Merge branch 'x86/asm' into x86/atomic

[pandora-kernel.git] / arch / x86 / kernel / alternative.c

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index c41f13c..7023773 100644 (file)
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -8,6 +8,7 @@
 #include <linux/vmalloc.h>
 #include <linux/memory.h>
 #include <linux/stop_machine.h>
+#include <linux/slab.h>
 #include <asm/alternative.h>
 #include <asm/sections.h>
 #include <asm/pgtable.h>
@@ -193,7 +194,7 @@ static void __init_or_module add_nops(void *insns, unsigned int len)
 }
 
 extern struct alt_instr __alt_instructions[], __alt_instructions_end[];
-extern u8 *__smp_locks[], *__smp_locks_end[];
+extern s32 __smp_locks[], __smp_locks_end[];
 static void *text_poke_early(void *addr, const void *opcode, size_t len);
 
 /* Replace instructions with better alternatives for this CPU type.
@@ -206,7 +207,7 @@ void __init_or_module apply_alternatives(struct alt_instr *start,
                                         struct alt_instr *end)
 {
        struct alt_instr *a;
-       char insnbuf[MAX_PATCH_LEN];
+       u8 insnbuf[MAX_PATCH_LEN];
 
        DPRINTK("%s: alt table %p -> %p\n", __func__, start, end);
        for (a = start; a < end; a++) {
@@ -224,6 +225,8 @@ void __init_or_module apply_alternatives(struct alt_instr *start,
                }
 #endif
                memcpy(insnbuf, a->replacement, a->replacementlen);
+               if (*insnbuf == 0xe8 && a->replacementlen == 5)
+                   *(s32 *)(insnbuf + 1) += a->replacement - a->instr;
                add_nops(insnbuf + a->replacementlen,
                         a->instrlen - a->replacementlen);
                text_poke_early(instr, insnbuf, a->instrlen);
@@ -232,37 +235,41 @@ void __init_or_module apply_alternatives(struct alt_instr *start,
 
 #ifdef CONFIG_SMP
 
-static void alternatives_smp_lock(u8 **start, u8 **end, u8 *text, u8 *text_end)
+static void alternatives_smp_lock(const s32 *start, const s32 *end,
+                                 u8 *text, u8 *text_end)
 {
-       u8 **ptr;
+       const s32 *poff;
 
        mutex_lock(&text_mutex);
-       for (ptr = start; ptr < end; ptr++) {
-               if (*ptr < text)
-                       continue;
-               if (*ptr > text_end)
+       for (poff = start; poff < end; poff++) {
+               u8 *ptr = (u8 *)poff + *poff;
+
+               if (!*poff || ptr < text || ptr >= text_end)
                        continue;
                /* turn DS segment override prefix into lock prefix */
-               text_poke(*ptr, ((unsigned char []){0xf0}), 1);
+               if (*ptr == 0x3e)
+                       text_poke(ptr, ((unsigned char []){0xf0}), 1);
        };
        mutex_unlock(&text_mutex);
 }
 
-static void alternatives_smp_unlock(u8 **start, u8 **end, u8 *text, u8 *text_end)
+static void alternatives_smp_unlock(const s32 *start, const s32 *end,
+                                   u8 *text, u8 *text_end)
 {
-       u8 **ptr;
+       const s32 *poff;
 
        if (noreplace_smp)
                return;
 
        mutex_lock(&text_mutex);
-       for (ptr = start; ptr < end; ptr++) {
-               if (*ptr < text)
-                       continue;
-               if (*ptr > text_end)
+       for (poff = start; poff < end; poff++) {
+               u8 *ptr = (u8 *)poff + *poff;
+
+               if (!*poff || ptr < text || ptr >= text_end)
                        continue;
                /* turn lock prefix into DS segment override prefix */
-               text_poke(*ptr, ((unsigned char []){0x3E}), 1);
+               if (*ptr == 0xf0)
+                       text_poke(ptr, ((unsigned char []){0x3E}), 1);
        };
        mutex_unlock(&text_mutex);
 }
@@ -273,8 +280,8 @@ struct smp_alt_module {
        char            *name;
 
        /* ptrs to lock prefixes */
-       u8              **locks;
-       u8              **locks_end;
+       const s32       *locks;
+       const s32       *locks_end;
 
        /* .text segment, needed to avoid patching init code ;) */
        u8              *text;
@@ -395,16 +402,19 @@ void alternatives_smp_switch(int smp)
 int alternatives_text_reserved(void *start, void *end)
 {
        struct smp_alt_module *mod;
-       u8 **ptr;
+       const s32 *poff;
        u8 *text_start = start;
        u8 *text_end = end;
 
        list_for_each_entry(mod, &smp_alt_modules, next) {
                if (mod->text > text_end || mod->text_end < text_start)
                        continue;
-               for (ptr = mod->locks; ptr < mod->locks_end; ptr++)
-                       if (text_start <= *ptr && text_end >= *ptr)
+               for (poff = mod->locks; poff < mod->locks_end; poff++) {
+                       const u8 *ptr = (const u8 *)poff + *poff;
+
+                       if (text_start <= ptr && text_end > ptr)
                                return 1;
+               }
        }
 
        return 0;
@@ -595,8 +605,8 @@ static int __kprobes stop_machine_text_poke(void *data)
                wrote_text = 1;
        } else {
                while (!wrote_text)
-                       smp_rmb();
-               sync_core();
+                       cpu_relax();
+               smp_mb();       /* Load wrote_text before following execution */
        }
 
        flush_icache_range((unsigned long)tpp->addr,