From patchwork Wed Oct 20 17:43:51 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: 12572855 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 BEA7DC433F5 for ; Wed, 20 Oct 2021 17:44:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A77CC6128E for ; Wed, 20 Oct 2021 17:44:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231148AbhJTRrL (ORCPT ); Wed, 20 Oct 2021 13:47:11 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:40460 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230464AbhJTRrH (ORCPT ); Wed, 20 Oct 2021 13:47:07 -0400 Received: from in02.mta.xmission.com ([166.70.13.52]:55052) by out02.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mdFe0-00GCwM-DG; Wed, 20 Oct 2021 11:44:52 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95]:47894 helo=localhost.localdomain) by in02.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mdFdz-001NdN-4w; Wed, 20 Oct 2021 11:44:51 -0600 From: "Eric W. Biederman" To: linux-kernel@vger.kernel.org Cc: linux-arch@vger.kernel.org, Linus Torvalds , Oleg Nesterov , Al Viro , Kees Cook , "Eric W. Biederman" , Thomas Bogendoerfer , Maciej Rozycki , linux-mips@vger.kernel.org Date: Wed, 20 Oct 2021 12:43:51 -0500 Message-Id: <20211020174406.17889-5-ebiederm@xmission.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <87y26nmwkb.fsf@disp2133> References: <87y26nmwkb.fsf@disp2133> MIME-Version: 1.0 X-XM-SPF: eid=1mdFdz-001NdN-4w;;;mid=<20211020174406.17889-5-ebiederm@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX18vAFcVjANIu4vDNha2bth++KrviZjJJPY= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH 05/20] signal/mips: Update (_save|_restore)_fp_context to fail with -EFAULT X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org When an instruction to save or restore a register from the stack fails in _save_fp_context or _restore_fp_context return with -EFAULT. This change was made to r2300_fpu.S[1] but it looks like it got lost with the introduction of EX2[2]. This is also what the other implementation of _save_fp_context and _restore_fp_context in r4k_fpu.S does, and what is needed for the callers to be able to handle the error. Furthermore calling do_exit(SIGSEGV) from bad_stack is wrong because it does not terminate the entire process it just terminates a single thread. As the changed code was the only caller of arch/mips/kernel/syscall.c:bad_stack remove the problematic and now unused helper function. Cc: Thomas Bogendoerfer Cc: Maciej Rozycki Cc: linux-mips@vger.kernel.org [1] 35938a00ba86 ("MIPS: Fix ISA I FP sigcontext access violation handling") [2] f92722dc4545 ("MIPS: Correct MIPS I FP sigcontext layout") Fixes: f92722dc4545 ("MIPS: Correct MIPS I FP sigcontext layout") Signed-off-by: "Eric W. Biederman" Reviewed-by: Kees Cook Acked-by: Maciej W. Rozycki Acked-by: Thomas Bogendoerfer --- arch/mips/kernel/r2300_fpu.S | 4 ++-- arch/mips/kernel/syscall.c | 9 --------- 2 files changed, 2 insertions(+), 11 deletions(-) diff --git a/arch/mips/kernel/r2300_fpu.S b/arch/mips/kernel/r2300_fpu.S index 12e58053544f..cbf6db98cfb3 100644 --- a/arch/mips/kernel/r2300_fpu.S +++ b/arch/mips/kernel/r2300_fpu.S @@ -29,8 +29,8 @@ #define EX2(a,b) \ 9: a,##b; \ .section __ex_table,"a"; \ - PTR 9b,bad_stack; \ - PTR 9b+4,bad_stack; \ + PTR 9b,fault; \ + PTR 9b+4,fault; \ .previous .set mips1 diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c index 2afa3eef486a..5512cd586e6e 100644 --- a/arch/mips/kernel/syscall.c +++ b/arch/mips/kernel/syscall.c @@ -240,12 +240,3 @@ SYSCALL_DEFINE3(cachectl, char *, addr, int, nbytes, int, op) { return -ENOSYS; } - -/* - * If we ever come here the user sp is bad. Zap the process right away. - * Due to the bad stack signaling wouldn't work. - */ -asmlinkage void bad_stack(void) -{ - do_exit(SIGSEGV); -} From patchwork Wed Oct 20 21:51:52 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Eric W. Biederman" X-Patchwork-Id: 12573427 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 631BCC433EF for ; Wed, 20 Oct 2021 21:52:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3DE1A6121E for ; Wed, 20 Oct 2021 21:52:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230442AbhJTVy1 (ORCPT ); Wed, 20 Oct 2021 17:54:27 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:51492 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229842AbhJTVy0 (ORCPT ); Wed, 20 Oct 2021 17:54:26 -0400 Received: from in02.mta.xmission.com ([166.70.13.52]:40000) by out01.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mdJVD-00FiWe-CQ; Wed, 20 Oct 2021 15:52:03 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95]:59328 helo=email.xmission.com) by in02.