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| author | Hugh Dickins <hughd@google.com> | 2013-04-29 15:07:44 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-05-07 20:33:09 -0700 |
| commit | 258497d192b2076453bc86a6299075f76dcabed1 (patch) | |
| tree | a767c1a282de319df44ee2d1ba2d015b9642f5ab /fs | |
| parent | d340c737c4f3bf3490365d2bc8c8ab4f90b02e75 (diff) | |
| download | lwn-258497d192b2076453bc86a6299075f76dcabed1.tar.gz lwn-258497d192b2076453bc86a6299075f76dcabed1.zip | |
mm: allow arch code to control the user page table ceiling
commit 6ee8630e02be6dd89926ca0fbc21af68b23dc087 upstream.
On architectures where a pgd entry may be shared between user and kernel
(e.g. ARM+LPAE), freeing page tables needs a ceiling other than 0.
This patch introduces a generic USER_PGTABLES_CEILING that arch code can
override. It is the responsibility of the arch code setting the ceiling
to ensure the complete freeing of the page tables (usually in
pgd_free()).
[catalin.marinas@arm.com: commit log; shift_arg_pages(), asm-generic/pgtables.h changes]
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/exec.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/exec.c b/fs/exec.c index a96a4885bbbf..87e731f020fb 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -613,7 +613,7 @@ static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) * when the old and new regions overlap clear from new_end. */ free_pgd_range(&tlb, new_end, old_end, new_end, - vma->vm_next ? vma->vm_next->vm_start : 0); + vma->vm_next ? vma->vm_next->vm_start : USER_PGTABLES_CEILING); } else { /* * otherwise, clean from old_start; this is done to not touch @@ -622,7 +622,7 @@ static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) * for the others its just a little faster. */ free_pgd_range(&tlb, old_start, old_end, new_end, - vma->vm_next ? vma->vm_next->vm_start : 0); + vma->vm_next ? vma->vm_next->vm_start : USER_PGTABLES_CEILING); } tlb_finish_mmu(&tlb, new_end, old_end); |