Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6

[linux-2.6-omap-h63xx.git] / arch / x86 / kernel / alternative.c

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 4c80f15574335d6b02bc93a7ed797c088c1da6c2..f5765870257124108ff0ad237653bb306bf126bf 100644 (file)
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -5,6 +5,7 @@
 #include <linux/kprobes.h>
 #include <linux/mm.h>
 #include <linux/vmalloc.h>
+#include <linux/memory.h>
 #include <asm/alternative.h>
 #include <asm/sections.h>
 #include <asm/pgtable.h>
@@ -12,7 +13,9 @@
 #include <asm/nmi.h>
 #include <asm/vsyscall.h>
 #include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
 #include <asm/io.h>
+#include <asm/fixmap.h>
 
 #define MAX_PATCH_LEN (255-1)
 
@@ -226,6 +229,7 @@ static void alternatives_smp_lock(u8 **start, u8 **end, u8 *text, u8 *text_end)
 {
        u8 **ptr;
 
+       mutex_lock(&text_mutex);
        for (ptr = start; ptr < end; ptr++) {
                if (*ptr < text)
                        continue;
@@ -234,6 +238,7 @@ static void alternatives_smp_lock(u8 **start, u8 **end, u8 *text, u8 *text_end)
                /* turn DS segment override prefix into lock prefix */
                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)
@@ -243,6 +248,7 @@ static void alternatives_smp_unlock(u8 **start, u8 **end, u8 *text, u8 *text_end
        if (noreplace_smp)
                return;
 
+       mutex_lock(&text_mutex);
        for (ptr = start; ptr < end; ptr++) {
                if (*ptr < text)
                        continue;
@@ -251,6 +257,7 @@ static void alternatives_smp_unlock(u8 **start, u8 **end, u8 *text, u8 *text_end
                /* turn lock prefix into DS segment override prefix */
                text_poke(*ptr, ((unsigned char []){0x3E}), 1);
        };
+       mutex_unlock(&text_mutex);
 }
 
 struct smp_alt_module {
@@ -500,15 +507,16 @@ void *text_poke_early(void *addr, const void *opcode, size_t len)
  * It means the size must be writable atomically and the address must be aligned
  * in a way that permits an atomic write. It also makes sure we fit on a single
  * page.
+ *
+ * Note: Must be called under text_mutex.
  */
 void *__kprobes text_poke(void *addr, const void *opcode, size_t len)
 {
+       unsigned long flags;
        char *vaddr;
-       int nr_pages = 2;
        struct page *pages[2];
        int i;
 
-       might_sleep();
        if (!core_kernel_text((unsigned long)addr)) {
                pages[0] = vmalloc_to_page(addr);
                pages[1] = vmalloc_to_page(addr + PAGE_SIZE);
@@ -518,18 +526,21 @@ void *__kprobes text_poke(void *addr, const void *opcode, size_t len)
                pages[1] = virt_to_page(addr + PAGE_SIZE);
        }
        BUG_ON(!pages[0]);
-       if (!pages[1])
-               nr_pages = 1;
-       vaddr = vmap(pages, nr_pages, VM_MAP, PAGE_KERNEL);
-       BUG_ON(!vaddr);
-       local_irq_disable();
+       local_irq_save(flags);
+       set_fixmap(FIX_TEXT_POKE0, page_to_phys(pages[0]));
+       if (pages[1])
+               set_fixmap(FIX_TEXT_POKE1, page_to_phys(pages[1]));
+       vaddr = (char *)fix_to_virt(FIX_TEXT_POKE0);
        memcpy(&vaddr[(unsigned long)addr & ~PAGE_MASK], opcode, len);
-       local_irq_enable();
-       vunmap(vaddr);
+       clear_fixmap(FIX_TEXT_POKE0);
+       if (pages[1])
+               clear_fixmap(FIX_TEXT_POKE1);
+       local_flush_tlb();
        sync_core();
        /* Could also do a CLFLUSH here to speed up CPU recovery; but
           that causes hangs on some VIA CPUs. */
        for (i = 0; i < len; i++)
                BUG_ON(((char *)addr)[i] != ((char *)opcode)[i]);
+       local_irq_restore(flags);
        return addr;
 }