From: Ingo Molnar Date: Fri, 11 Apr 2025 05:40:40 +0000 (+0200) Subject: x86/alternatives: Remove the tp_vec indirection X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=0494b16b9caed22ff78adb84cedb7460532eb3f0;p=users%2Fdwmw2%2Flinux.git x86/alternatives: Remove the tp_vec indirection At this point we are always working out of an uptodate text_poke_array, there's no need for smp_text_poke_int3_handler() to read via the int3_vec indirection - remove it. This simplifies the code: 1 file changed, 5 insertions(+), 15 deletions(-) Signed-off-by: Ingo Molnar Cc: Juergen Gross Cc: "H . Peter Anvin" Cc: Linus Torvalds Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20250411054105.2341982-29-mingo@kernel.org --- diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 0af2203944800..9937345e4c5ba 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -2466,15 +2466,6 @@ struct smp_text_poke_loc { u8 old; }; -struct text_poke_int3_vec { - int nr_entries; - struct smp_text_poke_loc *vec; -}; - -static DEFINE_PER_CPU(atomic_t, text_poke_array_refs); - -static struct text_poke_int3_vec int3_vec; - #define TP_ARRAY_NR_ENTRIES_MAX (PAGE_SIZE / sizeof(struct smp_text_poke_loc)) static struct smp_text_poke_array { @@ -2482,15 +2473,17 @@ static struct smp_text_poke_array { struct smp_text_poke_loc vec[TP_ARRAY_NR_ENTRIES_MAX]; } text_poke_array; +static DEFINE_PER_CPU(atomic_t, text_poke_array_refs); + static __always_inline -struct text_poke_int3_vec *try_get_desc(void) +struct smp_text_poke_array *try_get_desc(void) { atomic_t *refs = this_cpu_ptr(&text_poke_array_refs); if (!raw_atomic_inc_not_zero(refs)) return NULL; - return &int3_vec; + return &text_poke_array; } static __always_inline void put_desc(void) @@ -2519,7 +2512,7 @@ static __always_inline int patch_cmp(const void *key, const void *elt) noinstr int smp_text_poke_int3_handler(struct pt_regs *regs) { - struct text_poke_int3_vec *desc; + struct smp_text_poke_array *desc; struct smp_text_poke_loc *tp; int ret = 0; void *ip; @@ -2529,7 +2522,7 @@ noinstr int smp_text_poke_int3_handler(struct pt_regs *regs) /* * Having observed our INT3 instruction, we now must observe - * int3_vec with non-zero refcount: + * text_poke_array with non-zero refcount: * * text_poke_array_refs = 1 INT3 * WMB RMB @@ -2633,12 +2626,9 @@ static void smp_text_poke_batch_process(struct smp_text_poke_loc *tp, unsigned i WARN_ON_ONCE(tp != text_poke_array.vec); WARN_ON_ONCE(nr_entries != text_poke_array.nr_entries); - int3_vec.vec = tp; - int3_vec.nr_entries = nr_entries; - /* * Corresponds to the implicit memory barrier in try_get_desc() to - * ensure reading a non-zero refcount provides up to date int3_vec data. + * ensure reading a non-zero refcount provides up to date text_poke_array data. */ for_each_possible_cpu(i) atomic_set_release(per_cpu_ptr(&text_poke_array_refs, i), 1);