From patchwork Wed Oct 20 17:32:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Eric W. Biederman" X-Patchwork-Id: 12572805 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4CB51C433EF for ; Wed, 20 Oct 2021 17:32:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2D65A60F57 for ; Wed, 20 Oct 2021 17:32:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230179AbhJTRew (ORCPT ); Wed, 20 Oct 2021 13:34:52 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:39418 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229941AbhJTRew (ORCPT ); Wed, 20 Oct 2021 13:34:52 -0400 Received: from in01.mta.xmission.com ([166.70.13.51]:55338) by out01.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mdFS2-00EuET-9k; Wed, 20 Oct 2021 11:32:30 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95]:47416 helo=email.xmission.com) by in01.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mdFS0-009qGU-Te; Wed, 20 Oct 2021 11:32:29 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Cc: , Linus Torvalds , Oleg Nesterov , Al Viro , Kees Cook , Andy Lutomirski , Jonas Bonn , Stefan Kristiansson , Stafford Horne , openrisc@lists.librecores.org, Nick Hu , Greentime Hu , Vincent Chen , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , linux-s390@vger.kernel.org, Yoshinori Sato , Rich Felker , linux-sh@vger.kernel.org, linux-xtensa@linux-xtensa.org, Chris Zankel , Max Filippov , David Miller , sparclinux@vger.kernel.org, Thomas Bogendoerfer , Maciej Rozycki , linux-mips@vger.kernel.org, Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , linuxppc-dev@lists.ozlabs.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , H Peter Anvin , Greg Kroah-Hartman Date: Wed, 20 Oct 2021 12:32:20 -0500 Message-ID: <87y26nmwkb.fsf@disp2133> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 X-XM-SPF: eid=1mdFS0-009qGU-Te;;;mid=<87y26nmwkb.fsf@disp2133>;;;hst=in01.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1+QTFOF+6WLUwS/6b+bA87HzOEzbRhNKPA= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH 00/20] exit cleanups X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org While looking at some issues related to the exit path in the kernel I found several instances where the code is not using the existing abstractions properly. This set of changes introduces force_fatal_sig a way of sending a signal and not allowing it to be caught, and corrects the misuse of the existing abstractions that I found. A lot of the misuse of the existing abstractions are silly things such as doing something after calling a no return function, rolling BUG by hand, doing more work than necessary to terminate a kernel thread, or calling do_exit(SIGKILL) instead of calling force_sig(SIGKILL). It is my plan after sending all of these changes out for review to place them in a topic branch for sending Linus. Especially for the changes that depend upon the new helper force_fatal_sig this is important. Eric W. Biederman (20): exit/doublefault: Remove apparently bogus comment about rewind_stack_do_exit exit: Remove calls of do_exit after noreturn versions of die reboot: Remove the unreachable panic after do_exit in reboot(2) signal/sparc32: Remove unreachable do_exit in do_sparc_fault signal/mips: Update (_save|_restore)_fp_context to fail with -EFAULT signal/sh: Use force_sig(SIGKILL) instead of do_group_exit(SIGKILL) signal/powerpc: On swapcontext failure force SIGSEGV signal/sparc: In setup_tsb_params convert open coded BUG into BUG signal/vm86_32: Replace open coded BUG_ON with an actual BUG_ON signal/vm86_32: Properly send SIGSEGV when the vm86 state cannot be saved. signal/s390: Use force_sigsegv in default_trap_handler exit/kthread: Have kernel threads return instead of calling do_exit signal: Implement force_fatal_sig exit/syscall_user_dispatch: Send ordinary signals on failure signal/sparc32: Exit with a fatal signal when try_to_clear_window_buffer fails signal/sparc32: In setup_rt_frame and setup_fram use force_fatal_sig signal/x86: In emulate_vsyscall force a signal instead of calling do_exit exit/rtl8723bs: Replace the macro thread_exit with a simple return 0 exit/rtl8712: Replace the macro thread_exit with a simple return 0 exit/r8188eu: Replace the macro thread_exit with a simple return 0 arch/mips/kernel/r2300_fpu.S | 4 ++-- arch/mips/kernel/syscall.c | 9 -------- arch/nds32/kernel/traps.c | 2 +- arch/nds32/mm/fault.c | 6 +---- arch/openrisc/kernel/traps.c | 2 +- arch/openrisc/mm/fault.c | 4 +--- arch/powerpc/kernel/signal_32.c | 6 +++-- arch/powerpc/kernel/signal_64.c | 9 +++++--- arch/s390/include/asm/kdebug.h | 2 +- arch/s390/kernel/dumpstack.c | 2 +- arch/s390/kernel/traps.c | 2 +- arch/s390/mm/fault.c | 2 -- arch/sh/kernel/cpu/fpu.c | 10 +++++---- arch/sh/kernel/traps.c | 2 +- arch/sh/mm/fault.c | 2 -- arch/sparc/kernel/signal_32.c | 4 ++-- arch/sparc/kernel/windows.c | 6 +++-- arch/sparc/mm/fault_32.c | 1 - arch/sparc/mm/tsb.c | 2 +- arch/x86/entry/vsyscall/vsyscall_64.c | 3 ++- arch/x86/kernel/doublefault_32.c | 3 --- arch/x86/kernel/signal.c | 6 ++++- arch/x86/kernel/vm86_32.c | 8 +++---- arch/xtensa/kernel/traps.c | 2 +- arch/xtensa/mm/fault.c | 3 +-- drivers/firmware/stratix10-svc.c | 4 ++-- drivers/soc/ti/wkup_m3_ipc.c | 2 +- drivers/staging/r8188eu/core/rtw_cmd.c | 2 +- drivers/staging/r8188eu/core/rtw_mp.c | 2 +- drivers/staging/r8188eu/include/osdep_service.h | 2 -- drivers/staging/rtl8712/osdep_service.h | 1 - drivers/staging/rtl8712/rtl8712_cmd.c | 2 +- drivers/staging/rtl8723bs/core/rtw_cmd.c | 2 +- drivers/staging/rtl8723bs/core/rtw_xmit.c | 2 +- drivers/staging/rtl8723bs/hal/rtl8723bs_xmit.c | 2 +- .../rtl8723bs/include/osdep_service_linux.h | 2 -- fs/ocfs2/journal.c | 5 +---- include/linux/sched/signal.h | 1 + kernel/entry/syscall_user_dispatch.c | 12 ++++++---- kernel/kthread.c | 2 +- kernel/reboot.c | 1 - kernel/signal.c | 26 ++++++++++++++-------- net/batman-adv/tp_meter.c | 2 +- 43 files changed, 83 insertions(+), 91 deletions(-) Eric