diff options
Diffstat (limited to 'arch/i386/kernel/alternative.c')
| -rw-r--r-- | arch/i386/kernel/alternative.c | 64 |
1 files changed, 53 insertions, 11 deletions
diff --git a/arch/i386/kernel/alternative.c b/arch/i386/kernel/alternative.c index 583c238e17f..9eca21b49f6 100644 --- a/arch/i386/kernel/alternative.c +++ b/arch/i386/kernel/alternative.c @@ -1,4 +1,5 @@ #include <linux/module.h> +#include <linux/sched.h> #include <linux/spinlock.h> #include <linux/list.h> #include <asm/alternative.h> @@ -123,6 +124,20 @@ static unsigned char** find_nop_table(void) #endif /* CONFIG_X86_64 */ +static void nop_out(void *insns, unsigned int len) +{ + unsigned char **noptable = find_nop_table(); + + while (len > 0) { + unsigned int noplen = len; + if (noplen > ASM_NOP_MAX) + noplen = ASM_NOP_MAX; + memcpy(insns, noptable[noplen], noplen); + insns += noplen; + len -= noplen; + } +} + extern struct alt_instr __alt_instructions[], __alt_instructions_end[]; extern struct alt_instr __smp_alt_instructions[], __smp_alt_instructions_end[]; extern u8 *__smp_locks[], *__smp_locks_end[]; @@ -137,10 +152,9 @@ extern u8 __smp_alt_begin[], __smp_alt_end[]; void apply_alternatives(struct alt_instr *start, struct alt_instr *end) { - unsigned char **noptable = find_nop_table(); struct alt_instr *a; u8 *instr; - int diff, i, k; + int diff; DPRINTK("%s: alt table %p -> %p\n", __FUNCTION__, start, end); for (a = start; a < end; a++) { @@ -158,13 +172,7 @@ void apply_alternatives(struct alt_instr *start, struct alt_instr *end) #endif memcpy(instr, a->replacement, a->replacementlen); diff = a->instrlen - a->replacementlen; - /* Pad the rest with nops */ - for (i = a->replacementlen; diff > 0; diff -= k, i += k) { - k = diff; - if (k > ASM_NOP_MAX) - k = ASM_NOP_MAX; - memcpy(a->instr + i, noptable[k], k); - } + nop_out(instr + a->replacementlen, diff); } } @@ -208,7 +216,6 @@ static void alternatives_smp_lock(u8 **start, u8 **end, u8 *text, u8 *text_end) static void alternatives_smp_unlock(u8 **start, u8 **end, u8 *text, u8 *text_end) { - unsigned char **noptable = find_nop_table(); u8 **ptr; for (ptr = start; ptr < end; ptr++) { @@ -216,7 +223,7 @@ static void alternatives_smp_unlock(u8 **start, u8 **end, u8 *text, u8 *text_end continue; if (*ptr > text_end) continue; - **ptr = noptable[1][0]; + nop_out(*ptr, 1); }; } @@ -342,6 +349,40 @@ void alternatives_smp_switch(int smp) #endif +#ifdef CONFIG_PARAVIRT +void apply_paravirt(struct paravirt_patch *start, struct paravirt_patch *end) +{ + struct paravirt_patch *p; + + for (p = start; p < end; p++) { + unsigned int used; + + used = paravirt_ops.patch(p->instrtype, p->clobbers, p->instr, + p->len); +#ifdef CONFIG_DEBUG_PARAVIRT + { + int i; + /* Deliberately clobber regs using "not %reg" to find bugs. */ + for (i = 0; i < 3; i++) { + if (p->len - used >= 2 && (p->clobbers & (1 << i))) { + memcpy(p->instr + used, "\xf7\xd0", 2); + p->instr[used+1] |= i; + used += 2; + } + } + } +#endif + /* Pad the rest with nops */ + nop_out(p->instr + used, p->len - used); + } + + /* Sync to be conservative, in case we patched following instructions */ + sync_core(); +} +extern struct paravirt_patch __start_parainstructions[], + __stop_parainstructions[]; +#endif /* CONFIG_PARAVIRT */ + void __init alternative_instructions(void) { unsigned long flags; @@ -389,5 +430,6 @@ void __init alternative_instructions(void) alternatives_smp_switch(0); } #endif + apply_paravirt(__start_parainstructions, __stop_parainstructions); local_irq_restore(flags); } |