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

Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/kernel/alternative.c

@@ -498,12 +498,12 @@ 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 +517,9 @@ 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

mm/vmalloc.c

@@ -1257,6 +1257,7 @@ EXPORT_SYMBOL(vfree);
 void vunmap(const void *addr)
 {
 	BUG_ON(in_interrupt());
+	might_sleep();
 	__vunmap(addr, 0);
 }
 EXPORT_SYMBOL(vunmap);
@@ -1276,6 +1277,8 @@ void *vmap(struct page **pages, unsigned int count,
 {
 	struct vm_struct *area;
 
+	might_sleep();
+
 	if (count > num_physpages)
 		return NULL;