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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 2EDEBC4338F for ; Sun, 25 Jul 2021 17:21:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0D5C460F11 for ; Sun, 25 Jul 2021 17:21:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229829AbhGYQlZ (ORCPT ); Sun, 25 Jul 2021 12:41:25 -0400 Received: from zeniv-ca.linux.org.uk ([142.44.231.140]:46060 "EHLO zeniv-ca.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229545AbhGYQlY (ORCPT ); Sun, 25 Jul 2021 12:41:24 -0400 Received: from viro by zeniv-ca.linux.org.uk with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1m7hmz-003rwk-Eu; Sun, 25 Jul 2021 17:19:45 +0000 Date: Sun, 25 Jul 2021 17:19:45 +0000 From: Al Viro To: linux-m68k@lists.linux-m68k.org Cc: Geert Uytterhoeven , Greg Ungerer , linux-kernel@vger.kernel.org Subject: [PATCH 2/3] m68k: update ->thread.esp0 before calling syscall_trace() in ret_from_signal Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: Al Viro Precedence: bulk List-ID: X-Mailing-List: linux-m68k@vger.kernel.org We get there when sigreturn has performed obscene acts on kernel stack; in particular, the location of pt_regs has shifted. We are about to call syscall_trace(), which might stop for tracer. If that happens, we'd better have task_pt_regs() returning correct result... Fucked-up-by: Al Viro Fixes: bd6f56a75bb2 ("m68k: Missing syscall_trace() on sigreturn") Signed-off-by: Al Viro --- arch/m68k/kernel/entry.S | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/m68k/kernel/entry.S b/arch/m68k/kernel/entry.S index 9dd76fbb7c6b..ff9e842cec0f 100644 --- a/arch/m68k/kernel/entry.S +++ b/arch/m68k/kernel/entry.S @@ -186,6 +186,8 @@ ENTRY(ret_from_signal) movel %curptr@(TASK_STACK),%a1 tstb %a1@(TINFO_FLAGS+2) jge 1f + lea %sp@(SWITCH_STACK_SIZE),%a1 + movel %a1,%curptr@(TASK_THREAD+THREAD_ESP0) jbsr syscall_trace 1: RESTORE_SWITCH_STACK addql #4,%sp -- 2.11.0