From 6ee8630e02be6dd89926ca0fbc21af68b23dc087 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Mon, 29 Apr 2013 15:07:44 -0700 Subject: mm: allow arch code to control the user page table ceiling 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 Signed-off-by: Catalin Marinas Cc: Russell King Cc: [3.3+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mmap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'mm/mmap.c') diff --git a/mm/mmap.c b/mm/mmap.c index b2c363f7ae54..288958f05f1c 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2302,7 +2302,7 @@ static void unmap_region(struct mm_struct *mm, update_hiwater_rss(mm); unmap_vmas(&tlb, vma, start, end); 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); } @@ -2682,7 +2682,7 @@ void exit_mmap(struct mm_struct *mm) /* Use -1 here to ensure all VMAs in the mm are unmapped */ unmap_vmas(&tlb, vma, 0, -1); - free_pgtables(&tlb, vma, FIRST_USER_ADDRESS, 0); + free_pgtables(&tlb, vma, FIRST_USER_ADDRESS, USER_PGTABLES_CEILING); tlb_finish_mmu(&tlb, 0, -1); /* -- cgit v1.2.3