Merge branch 'iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip...

[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 a84ac7b570e6bb4582788da74a4c570e28fd65e9..4c80f15574335d6b02bc93a7ed797c088c1da6c2 100644 (file)
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -414,9 +414,17 @@ void __init alternative_instructions(void)
           that might execute the to be patched code.
           Other CPUs are not running. */
        stop_nmi();
-#ifdef CONFIG_X86_MCE
-       stop_mce();
-#endif
+
+       /*
+        * Don't stop machine check exceptions while patching.
+        * MCEs only happen when something got corrupted and in this
+        * case we must do something about the corruption.
+        * Ignoring it is worse than a unlikely patching race.
+        * Also machine checks tend to be broadcast and if one CPU
+        * goes into machine check the others follow quickly, so we don't
+        * expect a machine check to cause undue problems during to code
+        * patching.
+        */
 
        apply_alternatives(__alt_instructions, __alt_instructions_end);
 
@@ -456,9 +464,6 @@ void __init alternative_instructions(void)
                                (unsigned long)__smp_locks_end);
 
        restart_nmi();
-#ifdef CONFIG_X86_MCE
-       restart_mce();
-#endif
 }
 
 /**
@@ -498,12 +503,12 @@ void *text_poke_early(void *addr, const void *opcode, size_t len)
  */
 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);
@@ -517,9 +522,9 @@ void *__kprobes text_poke(void *addr, const void *opcode, size_t len)
                nr_pages = 1;
        vaddr = vmap(pages, nr_pages, VM_MAP, PAGE_KERNEL);
        BUG_ON(!vaddr);
-       local_irq_save(flags);
+       local_irq_disable();
        memcpy(&vaddr[(unsigned long)addr & ~PAGE_MASK], opcode, len);
-       local_irq_restore(flags);
+       local_irq_enable();
        vunmap(vaddr);
        sync_core();
        /* Could also do a CLFLUSH here to speed up CPU recovery; but