Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 1 | #include <linux/module.h> |
Al Viro | f6a5703 | 2006-10-18 01:47:25 -0400 | [diff] [blame] | 2 | #include <linux/sched.h> |
Pekka Paalanen | 2f1dafe | 2008-05-12 21:21:01 +0200 | [diff] [blame] | 3 | #include <linux/mutex.h> |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 4 | #include <linux/list.h> |
Jan Beulich | 8b5a10f | 2009-08-19 08:40:48 +0100 | [diff] [blame] | 5 | #include <linux/stringify.h> |
Andi Kleen | 19d36cc | 2007-07-22 11:12:31 +0200 | [diff] [blame] | 6 | #include <linux/kprobes.h> |
| 7 | #include <linux/mm.h> |
| 8 | #include <linux/vmalloc.h> |
Masami Hiramatsu | 3945dab | 2009-03-06 10:37:22 -0500 | [diff] [blame] | 9 | #include <linux/memory.h> |
Masami Hiramatsu | 3d55cc8 | 2010-02-25 08:34:38 -0500 | [diff] [blame] | 10 | #include <linux/stop_machine.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 11 | #include <linux/slab.h> |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 12 | #include <asm/alternative.h> |
| 13 | #include <asm/sections.h> |
Andi Kleen | 19d36cc | 2007-07-22 11:12:31 +0200 | [diff] [blame] | 14 | #include <asm/pgtable.h> |
Andi Kleen | 8f4e956 | 2007-07-22 11:12:32 +0200 | [diff] [blame] | 15 | #include <asm/mce.h> |
| 16 | #include <asm/nmi.h> |
Dave Jones | b097976 | 2007-10-14 22:57:45 +0200 | [diff] [blame] | 17 | #include <asm/vsyscall.h> |
Mathieu Desnoyers | e587cad | 2008-03-06 08:48:49 -0500 | [diff] [blame] | 18 | #include <asm/cacheflush.h> |
Masami Hiramatsu | 78ff7fa | 2009-03-06 10:37:54 -0500 | [diff] [blame] | 19 | #include <asm/tlbflush.h> |
Mathieu Desnoyers | e587cad | 2008-03-06 08:48:49 -0500 | [diff] [blame] | 20 | #include <asm/io.h> |
Masami Hiramatsu | 78ff7fa | 2009-03-06 10:37:54 -0500 | [diff] [blame] | 21 | #include <asm/fixmap.h> |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 22 | |
Andi Kleen | ab144f5 | 2007-08-10 22:31:03 +0200 | [diff] [blame] | 23 | #define MAX_PATCH_LEN (255-1) |
| 24 | |
Jan Beulich | 0948816 | 2007-07-21 17:10:25 +0200 | [diff] [blame] | 25 | #ifdef CONFIG_HOTPLUG_CPU |
| 26 | static int smp_alt_once; |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 27 | |
Gerd Hoffmann | d167a51 | 2006-06-26 13:56:16 +0200 | [diff] [blame] | 28 | static int __init bootonly(char *str) |
| 29 | { |
| 30 | smp_alt_once = 1; |
| 31 | return 1; |
| 32 | } |
Jeremy Fitzhardinge | b7fb4af | 2007-05-02 19:27:13 +0200 | [diff] [blame] | 33 | __setup("smp-alt-boot", bootonly); |
Jan Beulich | 0948816 | 2007-07-21 17:10:25 +0200 | [diff] [blame] | 34 | #else |
| 35 | #define smp_alt_once 1 |
| 36 | #endif |
| 37 | |
Jan Beulich | 8b5a10f | 2009-08-19 08:40:48 +0100 | [diff] [blame] | 38 | static int __initdata_or_module debug_alternative; |
Jeremy Fitzhardinge | b7fb4af | 2007-05-02 19:27:13 +0200 | [diff] [blame] | 39 | |
Gerd Hoffmann | d167a51 | 2006-06-26 13:56:16 +0200 | [diff] [blame] | 40 | static int __init debug_alt(char *str) |
| 41 | { |
| 42 | debug_alternative = 1; |
| 43 | return 1; |
| 44 | } |
Gerd Hoffmann | d167a51 | 2006-06-26 13:56:16 +0200 | [diff] [blame] | 45 | __setup("debug-alternative", debug_alt); |
| 46 | |
Jan Beulich | 0948816 | 2007-07-21 17:10:25 +0200 | [diff] [blame] | 47 | static int noreplace_smp; |
| 48 | |
Jeremy Fitzhardinge | b7fb4af | 2007-05-02 19:27:13 +0200 | [diff] [blame] | 49 | static int __init setup_noreplace_smp(char *str) |
| 50 | { |
| 51 | noreplace_smp = 1; |
| 52 | return 1; |
| 53 | } |
| 54 | __setup("noreplace-smp", setup_noreplace_smp); |
| 55 | |
Jeremy Fitzhardinge | 959b4fd | 2007-05-02 19:27:16 +0200 | [diff] [blame] | 56 | #ifdef CONFIG_PARAVIRT |
Jan Beulich | 8b5a10f | 2009-08-19 08:40:48 +0100 | [diff] [blame] | 57 | static int __initdata_or_module noreplace_paravirt = 0; |
Jeremy Fitzhardinge | 959b4fd | 2007-05-02 19:27:16 +0200 | [diff] [blame] | 58 | |
| 59 | static int __init setup_noreplace_paravirt(char *str) |
| 60 | { |
| 61 | noreplace_paravirt = 1; |
| 62 | return 1; |
| 63 | } |
| 64 | __setup("noreplace-paravirt", setup_noreplace_paravirt); |
| 65 | #endif |
Jeremy Fitzhardinge | b7fb4af | 2007-05-02 19:27:13 +0200 | [diff] [blame] | 66 | |
Gerd Hoffmann | d167a51 | 2006-06-26 13:56:16 +0200 | [diff] [blame] | 67 | #define DPRINTK(fmt, args...) if (debug_alternative) \ |
| 68 | printk(KERN_DEBUG fmt, args) |
| 69 | |
Jan Beulich | 8b5a10f | 2009-08-19 08:40:48 +0100 | [diff] [blame] | 70 | #if defined(GENERIC_NOP1) && !defined(CONFIG_X86_64) |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 71 | /* Use inline assembly to define this because the nops are defined |
| 72 | as inline assembly strings in the include files and we cannot |
| 73 | get them easily into strings. */ |
Jan Beulich | 8b5a10f | 2009-08-19 08:40:48 +0100 | [diff] [blame] | 74 | asm("\t" __stringify(__INITRODATA_OR_MODULE) "\nintelnops: " |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 75 | GENERIC_NOP1 GENERIC_NOP2 GENERIC_NOP3 GENERIC_NOP4 GENERIC_NOP5 GENERIC_NOP6 |
Steven Rostedt | f4be31e | 2008-04-09 19:04:07 -0400 | [diff] [blame] | 76 | GENERIC_NOP7 GENERIC_NOP8 |
| 77 | "\t.previous"); |
Jan Beulich | 121d7bf | 2007-10-17 18:04:37 +0200 | [diff] [blame] | 78 | extern const unsigned char intelnops[]; |
Jan Beulich | 8b5a10f | 2009-08-19 08:40:48 +0100 | [diff] [blame] | 79 | static const unsigned char *const __initconst_or_module |
| 80 | intel_nops[ASM_NOP_MAX+1] = { |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 81 | NULL, |
| 82 | intelnops, |
| 83 | intelnops + 1, |
| 84 | intelnops + 1 + 2, |
| 85 | intelnops + 1 + 2 + 3, |
| 86 | intelnops + 1 + 2 + 3 + 4, |
| 87 | intelnops + 1 + 2 + 3 + 4 + 5, |
