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 <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/20250411054105.2341982-29-mingo@kernel.org

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 0af2203944800147a3372517994b711813e77166..9937345e4c5babcff6ebf862837577ae8cb23f70 100644 (file)
--- 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);