diff options
| author | Luck, Tony <tony.luck@intel.com> | 2010-08-24 11:44:18 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-09-26 17:21:34 -0700 |
| commit | c837b58c0ea48760cc83a2e3ffddd92ac88dd156 (patch) | |
| tree | 9e7b1b1dd45ee3f8396b5a0b40de7d9a22a3dba4 /mm | |
| parent | 288841853e8c83bba82a35937ec19eba59f14548 (diff) | |
guard page for stacks that grow upwards
commit 8ca3eb08097f6839b2206e2242db4179aee3cfb3 upstream.
pa-risc and ia64 have stacks that grow upwards. Check that
they do not run into other mappings. By making VM_GROWSUP
0x0 on architectures that do not ever use it, we can avoid
some unpleasant #ifdefs in check_stack_guard_page().
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: dann frazier <dannf@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memory.c | 15 | ||||
| -rw-r--r-- | mm/mmap.c | 3 |
2 files changed, 11 insertions, 7 deletions
diff --git a/mm/memory.c b/mm/memory.c index 194dc17560ce..53c1da0d04a6 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2630,11 +2630,9 @@ out_release: } /* - * This is like a special single-page "expand_downwards()", - * except we must first make sure that 'address-PAGE_SIZE' + * This is like a special single-page "expand_{down|up}wards()", + * except we must first make sure that 'address{-|+}PAGE_SIZE' * doesn't hit another vma. - * - * The "find_vma()" will do the right thing even if we wrap */ static inline int check_stack_guard_page(struct vm_area_struct *vma, unsigned long address) { @@ -2653,6 +2651,15 @@ static inline int check_stack_guard_page(struct vm_area_struct *vma, unsigned lo expand_stack(vma, address - PAGE_SIZE); } + if ((vma->vm_flags & VM_GROWSUP) && address + PAGE_SIZE == vma->vm_end) { + struct vm_area_struct *next = vma->vm_next; + + /* As VM_GROWSDOWN but s/below/above/ */ + if (next && next->vm_start == address + PAGE_SIZE) + return next->vm_flags & VM_GROWSUP ? 0 : -ENOMEM; + + expand_upwards(vma, address + PAGE_SIZE); + } return 0; } diff --git a/mm/mmap.c b/mm/mmap.c index b309c75b497a..866a66669037 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1600,9 +1600,6 @@ static int acct_stack_growth(struct vm_area_struct *vma, unsigned long size, uns * PA-RISC uses this for its stack; IA64 for its Register Backing Store. * vma is the last one with address > vma->vm_end. Have to extend vma. */ -#ifndef CONFIG_IA64 -static -#endif int expand_upwards(struct vm_area_struct *vma, unsigned long address) { int error; |