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=-9.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 7F808C47256 for ; Tue, 5 May 2020 10:13:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4F078206CC for ; Tue, 5 May 2020 10:13:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="SSeEywTd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728703AbgEEKNX (ORCPT ); Tue, 5 May 2020 06:13:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39032 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1728695AbgEEKNV (ORCPT ); Tue, 5 May 2020 06:13:21 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B9E40C061A10; Tue, 5 May 2020 03:13:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=L0Fi4OmEy/vXWrkbLOxIAklPfYbCMsJaeMZCcyjYe7A=; b=SSeEywTdNRy7myQR+esW9J/mC7 /6W9EwmEodGph0fzN72evNwv8MSS9sHqWApw7jEGHLkQKf5k77BrzZEIT/BK4Wj94mtZe1vqMt9wl IxcVm3XLsDBMJ2D3qR5+e49+qm2lfxOzSChS/7xk/iiF0rCHjUoAxKwsstNEtHPgSL2r7zKk6L25N Mq79zli2EuZNkqK2X0GlKyvEcX/pjIDsl+S2SlkxYAi+HBXJJxAYSk4uoU0TCCtmqVjvlrKZF497J thSW4vB93lIW4NlCXFLP5R/DDbgu6c9Ij8zJIb36iOU6W+ODsZ1cQXYMRC02D684H5LdtQVzmohf9 FvXYW4Ow==; Received: from [2001:4bb8:191:66b6:c70:4a89:bc61:2] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jVuZa-0006uv-6l; Tue, 05 May 2020 10:13:10 +0000 From: Christoph Hellwig To: Andrew Morton , Alexander Viro Cc: Linus Torvalds , Jeremy Kerr , Arnd Bergmann , Oleg Nesterov , "Eric W . Biederman" , x86@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 4/7] signal: refactor copy_siginfo_to_user32 Date: Tue, 5 May 2020 12:12:53 +0200 Message-Id: <20200505101256.3121270-5-hch@lst.de> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200505101256.3121270-1-hch@lst.de> References: <20200505101256.3121270-1-hch@lst.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Factor out a copy_siginfo_to_external32 helper from copy_siginfo_to_user32 that fills out the compat_siginfo, but does so on a kernel space data structure. With that we can let architectures override copy_siginfo_to_user32 with their own implementations using copy_siginfo_to_external32. That allows moving the x32 SIGCHLD purely to x86 architecture code. As a nice side effect copy_siginfo_to_external32 also comes in handy for avoiding a set_fs() call in the coredump code later on. Contains improvements from Eric W. Biederman and Arnd Bergmann . Signed-off-by: Christoph Hellwig --- arch/x86/ia32/ia32_signal.c | 2 +- arch/x86/include/asm/compat.h | 8 ++- arch/x86/kernel/signal.c | 28 ++++++++- include/linux/compat.h | 11 +++- kernel/signal.c | 106 +++++++++++++++++----------------- 5 files changed, 96 insertions(+), 59 deletions(-) diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c index f9d8804144d09..81cf22398cd16 100644 --- a/arch/x86/ia32/ia32_signal.c +++ b/arch/x86/ia32/ia32_signal.c @@ -350,7 +350,7 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig, unsafe_put_user(*(__u64 *)set, (__u64 *)&frame->uc.uc_sigmask, Efault); user_access_end(); - if (__copy_siginfo_to_user32(&frame->info, &ksig->info, false)) + if (__copy_siginfo_to_user32(&frame->info, &ksig->info)) return -EFAULT; /* Set up registers for signal handler */ diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h index 52e9f3480f690..d4edf281fff49 100644 --- a/arch/x86/include/asm/compat.h +++ b/arch/x86/include/asm/compat.h @@ -214,7 +214,11 @@ static inline bool in_compat_syscall(void) #endif struct compat_siginfo; -int __copy_siginfo_to_user32(struct compat_siginfo __user *to, - const kernel_siginfo_t *from, bool x32_ABI); + +#ifdef CONFIG_X86_X32_ABI +int copy_siginfo_to_user32(struct compat_siginfo __user *to, + const kernel_siginfo_t *from); +#define copy_siginfo_to_user32 copy_siginfo_to_user32 +#endif /* CONFIG_X86_X32_ABI */ #endif /* _ASM_X86_COMPAT_H */ diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index 83b74fb38c8fc..f3df262e370b3 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -37,6 +37,7 @@ #include #ifdef CONFIG_X86_64 +#include #include #include #endif /* CONFIG_X86_64 */ @@ -511,6 +512,31 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig, } #endif /* CONFIG_X86_32 */ +#ifdef CONFIG_X86_X32_ABI +static int x32_copy_siginfo_to_user(struct compat_siginfo __user *to, + const struct kernel_siginfo *from) +{ + struct compat_siginfo new; + + copy_siginfo_to_external32(&new, from); + if (from->si_signo == SIGCHLD) { + new._sifields._sigchld_x32._utime = from->si_utime; + new._sifields._sigchld_x32._stime = from->si_stime; + } + if (copy_to_user(to, &new, sizeof(struct compat_siginfo))) + return -EFAULT; + return 0; +} + +int copy_siginfo_to_user32(struct compat_siginfo __user *to, + const struct kernel_siginfo *from) +{ + if (in_x32_syscall()) + return x32_copy_siginfo_to_user(to, from); + return __copy_siginfo_to_user32(to, from); +} +#endif /* CONFIG_X86_X32_ABI */ + static int x32_setup_rt_frame(struct ksignal *ksig, compat_sigset_t *set, struct pt_regs *regs) @@ -543,7 +569,7 @@ static int x32_setup_rt_frame(struct ksignal *ksig, user_access_end(); if (ksig->ka.sa.sa_flags & SA_SIGINFO) { - if (__copy_siginfo_to_user32(&frame->info, &ksig->info, true)) + if (x32_copy_siginfo_to_user(&frame->info, &ksig->info)) return -EFAULT; } diff --git a/include/linux/compat.h b/include/linux/compat.h index 0480ba4db5929..e90100c0de72e 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -402,8 +402,15 @@ long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask, unsigned long bitmap_size); long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask, unsigned long bitmap_size); -int copy_siginfo_from_user32(kernel_siginfo_t *to, const struct compat_siginfo __user *from); -int copy_siginfo_to_user32(struct compat_siginfo __user *to, const kernel_siginfo_t *from); +void copy_siginfo_to_external32(struct compat_siginfo *to, + const struct kernel_siginfo *from); +int copy_siginfo_from_user32(kernel_siginfo_t *to, + const struct compat_siginfo __user *from); +int __copy_siginfo_to_user32(struct compat_siginfo __user *to, + const kernel_siginfo_t *from); +#ifndef copy_siginfo_to_user32 +#define copy_siginfo_to_user32 __copy_siginfo_to_user32 +#endif int get_compat_sigevent(struct sigevent *event, const struct compat_sigevent __user *u_event); diff --git a/kernel/signal.c b/kernel/signal.c index 284fc1600063b..5ca48cc5da760 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -3235,94 +3235,94 @@ int copy_siginfo_from_user(kernel_siginfo_t *to, const siginfo_t __user *from) } #ifdef CONFIG_COMPAT -int copy_siginfo_to_user32(struct compat_siginfo __user *to, - const struct kernel_siginfo *from) -#if defined(CONFIG_X86_X32_ABI) || defined(CONFIG_IA32_EMULATION) -{ - return __copy_siginfo_to_user32(to, from, in_x32_syscall()); -} -int __copy_siginfo_to_user32(struct compat_siginfo __user *to, - const struct kernel_siginfo *from, bool x32_ABI) -#endif +/** + * copy_siginfo_to_external32 - copy a kernel siginfo into a compat user siginfo + * @to: compat siginfo destination + * @from: kernel siginfo source + * + * Note: This function does not work properly for the SIGCHLD on x32, but + * fortunately it doesn't have to. The only valid callers for this function