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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 19:51:55 -0700 |
commit | 273a82bee94d42ba58b264bc427cd75df65b81fc (patch) | |
tree | 29c58f1e1b209f4e6ab09fb0ea8188e52501d6db /mm | |
parent | ede49f3642cce1fe60ac81cb1953e7a8fd91e8ce (diff) | |
download | lwn-273a82bee94d42ba58b264bc427cd75df65b81fc.tar.gz lwn-273a82bee94d42ba58b264bc427cd75df65b81fc.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 'mm')
-rw-r--r-- | mm/mmap.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index 2add0a1a7aa6..3635d4789486 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1920,7 +1920,7 @@ static void unmap_region(struct mm_struct *mm, unmap_vmas(&tlb, vma, start, end, &nr_accounted, NULL); vm_unacct_memory(nr_accounted); free_pgtables(&tlb, vma, prev ? prev->vm_end : FIRST_USER_ADDRESS, - next ? next->vm_start : 0); + next ? next->vm_start : USER_PGTABLES_CEILING); tlb_finish_mmu(&tlb, start, end); } @@ -2308,7 +2308,7 @@ void exit_mmap(struct mm_struct *mm) unmap_vmas(&tlb, vma, 0, -1, &nr_accounted, NULL); vm_unacct_memory(nr_accounted); - free_pgtables(&tlb, vma, FIRST_USER_ADDRESS, 0); + free_pgtables(&tlb, vma, FIRST_USER_ADDRESS, USER_PGTABLES_CEILING); tlb_finish_mmu(&tlb, 0, -1); /* |