| 88 | intelnops + 1 + 2 + 3 + 4 + 5 + 6, |
| 89 | intelnops + 1 + 2 + 3 + 4 + 5 + 6 + 7, |
| 90 | }; |
Gerd Hoffmann | d167a51 | 2006-06-26 13:56:16 +0200 | [diff] [blame] | 91 | #endif |
| 92 | |
| 93 | #ifdef K8_NOP1 |
Jan Beulich | 8b5a10f | 2009-08-19 08:40:48 +0100 | [diff] [blame] | 94 | asm("\t" __stringify(__INITRODATA_OR_MODULE) "\nk8nops: " |
Gerd Hoffmann | d167a51 | 2006-06-26 13:56:16 +0200 | [diff] [blame] | 95 | K8_NOP1 K8_NOP2 K8_NOP3 K8_NOP4 K8_NOP5 K8_NOP6 |
Steven Rostedt | f4be31e | 2008-04-09 19:04:07 -0400 | [diff] [blame] | 96 | K8_NOP7 K8_NOP8 |
| 97 | "\t.previous"); |
Jan Beulich | 121d7bf | 2007-10-17 18:04:37 +0200 | [diff] [blame] | 98 | extern const unsigned char k8nops[]; |
Jan Beulich | 8b5a10f | 2009-08-19 08:40:48 +0100 | [diff] [blame] | 99 | static const unsigned char *const __initconst_or_module |
| 100 | k8_nops[ASM_NOP_MAX+1] = { |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 101 | NULL, |
| 102 | k8nops, |
| 103 | k8nops + 1, |
| 104 | k8nops + 1 + 2, |
| 105 | k8nops + 1 + 2 + 3, |
| 106 | k8nops + 1 + 2 + 3 + 4, |
| 107 | k8nops + 1 + 2 + 3 + 4 + 5, |
| 108 | k8nops + 1 + 2 + 3 + 4 + 5 + 6, |
| 109 | k8nops + 1 + 2 + 3 + 4 + 5 + 6 + 7, |
| 110 | }; |
Gerd Hoffmann | d167a51 | 2006-06-26 13:56:16 +0200 | [diff] [blame] | 111 | #endif |
| 112 | |
Jan Beulich | 8b5a10f | 2009-08-19 08:40:48 +0100 | [diff] [blame] | 113 | #if defined(K7_NOP1) && !defined(CONFIG_X86_64) |
| 114 | asm("\t" __stringify(__INITRODATA_OR_MODULE) "\nk7nops: " |
Gerd Hoffmann | d167a51 | 2006-06-26 13:56:16 +0200 | [diff] [blame] | 115 | K7_NOP1 K7_NOP2 K7_NOP3 K7_NOP4 K7_NOP5 K7_NOP6 |
Steven Rostedt | f4be31e | 2008-04-09 19:04:07 -0400 | [diff] [blame] | 116 | K7_NOP7 K7_NOP8 |
| 117 | "\t.previous"); |
Jan Beulich | 121d7bf | 2007-10-17 18:04:37 +0200 | [diff] [blame] | 118 | extern const unsigned char k7nops[]; |
Jan Beulich | 8b5a10f | 2009-08-19 08:40:48 +0100 | [diff] [blame] | 119 | static const unsigned char *const __initconst_or_module |
| 120 | k7_nops[ASM_NOP_MAX+1] = { |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 121 | NULL, |
| 122 | k7nops, |
| 123 | k7nops + 1, |
| 124 | k7nops + 1 + 2, |
| 125 | k7nops + 1 + 2 + 3, |
| 126 | k7nops + 1 + 2 + 3 + 4, |
| 127 | k7nops + 1 + 2 + 3 + 4 + 5, |
| 128 | k7nops + 1 + 2 + 3 + 4 + 5 + 6, |
| 129 | k7nops + 1 + 2 + 3 + 4 + 5 + 6 + 7, |
| 130 | }; |
Gerd Hoffmann | d167a51 | 2006-06-26 13:56:16 +0200 | [diff] [blame] | 131 | #endif |
| 132 | |
Jan Beulich | 32c464f | 2007-10-17 18:04:41 +0200 | [diff] [blame] | 133 | #ifdef P6_NOP1 |
Jan Beulich | 8b5a10f | 2009-08-19 08:40:48 +0100 | [diff] [blame] | 134 | asm("\t" __stringify(__INITRODATA_OR_MODULE) "\np6nops: " |
Jan Beulich | 32c464f | 2007-10-17 18:04:41 +0200 | [diff] [blame] | 135 | P6_NOP1 P6_NOP2 P6_NOP3 P6_NOP4 P6_NOP5 P6_NOP6 |
Steven Rostedt | f4be31e | 2008-04-09 19:04:07 -0400 | [diff] [blame] | 136 | P6_NOP7 P6_NOP8 |
| 137 | "\t.previous"); |
Jan Beulich | 32c464f | 2007-10-17 18:04:41 +0200 | [diff] [blame] | 138 | extern const unsigned char p6nops[]; |
Jan Beulich | 8b5a10f | 2009-08-19 08:40:48 +0100 | [diff] [blame] | 139 | static const unsigned char *const __initconst_or_module |
| 140 | p6_nops[ASM_NOP_MAX+1] = { |
Jan Beulich | 32c464f | 2007-10-17 18:04:41 +0200 | [diff] [blame] | 141 | NULL, |
| 142 | p6nops, |
| 143 | p6nops + 1, |
| 144 | p6nops + 1 + 2, |
| 145 | p6nops + 1 + 2 + 3, |
| 146 | p6nops + 1 + 2 + 3 + 4, |
| 147 | p6nops + 1 + 2 + 3 + 4 + 5, |
| 148 | p6nops + 1 + 2 + 3 + 4 + 5 + 6, |
| 149 | p6nops + 1 + 2 + 3 + 4 + 5 + 6 + 7, |
| 150 | }; |
| 151 | #endif |
| 152 | |
Gerd Hoffmann | d167a51 | 2006-06-26 13:56:16 +0200 | [diff] [blame] | 153 | #ifdef CONFIG_X86_64 |
| 154 | |
| 155 | extern char __vsyscall_0; |
Jan Beulich | 8b5a10f | 2009-08-19 08:40:48 +0100 | [diff] [blame] | 156 | static const unsigned char *const *__init_or_module find_nop_table(void) |
Gerd Hoffmann | d167a51 | 2006-06-26 13:56:16 +0200 | [diff] [blame] | 157 | { |
H. Peter Anvin | f31d731 | 2008-08-18 17:50:33 -0700 | [diff] [blame] | 158 | if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && |
| 159 | boot_cpu_has(X86_FEATURE_NOPL)) |
| 160 | return p6_nops; |
| 161 | else |
| 162 | return k8_nops; |
Gerd Hoffmann | d167a51 | 2006-06-26 13:56:16 +0200 | [diff] [blame] | 163 | } |
| 164 | |
| 165 | #else /* CONFIG_X86_64 */ |
| 166 | |
Jan Beulich | 8b5a10f | 2009-08-19 08:40:48 +0100 | [diff] [blame] | 167 | static const unsigned char *const *__init_or_module find_nop_table(void) |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 168 | { |
H. Peter Anvin | f31d731 | 2008-08-18 17:50:33 -0700 | [diff] [blame] | 169 | if (boot_cpu_has(X86_FEATURE_K8)) |
| 170 | return k8_nops; |
| 171 | else if (boot_cpu_has(X86_FEATURE_K7)) |
| 172 | return k7_nops; |
| 173 | else if (boot_cpu_has(X86_FEATURE_NOPL)) |
| 174 | return p6_nops; |
| 175 | else |
| 176 | return intel_nops; |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 177 | } |
| 178 | |
Gerd Hoffmann | d167a51 | 2006-06-26 13:56:16 +0200 | [diff] [blame] | 179 | #endif /* CONFIG_X86_64 */ |
| 180 | |
Andi Kleen | ab144f5 | 2007-08-10 22:31:03 +0200 | [diff] [blame] | 181 | /* Use this to add nops to a buffer, then text_poke the whole buffer. */ |
Jan Beulich | 8b5a10f | 2009-08-19 08:40:48 +0100 | [diff] [blame] | 182 | static void __init_or_module add_nops(void *insns, unsigned int len) |
Rusty Russell | 139ec7c | 2006-12-07 02:14:08 +0100 | [diff] [blame] | 183 | { |
Jan Beulich | 121d7bf | 2007-10-17 18:04:37 +0200 | [diff] [blame] | 184 | const unsigned char *const *noptable = find_nop_table(); |
