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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 5D043C433E7 for ; Wed, 14 Oct 2020 22:54:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 097DC20797 for ; Wed, 14 Oct 2020 22:54:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="PQ2llucr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730190AbgJNWyY (ORCPT ); Wed, 14 Oct 2020 18:54:24 -0400 Received: from mail.zx2c4.com ([192.95.5.64]:47737 "EHLO mail.zx2c4.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730189AbgJNWyY (ORCPT ); Wed, 14 Oct 2020 18:54:24 -0400 Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTP id 23c1002f; Wed, 14 Oct 2020 22:20:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=zx2c4.com; h=mime-version :references:in-reply-to:from:date:message-id:subject:to:cc :content-type; s=mail; bh=XHEkKwOSP573OP70L/G1jZ0zw04=; b=PQ2llu cr3zGJ+52nI/pqkMngSSZZ9wZNWDMwBl6uKh+xy690cAQFpDU38IrclZZMvbhEEg TlC3A7FeHR3m2FywHbaFSemG19VZW66w+bo/wnTN0D58Eps2+KSlKPNf2UEPPXjO 9cOi4gXE1aZeGmSVMySaKCU2DlRGkPHcnwpmLfota4omz+72DlgVJwxGcBVAQKSd nWZQb1Qe4Wz7lPSgRRulRxJ09QcEvoyw4SKiRi1f3F5xaTbTPiKKdeQ6eFY7l15G 2FjDC53qpvnU1robvQLw+aNvysJk0x4ECz/wLC1MGxBkD4v+TW3NI8mGhyLw9vtR T+oq8TX5x64CJrUg== Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id ee2c4fb9 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Wed, 14 Oct 2020 22:20:44 +0000 (UTC) Received: by mail-io1-f46.google.com with SMTP id k21so1675067ioa.9; Wed, 14 Oct 2020 15:54:19 -0700 (PDT) X-Gm-Message-State: AOAM530D2a2hbEvi3efQYP2heNl1xGxuRZcWqRSYOsXiFoYYysiMy78s +NVAbC4w9ww4Y4wtbIvvwzlK3keHOlCe1AFl2cI= X-Google-Smtp-Source: ABdhPJx7nd6uZrd5MITcpSjRtd7mzZC+L8JBlUV/DELdqVqYoh9IsAgj+V2g9lJeL+rJRWYAJRljcfDWts9sMse3T8Q= X-Received: by 2002:a5e:d606:: with SMTP id w6mr1206594iom.67.1602716059144; Wed, 14 Oct 2020 15:54:19 -0700 (PDT) MIME-Version: 1.0 References: <20200724012512.GK2786714@ZenIV.linux.org.uk> <20200724012546.302155-1-viro@ZenIV.linux.org.uk> <20200724012546.302155-20-viro@ZenIV.linux.org.uk> <20201014222650.GA390346@zx2c4.com> In-Reply-To: From: "Jason A. Donenfeld" Date: Thu, 15 Oct 2020 00:54:08 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 20/20] ppc: propagate the calling conventions change down to csum_partial_copy_generic() To: Linus Torvalds Cc: Al Viro , Linux Kernel Mailing List , linux-arch , Netdev Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org On Thu, Oct 15, 2020 at 12:53 AM Linus Torvalds wrote: > > On Wed, Oct 14, 2020 at 3:51 PM Linus Torvalds > wrote: > > > > I think it's this instruction: > > > > addi r1,r1,16 > > > > that should be removed from the function exit, because Al removed the > > > > - stwu r1,-16(r1) > > > > on function entry. > > > > So I think you end up with a corrupt stack pointer and basically > > random behavior. > > > > Mind trying that? (This is obviously all in > > arch/powerpc/lib/checksum_32.S, the csum_partial_copy_generic() > > function). > > Patch attached to make it easier to test. > > NOTE! This is ENTIRELY untested. My ppc asm is so rusty that I might > be barking entirely up the wrong tree, and I just made things much > worse. Indeed - exactly the same thing that's in my tree. Writing a commit message for it now. Jason