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mdJVA-002PXD-JP; Wed, 20 Oct 2021 15:52:02 -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 References: <87y26nmwkb.fsf@disp2133> Date: Wed, 20 Oct 2021 16:51:52 -0500 In-Reply-To: <87y26nmwkb.fsf@disp2133> (Eric W. Biederman's message of "Wed, 20 Oct 2021 12:32:20 -0500") Message-ID: <877de7jrev.fsf@disp2133> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 X-XM-SPF: eid=1mdJVA-002PXD-JP;;;mid=<877de7jrev.fsf@disp2133>;;;hst=in02.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX18ePEKUK1liVK4VGBQcsP6jPz9QJs+YQsA= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH 21/20] signal: Replace force_sigsegv(SIGSEGV) with force_fatal_sig(SIGSEGV) X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org Now that force_fatal_sig exists it is unnecessary and a bit confusing to use force_sigsegv in cases where the simpler force_fatal_sig is wanted. So change every instance we can to make the code clearer. Signed-off-by: "Eric W. Biederman" Acked-by: Geert Uytterhoeven Reviewed-by: Philippe Mathieu-Daudé --- arch/arc/kernel/process.c | 2 +- arch/m68k/kernel/traps.c | 2 +- arch/powerpc/kernel/signal_32.c | 2 +- arch/powerpc/kernel/signal_64.c | 4 ++-- arch/s390/kernel/traps.c | 2 +- arch/um/kernel/trap.c | 2 +- arch/x86/kernel/vm86_32.c | 2 +- fs/exec.c | 2 +- 8 files changed, 9 insertions(+), 9 deletions(-) diff --git a/arch/arc/kernel/process.c b/arch/arc/kernel/process.c index 3793876f42d9..8e90052f6f05 100644 --- a/arch/arc/kernel/process.c +++ b/arch/arc/kernel/process.c @@ -294,7 +294,7 @@ int elf_check_arch(const struct elf32_hdr *x) eflags = x->e_flags; if ((eflags & EF_ARC_OSABI_MSK) != EF_ARC_OSABI_CURRENT) { pr_err("ABI mismatch - you need newer toolchain\n"); - force_sigsegv(SIGSEGV); + force_fatal_sig(SIGSEGV); return 0; } diff --git a/arch/m68k/kernel/traps.c b/arch/m68k/kernel/traps.c index 5b19fcdcd69e..74045d164ddb 100644 --- a/arch/m68k/kernel/traps.c +++ b/arch/m68k/kernel/traps.c @@ -1150,7 +1150,7 @@ asmlinkage void set_esp0(unsigned long ssp) */ asmlinkage void fpsp040_die(void) { - force_sigsegv(SIGSEGV); + force_fatal_sig(SIGSEGV); } #ifdef CONFIG_M68KFPU_EMU diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c index 666f3da41232..933ab95805a6 100644 --- a/arch/powerpc/kernel/signal_32.c +++ b/arch/powerpc/kernel/signal_32.c @@ -1063,7 +1063,7 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx, * We kill the task with a SIGSEGV in this situation. */ if (do_setcontext(new_ctx, regs, 0)) { - force_sigsegv(SIGSEGV); + force_fatal_sig(SIGSEGV); return -EFAULT; } diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c index d8de622c9e4a..8ead9b3f47c6 100644 --- a/arch/powerpc/kernel/signal_64.c +++ b/arch/powerpc/kernel/signal_64.c @@ -704,7 +704,7 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx, */ if (__get_user_sigset(&set, &new_ctx->uc_sigmask)) { - force_sigsegv(SIGSEGV); + force_fatal_sig(SIGSEGV); return -EFAULT; } set_current_blocked(&set); @@ -713,7 +713,7 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx, return -EFAULT; if (__unsafe_restore_sigcontext(current, NULL, 0, &new_ctx->uc_mcontext)) { user_read_access_end(); - force_sigsegv(SIGSEGV); + force_fatal_sig(SIGSEGV); return -EFAULT; } user_read_access_end(); diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c index 51729ea2cf8e..01a7c68dcfb6 100644 --- a/arch/s390/kernel/traps.c +++ b/arch/s390/kernel/traps.c @@ -84,7 +84,7 @@ static void default_trap_handler(struct pt_regs *regs) { if (user_mode(regs)) { report_user_fault(regs, SIGSEGV, 0); - force_sigsegv(SIGSEGV); + force_fatal_sig(SIGSEGV); } else die(regs, "Unknown program exception"); } diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c index 3198c4767387..c32efb09db21 100644 --- a/arch/um/kernel/trap.c +++ b/arch/um/kernel/trap.c @@ -158,7 +158,7 @@ static void bad_segv(struct faultinfo fi, unsigned long ip) void fatal_sigsegv(void) { - force_sigsegv(SIGSEGV); + force_fatal_sig(SIGSEGV); do_signal(¤t->thread.regs); /* * This is to tell gcc that we're not returning - do_signal diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c index 040fd01be8b3..7ff0f622abd4 100644 --- a/arch/x86/kernel/vm86_32.c +++ b/arch/x86/kernel/vm86_32.c @@ -159,7 +159,7 @@ void save_v86_state(struct kernel_vm86_regs *regs, int retval) user_access_end(); Efault: pr_alert("could not access userspace vm86 info\n"); - force_sigsegv(SIGSEGV); + force_fatal_sig(SIGSEGV); } static int do_vm86_irq_handling(int subfunction, int irqnumber); diff --git a/fs/exec.c b/fs/exec.c index a098c133d8d7..ac7b51b51f38 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1852,7 +1852,7 @@ static int bprm_execve(struct linux_binprm *bprm, * SIGSEGV. */ if (bprm->point_of_no_return && !fatal_signal_pending(current)) - force_sigsegv(SIGSEGV); + force_fatal_sig(SIGSEGV); out_unmark: current->fs->in_exec = 0;