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>
diff --git a/mm/mmap.c b/mm/mmap.c
index e76f8d7..adb1252 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1774,7 +1774,7 @@
/*
* 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 @@
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)
{