From 8e4bff4cab0ddac6060645b0715210484d02ff40 Mon Sep 17 00:00:00 2001
From: Yuval Adam <_@yuv.al>
Date: Wed, 30 Aug 2017 08:25:59 +0000
Subject: Initial file dump from open source release

---
 arch/x86/kernel/jump_label.c | 59 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)
 create mode 100644 arch/x86/kernel/jump_label.c

(limited to 'arch/x86/kernel/jump_label.c')

diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c
new file mode 100644
index 00000000..2889b3d4
--- /dev/null
+++ b/arch/x86/kernel/jump_label.c
@@ -0,0 +1,59 @@
+/*
+ * jump label x86 support
+ *
+ * Copyright (C) 2009 Jason Baron <jbaron@redhat.com>
+ *
+ */
+#include <linux/jump_label.h>
+#include <linux/memory.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/jhash.h>
+#include <linux/cpu.h>
+#include <asm/kprobes.h>
+#include <asm/alternative.h>
+
+#ifdef HAVE_JUMP_LABEL
+
+union jump_code_union {
+	char code[JUMP_LABEL_NOP_SIZE];
+	struct {
+		char jump;
+		int offset;
+	} __attribute__((packed));
+};
+
+static void __jump_label_transform(struct jump_entry *entry,
+				   enum jump_label_type type,
+				   void *(*poker)(void *, const void *, size_t))
+{
+	union jump_code_union code;
+
+	if (type == JUMP_LABEL_ENABLE) {
+		code.jump = 0xe9;
+		code.offset = entry->target -
+				(entry->code + JUMP_LABEL_NOP_SIZE);
+	} else
+		memcpy(&code, ideal_nops[NOP_ATOMIC5], JUMP_LABEL_NOP_SIZE);
+
+	(*poker)((void *)entry->code, &code, JUMP_LABEL_NOP_SIZE);
+}
+
+void arch_jump_label_transform(struct jump_entry *entry,
+			       enum jump_label_type type)
+{
+	get_online_cpus();
+	mutex_lock(&text_mutex);
+	__jump_label_transform(entry, type, text_poke_smp);
+	mutex_unlock(&text_mutex);
+	put_online_cpus();
+}
+
+__init_or_module void arch_jump_label_transform_static(struct jump_entry *entry,
+				      enum jump_label_type type)
+{
+	__jump_label_transform(entry, type, text_poke_early);
+}
+
+#endif
-- 
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