1 files changed, 23 insertions, 61 deletions

diff --git a/arch/s390/kernel/alternative.c b/arch/s390/kernel/alternative.c
index 8e1f2aee85ef..e7bca29f9c34 100644
--- a/arch/s390/kernel/alternative.c
+++ b/arch/s390/kernel/alternative.c
@@ -1,11 +1,12 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <linux/module.h>
+#include <linux/cpu.h>
+#include <linux/smp.h>
+#include <asm/text-patching.h>
 #include <asm/alternative.h>
 #include <asm/facility.h>
 #include <asm/nospec-branch.h>
 
-#define MAX_PATCH_LEN (255 - 1)
-
 static int __initdata_or_module alt_instr_disabled;
 
 static int __init disable_alternative_instructions(char *str)
@@ -16,86 +17,30 @@ static int __init disable_alternative_instructions(char *str)
 
 early_param("noaltinstr", disable_alternative_instructions);
 
-struct brcl_insn {
-	u16 opc;
-	s32 disp;
-} __packed;
-
-static u16 __initdata_or_module nop16 = 0x0700;
-static u32 __initdata_or_module nop32 = 0x47000000;
-static struct brcl_insn __initdata_or_module nop48 = {
-	0xc004, 0
-};
-
-static const void *nops[] __initdata_or_module = {
-	&nop16,
-	&nop32,
-	&nop48
-};
-
-static void __init_or_module add_jump_padding(void *insns, unsigned int len)
-{
-	struct brcl_insn brcl = {
-		0xc0f4,
-		len / 2
-	};
-
-	memcpy(insns, &brcl, sizeof(brcl));
-	insns += sizeof(brcl);
-	len -= sizeof(brcl);
-
-	while (len > 0) {
-		memcpy(insns, &nop16, 2);
-		insns += 2;
-		len -= 2;
-	}
-}
-
-static void __init_or_module add_padding(void *insns, unsigned int len)
-{
-	if (len > 6)
-		add_jump_padding(insns, len);
-	else if (len >= 2)
-		memcpy(insns, nops[len / 2 - 1], len);
-}
-
 static void __init_or_module __apply_alternatives(struct alt_instr *start,
 						  struct alt_instr *end)
 {
 	struct alt_instr *a;
 	u8 *instr, *replacement;
-	u8 insnbuf[MAX_PATCH_LEN];
 
 	/*
 	 * The scan order should be from start to end. A later scanned
 	 * alternative code can overwrite previously scanned alternative code.
 	 */
 	for (a = start; a < end; a++) {
-		int insnbuf_sz = 0;
-
 		instr = (u8 *)&a->instr_offset + a->instr_offset;
 		replacement = (u8 *)&a->repl_offset + a->repl_offset;
 
-		if (!__test_facility(a->facility,
-				     S390_lowcore.alt_stfle_fac_list))
+		if (!__test_facility(a->facility, alt_stfle_fac_list))
 			continue;
 
-		if (unlikely(a->instrlen % 2 || a->replacementlen % 2)) {
+		if (unlikely(a->instrlen % 2)) {
 			WARN_ONCE(1, "cpu alternatives instructions length is "
 				     "odd, skipping patching\n");
 			continue;
 		}
 
-		memcpy(insnbuf, replacement, a->replacementlen);
-		insnbuf_sz = a->replacementlen;
-
-		if (a->instrlen > a->replacementlen) {
-			add_padding(insnbuf + a->replacementlen,
-				    a->instrlen - a->replacementlen);
-			insnbuf_sz += a->instrlen - a->replacementlen;
-		}
-
-		s390_kernel_write(instr, insnbuf, insnbuf_sz);
+		s390_kernel_write(instr, replacement, a->instrlen);
 	}
 }
 
@@ -111,3 +56,20 @@ void __init apply_alternative_instructions(void)
 {
 	apply_alternatives(__alt_instructions, __alt_instructions_end);
 }
+
+static void do_sync_core(void *info)
+{
+	sync_core();
+}
+
+void text_poke_sync(void)
+{
+	on_each_cpu(do_sync_core, NULL, 1);
+}
+
+void text_poke_sync_lock(void)
+{
+	cpus_read_lock();
+	text_poke_sync();
+	cpus_read_unlock();
+}