1 files changed, 57 insertions, 11 deletions

diff --git a/arch/i386/kernel/alternative.c b/arch/i386/kernel/alternative.c
index 28ab80649764..9eca21b49f6b 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);
         };
 }
 
@@ -342,8 +349,43 @@ 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;
         if (no_replacement) {
                 printk(KERN_INFO "(SMP-)alternatives turned off\n");
                 free_init_pages("SMP alternatives",
@@ -351,6 +393,8 @@ void __init alternative_instructions(void)
                                 (unsigned long)__smp_alt_end);
                 return;
         }
+
+        local_irq_save(flags);
         apply_alternatives(__alt_instructions, __alt_instructions_end);
 
         /* switch to patch-once-at-boottime-only mode and free the
@@ -386,4 +430,6 @@ void __init alternative_instructions(void)
                 alternatives_smp_switch(0);
         }
 #endif
+        apply_paravirt(__start_parainstructions, __stop_parainstructions);
+        local_irq_restore(flags);
 }