpu_ptr(&text_poke_array_refs, i), 1);



	/*

	 * Function tracing can enable thousands of places that need to be
@@ -2760,7 +2760,7 @@ static void text_poke_bp_batch(struct text_poke_loc *tp, unsigned int nr_entries 
	 * unused.

	 */

	for_each_possible_cpu(i) {

		atomic_t *refs = per_cpu_ptr(&bp_refs, i);

		atomic_t *refs = per_cpu_ptr(&text_poke_array_refs, i);



		if (unlikely(!atomic_dec_and_test(refs)))

			atomic_cond_read_acquire(refs, !VAL);