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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 46B0EC48BE5 for ; Sat, 12 Jun 2021 23:39:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0757C61108 for ; Sat, 12 Jun 2021 23:39:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231548AbhFLXla (ORCPT ); Sat, 12 Jun 2021 19:41:30 -0400 Received: from mail-pl1-f181.google.com ([209.85.214.181]:35565 "EHLO mail-pl1-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231479AbhFLXla (ORCPT ); Sat, 12 Jun 2021 19:41:30 -0400 Received: by mail-pl1-f181.google.com with SMTP id x19so4671776pln.2 for ; Sat, 12 Jun 2021 16:39:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=6DYIKrUXMcsL4MIVy/dc7Q9toGqp4qAGWl+gq54bqdk=; b=N53F1VinuVv0AWyAoc7M3J+1r59cTqMdDJ4f4JVqPQeMdsbm546Tpx6LTzuBd9/gTz L7HxF/MbrHGnrtAwIF/LL/FWQCxLEfRaf1X16VvkC/33S3oHeEtCRz3zgVejelgpmw26 pduA5sUg8/2G7hRi5j/J0Zy+pPisYuhVPqfgZbSkkWJ7cMCvZ8ShqWxFTmMHfUrs1RbN o3ZwlAqMIIrRB8XQjLzIrtkX1bVuoK/xm4jhdLlN8r1euWxALcI/jwit0VauIIF/3wC2 n9h/zs/A25hWBrMjPk9LFdDXIGNQPxCIoWtVXovWUvy11+e7nXMzNVe4P9o05kzezxp5 5hUg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=6DYIKrUXMcsL4MIVy/dc7Q9toGqp4qAGWl+gq54bqdk=; b=pt/rTx9/V50eoUhvo1QEu2qP3IrcXcMlbizp0uVkCN67IRW4ofu9goyIjdFeyJHZnw CDiUxfaw3RHN6ft/TxPbT5pGqdVHQE8JInKqLJ/GxXX7GfBTjBfuLy/fb6jJdOfZewcF g/8KDInxfzdVlQ7obX108KQMHFUnJMFLO77mHo8yAgndz92CuXRRR3dfNw//kC8iusGc N8mvAdLmomAstYeb4fos/flPuDK4gzKX+1Y1yZsHT+m+baprWW0PR0imPGfTspXTyiyG UeYiK6gfTyAlGmPCJRlAKRT0n4Yt/1UCQoCJKwZtaEA/Cumfqsdkn0L9nuJMnk8HYmNy 3feA== X-Gm-Message-State: AOAM531Jm2CleWfK2aNwMK3fAN5LHBcQZJrKpyXoCfOhXQ3OVFOSEZSV moJ0Yma4Vl405r9ImDSKgXs= X-Google-Smtp-Source: ABdhPJwU4fpMmMl7S0gj2YqbLjrsWqvDhDcG/GGfh6anjev0C45OjP7b3hwW0Kpk2L8MmhLfZcGNmg== X-Received: by 2002:a17:90a:17c8:: with SMTP id q66mr16070296pja.154.1623541103926; Sat, 12 Jun 2021 16:38:23 -0700 (PDT) Received: from xplor.waratah.dyndns.org (222-152-189-137-fibre.sparkbb.co.nz. [222.152.189.137]) by smtp.gmail.com with ESMTPSA id j9sm7876809pjy.25.2021.06.12.16.38.22 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sat, 12 Jun 2021 16:38:23 -0700 (PDT) Received: by xplor.waratah.dyndns.org (Postfix, from userid 1000) id CE17736040F; Sun, 13 Jun 2021 11:38:19 +1200 (NZST) From: Michael Schmitz To: geert@linux-m68k.org, linux-arch@vger.kernel.org, linux-m68k@lists.linux-m68k.org Cc: ebiederm@xmission.com, torvalds@linux-foundation.org, schwab@linux-m68k.org, Michael Schmitz Subject: [PATCH v1] m68k: save extra registers on sys_exit and sys_exit_group syscall entry Date: Sun, 13 Jun 2021 11:38:18 +1200 Message-Id: <1623541098-6532-1-git-send-email-schmitzmic@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <87sg1p30a1.fsf@disp2133> References: <87sg1p30a1.fsf@disp2133> Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org do_exit() calls prace_stop() which may require access to all saved registers. We only save those registers not preserved by C code currently. Provide a special syscall entry for exit and exit_group syscalls similar to that used by clone and clone3, which have the same requirements. No fix to io_uring appears to be needed, because m68k copy_thread treats kernel threads the same as e.g. alpha does, and copies only a subset of registers in that case. CC: Eric W. Biederman CC: Linus Torvalds CC: Andreas Schwab Signed-off-by: Michael Schmitz --- arch/m68k/kernel/entry.S | 14 ++++++++++++++ arch/m68k/kernel/process.c | 16 ++++++++++++++++ arch/m68k/kernel/syscalls/syscall.tbl | 4 ++-- 3 files changed, 32 insertions(+), 2 deletions(-) diff --git a/arch/m68k/kernel/entry.S b/arch/m68k/kernel/entry.S index 9dd76fb..1e067e6 100644 --- a/arch/m68k/kernel/entry.S +++ b/arch/m68k/kernel/entry.S @@ -76,6 +76,20 @@ ENTRY(__sys_clone3) lea %sp@(28),%sp rts +ENTRY(__sys_exit) + SAVE_SWITCH_STACK + pea %sp@(SWITCH_STACK_SIZE) + jbsr m68k_exit + lea %sp@(28),%sp + rts + +ENTRY(__sys_exit_group) + SAVE_SWITCH_STACK + pea %sp@(SWITCH_STACK_SIZE) + jbsr m68k_exit_group + lea %sp@(28),%sp + rts + ENTRY(sys_sigreturn) SAVE_SWITCH_STACK movel %sp,%sp@- | switch_stack pointer diff --git a/arch/m68k/kernel/process.c b/arch/m68k/kernel/process.c index da83cc8..df4e5f1 100644 --- a/arch/m68k/kernel/process.c +++ b/arch/m68k/kernel/process.c @@ -138,6 +138,22 @@ asmlinkage int m68k_clone3(struct pt_regs *regs) return sys_clone3((struct clone_args __user *)regs->d1, regs->d2); } +/* + * Because extra registers are saved on the stack after the sys_exit() + * arguments, this C wrapper extracts them from pt_regs * and then calls the + * generic sys_exit() implementation. + */ +asmlinkage int m68k_exit(struct pt_regs *regs) +{ + return sys_exit(regs->d1); +} + +/* Same for sys_exit_group ... */ +asmlinkage int m68k_exit_group(struct pt_regs *regs) +{ + return sys_exit_group(regs->d1); +} + int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg, struct task_struct *p, unsigned long tls) { diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl index 0dd019d..3d5b6fbc 100644 --- a/arch/m68k/kernel/syscalls/syscall.tbl +++ b/arch/m68k/kernel/syscalls/syscall.tbl @@ -8,7 +8,7 @@ # The is always "common" for this file # 0 common restart_syscall sys_restart_syscall -1 common exit sys_exit +1 common exit __sys_exit 2 common fork __sys_fork 3 common read sys_read 4 common write sys_write @@ -254,7 +254,7 @@ 244 common io_submit sys_io_submit 245 common io_cancel sys_io_cancel 246 common fadvise64 sys_fadvise64 -247 common exit_group sys_exit_group +247 common exit_group __sys_exit_group 248 common lookup_dcookie sys_lookup_dcookie 249 common epoll_create sys_epoll_create 250 common epoll_ctl sys_epoll_ctl -- 2.7.4