1 files changed, 57 insertions, 66 deletions

diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c
index 5ba8477c2cb7..a7949a54a0ff 100644
--- a/arch/x86/kernel/jump_label.c
+++ b/arch/x86/kernel/jump_label.c
@@ -15,54 +15,76 @@
 #include <asm/kprobes.h>
 #include <asm/alternative.h>
 #include <asm/text-patching.h>
+#include <asm/insn.h>
 
-static void bug_at(const void *ip, int line)
+int arch_jump_entry_size(struct jump_entry *entry)
 {
-	/*
-	 * The location is not an op that we were expecting.
-	 * Something went wrong. Crash the box, as something could be
-	 * corrupting the kernel.
-	 */
-	pr_crit("jump_label: Fatal kernel bug, unexpected op at %pS [%p] (%5ph) %d\n", ip, ip, ip, line);
-	BUG();
+	struct insn insn = {};
+
+	insn_decode_kernel(&insn, (void *)jump_entry_code(entry));
+	BUG_ON(insn.length != 2 && insn.length != 5);
+
+	return insn.length;
 }
 
-static const void *
-__jump_label_set_jump_code(struct jump_entry *entry, enum jump_label_type type, int init)
+struct jump_label_patch {
+	const void *code;
+	int size;
+};
+
+static struct jump_label_patch
+__jump_label_patch(struct jump_entry *entry, enum jump_label_type type)
 {
-	const unsigned char default_nop[] = { STATIC_KEY_INIT_NOP };
-	const unsigned char *ideal_nop = ideal_nops[NOP_ATOMIC5];
-	const void *expect, *code;
+	const void *expect, *code, *nop;
 	const void *addr, *dest;
-	int line;
+	int size;
 
 	addr = (void *)jump_entry_code(entry);
 	dest = (void *)jump_entry_target(entry);
 
-	code = text_gen_insn(JMP32_INSN_OPCODE, addr, dest);
+	size = arch_jump_entry_size(entry);
+	switch (size) {
+	case JMP8_INSN_SIZE:
+		code = text_gen_insn(JMP8_INSN_OPCODE, addr, dest);
+		nop = x86_nops[size];
+		break;
 
-	if (init) {
-		expect = default_nop; line = __LINE__;
-	} else if (type == JUMP_LABEL_JMP) {
-		expect = ideal_nop; line = __LINE__;
-	} else {
-		expect = code; line = __LINE__;
+	case JMP32_INSN_SIZE:
+		code = text_gen_insn(JMP32_INSN_OPCODE, addr, dest);
+		nop = x86_nops[size];
+		break;
+
+	default: BUG();
 	}
 
-	if (memcmp(addr, expect, JUMP_LABEL_NOP_SIZE))
-		bug_at(addr, line);
+	if (type == JUMP_LABEL_JMP)
+		expect = nop;
+	else
+		expect = code;
+
+	if (memcmp(addr, expect, size)) {
+		/*
+		 * The location is not an op that we were expecting.
+		 * Something went wrong. Crash the box, as something could be
+		 * corrupting the kernel.
+		 */
+		pr_crit("jump_label: Fatal kernel bug, unexpected op at %pS [%p] (%5ph != %5ph)) size:%d type:%d\n",
+				addr, addr, addr, expect, size, type);
+		BUG();
+	}
 
 	if (type == JUMP_LABEL_NOP)
-		code = ideal_nop;
+		code = nop;
 
-	return code;
+	return (struct jump_label_patch){.code = code, .size = size};
 }
 
-static inline void __jump_label_transform(struct jump_entry *entry,
-					  enum jump_label_type type,
-					  int init)
+static __always_inline void
+__jump_label_transform(struct jump_entry *entry,
+		       enum jump_label_type type,
+		       int init)
 {
-	const void *opcode = __jump_label_set_jump_code(entry, type, init);
+	const struct jump_label_patch jlp = __jump_label_patch(entry, type);
 
 	/*
 	 * As long as only a single processor is running and the code is still
@@ -76,12 +98,11 @@ static inline void __jump_label_transform(struct jump_entry *entry,
 	 * always nop being the 'currently valid' instruction
 	 */
 	if (init || system_state == SYSTEM_BOOTING) {
-		text_poke_early((void *)jump_entry_code(entry), opcode,
-				JUMP_LABEL_NOP_SIZE);
+		text_poke_early((void *)jump_entry_code(entry), jlp.code, jlp.size);
 		return;
 	}
 
-	text_poke_bp((void *)jump_entry_code(entry), opcode, JUMP_LABEL_NOP_SIZE, NULL);
+	smp_text_poke_single((void *)jump_entry_code(entry), jlp.code, jlp.size, NULL);
 }
 
 static void __ref jump_label_transform(struct jump_entry *entry,
@@ -102,7 +123,7 @@ void arch_jump_label_transform(struct jump_entry *entry,
 bool arch_jump_label_transform_queue(struct jump_entry *entry,
 				     enum jump_label_type type)
 {
-	const void *opcode;
+	struct jump_label_patch jlp;
 
 	if (system_state == SYSTEM_BOOTING) {
 		/*
@@ -113,9 +134,8 @@ bool arch_jump_label_transform_queue(struct jump_entry *entry,
 	}
 
 	mutex_lock(&text_mutex);
-	opcode = __jump_label_set_jump_code(entry, type, 0);
-	text_poke_queue((void *)jump_entry_code(entry),
-			opcode, JUMP_LABEL_NOP_SIZE, NULL);
+	jlp = __jump_label_patch(entry, type);
+	smp_text_poke_batch_add((void *)jump_entry_code(entry), jlp.code, jlp.size, NULL);
 	mutex_unlock(&text_mutex);
 	return true;
 }
@@ -123,35 +143,6 @@ bool arch_jump_label_transform_queue(struct jump_entry *entry,
 void arch_jump_label_transform_apply(void)
 {
 	mutex_lock(&text_mutex);
-	text_poke_finish();
+	smp_text_poke_batch_finish();
 	mutex_unlock(&text_mutex);
 }
-
-static enum {
-	JL_STATE_START,
-	JL_STATE_NO_UPDATE,
-	JL_STATE_UPDATE,
-} jlstate __initdata_or_module = JL_STATE_START;
-
-__init_or_module void arch_jump_label_transform_static(struct jump_entry *entry,
-				      enum jump_label_type type)
-{
-	/*
-	 * This function is called at boot up and when modules are
-	 * first loaded. Check if the default nop, the one that is
-	 * inserted at compile time, is the ideal nop. If it is, then
-	 * we do not need to update the nop, and we can leave it as is.
-	 * If it is not, then we need to update the nop to the ideal nop.
-	 */
-	if (jlstate == JL_STATE_START) {
-		const unsigned char default_nop[] = { STATIC_KEY_INIT_NOP };
-		const unsigned char *ideal_nop = ideal_nops[NOP_ATOMIC5];
-
-		if (memcmp(ideal_nop, default_nop, 5) != 0)
-			jlstate = JL_STATE_UPDATE;
-		else
-			jlstate = JL_STATE_NO_UPDATE;
-	}
-	if (jlstate == JL_STATE_UPDATE)
-		jump_label_transform(entry, type, 1);
-}