are + * copy_siginfo_to_user32, which is overriden for x32 and the coredump code. + * The latter does not care because SIGCHLD will never cause a coredump. + */ +void copy_siginfo_to_external32(struct compat_siginfo *to, + const struct kernel_siginfo *from) { - struct compat_siginfo new; - memset(&new, 0, sizeof(new)); + memset(to, 0, sizeof(*to)); - new.si_signo = from->si_signo; - new.si_errno = from->si_errno; - new.si_code = from->si_code; + to->si_signo = from->si_signo; + to->si_errno = from->si_errno; + to->si_code = from->si_code; switch(siginfo_layout(from->si_signo, from->si_code)) { case SIL_KILL: - new.si_pid = from->si_pid; - new.si_uid = from->si_uid; + to->si_pid = from->si_pid; + to->si_uid = from->si_uid; break; case SIL_TIMER: - new.si_tid = from->si_tid; - new.si_overrun = from->si_overrun; - new.si_int = from->si_int; + to->si_tid = from->si_tid; + to->si_overrun = from->si_overrun; + to->si_int = from->si_int; break; case SIL_POLL: - new.si_band = from->si_band; - new.si_fd = from->si_fd; + to->si_band = from->si_band; + to->si_fd = from->si_fd; break; case SIL_FAULT: - new.si_addr = ptr_to_compat(from->si_addr); + to->si_addr = ptr_to_compat(from->si_addr); #ifdef __ARCH_SI_TRAPNO - new.si_trapno = from->si_trapno; + to->si_trapno = from->si_trapno; #endif break; case SIL_FAULT_MCEERR: - new.si_addr = ptr_to_compat(from->si_addr); + to->si_addr = ptr_to_compat(from->si_addr); #ifdef __ARCH_SI_TRAPNO - new.si_trapno = from->si_trapno; + to->si_trapno = from->si_trapno; #endif - new.si_addr_lsb = from->si_addr_lsb; + to->si_addr_lsb = from->si_addr_lsb; break; case SIL_FAULT_BNDERR: - new.si_addr = ptr_to_compat(from->si_addr); + to->si_addr = ptr_to_compat(from->si_addr); #ifdef __ARCH_SI_TRAPNO - new.si_trapno = from->si_trapno; + to->si_trapno = from->si_trapno; #endif - new.si_lower = ptr_to_compat(from->si_lower); - new.si_upper = ptr_to_compat(from->si_upper); + to->si_lower = ptr_to_compat(from->si_lower); + to->si_upper = ptr_to_compat(from->si_upper); break; case SIL_FAULT_PKUERR: - new.si_addr = ptr_to_compat(from->si_addr); + to->si_addr = ptr_to_compat(from->si_addr); #ifdef __ARCH_SI_TRAPNO - new.si_trapno = from->si_trapno; + to->si_trapno = from->si_trapno; #endif - new.si_pkey = from->si_pkey; + to->si_pkey = from->si_pkey; break; case SIL_CHLD: - new.si_pid = from->si_pid; - new.si_uid = from->si_uid; - new.si_status = from->si_status; -#ifdef CONFIG_X86_X32_ABI - if (x32_ABI) { - new._sifields._sigchld_x32._utime = from->si_utime; - new._sifields._sigchld_x32._stime = from->si_stime; - } else -#endif - { - new.si_utime = from->si_utime; - new.si_stime = from->si_stime; - } + to->si_pid = from->si_pid; + to->si_uid = from->si_uid; + to->si_status = from->si_status; + to->si_utime = from->si_utime; + to->si_stime = from->si_stime; break; case SIL_RT: - new.si_pid = from->si_pid; - new.si_uid = from->si_uid; - new.si_int = from->si_int; + to->si_pid = from->si_pid; + to->si_uid = from->si_uid; + to->si_int = from->si_int; break; case SIL_SYS: - new.si_call_addr = ptr_to_compat(from->si_call_addr); - new.si_syscall = from->si_syscall; - new.si_arch = from->si_arch; + to->si_call_addr = ptr_to_compat(from->si_call_addr); + to->si_syscall = from->si_syscall; + to->si_arch = from->si_arch; break; } +} +int __copy_siginfo_to_user32(struct compat_siginfo __user *to, + const struct kernel_siginfo *from) +{ + struct compat_siginfo new; + + copy_siginfo_to_external32(&new, from); if (copy_to_user(to, &new, sizeof(struct compat_siginfo))) return -EFAULT; - return 0; } -- 2.26.2