From patchwork Wed Aug 21 15:21:55 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 1150945 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 46DBJj3w9Bz9sBF for ; Thu, 22 Aug 2019 01:23:49 +1000 (AEST) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=c-s.fr Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=c-s.fr header.i=@c-s.fr header.b="PfpbmyeO"; dkim-atps=neutral Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 46DBJj2gMVzDqbt for ; Thu, 22 Aug 2019 01:23:49 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=c-s.fr (client-ip=93.17.236.30; helo=pegase1.c-s.fr; envelope-from=christophe.leroy@c-s.fr; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=c-s.fr Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=c-s.fr header.i=@c-s.fr header.b="PfpbmyeO"; dkim-atps=neutral Received: from pegase1.c-s.fr (pegase1.c-s.fr [93.17.236.30]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 46DBGb3cHTzDqQY for ; Thu, 22 Aug 2019 01:21:59 +1000 (AEST) Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 46DBGT3qLvz9v10J; Wed, 21 Aug 2019 17:21:53 +0200 (CEST) Authentication-Results: localhost; dkim=pass reason="1024-bit key; insecure key" header.d=c-s.fr header.i=@c-s.fr header.b=PfpbmyeO; dkim-adsp=pass; dkim-atps=neutral X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id Yea5GLHY7gcW; Wed, 21 Aug 2019 17:21:53 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 46DBGT2m02z9v10H; Wed, 21 Aug 2019 17:21:53 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=c-s.fr; s=mail; t=1566400913; bh=I8W+l3URIFEwj3Ss1WM0wfluCLpBRXTInP46mMV22d4=; h=From:Subject:To:Cc:Date:From; b=PfpbmyeOY7IMD4ZIOr8lWmZb7POGDj+V4KjBacdBHmV5U1bpIdw7UghNP/ClJ8x1L hH6aYGyaO5yCq5uwuKQjWAGhn0/GukAbkfBDszDN+nClH2fiPh8g+bI5XKk9LiuZbG jDMU7ro+YKk32+GM7Oe7WEXN8TTg+eY+zv0iNhWI= Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id A00128B7F7; Wed, 21 Aug 2019 17:21:55 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id gD5cCgbd2cwg; Wed, 21 Aug 2019 17:21:55 +0200 (CEST) Received: from pc16032vm.idsi0.si.c-s.fr (po15451.idsi0.si.c-s.fr [172.25.230.101]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 7FDAB8B7EE; Wed, 21 Aug 2019 17:21:55 +0200 (CEST) Received: by pc16032vm.idsi0.si.c-s.fr (Postfix, from userid 0) id 70ADB6B708; Wed, 21 Aug 2019 15:21:55 +0000 (UTC) Message-Id: <4f88d7e6fda53b5f80a71040ab400242f6c8cb93.1566400889.git.christophe.leroy@c-s.fr> From: Christophe Leroy Subject: [PATCH] powerpc/mm: tell if a bad page fault on data is read or write. To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman Date: Wed, 21 Aug 2019 15:21:55 +0000 (UTC) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" DSISR has a bit to tell if the fault is due to a read or a write. Display it. Signed-off-by: Christophe Leroy Reviewed-by: Santosh Sivaraj --- arch/powerpc/mm/fault.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 8432c281de92..b5047f9b5dec 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -645,6 +645,7 @@ NOKPROBE_SYMBOL(do_page_fault); void bad_page_fault(struct pt_regs *regs, unsigned long address, int sig) { const struct exception_table_entry *entry; + int is_write = page_fault_is_write(regs->dsisr); /* Are we prepared to handle this fault? */ if ((entry = search_exception_tables(regs->nip)) != NULL) { @@ -658,9 +659,10 @@ void bad_page_fault(struct pt_regs *regs, unsigned long address, int sig) case 0x300: case 0x380: case 0xe00: - pr_alert("BUG: %s at 0x%08lx\n", + pr_alert("BUG: %s on %s at 0x%08lx\n", regs->dar < PAGE_SIZE ? "Kernel NULL pointer dereference" : - "Unable to handle kernel data access", regs->dar); + "Unable to handle kernel data access", + is_write ? "write" : "read", regs->dar); break; case 0x400: case 0x480: