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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,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 BD9B5C43441 for ; Tue, 27 Nov 2018 09:35:45 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 743B52086B for ; Tue, 27 Nov 2018 09:35:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 743B52086B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 433zDH4P5SzDqjZ for ; Tue, 27 Nov 2018 20:35:43 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Received: from ozlabs.org (bilbo.ozlabs.org [203.11.71.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 433yws61yhzDqdl for ; Tue, 27 Nov 2018 20:22:21 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Received: by ozlabs.org (Postfix, from userid 1034) id 433yws366jz9s9G; Tue, 27 Nov 2018 20:22:21 +1100 (AEDT) X-powerpc-patch-notification: thanks X-powerpc-patch-commit: 5249497a7bb6334fcc128588d6a7e1e21786515a In-Reply-To: <1540996702-27161-1-git-send-email-leitao@debian.org> To: Breno Leitao , linuxppc-dev@lists.ozlabs.org From: Michael Ellerman Subject: Re: [v2,1/3] selftests/powerpc: Allocate base registers Message-Id: <433yws366jz9s9G@ozlabs.org> Date: Tue, 27 Nov 2018 20:22:21 +1100 (AEDT) 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: Breno Leitao Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Wed, 2018-10-31 at 14:38:20 UTC, Breno Leitao wrote: > Some ptrace selftests are passing input operands using a constraint that > can allocate any register for the operand, and using these registers on > load/store operations. > > If the register allocated by the compiler happens to be zero (r0), it might > cause an invalid memory address access, since load and store operations > consider the content of 0x0 address if the base register is r0, instead of > the content of the r0 register. For example: > > r1 := 0xdeadbeef > r0 := 0xdeadbeef > > ld r2, 0(1) /* will load into r2 the content of r1 address */ > ld r2, 0(0) /* will load into r2 the content of 0x0 */ > > In order to avoid this possible problem, the inline assembly constraint > should be aware that these registers will be used as a base register, thus, > r0 should not be allocated. > > Other than that, this patch removes inline assembly operands that are not > used by the tests. > > Signed-off-by: Breno Leitao > Reviewed-by: Segher Boessenkool Series applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/5249497a7bb6334fcc128588d6a7e1 cheers