[PATCH] vmalloc might sleep

[PATCH] vmalloc might sleep

[Matthew Wilcox]

So let's whack people upside the head when they misuse it.

vmalloc-might-sleep.diff:

Index: mm/vmalloc.c
===================================================================
RCS file: /var/cvs/linux-2.6/mm/vmalloc.c,v
retrieving revision 1.2
diff -u -p -r1.2 vmalloc.c
--- a/mm/vmalloc.c	23 Aug 2003 02:47:26 -0000	1.2
+++ b/mm/vmalloc.c	31 Aug 2003 03:04:25 -0000
@@ -438,7 +438,8 @@ fail:
  */
 void *vmalloc(unsigned long size)
 {
-       return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL);
+	might_sleep();
+	return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL);
 }
 
 /**
@@ -451,6 +452,7 @@ void *vmalloc(unsigned long size)
  */
 void *vmalloc_32(unsigned long size)
 {
+	might_sleep();
 	return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL);
 }
 

-- 
"It's not Hollywood.  War is real, war is primarily not about defeat or
victory, it is about death.  I've seen thousands and thousands of dead bodies.
Do you think I want to have an academic debate on this subject?" -- Robert Fisk

Re: [PATCH] vmalloc might sleep

[viro]

On Sun, Aug 31, 2003 at 04:06:43AM +0100, Matthew Wilcox wrote:
> 
> So let's whack people upside the head when they misuse it.
> 
> vmalloc-might-sleep.diff:
> 
> Index: mm/vmalloc.c
> ===================================================================
> RCS file: /var/cvs/linux-2.6/mm/vmalloc.c,v
> retrieving revision 1.2
> diff -u -p -r1.2 vmalloc.c
> --- a/mm/vmalloc.c	23 Aug 2003 02:47:26 -0000	1.2
> +++ b/mm/vmalloc.c	31 Aug 2003 03:04:25 -0000
> @@ -438,7 +438,8 @@ fail:
>   */
>  void *vmalloc(unsigned long size)
>  {
> -       return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL);
> +	might_sleep();
> +	return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL);

__vmalloc() goes kmalloc() to get an array of struct page pointers.  And
both for vmalloc() and vmalloc_32() kmalloc() will be called with GFP_KERNEL
as gfp_mask.  Which already has might_sleep().