Rusty Russell | 139ec7c | 2006-12-07 02:14:08 +0100 | [diff] [blame] | 185 | |
| 186 | while (len > 0) { |
| 187 | unsigned int noplen = len; |
| 188 | if (noplen > ASM_NOP_MAX) |
| 189 | noplen = ASM_NOP_MAX; |
Andi Kleen | ab144f5 | 2007-08-10 22:31:03 +0200 | [diff] [blame] | 190 | memcpy(insns, noptable[noplen], noplen); |
Rusty Russell | 139ec7c | 2006-12-07 02:14:08 +0100 | [diff] [blame] | 191 | insns += noplen; |
| 192 | len -= noplen; |
| 193 | } |
| 194 | } |
| 195 | |
Gerd Hoffmann | d167a51 | 2006-06-26 13:56:16 +0200 | [diff] [blame] | 196 | extern struct alt_instr __alt_instructions[], __alt_instructions_end[]; |
Jan Beulich | 5967ed8 | 2010-04-21 16:08:14 +0100 | [diff] [blame] | 197 | extern s32 __smp_locks[], __smp_locks_end[]; |
Jason Baron | fa6f2cc | 2010-09-17 11:08:56 -0400 | [diff] [blame] | 198 | void *text_poke_early(void *addr, const void *opcode, size_t len); |
Gerd Hoffmann | d167a51 | 2006-06-26 13:56:16 +0200 | [diff] [blame] | 199 | |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 200 | /* Replace instructions with better alternatives for this CPU type. |
| 201 | This runs before SMP is initialized to avoid SMP problems with |
| 202 | self modifying code. This implies that assymetric systems where |
| 203 | APs have less capabilities than the boot processor are not handled. |
| 204 | Tough. Make sure you disable such features by hand. */ |
| 205 | |
Jan Beulich | 8b5a10f | 2009-08-19 08:40:48 +0100 | [diff] [blame] | 206 | void __init_or_module apply_alternatives(struct alt_instr *start, |
| 207 | struct alt_instr *end) |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 208 | { |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 209 | struct alt_instr *a; |
Jan Beulich | 1b1d925 | 2009-12-18 16:12:56 +0000 | [diff] [blame] | 210 | u8 insnbuf[MAX_PATCH_LEN]; |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 211 | |
Harvey Harrison | 77bf90e | 2008-03-03 11:37:23 -0800 | [diff] [blame] | 212 | DPRINTK("%s: alt table %p -> %p\n", __func__, start, end); |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 213 | for (a = start; a < end; a++) { |
Andi Kleen | ab144f5 | 2007-08-10 22:31:03 +0200 | [diff] [blame] | 214 | u8 *instr = a->instr; |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 215 | BUG_ON(a->replacementlen > a->instrlen); |
Andi Kleen | ab144f5 | 2007-08-10 22:31:03 +0200 | [diff] [blame] | 216 | BUG_ON(a->instrlen > sizeof(insnbuf)); |
H. Peter Anvin | 3b770a2 | 2010-07-13 14:57:50 -0700 | [diff] [blame] | 217 | BUG_ON(a->cpuid >= NCAPINTS*32); |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 218 | if (!boot_cpu_has(a->cpuid)) |
| 219 | continue; |
Gerd Hoffmann | d167a51 | 2006-06-26 13:56:16 +0200 | [diff] [blame] | 220 | #ifdef CONFIG_X86_64 |
| 221 | /* vsyscall code is not mapped yet. resolve it manually. */ |
| 222 | if (instr >= (u8 *)VSYSCALL_START && instr < (u8*)VSYSCALL_END) { |
| 223 | instr = __va(instr - (u8*)VSYSCALL_START + (u8*)__pa_symbol(&__vsyscall_0)); |
| 224 | DPRINTK("%s: vsyscall fixup: %p => %p\n", |
Harvey Harrison | 77bf90e | 2008-03-03 11:37:23 -0800 | [diff] [blame] | 225 | __func__, a->instr, instr); |
Gerd Hoffmann | d167a51 | 2006-06-26 13:56:16 +0200 | [diff] [blame] | 226 | } |
| 227 | #endif |
Andi Kleen | ab144f5 | 2007-08-10 22:31:03 +0200 | [diff] [blame] | 228 | memcpy(insnbuf, a->replacement, a->replacementlen); |
Jan Beulich | 1b1d925 | 2009-12-18 16:12:56 +0000 | [diff] [blame] | 229 | if (*insnbuf == 0xe8 && a->replacementlen == 5) |
| 230 | *(s32 *)(insnbuf + 1) += a->replacement - a->instr; |
Andi Kleen | ab144f5 | 2007-08-10 22:31:03 +0200 | [diff] [blame] | 231 | add_nops(insnbuf + a->replacementlen, |
| 232 | a->instrlen - a->replacementlen); |
Mathieu Desnoyers | e587cad | 2008-03-06 08:48:49 -0500 | [diff] [blame] | 233 | text_poke_early(instr, insnbuf, a->instrlen); |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 234 | } |
| 235 | } |
| 236 | |
Gerd Hoffmann | 8ec4d41 | 2006-07-01 04:36:18 -0700 | [diff] [blame] | 237 | #ifdef CONFIG_SMP |
| 238 | |
Jan Beulich | 5967ed8 | 2010-04-21 16:08:14 +0100 | [diff] [blame] | 239 | static void alternatives_smp_lock(const s32 *start, const s32 *end, |
| 240 | u8 *text, u8 *text_end) |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 241 | { |
Jan Beulich | 5967ed8 | 2010-04-21 16:08:14 +0100 | [diff] [blame] | 242 | const s32 *poff; |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 243 | |
Masami Hiramatsu | 3945dab | 2009-03-06 10:37:22 -0500 | [diff] [blame] | 244 | mutex_lock(&text_mutex); |
Jan Beulich | 5967ed8 | 2010-04-21 16:08:14 +0100 | [diff] [blame] | 245 | for (poff = start; poff < end; poff++) { |
| 246 | u8 *ptr = (u8 *)poff + *poff; |
| 247 | |
| 248 | if (!*poff || ptr < text || ptr >= text_end) |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 249 | continue; |
Mathieu Desnoyers | f88f07e | 2008-08-14 16:58:15 -0400 | [diff] [blame] | 250 | /* turn DS segment override prefix into lock prefix */ |
H. Peter Anvin | d9c5841 | 2010-04-29 16:53:17 -0700 | [diff] [blame] | 251 | if (*ptr == 0x3e) |
| 252 | text_poke(ptr, ((unsigned char []){0xf0}), 1); |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 253 | }; |
Masami Hiramatsu | 3945dab | 2009-03-06 10:37:22 -0500 | [diff] [blame] | 254 | mutex_unlock(&text_mutex); |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 255 | } |
| 256 | |
Jan Beulich | 5967ed8 | 2010-04-21 16:08:14 +0100 | [diff] [blame] | 257 | static void alternatives_smp_unlock(const s32 *start, const s32 *end, |
| 258 | u8 *text, u8 *text_end) |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 259 | { |
