From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 443D6C004C9 for ; Tue, 7 May 2019 07:36:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1F20E21019 for ; Tue, 7 May 2019 07:36:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726862AbfEGHgr (ORCPT ); Tue, 7 May 2019 03:36:47 -0400 Received: from mx2.suse.de ([195.135.220.15]:56868 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726449AbfEGHgr (ORCPT ); Tue, 7 May 2019 03:36:47 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 83F24AD17; Tue, 7 May 2019 07:36:46 +0000 (UTC) From: Andreas Schwab To: linux-riscv@lists.infradead.org Subject: [PATCH] riscv: fix locking violation in page fault handler CC: linux-kernel@vger.kernel.org X-Yow: I'm rated PG-34!! Date: Tue, 07 May 2019 09:36:46 +0200 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When a user mode process accesses an address in the vmalloc area do_page_fault tries to unlock the mmap semaphore when it isn't locked. Signed-off-by: Andreas Schwab --- arch/riscv/mm/fault.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c index 88401d5125bc..c51878e5a66a 100644 --- a/arch/riscv/mm/fault.c +++ b/arch/riscv/mm/fault.c @@ -181,6 +181,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs) up_read(&mm->mmap_sem); /* User mode accesses just cause a SIGSEGV */ if (user_mode(regs)) { +bad_area_do_trap: do_trap(regs, SIGSEGV, code, addr, tsk); return; } @@ -230,7 +231,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs) int index; if (user_mode(regs)) - goto bad_area; + goto bad_area_do_trap; /* * Synchronize this task's top level page-table -- 2.21.0 -- Andreas Schwab, SUSE Labs, schwab@suse.de GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7 "And now for something completely different."