From patchwork Mon May 3 20:38:06 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: 1473360 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=sparclinux-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4FYvvx05lKz9sV5 for ; Tue, 4 May 2021 06:39:09 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229753AbhECUkB (ORCPT ); Mon, 3 May 2021 16:40:01 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:56182 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229715AbhECUj4 (ORCPT ); Mon, 3 May 2021 16:39:56 -0400 Received: from in02.mta.xmission.com ([166.70.13.52]) by out01.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1ldfLJ-00HIYI-46; Mon, 03 May 2021 14:39:01 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95] helo=fess.int.ebiederm.org) by in02.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1ldfLH-00E76Y-Jc; Mon, 03 May 2021 14:39:00 -0600 From: "Eric W. Beiderman" To: Marco Elver Cc: Arnd Bergmann , Florian Weimer , "David S. Miller" , Peter Zijlstra , Ingo Molnar , Thomas Gleixner , Peter Collingbourne , Dmitry Vyukov , Alexander Potapenko , sparclinux , linux-arch , Linux Kernel Mailing List , Linux API , kasan-dev , "Eric W. Biederman" Date: Mon, 3 May 2021 15:38:06 -0500 Message-Id: <20210503203814.25487-4-ebiederm@xmission.com> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210503203814.25487-1-ebiederm@xmission.com> References: <20210503203814.25487-1-ebiederm@xmission.com> MIME-Version: 1.0 X-XM-SPF: eid=1ldfLH-00E76Y-Jc;;;mid=<20210503203814.25487-4-ebiederm@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX186YKRMudYyrGqdB/6JL/jwCZDR82Moz7c= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on sa07.xmission.com X-Spam-Level: *** X-Spam-Status: No, score=3.4 required=8.0 tests=ALL_TRUSTED,BAYES_50, DCC_CHECK_NEGATIVE,FVGT_m_MULTI_ODD,T_TM2_M_HEADER_IN_MSG, T_TooManySym_01,T_XMDrugObfuBody_08,XMNoVowels,XMSubLong autolearn=disabled version=3.4.2 X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.5000] * 0.7 XMSubLong Long Subject * 1.5 XMNoVowels Alpha-numberic number with no vowels * 0.0 T_TM2_M_HEADER_IN_MSG BODY: No description available. * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa07 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject * 0.4 FVGT_m_MULTI_ODD Contains multiple odd letter combinations * 1.0 T_XMDrugObfuBody_08 obfuscated drug references X-Spam-DCC: XMission; sa07 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ***;Marco Elver X-Spam-Relay-Country: X-Spam-Timing: total 711 ms - load_scoreonly_sql: 0.08 (0.0%), signal_user_changed: 11 (1.5%), b_tie_ro: 9 (1.3%), parse: 1.09 (0.2%), extract_message_metadata: 14 (1.9%), get_uri_detail_list: 3.8 (0.5%), tests_pri_-1000: 13 (1.8%), tests_pri_-950: 1.26 (0.2%), tests_pri_-900: 1.04 (0.1%), tests_pri_-90: 138 (19.5%), check_bayes: 137 (19.2%), b_tokenize: 15 (2.1%), b_tok_get_all: 10 (1.4%), b_comp_prob: 2.6 (0.4%), b_tok_touch_all: 106 (14.9%), b_finish: 0.86 (0.1%), tests_pri_0: 515 (72.5%), check_dkim_signature: 0.69 (0.1%), check_dkim_adsp: 2.2 (0.3%), poll_dns_idle: 0.50 (0.1%), tests_pri_10: 3.3 (0.5%), tests_pri_500: 11 (1.5%), rewrite_mail: 0.00 (0.0%) Subject: [PATCH 04/12] siginfo: Move si_trapno inside the union inside _si_fault 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: sparclinux@vger.kernel.org From: "Eric W. Biederman" It turns out that linux uses si_trapno very sparingly, and as such