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| author | Michal Hocko <mhocko@suse.cz> | 2011-05-24 17:11:44 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-05-25 08:39:12 -0700 |
| commit | d05f3169c0fbca16132ec7c2be71685c6de638b5 (patch) | |
| tree | 37d82004869fa4e530617883f12cab7538dbd4a6 | |
| parent | 248ac0e1943ad1796393d281b096184719eb3f97 (diff) | |
| download | kernel-common-d05f3169c0fbca16132ec7c2be71685c6de638b5.tar.gz kernel-common-d05f3169c0fbca16132ec7c2be71685c6de638b5.tar.bz2 kernel-common-d05f3169c0fbca16132ec7c2be71685c6de638b5.zip | |
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.c | 2 | ||||
| -rw-r--r-- | include/linux/mm.h | 8 | ||||
| -rw-r--r-- | mm/memory.c | 2 | ||||
| -rw-r--r-- | mm/mmap.c | 7 |
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) { |