Re: __vmalloc with GFP_ATOMIC causes 'sleeping from invalid context'

From: Giridhar Pemmasani
Date: Mon May 22 2006 - 18:58:40 EST


On Mon, 22 May 2006 14:56:35 -0700, Andrew Morton <akpm@xxxxxxxx> said:

> It was wrong for get_vm_area_node() to have assumed that it could
> use GFP_KERNEL.

> Please just change the top-level API of get_vm_area_node() to
> take a gfp_t and don't worry about the get_vm_area_node_mask()
> thing.

> The only callers of get_vm_area_node() are in vmalloc.c anyway.
> We could in fact make it static, but I guess exposing it as an
> API call makes sense.

In addition, I added BUG_ON(in_interrupt()), as suggested by Nick
Piggin earlier. The patch is against 2.6.17-rc4.

Thanks,
Giri

Signed-off-by: Giridhar Pemmasani <giri@xxxxxxxxxxxxxxxxx>

---

diff -Naur linux-2.6.17-rc4.orig/include/linux/vmalloc.h linux-2.6.17-rc4/include/linux/vmalloc.h
--- linux-2.6.17-rc4.orig/include/linux/vmalloc.h 2006-05-22 18:48:33.000000000 -0400
+++ linux-2.6.17-rc4/include/linux/vmalloc.h 2006-05-22 18:50:40.000000000 -0400
@@ -53,7 +53,8 @@
extern struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
unsigned long start, unsigned long end);
extern struct vm_struct *get_vm_area_node(unsigned long size,
- unsigned long flags, int node);
+ unsigned long flags, int node,
+ gfp_t gfp_mask);
extern struct vm_struct *remove_vm_area(void *addr);
extern struct vm_struct *__remove_vm_area(void *addr);
extern int map_vm_area(struct vm_struct *area, pgprot_t prot,
diff -Naur linux-2.6.17-rc4.orig/mm/vmalloc.c linux-2.6.17-rc4/mm/vmalloc.c
--- linux-2.6.17-rc4.orig/mm/vmalloc.c 2006-05-22 18:48:40.000000000 -0400
+++ linux-2.6.17-rc4/mm/vmalloc.c 2006-05-22 18:47:09.000000000 -0400
@@ -157,13 +157,15 @@
return err;
}

-struct vm_struct *__get_vm_area_node(unsigned long size, unsigned long flags,
- unsigned long start, unsigned long end, int node)
+static struct vm_struct *__get_vm_area_node(unsigned long size, unsigned long flags,
+ unsigned long start, unsigned long end,
+ int node, gfp_t gfp_mask)
{
struct vm_struct **p, *tmp, *area;
unsigned long align = 1;
unsigned long addr;

+ BUG_ON(in_interrupt());
if (flags & VM_IOREMAP) {
int bit = fls(size);

@@ -177,7 +179,7 @@
addr = ALIGN(start, align);
size = PAGE_ALIGN(size);

- area = kmalloc_node(sizeof(*area), GFP_KERNEL, node);
+ area = kmalloc_node(sizeof(*area), gfp_mask, node);
if (unlikely(!area))
return NULL;

@@ -233,7 +235,7 @@
struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
unsigned long start, unsigned long end)
{
- return __get_vm_area_node(size, flags, start, end, -1);
+ return __get_vm_area_node(size, flags, start, end, -1, GFP_KERNEL);
}

/**
@@ -251,9 +253,11 @@
return __get_vm_area(size, flags, VMALLOC_START, VMALLOC_END);
}

-struct vm_struct *get_vm_area_node(unsigned long size, unsigned long flags, int node)
+struct vm_struct *get_vm_area_node(unsigned long size, unsigned long flags,
+ int node, gfp_t gfp_mask)
{
- return __get_vm_area_node(size, flags, VMALLOC_START, VMALLOC_END, node);
+ return __get_vm_area_node(size, flags, VMALLOC_START, VMALLOC_END, node,
+ gfp_mask);
}

/* Caller must hold vmlist_lock */
@@ -471,7 +475,7 @@
if (!size || (size >> PAGE_SHIFT) > num_physpages)
return NULL;

- area = get_vm_area_node(size, VM_ALLOC, node);
+ area = get_vm_area_node(size, VM_ALLOC, node, gfp_mask);
if (!area)
return NULL;


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