Jan Beulich | 5967ed8 | 2010-04-21 16:08:14 +0100 | [diff] [blame] | 260 | const s32 *poff; |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 261 | |
Jeremy Fitzhardinge | b7fb4af | 2007-05-02 19:27:13 +0200 | [diff] [blame] | 262 | if (noreplace_smp) |
| 263 | return; |
| 264 | |
Masami Hiramatsu | 3945dab | 2009-03-06 10:37:22 -0500 | [diff] [blame] | 265 | mutex_lock(&text_mutex); |
Jan Beulich | 5967ed8 | 2010-04-21 16:08:14 +0100 | [diff] [blame] | 266 | for (poff = start; poff < end; poff++) { |
| 267 | u8 *ptr = (u8 *)poff + *poff; |
| 268 | |
| 269 | if (!*poff || ptr < text || ptr >= text_end) |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 270 | continue; |
Mathieu Desnoyers | f88f07e | 2008-08-14 16:58:15 -0400 | [diff] [blame] | 271 | /* turn lock prefix into DS segment override prefix */ |
H. Peter Anvin | d9c5841 | 2010-04-29 16:53:17 -0700 | [diff] [blame] | 272 | if (*ptr == 0xf0) |
| 273 | text_poke(ptr, ((unsigned char []){0x3E}), 1); |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 274 | }; |
Masami Hiramatsu | 3945dab | 2009-03-06 10:37:22 -0500 | [diff] [blame] | 275 | mutex_unlock(&text_mutex); |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 276 | } |
| 277 | |
| 278 | struct smp_alt_module { |
| 279 | /* what is this ??? */ |
| 280 | struct module *mod; |
| 281 | char *name; |
| 282 | |
| 283 | /* ptrs to lock prefixes */ |
Jan Beulich | 5967ed8 | 2010-04-21 16:08:14 +0100 | [diff] [blame] | 284 | const s32 *locks; |
| 285 | const s32 *locks_end; |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 286 | |
| 287 | /* .text segment, needed to avoid patching init code ;) */ |
| 288 | u8 *text; |
| 289 | u8 *text_end; |
| 290 | |
| 291 | struct list_head next; |
| 292 | }; |
| 293 | static LIST_HEAD(smp_alt_modules); |
Pekka Paalanen | 2f1dafe | 2008-05-12 21:21:01 +0200 | [diff] [blame] | 294 | static DEFINE_MUTEX(smp_alt); |
Andi Kleen | ca74a6f | 2008-01-30 13:33:17 +0100 | [diff] [blame] | 295 | static int smp_mode = 1; /* protected by smp_alt */ |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 296 | |
Jan Beulich | 8b5a10f | 2009-08-19 08:40:48 +0100 | [diff] [blame] | 297 | void __init_or_module alternatives_smp_module_add(struct module *mod, |
| 298 | char *name, |
| 299 | void *locks, void *locks_end, |
| 300 | void *text, void *text_end) |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 301 | { |
| 302 | struct smp_alt_module *smp; |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 303 | |
Jeremy Fitzhardinge | b7fb4af | 2007-05-02 19:27:13 +0200 | [diff] [blame] | 304 | if (noreplace_smp) |
| 305 | return; |
| 306 | |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 307 | if (smp_alt_once) { |
| 308 | if (boot_cpu_has(X86_FEATURE_UP)) |
| 309 | alternatives_smp_unlock(locks, locks_end, |
| 310 | text, text_end); |
| 311 | return; |
| 312 | } |
| 313 | |
| 314 | smp = kzalloc(sizeof(*smp), GFP_KERNEL); |
| 315 | if (NULL == smp) |
| 316 | return; /* we'll run the (safe but slow) SMP code then ... */ |
| 317 | |
| 318 | smp->mod = mod; |
| 319 | smp->name = name; |
| 320 | smp->locks = locks; |
| 321 | smp->locks_end = locks_end; |
| 322 | smp->text = text; |
| 323 | smp->text_end = text_end; |
| 324 | DPRINTK("%s: locks %p -> %p, text %p -> %p, name %s\n", |
Harvey Harrison | 77bf90e | 2008-03-03 11:37:23 -0800 | [diff] [blame] | 325 | __func__, smp->locks, smp->locks_end, |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 326 | smp->text, smp->text_end, smp->name); |
| 327 | |
Pekka Paalanen | 2f1dafe | 2008-05-12 21:21:01 +0200 | [diff] [blame] | 328 | mutex_lock(&smp_alt); |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 329 | list_add_tail(&smp->next, &smp_alt_modules); |
| 330 | if (boot_cpu_has(X86_FEATURE_UP)) |
| 331 | alternatives_smp_unlock(smp->locks, smp->locks_end, |
| 332 | smp->text, smp->text_end); |
Pekka Paalanen | 2f1dafe | 2008-05-12 21:21:01 +0200 | [diff] [blame] | 333 | mutex_unlock(&smp_alt); |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 334 | } |
| 335 | |
Jan Beulich | 8b5a10f | 2009-08-19 08:40:48 +0100 | [diff] [blame] | 336 | void __init_or_module alternatives_smp_module_del(struct module *mod) |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 337 | { |
| 338 | struct smp_alt_module *item; |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 339 | |
Jeremy Fitzhardinge | b7fb4af | 2007-05-02 19:27:13 +0200 | [diff] [blame] | 340 | if (smp_alt_once || noreplace_smp) |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 341 | return; |
| 342 | |
Pekka Paalanen | 2f1dafe | 2008-05-12 21:21:01 +0200 | [diff] [blame] | 343 | mutex_lock(&smp_alt); |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 344 | list_for_each_entry(item, &smp_alt_modules, next) { |
| 345 | if (mod != item->mod) |
| 346 | continue; |
| 347 | list_del(&item->next); |
Pekka Paalanen | 2f1dafe | 2008-05-12 21:21:01 +0200 | [diff] [blame] | 348 | mutex_unlock(&smp_alt); |
Harvey Harrison | 77bf90e | 2008-03-03 11:37:23 -0800 | [diff] [blame] | 349 | DPRINTK("%s: %s\n", __func__, item->name); |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 350 | kfree(item); |
| 351 | return; |
| 352 | } |
Pekka Paalanen | 2f1dafe | 2008-05-12 21:21:01 +0200 | [diff] [blame] | 353 | mutex_unlock(&smp_alt); |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 354 | } |
| 355 | |
Suresh Siddha | 3fb82d5 | 2010-11-23 16:11:40 -0800 | [diff] [blame] | 356 | bool skip_smp_alternatives; |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 357 | void alternatives_smp_switch(int smp) |
| 358 | { |
| 359 | struct smp_alt_module *mod; |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 360 | |
