Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751758AbWJVCcj (ORCPT ); Sat, 21 Oct 2006 22:32:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751762AbWJVCcj (ORCPT ); Sat, 21 Oct 2006 22:32:39 -0400 Received: from ftp.linux-mips.org ([194.74.144.162]:44441 "EHLO ftp.linux-mips.org") by vger.kernel.org with ESMTP id S1751758AbWJVCci (ORCPT ); Sat, 21 Oct 2006 22:32:38 -0400 Date: Sun, 22 Oct 2006 03:32:59 +0100 From: Ralf Baechle To: Linus Torvalds , Andrew Morton Cc: linux-kernel@vger.kernel.org, Atsushi Nemoto Subject: Re: [PATCH 3/3] MIPS: Fix COW D-cache aliasing on fork Message-ID: <20061022023259.GA7258@linux-mips.org> References: <1161275748231-git-send-email-ralf@linux-mips.org> <1161275750378-git-send-email-ralf@linux-mips.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1161275750378-git-send-email-ralf@linux-mips.org> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3422 Lines: 100 With parts of the previous patch 3/3 just having been applied this new patch replaces it. < ---- snip ---- > From: Atsushi Nemoto MIPS: Fix COW D-cache aliasing on fork Provide a custom copy_user_highpage() to deal with aliasing issues on MIPS. It uses kmap_coherent() to map an user page for kernel with same color. The main part of this patch was originally written by Ralf Baechle; Atushi Nemoto did the the debugging. Signed-off-by: Atsushi Nemoto Signed-off-by: Ralf Baechle arch/mips/mm/init.c | 25 +++++++++++++++++++++++++ include/asm-mips/page.h | 17 ++++++----------- 2 files changed, 31 insertions(+), 11 deletions(-) Index: upstream-alias/arch/mips/mm/init.c =================================================================== --- upstream-alias.orig/arch/mips/mm/init.c 2006-10-22 03:08:41.000000000 +0100 +++ upstream-alias/arch/mips/mm/init.c 2006-10-22 03:08:45.000000000 +0100 @@ -203,6 +203,31 @@ static inline void kunmap_coherent(struc preempt_check_resched(); } +void copy_user_highpage(struct page *to, struct page *from, + unsigned long vaddr, struct vm_area_struct *vma) +{ + void *vfrom, *vto; + + vto = kmap_atomic(to, KM_USER1); + if (cpu_has_dc_aliases) { + vfrom = kmap_coherent(from, vaddr); + copy_page(vto, vfrom); + kunmap_coherent(from); + } else { + vfrom = kmap_atomic(from, KM_USER0); + copy_page(vto, vfrom); + kunmap_atomic(vfrom, KM_USER0); + } + if (((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc) || + pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK)) + flush_data_cache_page((unsigned long)vto); + kunmap_atomic(vto, KM_USER1); + /* Make sure this page is cleared on other CPU's too before using it */ + smp_wmb(); +} + +EXPORT_SYMBOL(copy_user_highpage); + void copy_to_user_page(struct vm_area_struct *vma, struct page *page, unsigned long vaddr, void *dst, const void *src, unsigned long len) Index: upstream-alias/include/asm-mips/page.h =================================================================== --- upstream-alias.orig/include/asm-mips/page.h 2006-10-22 03:08:41.000000000 +0100 +++ upstream-alias/include/asm-mips/page.h 2006-10-22 03:08:45.000000000 +0100 @@ -34,8 +34,6 @@ #ifndef __ASSEMBLY__ -#include - extern void clear_page(void * page); extern void copy_page(void * to, void * from); @@ -59,16 +57,13 @@ static inline void clear_user_page(void flush_data_cache_page((unsigned long)addr); } -static inline void copy_user_page(void *vto, void *vfrom, unsigned long vaddr, - struct page *to) -{ - extern void (*flush_data_cache_page)(unsigned long addr); +extern void copy_user_page(void *vto, void *vfrom, unsigned long vaddr, + struct page *to); +struct vm_area_struct; +extern void copy_user_highpage(struct page *to, struct page *from, + unsigned long vaddr, struct vm_area_struct *vma); - copy_page(vto, vfrom); - if (!cpu_has_ic_fills_f_dc || - pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK)) - flush_data_cache_page((unsigned long)vto); -} +#define __HAVE_ARCH_COPY_USER_HIGHPAGE /* * These are used to make use of C type-checking.. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/