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Diffstat (limited to 'arch/x86/kernel/jump_label.c')
-rw-r--r--arch/x86/kernel/jump_label.c59
1 files changed, 59 insertions, 0 deletions
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