Merge master.kernel.org:/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw

[pandora-kernel.git] / arch / i386 / kernel / alternative.c

diff --git a/arch/i386/kernel/alternative.c b/arch/i386/kernel/alternative.c
index 7b421b3..9eca21b 100644 (file)
--- 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);
        };
 }
 
@@ -303,6 +310,16 @@ void alternatives_smp_switch(int smp)
        struct smp_alt_module *mod;
        unsigned long flags;
 
+#ifdef CONFIG_LOCKDEP
+       /*
+        * A not yet fixed binutils section handling bug prevents
+        * alternatives-replacement from working reliably, so turn
+        * it off:
+        */
+       printk("lockdep: not fixing up alternatives.\n");
+       return;
+#endif
+
        if (no_replacement || smp_alt_once)
                return;
        BUG_ON(!smp && (num_online_cpus() > 1));
@@ -332,8 +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",
@@ -341,6 +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
@@ -376,4 +430,6 @@ void __init alternative_instructions(void)
                alternatives_smp_switch(0);
        }
 #endif
+       apply_paravirt(__start_parainstructions, __stop_parainstructions);
+       local_irq_restore(flags);
 }