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=-3.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 694C0C433E6 for ; Sun, 30 Aug 2020 04:41:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3C6A2208DB for ; Sun, 30 Aug 2020 04:41:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="oIvGVXCN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726078AbgH3Ek5 (ORCPT ); Sun, 30 Aug 2020 00:40:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42468 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725815AbgH3Ekz (ORCPT ); Sun, 30 Aug 2020 00:40:55 -0400 Received: from mail-il1-x143.google.com (mail-il1-x143.google.com [IPv6:2607:f8b0:4864:20::143]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7059CC061573 for ; Sat, 29 Aug 2020 21:40:55 -0700 (PDT) Received: by mail-il1-x143.google.com with SMTP id q14so3947708ilm.2 for ; Sat, 29 Aug 2020 21:40:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=HHWDMq/nbO4xHE4a0KqcQiAEa78+4OGfNY+553VihpA=; b=oIvGVXCNlLGgwIZeCgWK+LINRZM6tE8Fy0EICDHiZqnaqDcBZaxirt4X7zZZzXpN+I m8Iye277Hzg8IzN5WcPFqm8R4U6o2lTwrv3mdi7/6zbfNOjMYPDr5sS7JcFV/Fi1d8W7 mqQY5NKNRemjIm9VF6eEebcNaXWrLLkQuUo2sFAG5ZQn+hGVFpCIvDkIup35FPjeVnb9 paGHyjWKtJeVeEBs8VS0C1x7Y0wo8oAGImx2vzHQM9JrYO8SKn/QNdx+FdJ1DSfqCfFW 1JmSo6quY+Drh2k5ofagjJUCfAzcxBGe5tNyct5JFg5EhiVlgPVNIxQN3m+MFghZ/reK /abg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=HHWDMq/nbO4xHE4a0KqcQiAEa78+4OGfNY+553VihpA=; b=JUn8qBEul35RBi69dYhRBhF5erbOwHgHDjl/X4NRueEtuRhpXp8tZzSfNhZ7N9GcV3 Ys44nEGucwVjThUPCK5eS/fLRovQgxFDAz13BpUKZ5HjT4l6E8OanFKXiQJKGpk77k9p j3miePHJ0Kj9w9xIQ/S38UIBWTdhdLDWFtNmkkjwqFv57q5BoUXsHkjVELjTJvPQSCaP GiNilYRXdP+xPYq/hi7Q/NwoW517N1ZBIEJSeGi2fsm5MXGD9PTMTOr8Wng8jWeu971O Bg6G+Rud7MZzx77lyY6oOFpZZ/AgwYy5zzHUECTjTU5tcPqkZDsaqpZnHnVyCRFjLz41 z0rA== X-Gm-Message-State: AOAM532o0WmsbU0Zv1nrZM4G+2pgIVJheF9+NJihkgZP24i/j0x1BB76 dGnxwt86kFqeAwb/PhLtDRe1gkSh4MxHYCERzQ== X-Google-Smtp-Source: ABdhPJyswRQJrqQ6CNwwCr4ZFRbkXMz3EXEYiZmPALIPayfK8vBxYKHmTP+7ld1GVqWc67Sn09tff89X/btVnlDY8DI= X-Received: by 2002:a92:6a09:: with SMTP id f9mr4725159ilc.273.1598762453371; Sat, 29 Aug 2020 21:40:53 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Brian Gerst Date: Sun, 30 Aug 2020 00:40:42 -0400 Message-ID: Subject: Re: ptrace_syscall_32 is failing To: Andy Lutomirski Cc: Thomas Gleixner , X86 ML , LKML Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Aug 29, 2020 at 12:52 PM Andy Lutomirski wrote: > > Seems to be a recent regression, maybe related to entry/exit work changes. > > # ./tools/testing/selftests/x86/ptrace_syscall_32 > [RUN] Check int80 return regs > [OK] getpid() preserves regs > [OK] kill(getpid(), SIGUSR1) preserves regs > [RUN] Check AT_SYSINFO return regs > [OK] getpid() preserves regs > [OK] kill(getpid(), SIGUSR1) preserves regs > [RUN] ptrace-induced syscall restart > Child will make one syscall > [RUN] SYSEMU > [FAIL] Initial args are wrong (nr=224, args=10 11 12 13 14 4289172732) > [RUN] Restart the syscall (ip = 0xf7f3b549) > [OK] Restarted nr and args are correct > [RUN] Change nr and args and restart the syscall (ip = 0xf7f3b549) > [OK] Replacement nr and args are correct > [OK] Child exited cleanly > [RUN] kernel syscall restart under ptrace > Child will take a nap until signaled > [RUN] SYSCALL > [FAIL] Initial args are wrong (nr=29, args=0 0 0 0 0 4289172732) > [RUN] SYSCALL > [OK] Args after SIGUSR1 are correct (ax = -514) > [OK] Child got SIGUSR1 > [RUN] Step again > [OK] pause(2) restarted correctly Bisected to commit 0b085e68f407 ("x86/entry: Consolidate 32/64 bit syscall entry"). It looks like it is because syscall_enter_from_user_mode() is called before reading the 6th argument from the user stack. -- Brian Gerst