Ingo Molnar | 3047e99 | 2006-07-03 00:24:57 -0700 | [diff] [blame] | 361 | #ifdef CONFIG_LOCKDEP |
| 362 | /* |
Ingo Molnar | 17abecf | 2008-01-30 13:33:24 +0100 | [diff] [blame] | 363 | * Older binutils section handling bug prevented |
| 364 | * alternatives-replacement from working reliably. |
| 365 | * |
| 366 | * If this still occurs then you should see a hang |
| 367 | * or crash shortly after this line: |
Ingo Molnar | 3047e99 | 2006-07-03 00:24:57 -0700 | [diff] [blame] | 368 | */ |
Ingo Molnar | 17abecf | 2008-01-30 13:33:24 +0100 | [diff] [blame] | 369 | printk("lockdep: fixing up alternatives.\n"); |
Ingo Molnar | 3047e99 | 2006-07-03 00:24:57 -0700 | [diff] [blame] | 370 | #endif |
| 371 | |
Suresh Siddha | 3fb82d5 | 2010-11-23 16:11:40 -0800 | [diff] [blame] | 372 | if (noreplace_smp || smp_alt_once || skip_smp_alternatives) |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 373 | return; |
| 374 | BUG_ON(!smp && (num_online_cpus() > 1)); |
| 375 | |
Pekka Paalanen | 2f1dafe | 2008-05-12 21:21:01 +0200 | [diff] [blame] | 376 | mutex_lock(&smp_alt); |
Andi Kleen | ca74a6f | 2008-01-30 13:33:17 +0100 | [diff] [blame] | 377 | |
| 378 | /* |
| 379 | * Avoid unnecessary switches because it forces JIT based VMs to |
| 380 | * throw away all cached translations, which can be quite costly. |
| 381 | */ |
| 382 | if (smp == smp_mode) { |
| 383 | /* nothing */ |
| 384 | } else if (smp) { |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 385 | printk(KERN_INFO "SMP alternatives: switching to SMP code\n"); |
Jeremy Fitzhardinge | 53756d3 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 386 | clear_cpu_cap(&boot_cpu_data, X86_FEATURE_UP); |
| 387 | clear_cpu_cap(&cpu_data(0), X86_FEATURE_UP); |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 388 | list_for_each_entry(mod, &smp_alt_modules, next) |
| 389 | alternatives_smp_lock(mod->locks, mod->locks_end, |
| 390 | mod->text, mod->text_end); |
| 391 | } else { |
| 392 | printk(KERN_INFO "SMP alternatives: switching to UP code\n"); |
Jeremy Fitzhardinge | 53756d3 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 393 | set_cpu_cap(&boot_cpu_data, X86_FEATURE_UP); |
| 394 | set_cpu_cap(&cpu_data(0), X86_FEATURE_UP); |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 395 | list_for_each_entry(mod, &smp_alt_modules, next) |
| 396 | alternatives_smp_unlock(mod->locks, mod->locks_end, |
| 397 | mod->text, mod->text_end); |
| 398 | } |
Andi Kleen | ca74a6f | 2008-01-30 13:33:17 +0100 | [diff] [blame] | 399 | smp_mode = smp; |
Pekka Paalanen | 2f1dafe | 2008-05-12 21:21:01 +0200 | [diff] [blame] | 400 | mutex_unlock(&smp_alt); |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 401 | } |
| 402 | |
Masami Hiramatsu | 2cfa197 | 2010-02-02 16:49:11 -0500 | [diff] [blame] | 403 | /* Return 1 if the address range is reserved for smp-alternatives */ |
| 404 | int alternatives_text_reserved(void *start, void *end) |
| 405 | { |
| 406 | struct smp_alt_module *mod; |
Jan Beulich | 5967ed8 | 2010-04-21 16:08:14 +0100 | [diff] [blame] | 407 | const s32 *poff; |
Masami Hiramatsu | 076dc4a6 | 2010-02-05 12:16:47 -0500 | [diff] [blame] | 408 | u8 *text_start = start; |
| 409 | u8 *text_end = end; |
Masami Hiramatsu | 2cfa197 | 2010-02-02 16:49:11 -0500 | [diff] [blame] | 410 | |
| 411 | list_for_each_entry(mod, &smp_alt_modules, next) { |
Masami Hiramatsu | 076dc4a6 | 2010-02-05 12:16:47 -0500 | [diff] [blame] | 412 | if (mod->text > text_end || mod->text_end < text_start) |
Masami Hiramatsu | 2cfa197 | 2010-02-02 16:49:11 -0500 | [diff] [blame] | 413 | continue; |
Jan Beulich | 5967ed8 | 2010-04-21 16:08:14 +0100 | [diff] [blame] | 414 | for (poff = mod->locks; poff < mod->locks_end; poff++) { |
| 415 | const u8 *ptr = (const u8 *)poff + *poff; |
| 416 | |
| 417 | if (text_start <= ptr && text_end > ptr) |
Masami Hiramatsu | 2cfa197 | 2010-02-02 16:49:11 -0500 | [diff] [blame] | 418 | return 1; |
Jan Beulich | 5967ed8 | 2010-04-21 16:08:14 +0100 | [diff] [blame] | 419 | } |
Masami Hiramatsu | 2cfa197 | 2010-02-02 16:49:11 -0500 | [diff] [blame] | 420 | } |
| 421 | |
| 422 | return 0; |
| 423 | } |
Gerd Hoffmann | 8ec4d41 | 2006-07-01 04:36:18 -0700 | [diff] [blame] | 424 | #endif |
| 425 | |
Rusty Russell | 139ec7c | 2006-12-07 02:14:08 +0100 | [diff] [blame] | 426 | #ifdef CONFIG_PARAVIRT |
Jan Beulich | 8b5a10f | 2009-08-19 08:40:48 +0100 | [diff] [blame] | 427 | void __init_or_module apply_paravirt(struct paravirt_patch_site *start, |
| 428 | struct paravirt_patch_site *end) |
Rusty Russell | 139ec7c | 2006-12-07 02:14:08 +0100 | [diff] [blame] | 429 | { |
Jeremy Fitzhardinge | 98de032 | 2007-05-02 19:27:14 +0200 | [diff] [blame] | 430 | struct paravirt_patch_site *p; |
Andi Kleen | ab144f5 | 2007-08-10 22:31:03 +0200 | [diff] [blame] | 431 | char insnbuf[MAX_PATCH_LEN]; |
Rusty Russell | 139ec7c | 2006-12-07 02:14:08 +0100 | [diff] [blame] | 432 | |
Jeremy Fitzhardinge | 959b4fd | 2007-05-02 19:27:16 +0200 | [diff] [blame] | 433 | if (noreplace_paravirt) |
| 434 | return; |
| 435 | |
Rusty Russell | 139ec7c | 2006-12-07 02:14:08 +0100 | [diff] [blame] | 436 | for (p = start; p < end; p++) { |
| 437 | unsigned int used; |
| 438 | |
Andi Kleen | ab144f5 | 2007-08-10 22:31:03 +0200 | [diff] [blame] | 439 | BUG_ON(p->len > MAX_PATCH_LEN); |
Chris Wright | d34fda4 | 2007-08-18 14:31:41 -0700 | [diff] [blame] | 440 | /* prep the buffer with the original instructions */ |
| 441 | memcpy(insnbuf, p->instr, p->len); |
Jeremy Fitzhardinge | 93b1eab | 2007-10-16 11:51:29 -0700 | [diff] [blame] | 442 | used = pv_init_ops.patch(p->instrtype, p->clobbers, insnbuf, |
