diff options
Diffstat (limited to 'arch/x86/kernel/alternative.c')
-rw-r--r-- | arch/x86/kernel/alternative.c | 198 |
1 files changed, 21 insertions, 177 deletions
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index f902f28d9dff..80adf5a81a79 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -75,186 +75,30 @@ do { \ } \ } while (0) -/* - * Each GENERIC_NOPX is of X bytes, and defined as an array of bytes - * that correspond to that nop. Getting from one nop to the next, we - * add to the array the offset that is equal to the sum of all sizes of - * nops preceding the one we are after. - * - * Note: The GENERIC_NOP5_ATOMIC is at the end, as it breaks the - * nice symmetry of sizes of the previous nops. - */ -#if defined(GENERIC_NOP1) && !defined(CONFIG_X86_64) -static const unsigned char intelnops[] = +const unsigned char x86nops[] = { - GENERIC_NOP1, - GENERIC_NOP2, - GENERIC_NOP3, - GENERIC_NOP4, - GENERIC_NOP5, - GENERIC_NOP6, - GENERIC_NOP7, - GENERIC_NOP8, - GENERIC_NOP5_ATOMIC -}; -static const unsigned char * const intel_nops[ASM_NOP_MAX+2] = -{ - NULL, - intelnops, - intelnops + 1, - intelnops + 1 + 2, - intelnops + 1 + 2 + 3, - intelnops + 1 + 2 + 3 + 4, - intelnops + 1 + 2 + 3 + 4 + 5, - intelnops + 1 + 2 + 3 + 4 + 5 + 6, - intelnops + 1 + 2 + 3 + 4 + 5 + 6 + 7, - intelnops + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8, + BYTES_NOP1, + BYTES_NOP2, + BYTES_NOP3, + BYTES_NOP4, + BYTES_NOP5, + BYTES_NOP6, + BYTES_NOP7, + BYTES_NOP8, }; -#endif -#ifdef K8_NOP1 -static const unsigned char k8nops[] = -{ - K8_NOP1, - K8_NOP2, - K8_NOP3, - K8_NOP4, - K8_NOP5, - K8_NOP6, - K8_NOP7, - K8_NOP8, - K8_NOP5_ATOMIC -}; -static const unsigned char * const k8_nops[ASM_NOP_MAX+2] = -{ - NULL, - k8nops, - k8nops + 1, - k8nops + 1 + 2, - k8nops + 1 + 2 + 3, - k8nops + 1 + 2 + 3 + 4, - k8nops + 1 + 2 + 3 + 4 + 5, - k8nops + 1 + 2 + 3 + 4 + 5 + 6, - k8nops + 1 + 2 + 3 + 4 + 5 + 6 + 7, - k8nops + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8, -}; -#endif - -#if defined(K7_NOP1) && !defined(CONFIG_X86_64) -static const unsigned char k7nops[] = -{ - K7_NOP1, - K7_NOP2, - K7_NOP3, - K7_NOP4, - K7_NOP5, - K7_NOP6, - K7_NOP7, - K7_NOP8, - K7_NOP5_ATOMIC -}; -static const unsigned char * const k7_nops[ASM_NOP_MAX+2] = -{ - NULL, - k7nops, - k7nops + 1, - k7nops + 1 + 2, - k7nops + 1 + 2 + 3, - k7nops + 1 + 2 + 3 + 4, - k7nops + 1 + 2 + 3 + 4 + 5, - k7nops + 1 + 2 + 3 + 4 + 5 + 6, - k7nops + 1 + 2 + 3 + 4 + 5 + 6 + 7, - k7nops + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8, -}; -#endif - -#ifdef P6_NOP1 -static const unsigned char p6nops[] = -{ - P6_NOP1, - P6_NOP2, - P6_NOP3, - P6_NOP4, - P6_NOP5, - P6_NOP6, - P6_NOP7, - P6_NOP8, - P6_NOP5_ATOMIC -}; -static const unsigned char * const p6_nops[ASM_NOP_MAX+2] = +const