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| author | Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz> | 2011-05-09 13:01:09 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-05-21 15:13:07 -0700 |
| commit | e277c750ea81076d8dc68694acc7994a024d83b2 (patch) | |
| tree | 5bb1a87f3c6f05d348a823be4d1685431bf09bcb /include/linux | |
| parent | 3dead919f4cf95df59d8df06c1fa559c55571384 (diff) | |
| download | linux-2.6.38-lt-ux500-e277c750ea81076d8dc68694acc7994a024d83b2.tar.gz | |
Don't lock guardpage if the stack is growing up
commit a09a79f66874c905af35d5bb5e5f2fdc7b6b894d upstream.
Linux kernel excludes guard page when performing mlock on a VMA with
down-growing stack. However, some architectures have up-growing stack
and locking the guard page should be excluded in this case too.
This patch fixes lvm2 on PA-RISC (and possibly other architectures with
up-growing stack). lvm2 calculates number of used pages when locking and
when unlocking and reports an internal error if the numbers mismatch.
[ Patch changed fairly extensively to also fix /proc/<pid>/maps for the
grows-up case, and to move things around a bit to clean it all up and
share the infrstructure with the /proc bits.
Tested on ia64 that has both grow-up and grow-down segments - Linus ]
Signed-off-by: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Tested-by: Tony Luck <tony.luck@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/mm.h | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 248c9468503..957a90b962f 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -994,11 +994,33 @@ int set_page_dirty_lock(struct page *page); int clear_page_dirty_for_io(struct page *page); /* Is the vma a continuation of the stack vma above it? */ -static inline int vma_stack_continue(struct vm_area_struct *vma, unsigned long addr) +static inline int vma_growsdown(struct vm_area_struct *vma, unsigned long addr) { return vma && (vma->vm_end == addr) && (vma->vm_flags & VM_GROWSDOWN); } +static inline int stack_guard_page_start(struct vm_area_struct *vma, + unsigned long addr) +{ + return (vma->vm_flags & VM_GROWSDOWN) && + (vma->vm_start == addr) && + !vma_growsdown(vma->vm_prev, addr); +} + +/* Is the vma a continuation of the stack vma below it? */ +static inline int vma_growsup(struct vm_area_struct *vma, unsigned long addr) +{ + return vma && (vma->vm_start == addr) && (vma->vm_flags & VM_GROWSUP); +} + +static inline int stack_guard_page_end(struct vm_area_struct *vma, + unsigned long addr) +{ + return (vma->vm_flags & VM_GROWSUP) && + (vma->vm_end == addr) && + !vma_growsup(vma->vm_next, addr); +} + extern unsigned long move_page_tables(struct vm_area_struct *vma, unsigned long old_addr, struct vm_area_struct *new_vma, unsigned long new_addr, unsigned long len); |