1 files changed, 14 insertions, 9 deletions

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index a84ac7b570e..4c80f155743 100644
--- 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