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=-9.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 8BE49C43457 for ; Wed, 14 Oct 2020 23:02:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2C56D22264 for ; Wed, 14 Oct 2020 23:02:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="gYz9PJ4B" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388282AbgJNXCe (ORCPT ); Wed, 14 Oct 2020 19:02:34 -0400 Received: from mail.zx2c4.com ([192.95.5.64]:42481 "EHLO mail.zx2c4.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731265AbgJNXCS (ORCPT ); Wed, 14 Oct 2020 19:02:18 -0400 Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTP id 075e12dc; Wed, 14 Oct 2020 22:28:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=zx2c4.com; h=from:to:cc :subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; s=mail; bh=EPozuoj+BDm/fNTp6nmCgRrnb EI=; b=gYz9PJ4B7EuU6vk6qPqdAddg4bDnwzOOhB6j96pC1QC6JhgGVLnYQz//V MCUGHyzXTkEynX7iFMjllnvi0ui1qLCCbWWq0E6/JfxIbFUmwx85fYInWLGTU2x8 uGMPSFB6nnmKrmWU585OZjOG9jA9TOlN56cqtPJG6LWOlxlD0RJsWYdrar/f8hVM 1zTcSfx+0yvy532DRFJMpXnnpv6TJp4EZ5C+x36/7kFXFanjjCpD+5ol4Sh/8jd6 aj0bz65xTT3as0O4g2fOyDLcEbpkGSKn1Fh7X1lw7JrRZdsIiBt2eJ0C13DqlPUO kF+2z+5Ug6eHBHfoQXEPlMCqc9wZA== Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 992bda79 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Wed, 14 Oct 2020 22:28:40 +0000 (UTC) From: "Jason A. Donenfeld" To: Al Viro , Linus Torvalds , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, netdev@vger.kernel.org Cc: "Jason A. Donenfeld" Subject: [PATCH] powerpc32: don't adjust unmoved stack pointer in csum_partial_copy_generic() epilogue Date: Thu, 15 Oct 2020 01:02:09 +0200 Message-Id: <20201014230209.427011-1-Jason@zx2c4.com> In-Reply-To: <20201014222650.GA390346@zx2c4.com> References: <20201014222650.GA390346@zx2c4.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A recent change to the checksum code removed usage of some extra arguments, alongside with storage on the stack for those, and the stack pointer no longer needed to be adjusted in the function prologue. But, a left over subtraction wasn't removed in the function epilogue, causing the function to return with the stack pointer moved 16 bytes away from where it should have. This corrupted local state and lead to weird crashes. This commit simply removes the leftover instruction from the epilogue. Fixes: 70d65cd555c5 ("ppc: propagate the calling conventions change down to csum_partial_copy_generic()") Cc: Al Viro Signed-off-by: Jason A. Donenfeld --- arch/powerpc/lib/checksum_32.S | 1 - 1 file changed, 1 deletion(-) diff --git a/arch/powerpc/lib/checksum_32.S b/arch/powerpc/lib/checksum_32.S index ec5cd2dede35..27d9070617df 100644 --- a/arch/powerpc/lib/checksum_32.S +++ b/arch/powerpc/lib/checksum_32.S @@ -236,7 +236,6 @@ _GLOBAL(csum_partial_copy_generic) slwi r0,r0,8 adde r12,r12,r0 66: addze r3,r12 - addi r1,r1,16 beqlr+ cr7 rlwinm r3,r3,8,0,31 /* odd destination address: rotate one byte */ blr -- 2.28.0