From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20120527002616.885608407@linuxfoundation.org> Date: Sun, 27 May 2012 09:26:33 +0900 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Richard Weinberger Subject: [ 20/55] um: Fix __swp_type() In-Reply-To: <20120527005203.GA2146@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Richard Weinberger commit 2b76ebaa728f8a3967c52aa189261c72fe56a6f1 upstream. The current __swp_type() function uses a too small bitshift. Using more than one swap files causes bad pages because the type bits clash with other page flags. Analyzed-by: Hugh Dickins Signed-off-by: Richard Weinberger Signed-off-by: Greg Kroah-Hartman --- arch/um/include/asm/pgtable.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/um/include/asm/pgtable.h +++ b/arch/um/include/asm/pgtable.h @@ -346,11 +346,11 @@ extern pte_t *virt_to_pte(struct mm_stru #define update_mmu_cache(vma,address,ptep) do ; while (0) /* Encode and de-code a swap entry */ -#define __swp_type(x) (((x).val >> 4) & 0x3f) +#define __swp_type(x) (((x).val >> 5) & 0x1f) #define __swp_offset(x) ((x).val >> 11) #define __swp_entry(type, offset) \ - ((swp_entry_t) { ((type) << 4) | ((offset) << 11) }) + ((swp_entry_t) { ((type) << 5) | ((offset) << 11) }) #define __pte_to_swp_entry(pte) \ ((swp_entry_t) { pte_val(pte_mkuptodate(pte)) }) #define __swp_entry_to_pte(x) ((pte_t) { (x).val })