| 443 | (unsigned long)p->instr, p->len); |
Jeremy Fitzhardinge | 7f63c41 | 2007-05-02 19:27:13 +0200 | [diff] [blame] | 444 | |
Jeremy Fitzhardinge | 63f7027 | 2007-05-02 19:27:14 +0200 | [diff] [blame] | 445 | BUG_ON(used > p->len); |
| 446 | |
Rusty Russell | 139ec7c | 2006-12-07 02:14:08 +0100 | [diff] [blame] | 447 | /* Pad the rest with nops */ |
Andi Kleen | ab144f5 | 2007-08-10 22:31:03 +0200 | [diff] [blame] | 448 | add_nops(insnbuf + used, p->len - used); |
Mathieu Desnoyers | e587cad | 2008-03-06 08:48:49 -0500 | [diff] [blame] | 449 | text_poke_early(p->instr, insnbuf, p->len); |
Rusty Russell | 139ec7c | 2006-12-07 02:14:08 +0100 | [diff] [blame] | 450 | } |
Rusty Russell | 139ec7c | 2006-12-07 02:14:08 +0100 | [diff] [blame] | 451 | } |
Jeremy Fitzhardinge | 98de032 | 2007-05-02 19:27:14 +0200 | [diff] [blame] | 452 | extern struct paravirt_patch_site __start_parainstructions[], |
Rusty Russell | 139ec7c | 2006-12-07 02:14:08 +0100 | [diff] [blame] | 453 | __stop_parainstructions[]; |
| 454 | #endif /* CONFIG_PARAVIRT */ |
| 455 | |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 456 | void __init alternative_instructions(void) |
| 457 | { |
Andi Kleen | 8f4e956 | 2007-07-22 11:12:32 +0200 | [diff] [blame] | 458 | /* The patching is not fully atomic, so try to avoid local interruptions |
| 459 | that might execute the to be patched code. |
| 460 | Other CPUs are not running. */ |
| 461 | stop_nmi(); |
Andi Kleen | 123aa76 | 2009-02-12 13:39:27 +0100 | [diff] [blame] | 462 | |
| 463 | /* |
| 464 | * Don't stop machine check exceptions while patching. |
| 465 | * MCEs only happen when something got corrupted and in this |
| 466 | * case we must do something about the corruption. |
| 467 | * Ignoring it is worse than a unlikely patching race. |
| 468 | * Also machine checks tend to be broadcast and if one CPU |
| 469 | * goes into machine check the others follow quickly, so we don't |
| 470 | * expect a machine check to cause undue problems during to code |
| 471 | * patching. |
| 472 | */ |
Andi Kleen | 8f4e956 | 2007-07-22 11:12:32 +0200 | [diff] [blame] | 473 | |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 474 | apply_alternatives(__alt_instructions, __alt_instructions_end); |
| 475 | |
| 476 | /* switch to patch-once-at-boottime-only mode and free the |
| 477 | * tables in case we know the number of CPUs will never ever |
| 478 | * change */ |
| 479 | #ifdef CONFIG_HOTPLUG_CPU |
| 480 | if (num_possible_cpus() < 2) |
| 481 | smp_alt_once = 1; |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 482 | #endif |
| 483 | |
Gerd Hoffmann | 8ec4d41 | 2006-07-01 04:36:18 -0700 | [diff] [blame] | 484 | #ifdef CONFIG_SMP |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 485 | if (smp_alt_once) { |
| 486 | if (1 == num_possible_cpus()) { |
| 487 | printk(KERN_INFO "SMP alternatives: switching to UP code\n"); |
Jeremy Fitzhardinge | 53756d3 | 2008-01-30 13:30:55 +0100 | [diff] [blame] | 488 | set_cpu_cap(&boot_cpu_data, X86_FEATURE_UP); |
| 489 | set_cpu_cap(&cpu_data(0), X86_FEATURE_UP); |
| 490 | |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 491 | alternatives_smp_unlock(__smp_locks, __smp_locks_end, |
| 492 | _text, _etext); |
| 493 | } |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 494 | } else { |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 495 | alternatives_smp_module_add(NULL, "core kernel", |
| 496 | __smp_locks, __smp_locks_end, |
| 497 | _text, _etext); |
Andi Kleen | ca74a6f | 2008-01-30 13:33:17 +0100 | [diff] [blame] | 498 | |
| 499 | /* Only switch to UP mode if we don't immediately boot others */ |
Thomas Gleixner | 649c665 | 2008-10-05 16:52:24 +0200 | [diff] [blame] | 500 | if (num_present_cpus() == 1 || setup_max_cpus <= 1) |
Andi Kleen | ca74a6f | 2008-01-30 13:33:17 +0100 | [diff] [blame] | 501 | alternatives_smp_switch(0); |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 502 | } |
Gerd Hoffmann | 8ec4d41 | 2006-07-01 04:36:18 -0700 | [diff] [blame] | 503 | #endif |
Jeremy Fitzhardinge | 441d40d | 2007-05-02 19:27:16 +0200 | [diff] [blame] | 504 | apply_paravirt(__parainstructions, __parainstructions_end); |
Andi Kleen | 8f4e956 | 2007-07-22 11:12:32 +0200 | [diff] [blame] | 505 | |
Fengguang Wu | f68fd5f | 2007-10-17 18:04:34 +0200 | [diff] [blame] | 506 | if (smp_alt_once) |
| 507 | free_init_pages("SMP alternatives", |
| 508 | (unsigned long)__smp_locks, |
| 509 | (unsigned long)__smp_locks_end); |
| 510 | |
Andi Kleen | 8f4e956 | 2007-07-22 11:12:32 +0200 | [diff] [blame] | 511 | restart_nmi(); |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 512 | } |
Andi Kleen | 19d36cc | 2007-07-22 11:12:31 +0200 | [diff] [blame] | 513 | |
Mathieu Desnoyers | e587cad | 2008-03-06 08:48:49 -0500 | [diff] [blame] | 514 | /** |
| 515 | * text_poke_early - Update instructions on a live kernel at boot time |
| 516 | * @addr: address to modify |
| 517 | * @opcode: source of the copy |
| 518 | * @len: length to copy |
| 519 | * |
Andi Kleen | 19d36cc | 2007-07-22 11:12:31 +0200 | [diff] [blame] | 520 | * When you use this code to patch more than one byte of an instruction |
| 521 | * you need to make sure that other CPUs cannot execute this code in parallel. |
Mathieu Desnoyers | e587cad | 2008-03-06 08:48:49 -0500 | [diff] [blame] | 522 | * Also no thread must be currently preempted in the middle of these |
| 523 | * instructions. And on the local CPU you need to be protected again NMI or MCE |
| 524 | * handlers seeing an inconsistent instruction while you patch. |
Andi Kleen | 19d36cc | 2007-07-22 11:12:31 +0200 | [diff] [blame] | 525 | */ |
