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authorHugh Dickins <hughd@google.com>2013-04-29 15:07:44 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-05-07 19:51:55 -0700
commit273a82bee94d42ba58b264bc427cd75df65b81fc (patch)
tree29c58f1e1b209f4e6ab09fb0ea8188e52501d6db /mm
parentede49f3642cce1fe60ac81cb1953e7a8fd91e8ce (diff)
downloadlwn-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.c4
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);
/*