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authorMichal Hocko <mhocko@suse.cz>2011-05-25 04:11:44 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2011-05-25 19:39:12 +0400
commitd05f3169c0fbca16132ec7c2be71685c6de638b5 (patch)
tree37d82004869fa4e530617883f12cab7538dbd4a6
parent248ac0e1943ad1796393d281b096184719eb3f97 (diff)
downloadlinux-d05f3169c0fbca16132ec7c2be71685c6de638b5.tar.xz
mm: make expand_downwards() symmetrical with expand_upwards()
Currently we have expand_upwards exported while expand_downwards is accessible only via expand_stack or expand_stack_downwards. check_stack_guard_page is a nice example of the asymmetry. It uses expand_stack for VM_GROWSDOWN while expand_upwards is called for VM_GROWSUP case. Let's clean this up by exporting both functions and make those names consistent. Let's use expand_{upwards,downwards} because expanding doesn't always involve stack manipulation (an example is ia64_do_page_fault which uses expand_upwards for registers backing store expansion). expand_downwards has to be defined for both CONFIG_STACK_GROWS{UP,DOWN} because get_arg_page calls the downwards version in the early process initialization phase for growsup configuration. Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: Hugh Dickins <hughd@google.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/exec.c2
-rw-r--r--include/linux/mm.h8
-rw-r--r--mm/memory.c2
-rw-r--r--mm/mmap.c7
4 files changed, 8 insertions, 11 deletions
diff --git a/fs/exec.c b/fs/exec.c
index c1cf372f17a7..e276d5e0abb9 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -200,7 +200,7 @@ static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
#ifdef CONFIG_STACK_GROWSUP
if (write) {
- ret = expand_stack_downwards(bprm->vma, pos);
+ ret = expand_downwards(bprm->vma, pos);
if (ret < 0)
return NULL;
}
diff --git a/include/linux/mm.h b/include/linux/mm.h
index e173cd297d88..d2948af126ca 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1518,15 +1518,17 @@ unsigned long ra_submit(struct file_ra_state *ra,
struct address_space *mapping,
struct file *filp);
-/* Do stack extension */
+/* Generic expand stack which grows the stack according to GROWS{UP,DOWN} */
extern int expand_stack(struct vm_area_struct *vma, unsigned long address);
+
+/* CONFIG_STACK_GROWSUP still needs to to grow downwards at some places */
+extern int expand_downwards(struct vm_area_struct *vma,
+ unsigned long address);
#if VM_GROWSUP
extern int expand_upwards(struct vm_area_struct *vma, unsigned long address);
#else
#define expand_upwards(vma, address) do { } while (0)
#endif
-extern int expand_stack_downwards(struct vm_area_struct *vma,
- unsigned long address);
/* Look up the first VMA which satisfies addr < vm_end, NULL if none. */
extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
diff --git a/mm/memory.c b/mm/memory.c
index 61e66f026563..4c6ea10f3d18 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2966,7 +2966,7 @@ static inline int check_stack_guard_page(struct vm_area_struct *vma, unsigned lo
if (prev && prev->vm_end == address)
return prev->vm_flags & VM_GROWSDOWN ? 0 : -ENOMEM;
- expand_stack(vma, address - PAGE_SIZE);
+ expand_downwards(vma, address - PAGE_SIZE);
}
if ((vma->vm_flags & VM_GROWSUP) && address + PAGE_SIZE == vma->vm_end) {
struct vm_area_struct *next = vma->vm_next;
diff --git a/mm/mmap.c b/mm/mmap.c
index e76f8d752884..adb12527fd0e 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1774,7 +1774,7 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
/*
* vma is the first one with address < vma->vm_start. Have to extend vma.
*/
-static int expand_downwards(struct vm_area_struct *vma,
+int expand_downwards(struct vm_area_struct *vma,
unsigned long address)
{
int error;
@@ -1821,11 +1821,6 @@ static int expand_downwards(struct vm_area_struct *vma,
return error;
}
-int expand_stack_downwards(struct vm_area_struct *vma, unsigned long address)
-{
- return expand_downwards(vma, address);
-}
-
#ifdef CONFIG_STACK_GROWSUP
int expand_stack(struct vm_area_struct *vma, unsigned long address)
{