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authorMikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>2011-05-09 13:01:09 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2011-05-21 15:13:07 -0700
commite277c750ea81076d8dc68694acc7994a024d83b2 (patch)
tree5bb1a87f3c6f05d348a823be4d1685431bf09bcb /include
parent3dead919f4cf95df59d8df06c1fa559c55571384 (diff)
downloadlinux-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')
-rw-r--r--include/linux/mm.h24
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);