x86/alternatives: Simplify smp_text_poke_batch_process()

This function is now using the text_poke_array state exclusively,
make that explicit by removing the redundant input parameters.

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/20250411054105.2341982-34-mingo@kernel.org

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 97cb954467ff81c24568f23b5b929630c9c19574..08ac3c7ad6f8c406a8956cb2804b92d5c6aea7fa 100644 (file)
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -2591,8 +2591,8 @@ out_put:
 
 /**
  * smp_text_poke_batch_process() -- update instructions on live kernel on SMP
- * @tp:                        vector of instructions to patch
- * @nr_entries:                number of entries in the vector
+ * @text_poke_array.vec:               vector of instructions to patch
+ * @text_poke_array.nr_entries:        number of entries in the vector
  *
  * Modify multi-byte instruction by using int3 breakpoint on SMP.
  * We completely avoid stop_machine() here, and achieve the
@@ -2610,7 +2610,7 @@ out_put:
  *               replacing opcode
  *     - sync cores
  */
-static void smp_text_poke_batch_process(struct smp_text_poke_loc *tp, unsigned int nr_entries)
+static void smp_text_poke_batch_process(void)
 {
        unsigned char int3 = INT3_INSN_OPCODE;
        unsigned int i;
@@ -2618,9 +2618,6 @@ static void smp_text_poke_batch_process(struct smp_text_poke_loc *tp, unsigned i
 
        lockdep_assert_held(&text_mutex);
 
-       WARN_ON_ONCE(tp != text_poke_array.vec);
-       WARN_ON_ONCE(nr_entries != text_poke_array.nr_entries);
-
        /*
         * Corresponds to the implicit memory barrier in try_get_text_poke_array() to
         * ensure reading a non-zero refcount provides up to date text_poke_array data.
@@ -2640,16 +2637,16 @@ static void smp_text_poke_batch_process(struct smp_text_poke_loc *tp, unsigned i
 
        /*
         * Corresponding read barrier in int3 notifier for making sure the
-        * nr_entries and handler are correctly ordered wrt. patching.
+        * text_poke_array.nr_entries and handler are correctly ordered wrt. patching.
         */
        smp_wmb();
 
        /*
         * First step: add a int3 trap to the address that will be patched.
         */
-       for (i = 0; i < nr_entries; i++) {
-               tp[i].old = *(u8 *)text_poke_addr(&tp[i]);
-               text_poke(text_poke_addr(&tp[i]), &int3, INT3_INSN_SIZE);
+       for (i = 0; i < text_poke_array.nr_entries; i++) {
+               text_poke_array.vec[i].old = *(u8 *)text_poke_addr(&text_poke_array.vec[i]);
+               text_poke(text_poke_addr(&text_poke_array.vec[i]), &int3, INT3_INSN_SIZE);
        }
 
        text_poke_sync();
@@ -2657,15 +2654,15 @@ static void smp_text_poke_batch_process(struct smp_text_poke_loc *tp, unsigned i
        /*
         * Second step: update all but the first byte of the patched range.
         */
-       for (do_sync = 0, i = 0; i < nr_entries; i++) {
-               u8 old[POKE_MAX_OPCODE_SIZE+1] = { tp[i].old, };
+       for (do_sync = 0, i = 0; i < text_poke_array.nr_entries; i++) {
+               u8 old[POKE_MAX_OPCODE_SIZE+1] = { text_poke_array.vec[i].old, };
                u8 _new[POKE_MAX_OPCODE_SIZE+1];
-               const u8 *new = tp[i].text;
-               int len = tp[i].len;
+               const u8 *new = text_poke_array.vec[i].text;
+               int len = text_poke_array.vec[i].len;
 
                if (len - INT3_INSN_SIZE > 0) {
                        memcpy(old + INT3_INSN_SIZE,
-                              text_poke_addr(&tp[i]) + INT3_INSN_SIZE,
+                              text_poke_addr(&text_poke_array.vec[i]) + INT3_INSN_SIZE,
                               len - INT3_INSN_SIZE);
 
                        if (len == 6) {
@@ -2674,7 +2671,7 @@ static void smp_text_poke_batch_process(struct smp_text_poke_loc *tp, unsigned i
                                new = _new;
                        }
 
-                       text_poke(text_poke_addr(&tp[i]) + INT3_INSN_SIZE,
+                       text_poke(text_poke_addr(&text_poke_array.vec[i]) + INT3_INSN_SIZE,
                                  new + INT3_INSN_SIZE,
                                  len - INT3_INSN_SIZE);
 
@@ -2705,7 +2702,7 @@ static void smp_text_poke_batch_process(struct smp_text_poke_loc *tp, unsigned i
                 * The old instruction is recorded so that the event can be
                 * processed forwards or backwards.
                 */
-               perf_event_text_poke(text_poke_addr(&tp[i]), old, len, new, len);
+               perf_event_text_poke(text_poke_addr(&text_poke_array.vec[i]), old, len, new, len);
        }
 
        if (do_sync) {
@@ -2721,16 +2718,16 @@ static void smp_text_poke_batch_process(struct smp_text_poke_loc *tp, unsigned i
         * Third step: replace the first byte (int3) by the first byte of
         * replacing opcode.
         */
-       for (do_sync = 0, i = 0; i < nr_entries; i++) {
-               u8 byte = tp[i].text[0];
+       for (do_sync = 0, i = 0; i < text_poke_array.nr_entries; i++) {
+               u8 byte = text_poke_array.vec[i].text[0];
 
-               if (tp[i].len == 6)
+               if (text_poke_array.vec[i].len == 6)
                        byte = 0x0f;
 
                if (byte == INT3_INSN_OPCODE)
                        continue;
 
-               text_poke(text_poke_addr(&tp[i]), &byte, INT3_INSN_SIZE);
+               text_poke(text_poke_addr(&text_poke_array.vec[i]), &byte, INT3_INSN_SIZE);
                do_sync++;
        }
 
@@ -2859,7 +2856,7 @@ static bool text_poke_addr_ordered(void *addr)
 void smp_text_poke_batch_finish(void)
 {
        if (text_poke_array.nr_entries) {
-               smp_text_poke_batch_process(text_poke_array.vec, text_poke_array.nr_entries);
+               smp_text_poke_batch_process();
                text_poke_array.nr_entries = 0;
        }
 }
@@ -2869,7 +2866,7 @@ static void smp_text_poke_batch_flush(void *addr)
        lockdep_assert_held(&text_mutex);
 
        if (text_poke_array.nr_entries == TP_ARRAY_NR_ENTRIES_MAX || !text_poke_addr_ordered(addr)) {
-               smp_text_poke_batch_process(text_poke_array.vec, text_poke_array.nr_entries);
+               smp_text_poke_batch_process();
                text_poke_array.nr_entries = 0;
        }
 }