Jason Baron | fa6f2cc | 2010-09-17 11:08:56 -0400 | [diff] [blame] | 526 | void *__init_or_module text_poke_early(void *addr, const void *opcode, |
Jan Beulich | 8b5a10f | 2009-08-19 08:40:48 +0100 | [diff] [blame] | 527 | size_t len) |
Andi Kleen | 19d36cc | 2007-07-22 11:12:31 +0200 | [diff] [blame] | 528 | { |
Mathieu Desnoyers | e587cad | 2008-03-06 08:48:49 -0500 | [diff] [blame] | 529 | unsigned long flags; |
| 530 | local_irq_save(flags); |
Andi Kleen | 19d36cc | 2007-07-22 11:12:31 +0200 | [diff] [blame] | 531 | memcpy(addr, opcode, len); |
| 532 | sync_core(); |
Ben Hutchings | 5367b68 | 2009-09-10 02:53:50 +0100 | [diff] [blame] | 533 | local_irq_restore(flags); |
Andi Kleen | a534b67 | 2007-09-06 16:59:52 +0200 | [diff] [blame] | 534 | /* Could also do a CLFLUSH here to speed up CPU recovery; but |
| 535 | that causes hangs on some VIA CPUs. */ |
Mathieu Desnoyers | e587cad | 2008-03-06 08:48:49 -0500 | [diff] [blame] | 536 | return addr; |
| 537 | } |
| 538 | |
| 539 | /** |
| 540 | * text_poke - Update instructions on a live kernel |
| 541 | * @addr: address to modify |
| 542 | * @opcode: source of the copy |
| 543 | * @len: length to copy |
| 544 | * |
| 545 | * Only atomic text poke/set should be allowed when not doing early patching. |
| 546 | * It means the size must be writable atomically and the address must be aligned |
| 547 | * in a way that permits an atomic write. It also makes sure we fit on a single |
| 548 | * page. |
Masami Hiramatsu | 78ff7fa | 2009-03-06 10:37:54 -0500 | [diff] [blame] | 549 | * |
| 550 | * Note: Must be called under text_mutex. |
Mathieu Desnoyers | e587cad | 2008-03-06 08:48:49 -0500 | [diff] [blame] | 551 | */ |
| 552 | void *__kprobes text_poke(void *addr, const void *opcode, size_t len) |
| 553 | { |
Masami Hiramatsu | 78ff7fa | 2009-03-06 10:37:54 -0500 | [diff] [blame] | 554 | unsigned long flags; |
Mathieu Desnoyers | e587cad | 2008-03-06 08:48:49 -0500 | [diff] [blame] | 555 | char *vaddr; |
Mathieu Desnoyers | b7b66ba | 2008-04-24 11:03:33 -0400 | [diff] [blame] | 556 | struct page *pages[2]; |
| 557 | int i; |
Mathieu Desnoyers | e587cad | 2008-03-06 08:48:49 -0500 | [diff] [blame] | 558 | |
Mathieu Desnoyers | b7b66ba | 2008-04-24 11:03:33 -0400 | [diff] [blame] | 559 | if (!core_kernel_text((unsigned long)addr)) { |
| 560 | pages[0] = vmalloc_to_page(addr); |
| 561 | pages[1] = vmalloc_to_page(addr + PAGE_SIZE); |
Mathieu Desnoyers | 15a601e | 2008-03-12 11:54:16 -0400 | [diff] [blame] | 562 | } else { |
Mathieu Desnoyers | b7b66ba | 2008-04-24 11:03:33 -0400 | [diff] [blame] | 563 | pages[0] = virt_to_page(addr); |
Ingo Molnar | 00c6b2d | 2008-04-25 17:07:03 +0200 | [diff] [blame] | 564 | WARN_ON(!PageReserved(pages[0])); |
Mathieu Desnoyers | b7b66ba | 2008-04-24 11:03:33 -0400 | [diff] [blame] | 565 | pages[1] = virt_to_page(addr + PAGE_SIZE); |
Mathieu Desnoyers | e587cad | 2008-03-06 08:48:49 -0500 | [diff] [blame] | 566 | } |
Mathieu Desnoyers | b7b66ba | 2008-04-24 11:03:33 -0400 | [diff] [blame] | 567 | BUG_ON(!pages[0]); |
Masami Hiramatsu | 7cf4942 | 2009-03-09 12:40:40 -0400 | [diff] [blame] | 568 | local_irq_save(flags); |
Masami Hiramatsu | 78ff7fa | 2009-03-06 10:37:54 -0500 | [diff] [blame] | 569 | set_fixmap(FIX_TEXT_POKE0, page_to_phys(pages[0])); |
| 570 | if (pages[1]) |
| 571 | set_fixmap(FIX_TEXT_POKE1, page_to_phys(pages[1])); |
| 572 | vaddr = (char *)fix_to_virt(FIX_TEXT_POKE0); |
Mathieu Desnoyers | b7b66ba | 2008-04-24 11:03:33 -0400 | [diff] [blame] | 573 | memcpy(&vaddr[(unsigned long)addr & ~PAGE_MASK], opcode, len); |
Masami Hiramatsu | 78ff7fa | 2009-03-06 10:37:54 -0500 | [diff] [blame] | 574 | clear_fixmap(FIX_TEXT_POKE0); |
| 575 | if (pages[1]) |
| 576 | clear_fixmap(FIX_TEXT_POKE1); |
| 577 | local_flush_tlb(); |
Mathieu Desnoyers | e587cad | 2008-03-06 08:48:49 -0500 | [diff] [blame] | 578 | sync_core(); |
| 579 | /* Could also do a CLFLUSH here to speed up CPU recovery; but |
| 580 | that causes hangs on some VIA CPUs. */ |
Mathieu Desnoyers | b7b66ba | 2008-04-24 11:03:33 -0400 | [diff] [blame] | 581 | for (i = 0; i < len; i++) |
| 582 | BUG_ON(((char *)addr)[i] != ((char *)opcode)[i]); |
Masami Hiramatsu | 7cf4942 | 2009-03-09 12:40:40 -0400 | [diff] [blame] | 583 | local_irq_restore(flags); |
Mathieu Desnoyers | e587cad | 2008-03-06 08:48:49 -0500 | [diff] [blame] | 584 | return addr; |
Andi Kleen | 19d36cc | 2007-07-22 11:12:31 +0200 | [diff] [blame] | 585 | } |
Masami Hiramatsu | 3d55cc8 | 2010-02-25 08:34:38 -0500 | [diff] [blame] | 586 | |
| 587 | /* |
| 588 | * Cross-modifying kernel text with stop_machine(). |
| 589 | * This code originally comes from immediate value. |
| 590 | */ |
| 591 | static atomic_t stop_machine_first; |
| 592 | static int wrote_text; |
| 593 | |
| 594 | struct text_poke_params { |
Masami Hiramatsu | 7deb18d | 2010-12-03 18:54:22 +0900 | [diff] [blame] | 595 | struct text_poke_param *params; |
| 596 | int nparams; |
Masami Hiramatsu | 3d55cc8 | 2010-02-25 08:34:38 -0500 | [diff] [blame] | 597 | }; |
| 598 | |
| 599 | static int __kprobes stop_machine_text_poke(void *data) |
| 600 | { |
| 601 | struct text_poke_params *tpp = data; |
Masami Hiramatsu | 7deb18d | 2010-12-03 18:54:22 +0900 | [diff] [blame] | 602 | struct text_poke_param *p; |
| 603 | int i; |
Masami Hiramatsu | 3d55cc8 | 2010-02-25 08:34:38 -0500 | [diff] [blame] | 604 | |
| 605 | if (atomic_dec_and_test(&stop_machine_first)) { |
Masami Hiramatsu | 7deb18d | 2010-12-03 18:54:22 +0900 | [diff] [blame] | 606 | for (i = 0; i < tpp->nparams; i++) { |
| 607 | p = &tpp->params[i]; |
| 608 | text_poke(p->addr, p->opcode, p->len); |
| 609 | } |
