From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from toomuch.toronto.redhat.com (unknown [172.16.14.22]) by touchme.toronto.redhat.com (Postfix) with ESMTP id E8EA2B8036 for ; Thu, 23 May 2002 16:57:36 -0400 (EDT) Received: (from bcrl@localhost) by toomuch.toronto.redhat.com (8.11.6/8.11.2) id g4NKvak29022 for linux-mm@kvack.org; Thu, 23 May 2002 16:57:36 -0400 Date: Thu, 23 May 2002 16:57:36 -0400 From: Benjamin LaHaise Subject: [bcrl@redhat.com: [PATCH] 2.4.19-pre8 vm86 smp locking fix] Message-ID: <20020523165736.B27881@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: owner-linux-mm@kvack.org Return-Path: To: linux-mm@kvack.org List-ID: ----- Forwarded message from Benjamin LaHaise ----- Subject: [PATCH] 2.4.19-pre8 vm86 smp locking fix From: Benjamin LaHaise To: Linux Kernel , linux-mm@redhat.com Date: Thu, 23 May 2002 16:51:05 -0400 arch/i386/kernel/vm86.c performs page table operations without obtaining any locks. This patch obtains page_table_lock around the the table walk and modification. -ben -- "You will be reincarnated as a toad; and you will be much happier." diff -urN v2.4.19-pre8/arch/i386/kernel/vm86.c work/arch/i386/kernel/vm86.c --- v2.4.19-pre8/arch/i386/kernel/vm86.c Thu Mar 7 16:39:56 2002 +++ work/arch/i386/kernel/vm86.c Thu May 23 16:21:38 2002 @@ -97,21 +97,22 @@ pte_t *pte; int i; + spin_lock(&tsk->mm->page_table_lock); pgd = pgd_offset(tsk->mm, 0xA0000); if (pgd_none(*pgd)) - return; + goto out; if (pgd_bad(*pgd)) { pgd_ERROR(*pgd); pgd_clear(pgd); - return; + goto out; } pmd = pmd_offset(pgd, 0xA0000); if (pmd_none(*pmd)) - return; + goto out; if (pmd_bad(*pmd)) { pmd_ERROR(*pmd); pmd_clear(pmd); - return; + goto out; } pte = pte_offset(pmd, 0xA0000); for (i = 0; i < 32; i++) { @@ -119,6 +120,8 @@ set_pte(pte, pte_wrprotect(*pte)); pte++; } +out: + spin_unlock(&tsk->mm->page_table_lock); flush_tlb(); } ----- End forwarded message ----- -- "You will be reincarnated as a toad; and you will be much happier." -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/