In mm/vmalloc.c, make usage of guard pages dependant
on CONFIG_DEBUG_PAGEALLOC.
Signed-off-by: Glauber Costa <[EMAIL PROTECTED]>
---
mm/vmalloc.c | 25 +++++++++++++++----------
1 files changed, 15 insertions(+), 10 deletions(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 6fe2003..ed73c6f 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -28,6 +28,11 @@
#include <asm/uaccess.h>
#include <asm/tlbflush.h>
+#ifdef CONFIG_DEBUG_PAGEALLOC
+#define GUARD_PAGE_SIZE PAGE_SIZE
+#else
+#define GUARD_PAGE_SIZE 0
+#endif
/*** Page table manipulation functions ***/
@@ -363,7 +368,7 @@ retry:
}
while (addr + size >= first->va_start && addr + size <= vend) {
- addr = ALIGN(first->va_end + PAGE_SIZE, align);
+ addr = ALIGN(first->va_end, align);
n = rb_next(&first->rb_node);
if (n)
@@ -954,7 +959,7 @@ void unmap_kernel_range(unsigned long addr, unsigned long
size)
int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages)
{
unsigned long addr = (unsigned long)area->addr;
- unsigned long end = addr + area->size - PAGE_SIZE;
+ unsigned long end = addr + area->size - GUARD_PAGE_SIZE;
int err;
err = vmap_page_range(addr, end, prot, *pages);
@@ -1003,7 +1008,7 @@ static struct vm_struct *__get_vm_area_node(unsigned long
size,
/*
* We always allocate a guard page.
*/
- size += PAGE_SIZE;
+ size += GUARD_PAGE_SIZE;
va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
if (IS_ERR(va)) {
@@ -1098,7 +1103,7 @@ struct vm_struct *remove_vm_area(const void *addr)
struct vm_struct *vm = va->private;
struct vm_struct *tmp, **p;
free_unmap_vmap_area(va);
- vm->size -= PAGE_SIZE;
+ vm->size -= GUARD_PAGE_SIZE;
write_lock(&vmlist_lock);
for (p = &vmlist; (tmp = *p) != vm; p = &tmp->next)
@@ -1226,7 +1231,7 @@ static void *__vmalloc_area_node(struct vm_struct *area,
gfp_t gfp_mask,
struct page **pages;
unsigned int nr_pages, array_size, i;
- nr_pages = (area->size - PAGE_SIZE) >> PAGE_SHIFT;
+ nr_pages = (area->size - GUARD_PAGE_SIZE) >> PAGE_SHIFT;
array_size = (nr_pages * sizeof(struct page *));
area->nr_pages = nr_pages;
@@ -1451,7 +1456,7 @@ long vread(char *buf, char *addr, unsigned long count)
read_lock(&vmlist_lock);
for (tmp = vmlist; tmp; tmp = tmp->next) {
vaddr = (char *) tmp->addr;
- if (addr >= vaddr + tmp->size - PAGE_SIZE)
+ if (addr >= vaddr + tmp->size - GUARD_PAGE_SIZE)
continue;
while (addr < vaddr) {
if (count == 0)
@@ -1461,7 +1466,7 @@ long vread(char *buf, char *addr, unsigned long count)
addr++;
count--;
}
- n = vaddr + tmp->size - PAGE_SIZE - addr;
+ n = vaddr + tmp->size - GUARD_PAGE_SIZE - addr;
do {
if (count == 0)
goto finished;
@@ -1489,7 +1494,7 @@ long vwrite(char *buf, char *addr, unsigned long count)
read_lock(&vmlist_lock);
for (tmp = vmlist; tmp; tmp = tmp->next) {
vaddr = (char *) tmp->addr;
- if (addr >= vaddr + tmp->size - PAGE_SIZE)
+ if (addr >= vaddr + tmp->size - GUARD_PAGE_SIZE)
continue;
while (addr < vaddr) {
if (count == 0)
@@ -1498,7 +1503,7 @@ long vwrite(char *buf, char *addr, unsigned long count)
addr++;
count--;
}
- n = vaddr + tmp->size - PAGE_SIZE - addr;
+ n = vaddr + tmp->size - GUARD_PAGE_SIZE - addr;
do {
if (count == 0)
goto finished;
@@ -1544,7 +1549,7 @@ int remap_vmalloc_range(struct vm_area_struct *vma, void
*addr,
if (!(area->flags & VM_USERMAP))
return -EINVAL;
- if (usize + (pgoff << PAGE_SHIFT) > area->size - PAGE_SIZE)
+ if (usize + (pgoff << PAGE_SHIFT) > area->size - GUARD_PAGE_SIZE)
return -EINVAL;
addr += pgoff << PAGE_SHIFT;
--
1.5.6.5
--
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