unsigned char * const x86_nops[ASM_NOP_MAX+1] = { NULL, - p6nops, - p6nops + 1, - p6nops + 1 + 2, - p6nops + 1 + 2 + 3, - p6nops + 1 + 2 + 3 + 4, - p6nops + 1 + 2 + 3 + 4 + 5, - p6nops + 1 + 2 + 3 + 4 + 5 + 6, - p6nops + 1 + 2 + 3 + 4 + 5 + 6 + 7, - p6nops + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8, + x86nops, + x86nops + 1, + x86nops + 1 + 2, + x86nops + 1 + 2 + 3, + x86nops + 1 + 2 + 3 + 4, + x86nops + 1 + 2 + 3 + 4 + 5, + x86nops + 1 + 2 + 3 + 4 + 5 + 6, + x86nops + 1 + 2 + 3 + 4 + 5 + 6 + 7, }; -#endif - -/* Initialize these to a safe default */ -#ifdef CONFIG_X86_64 -const unsigned char * const *ideal_nops = p6_nops; -#else -const unsigned char * const *ideal_nops = intel_nops; -#endif - -void __init arch_init_ideal_nops(void) -{ - switch (boot_cpu_data.x86_vendor) { - case X86_VENDOR_INTEL: - /* - * Due to a decoder implementation quirk, some - * specific Intel CPUs actually perform better with - * the "k8_nops" than with the SDM-recommended NOPs. - */ - if (boot_cpu_data.x86 == 6 && - boot_cpu_data.x86_model >= 0x0f && - boot_cpu_data.x86_model != 0x1c && - boot_cpu_data.x86_model != 0x26 && - boot_cpu_data.x86_model != 0x27 && - boot_cpu_data.x86_model < 0x30) { - ideal_nops = k8_nops; - } else if (boot_cpu_has(X86_FEATURE_NOPL)) { - ideal_nops = p6_nops; - } else { -#ifdef CONFIG_X86_64 - ideal_nops = k8_nops; -#else - ideal_nops = intel_nops; -#endif - } - break; - - case X86_VENDOR_HYGON: - ideal_nops = p6_nops; - return; - - case X86_VENDOR_AMD: - if (boot_cpu_data.x86 > 0xf) { - ideal_nops = p6_nops; - return; - } - - fallthrough; - - default: -#ifdef CONFIG_X86_64 - ideal_nops = k8_nops; -#else - if (boot_cpu_has(X86_FEATURE_K8)) - ideal_nops = k8_nops; - else if (boot_cpu_has(X86_FEATURE_K7)) - ideal_nops = k7_nops; - else - ideal_nops = intel_nops; -#endif - } -} /* Use this to add nops to a buffer, then text_poke the whole buffer. */ static void __init_or_module add_nops(void *insns, unsigned int len) @@ -263,7 +107,7 @@ static void __init_or_module add_nops(void *insns, unsigned int len) unsigned int noplen = len; if (noplen > ASM_NOP_MAX) noplen = ASM_NOP_MAX; - memcpy(insns, ideal_nops[noplen], noplen); + memcpy(insns, x86_nops[noplen], noplen); insns += noplen; len -= noplen; } @@ -1338,13 +1182,13 @@ static void text_poke_loc_init(struct text_poke_loc *tp, void *addr, default: /* assume NOP */ switch (len) { case 2: /* NOP2 -- emulate as JMP8+0 */ - BUG_ON(memcmp(emulate, ideal_nops[len], len)); + BUG_ON(memcmp(emulate, x86_nops[len], len)); tp->opcode = JMP8_INSN_OPCODE; tp->rel32 = 0; break; case 5: /* NOP5 -- emulate as JMP32+0 */ - BUG_ON(memcmp(emulate, ideal_nops[NOP_ATOMIC5], len)); + BUG_ON(memcmp(emulate, x86_nops[len], len)); tp->opcode = JMP32_INSN_OPCODE; tp->rel32 = 0; break; |