x86: make vmap yell louder when it is used under irqs_disabled()

Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index a84ac7b..6907b8e 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -498,12 +498,12 @@
  */
 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 +517,9 @@
 		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