it can be considered extra information for a very narrow selection of signals, rather than information that is present with every fault reported in siginfo. As such move si_trapno inside the union inside of _si_fault. This results in no change in placement, and makes it eaiser to extend _si_fault in the future as this reduces the number of special cases. In particular with si_trapno included in the union it is no longer a concern that the union must be pointer alligned on most architectures because the union followes immediately after si_addr which is a pointer. This change results in a difference in siginfo field placement on sparc and alpha for the fields si_addr_lsb, si_lower, si_upper, si_pkey, and si_perf. These architectures do not implement the signals that would use si_addr_lsb, si_lower, si_upper, si_pkey, and si_perf. Further these architecture have not yet implemented the userspace that would use si_perf. The point of this change is in fact to correct these placement issues before sparc or alpha grow userspace that cares. This change was discussed[1] and the agreement is that this change is currently safe. [1]: https://lkml.kernel.org/r/CAK8P3a0+uKYwL1NhY6Hvtieghba2hKYGD6hcKx5n8=4Gtt+pHA@mail.gmail.com Acked-by: Marco Elver v1: https://lkml.kernel.org/r/m1tunns7yf.fsf_-_@fess.ebiederm.org Signed-off-by: "Eric W. Biederman" --- arch/sparc/kernel/signal32.c | 10 +++++----- arch/sparc/kernel/signal_64.c | 10 +++++----- arch/x86/kernel/signal_compat.c | 3 +++ include/linux/compat.h | 5 ++--- include/uapi/asm-generic/siginfo.h | 7 ++----- kernel/signal.c | 1 + 6 files changed, 18 insertions(+), 18 deletions(-) diff --git a/arch/sparc/kernel/signal32.c b/arch/sparc/kernel/signal32.c index 778ed5c26d4a..73fd8700df3e 100644 --- a/arch/sparc/kernel/signal32.c +++ b/arch/sparc/kernel/signal32.c @@ -772,10 +772,10 @@ static_assert(offsetof(compat_siginfo_t, si_int) == 0x14); static_assert(offsetof(compat_siginfo_t, si_ptr) == 0x14); static_assert(offsetof(compat_siginfo_t, si_addr) == 0x0c); static_assert(offsetof(compat_siginfo_t, si_trapno) == 0x10); -static_assert(offsetof(compat_siginfo_t, si_addr_lsb) == 0x14); -static_assert(offsetof(compat_siginfo_t, si_lower) == 0x18); -static_assert(offsetof(compat_siginfo_t, si_upper) == 0x1c); -static_assert(offsetof(compat_siginfo_t, si_pkey) == 0x18); -static_assert(offsetof(compat_siginfo_t, si_perf) == 0x14); +static_assert(offsetof(compat_siginfo_t, si_addr_lsb) == 0x10); +static_assert(offsetof(compat_siginfo_t, si_lower) == 0x14); +static_assert(offsetof(compat_siginfo_t, si_upper) == 0x18); +static_assert(offsetof(compat_siginfo_t, si_pkey) == 0x14); +static_assert(offsetof(compat_siginfo_t, si_perf) == 0x10); static_assert(offsetof(compat_siginfo_t, si_band) == 0x0c); static_assert(offsetof(compat_siginfo_t, si_fd) == 0x10); diff --git a/arch/sparc/kernel/signal_64.c b/arch/sparc/kernel/signal_64.c index c9bbf5f29078..17913daa66c6 100644 --- a/arch/sparc/kernel/signal_64.c +++ b/arch/sparc/kernel/signal_64.c @@ -582,10 +582,10 @@ static_assert(offsetof(siginfo_t, si_int) == 0x18); static_assert(offsetof(siginfo_t, si_ptr) == 0x18); static_assert(offsetof(siginfo_t, si_addr) == 0x10); static_assert(offsetof(siginfo_t, si_trapno) == 0x18); -static_assert(offsetof(siginfo_t, si_addr_lsb) == 0x20); -static_assert(offsetof(siginfo_t, si_lower) == 0x28); -static_assert(offsetof(siginfo_t, si_upper) == 