From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 373874968FA; Tue, 3 Mar 2026 16:09:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.95.11.211 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772554200; cv=none; b=f51chATlkc0yMPYdCIVpk7CMQnhnY65JaBqbnkHI87FOxTej1hDdTUHHBYcOgeK/BhOsuTynqg1ubCWGUytND3eTcJCMk/un7uXkFH/GnEUq76ZVKoKCm+TLwAGG7E/cx3DmSMsq7RwkRAxrkxXSbMIiXbBuSCs74aLRYaTszFA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772554200; c=relaxed/simple; bh=uFvTetz8mGOK5z7k8vb3s1w2REY1A27szgf4KAs3bOU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jPggJoe5INkAaTYQCJYPGowQwAUoVk2CyRGEOFxGT3/kDqQLZXTlALfrc89i7/NYMJ0DfQsz7IuzETLw23LAeyfHDcLbFCQS0Htn/R4CaiJODEnRrcyGqGmonK4oOGQPPWvUFZwwxraZuwqaQU9RUaCWHxxdYyyX0WZnnfZSFSc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lst.de; spf=pass smtp.mailfrom=lst.de; arc=none smtp.client-ip=213.95.11.211 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lst.de Received: by verein.lst.de (Postfix, from userid 2407) id 6BC1768C4E; Tue, 3 Mar 2026 17:09:55 +0100 (CET) Date: Tue, 3 Mar 2026 17:09:55 +0100 From: Christoph Hellwig To: Eric Biggers Cc: Christoph Hellwig , Andrew Morton , Richard Henderson , Matt Turner , Magnus Lindholm , Russell King , Catalin Marinas , Will Deacon , Huacai Chen , WANG Xuerui , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , "David S. Miller" , Andreas Larsson , Richard Weinberger , Anton Ivanov , Johannes Berg , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Herbert Xu , Dan Williams , Chris Mason , David Sterba , Arnd Bergmann , Song Liu , Yu Kuai , Li Nan , linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-crypto@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-arch@vger.kernel.org, linux-raid@vger.kernel.org Subject: Re: [PATCH 24/25] xor: pass the entire operation to the low-level ops Message-ID: <20260303160955.GJ7021@lst.de> References: <20260226151106.144735-1-hch@lst.de> <20260226151106.144735-25-hch@lst.de> <20260228065810.GJ65277@quark> Precedence: bulk X-Mailing-List: linux-alpha@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260228065810.GJ65277@quark> User-Agent: Mutt/1.5.17 (2007-11-01) On Fri, Feb 27, 2026 at 10:58:10PM -0800, Eric Biggers wrote: > On Thu, Feb 26, 2026 at 07:10:36AM -0800, Christoph Hellwig wrote: > > +#define __DO_XOR_BLOCKS(_name, _handle1, _handle2, _handle3, _handle4) \ > > +void \ > > +xor_gen_##_name(void *dest, void **srcs, unsigned int src_cnt, \ > > + unsigned int bytes) \ > > +{ \ > > + unsigned int src_off = 0; \ > > + \ > > + while (src_cnt > 0) { \ > > + unsigned int this_cnt = min(src_cnt, 4); \ > > + unsigned long *p1 = (unsigned long *)srcs[src_off]; \ > > + unsigned long *p2 = (unsigned long *)srcs[src_off + 1]; \ > > + unsigned long *p3 = (unsigned long *)srcs[src_off + 2]; \ > > + unsigned long *p4 = (unsigned long *)srcs[src_off + 3]; \ > > This reads out of bounds if src_cnt isn't a multiple of 4. Assuming the compiler doesn't do the obvious optimization and drop it, but yes, should be easy enough to avoid this. 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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F2057EDA693 for ; Tue, 3 Mar 2026 16:10:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=onWOSpu73c5kBs7Ydn8jWqGAuGMfxBpnCjJYXEnsqcQ=; b=MHZQTeLOJuxjdZ 92fsXGoIDM9hcidIYsjFWGbKsecb/+w17VcsZqEmtbgasakWREByjOy/tSfhEXaWNXmf64vz71T5d TGBXHKODDyEHFgH57tmFfxqe3eF1MGwyPlGEhMvYBG6m1szH3Me55SXm1pdVkUzBIMi6rq8OdGCBg /bdfpaAgfi7APvO/F1CS5Gl1E7KMQmsB2H9uG4Nn+DhDZXu82UdHoNOiqmQhVgxYQ8hMK3iVDqw9e 9e85cdForMdo/83npCSJH7GRAdGZ40KyLf5l7vty0T5rtlf0d93UWDbGAjVbZf7VjmNK+q4zTQrxo 9qyrCNt9rK17AQL97WnQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vxSJu-0000000FWsJ-13fm; Tue, 03 Mar 2026 16:10:02 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vxSJr-0000000FWrN-1WvC; Tue, 03 Mar 2026 16:10:00 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 6BC1768C4E; Tue, 3 Mar 2026 17:09:55 +0100 (CET) Date: Tue, 3 Mar 2026 17:09:55 +0100 From: Christoph Hellwig To: Eric Biggers Cc: Christoph Hellwig , Andrew Morton , Richard Henderson , Matt Turner , Magnus Lindholm , Russell King , Catalin Marinas , Will Deacon , Huacai Chen , WANG Xuerui , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , "David S. Miller" , Andreas Larsson , Richard Weinberger , Anton Ivanov , Johannes Berg , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Herbert Xu , Dan Williams , Chris Mason , David Sterba , Arnd Bergmann , Song Liu , Yu Kuai , Li Nan , linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-crypto@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-arch@vger.kernel.org, linux-raid@vger.kernel.org Subject: Re: [PATCH 24/25] xor: pass the entire operation to the low-level ops Message-ID: <20260303160955.GJ7021@lst.de> References: <20260226151106.144735-1-hch@lst.de> <20260226151106.144735-25-hch@lst.de> <20260228065810.GJ65277@quark> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20260228065810.GJ65277@quark> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260303_080959_552504_0A80F872 X-CRM114-Status: GOOD ( 15.86 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Fri, Feb 27, 2026 at 10:58:10PM -0800, Eric Biggers wrote: > On Thu, Feb 26, 2026 at 07:10:36AM -0800, Christoph Hellwig wrote: > > +#define __DO_XOR_BLOCKS(_name, _handle1, _handle2, _handle3, _handle4) \ > > +void \ > > +xor_gen_##_name(void *dest, void **srcs, unsigned int src_cnt, \ > > + unsigned int bytes) \ > > +{ \ > > + unsigned int src_off = 0; \ > > + \ > > + while (src_cnt > 0) { \ > > + unsigned int this_cnt = min(src_cnt, 4); \ > > + unsigned long *p1 = (unsigned long *)srcs[src_off]; \ > > + unsigned long *p2 = (unsigned long *)srcs[src_off + 1]; \ > > + unsigned long *p3 = (unsigned long *)srcs[src_off + 2]; \ > > + unsigned long *p4 = (unsigned long *)srcs[src_off + 3]; \ > > This reads out of bounds if src_cnt isn't a multiple of 4. Assuming the compiler doesn't do the obvious optimization and drop it, but yes, should be easy enough to avoid this. _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv