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d9f5ab7b JB |
1 | /* |
2 | * jump label x86 support | |
3 | * | |
4 | * Copyright (C) 2009 Jason Baron <jbaron@redhat.com> | |
5 | * | |
6 | */ | |
7 | #include <linux/jump_label.h> | |
8 | #include <linux/memory.h> | |
9 | #include <linux/uaccess.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/list.h> | |
12 | #include <linux/jhash.h> | |
13 | #include <linux/cpu.h> | |
14 | #include <asm/kprobes.h> | |
15 | #include <asm/alternative.h> | |
16 | ||
17 | #ifdef HAVE_JUMP_LABEL | |
18 | ||
19 | union jump_code_union { | |
20 | char code[JUMP_LABEL_NOP_SIZE]; | |
21 | struct { | |
22 | char jump; | |
23 | int offset; | |
24 | } __attribute__((packed)); | |
25 | }; | |
26 | ||
e71a5be1 JF |
27 | static void __jump_label_transform(struct jump_entry *entry, |
28 | enum jump_label_type type, | |
29 | void *(*poker)(void *, const void *, size_t)) | |
d9f5ab7b JB |
30 | { |
31 | union jump_code_union code; | |
32 | ||
33 | if (type == JUMP_LABEL_ENABLE) { | |
34 | code.jump = 0xe9; | |
35 | code.offset = entry->target - | |
36 | (entry->code + JUMP_LABEL_NOP_SIZE); | |
37 | } else | |
dc326fca | 38 | memcpy(&code, ideal_nops[NOP_ATOMIC5], JUMP_LABEL_NOP_SIZE); |
e71a5be1 JF |
39 | |
40 | (*poker)((void *)entry->code, &code, JUMP_LABEL_NOP_SIZE); | |
41 | } | |
42 | ||
43 | void arch_jump_label_transform(struct jump_entry *entry, | |
44 | enum jump_label_type type) | |
45 | { | |
d9f5ab7b JB |
46 | get_online_cpus(); |
47 | mutex_lock(&text_mutex); | |
e71a5be1 | 48 | __jump_label_transform(entry, type, text_poke_smp); |
d9f5ab7b JB |
49 | mutex_unlock(&text_mutex); |
50 | put_online_cpus(); | |
51 | } | |
52 | ||
9cdbe1cb | 53 | __init_or_module void arch_jump_label_transform_static(struct jump_entry *entry, |
e71a5be1 JF |
54 | enum jump_label_type type) |
55 | { | |
56 | __jump_label_transform(entry, type, text_poke_early); | |
57 | } | |
58 | ||
d9f5ab7b | 59 | #endif |