0x30); -static_assert(offsetof(siginfo_t, si_pkey) == 0x28); -static_assert(offsetof(siginfo_t, si_perf) == 0x20); +static_assert(offsetof(siginfo_t, si_addr_lsb) == 0x18); +static_assert(offsetof(siginfo_t, si_lower) == 0x20); +static_assert(offsetof(siginfo_t, si_upper) == 0x28); +static_assert(offsetof(siginfo_t, si_pkey) == 0x20); +static_assert(offsetof(siginfo_t, si_perf) == 0x18); static_assert(offsetof(siginfo_t, si_band) == 0x10); static_assert(offsetof(siginfo_t, si_fd) == 0x14); diff --git a/arch/x86/kernel/signal_compat.c b/arch/x86/kernel/signal_compat.c index 0e5d0a7e203b..a9fcabd8a5e5 100644 --- a/arch/x86/kernel/signal_compat.c +++ b/arch/x86/kernel/signal_compat.c @@ -127,6 +127,9 @@ static inline void signal_compat_build_tests(void) BUILD_BUG_ON(offsetof(siginfo_t, si_addr) != 0x10); BUILD_BUG_ON(offsetof(compat_siginfo_t, si_addr) != 0x0C); + BUILD_BUG_ON(offsetof(siginfo_t, si_trapno) != 0x18); + BUILD_BUG_ON(offsetof(compat_siginfo_t, si_trapno) != 0x10); + BUILD_BUG_ON(offsetof(siginfo_t, si_addr_lsb) != 0x18); BUILD_BUG_ON(offsetof(compat_siginfo_t, si_addr_lsb) != 0x10); diff --git a/include/linux/compat.h b/include/linux/compat.h index f0d2dd35d408..6af7bef15e94 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -214,12 +214,11 @@ typedef struct compat_siginfo { /* SIGILL, SIGFPE, SIGSEGV, SIGBUS, SIGTRAP, SIGEMT */ struct { compat_uptr_t _addr; /* faulting insn/memory ref. */ -#ifdef __ARCH_SI_TRAPNO - int _trapno; /* TRAP # which caused the signal */ -#endif #define __COMPAT_ADDR_BND_PKEY_PAD (__alignof__(compat_uptr_t) < sizeof(short) ? \ sizeof(short) : __alignof__(compat_uptr_t)) union { + /* used on alpha and sparc */ + int _trapno; /* TRAP # which caused the signal */ /* * used when si_code=BUS_MCEERR_AR or * used when si_code=BUS_MCEERR_AO diff --git a/include/uapi/asm-generic/siginfo.h b/include/uapi/asm-generic/siginfo.h index 03d6f6d2c1fe..e663bf117b46 100644 --- a/include/uapi/asm-generic/siginfo.h +++ b/include/uapi/asm-generic/siginfo.h @@ -63,9 +63,6 @@ union __sifields { /* SIGILL, SIGFPE, SIGSEGV, SIGBUS, SIGTRAP, SIGEMT */ struct { void __user *_addr; /* faulting insn/memory ref. */ -#ifdef __ARCH_SI_TRAPNO - int _trapno; /* TRAP # which caused the signal */ -#endif #ifdef __ia64__ int _imm; /* immediate value for "break" */ unsigned int _flags; /* see ia64 si_flags */ @@ -75,6 +72,8 @@ union __sifields { #define __ADDR_BND_PKEY_PAD (__alignof__(void *) < sizeof(short) ? \ sizeof(short) : __alignof__(void *)) union { + /* used on alpha and sparc */ + int _trapno; /* TRAP # which caused the signal */ /* * used when si_code=BUS_MCEERR_AR or * used when si_code=BUS_MCEERR_AO @@ -150,9 +149,7 @@ typedef struct siginfo { #define si_int _sifields._rt._sigval.sival_int #define si_ptr _sifields._rt._sigval.sival_ptr #define si_addr _sifields._sigfault._addr -#ifdef __ARCH_SI_TRAPNO #define si_trapno _sifields._sigfault._trapno -#endif #define si_addr_lsb _sifields._sigfault._addr_lsb #define si_lower _sifields._sigfault._addr_bnd._lower #define si_upper _sifields._sigfault._addr_bnd._upper diff --git a/kernel/signal.c b/kernel/signal.c index c3017aa8024a..65888aec65a0 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -4607,6 +4607,7 @@ static inline void siginfo_buildtime_checks(void) /* sigfault */ CHECK_OFFSET(si_addr); + CHECK_OFFSET(si_trapno); CHECK_OFFSET(si_addr_lsb); CHECK_OFFSET(si_lower); CHECK_OFFSET(si_upper);