Masami Hiramatsu | 3d55cc8 | 2010-02-25 08:34:38 -0500 | [diff] [blame] | 610 | smp_wmb(); /* Make sure other cpus see that this has run */ |
| 611 | wrote_text = 1; |
| 612 | } else { |
| 613 | while (!wrote_text) |
Masami Hiramatsu | e5a1101 | 2010-03-03 22:38:50 -0500 | [diff] [blame] | 614 | cpu_relax(); |
| 615 | smp_mb(); /* Load wrote_text before following execution */ |
Masami Hiramatsu | 3d55cc8 | 2010-02-25 08:34:38 -0500 | [diff] [blame] | 616 | } |
| 617 | |
Masami Hiramatsu | 7deb18d | 2010-12-03 18:54:22 +0900 | [diff] [blame] | 618 | for (i = 0; i < tpp->nparams; i++) { |
| 619 | p = &tpp->params[i]; |
| 620 | flush_icache_range((unsigned long)p->addr, |
| 621 | (unsigned long)p->addr + p->len); |
| 622 | } |
Mathieu Desnoyers | 0e00f7a | 2011-03-03 11:01:37 -0500 | [diff] [blame^] | 623 | /* |
| 624 | * Intel Archiecture Software Developer's Manual section 7.1.3 specifies |
| 625 | * that a core serializing instruction such as "cpuid" should be |
| 626 | * executed on _each_ core before the new instruction is made visible. |
| 627 | */ |
| 628 | sync_core(); |
Masami Hiramatsu | 3d55cc8 | 2010-02-25 08:34:38 -0500 | [diff] [blame] | 629 | return 0; |
| 630 | } |
| 631 | |
| 632 | /** |
| 633 | * text_poke_smp - Update instructions on a live kernel on SMP |
| 634 | * @addr: address to modify |
| 635 | * @opcode: source of the copy |
| 636 | * @len: length to copy |
| 637 | * |
| 638 | * Modify multi-byte instruction by using stop_machine() on SMP. This allows |
| 639 | * user to poke/set multi-byte text on SMP. Only non-NMI/MCE code modifying |
| 640 | * should be allowed, since stop_machine() does _not_ protect code against |
| 641 | * NMI and MCE. |
| 642 | * |
| 643 | * Note: Must be called under get_online_cpus() and text_mutex. |
| 644 | */ |
| 645 | void *__kprobes text_poke_smp(void *addr, const void *opcode, size_t len) |
| 646 | { |
| 647 | struct text_poke_params tpp; |
Masami Hiramatsu | 7deb18d | 2010-12-03 18:54:22 +0900 | [diff] [blame] | 648 | struct text_poke_param p; |
Masami Hiramatsu | 3d55cc8 | 2010-02-25 08:34:38 -0500 | [diff] [blame] | 649 | |
Masami Hiramatsu | 7deb18d | 2010-12-03 18:54:22 +0900 | [diff] [blame] | 650 | p.addr = addr; |
| 651 | p.opcode = opcode; |
| 652 | p.len = len; |
| 653 | tpp.params = &p; |
| 654 | tpp.nparams = 1; |
Masami Hiramatsu | 3d55cc8 | 2010-02-25 08:34:38 -0500 | [diff] [blame] | 655 | atomic_set(&stop_machine_first, 1); |
| 656 | wrote_text = 0; |
Masami Hiramatsu | 3caa3751 | 2010-10-14 12:10:36 +0900 | [diff] [blame] | 657 | /* Use __stop_machine() because the caller already got online_cpus. */ |
Jason Baron | 404ba5d | 2010-10-28 11:20:27 -0400 | [diff] [blame] | 658 | __stop_machine(stop_machine_text_poke, (void *)&tpp, cpu_online_mask); |
Masami Hiramatsu | 3d55cc8 | 2010-02-25 08:34:38 -0500 | [diff] [blame] | 659 | return addr; |
| 660 | } |
| 661 | |
Masami Hiramatsu | 7deb18d | 2010-12-03 18:54:22 +0900 | [diff] [blame] | 662 | /** |
| 663 | * text_poke_smp_batch - Update instructions on a live kernel on SMP |
| 664 | * @params: an array of text_poke parameters |
| 665 | * @n: the number of elements in params. |
| 666 | * |
| 667 | * Modify multi-byte instruction by using stop_machine() on SMP. Since the |
| 668 | * stop_machine() is heavy task, it is better to aggregate text_poke requests |
| 669 | * and do it once if possible. |
| 670 | * |
| 671 | * Note: Must be called under get_online_cpus() and text_mutex. |
| 672 | */ |
| 673 | void __kprobes text_poke_smp_batch(struct text_poke_param *params, int n) |
| 674 | { |
| 675 | struct text_poke_params tpp = {.params = params, .nparams = n}; |
| 676 | |
| 677 | atomic_set(&stop_machine_first, 1); |
| 678 | wrote_text = 0; |
Peter Zijlstra | d91309f | 2011-02-11 22:07:46 +0100 | [diff] [blame] | 679 | __stop_machine(stop_machine_text_poke, (void *)&tpp, NULL); |
Masami Hiramatsu | 7deb18d | 2010-12-03 18:54:22 +0900 | [diff] [blame] | 680 | } |
| 681 | |
Jason Baron | bf5438fc | 2010-09-17 11:09:00 -0400 | [diff] [blame] | 682 | #if defined(CONFIG_DYNAMIC_FTRACE) || defined(HAVE_JUMP_LABEL) |
Jason Baron | f49aa44 | 2010-09-17 11:08:51 -0400 | [diff] [blame] | 683 | |
H. Peter Anvin | 2d1d712 | 2010-10-27 21:09:15 -0700 | [diff] [blame] | 684 | #ifdef CONFIG_X86_64 |
| 685 | unsigned char ideal_nop5[5] = { 0x66, 0x66, 0x66, 0x66, 0x90 }; |
| 686 | #else |
| 687 | unsigned char ideal_nop5[5] = { 0x3e, 0x8d, 0x74, 0x26, 0x00 }; |
| 688 | #endif |
Jason Baron | f49aa44 | 2010-09-17 11:08:51 -0400 | [diff] [blame] | 689 | |
| 690 | void __init arch_init_ideal_nop5(void) |
| 691 | { |
Jason Baron | f49aa44 | 2010-09-17 11:08:51 -0400 | [diff] [blame] | 692 | /* |
H. Peter Anvin | 2d1d712 | 2010-10-27 21:09:15 -0700 | [diff] [blame] | 693 | * There is no good nop for all x86 archs. This selection |
| 694 | * algorithm should be unified with the one in find_nop_table(), |
| 695 | * but this should be good enough for now. |
Jason Baron | f49aa44 | 2010-09-17 11:08:51 -0400 | [diff] [blame] | 696 | * |
H. Peter Anvin | 2d1d712 | 2010-10-27 21:09:15 -0700 | [diff] [blame] | 697 | * For cases other than the ones below, use the safe (as in |
| 698 | * always functional) defaults above. |
Jason Baron | f49aa44 | 2010-09-17 11:08:51 -0400 | [diff] [blame] | 699 | */ |
H. Peter Anvin | 2d1d712 | 2010-10-27 21:09:15 -0700 | [diff] [blame] | 700 | #ifdef CONFIG_X86_64 |
| 701 | /* Don't use these on 32 bits due to broken virtualizers */ |
| 702 | if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) |
| 703 | memcpy(ideal_nop5, p6_nops[5], 5); |
| 704 | #endif |
Jason Baron | f49aa44 | 2010-09-17 11:08:51 -0400 | [diff] [blame] | 705 | } |
| 706 | #endif |