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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 81EACC4741F for ; Fri, 30 Oct 2020 15:50:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E825E22243 for ; Fri, 30 Oct 2020 15:50:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604073008; bh=fY6p+lkklIuvlOl6LSOK1NSbGCEH/SLgf43BZ+YXIi4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=YNyBkc3SgUHljXmCz+7/Nl2lsbZPu+cEa8g95oDqdFI3prkauABISulJ4PVDiiCMi cBF4UPktUXwiRbd5Me4+rZPcxmQFijV+kwTaZdoMkF4ZIaU482B8R+ABEccj7RsZRB gzOray5q2g6+RqpnjiaU1WF2p64B7HbBdjxD8bo8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727186AbgJ3Ptj (ORCPT ); Fri, 30 Oct 2020 11:49:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:42144 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727215AbgJ3Pti (ORCPT ); Fri, 30 Oct 2020 11:49:38 -0400 Received: from localhost.localdomain (HSI-KBW-46-223-126-90.hsi.kabel-badenwuerttemberg.de [46.223.126.90]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1AF182223F; Fri, 30 Oct 2020 15:49:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604072977; bh=fY6p+lkklIuvlOl6LSOK1NSbGCEH/SLgf43BZ+YXIi4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OncIA6fgT7xFpJo++EiS1WLvS/pajpXd+csgRgpXj9iJfxdcXoVFvkZC2udyZ7Gc0 A7YWdxoVLtkUb/MfCSuNuR2coybydBXmuGgODODKEQw7OYawqvdhClLdjklrO58mlD gWrbJrvaqoWYAbuuzGAp2QfG0RB11vi75z2ReBXs= From: Arnd Bergmann To: Russell King , Christoph Hellwig Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, viro@zeniv.linux.org.uk, linus.walleij@linaro.org, arnd@arndb.de Subject: [PATCH 4/9] ARM: syscall: always store thread_info->syscall Date: Fri, 30 Oct 2020 16:49:14 +0100 Message-Id: <20201030154919.1246645-4-arnd@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20201030154919.1246645-1-arnd@kernel.org> References: <20201030154519.1245983-1-arnd@kernel.org> <20201030154919.1246645-1-arnd@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org From: Arnd Bergmann The system call number is used in a a couple of places, in particular ptrace, seccomp and /proc//syscall. The last one apparently never worked reliably on ARM for tasks that are not currently getting traced. Storing the syscall number in the normal entry path makes it work, as well as allowing us to see if the current system call is for OABI compat mode, which is the next thing I want to hook into. Signed-off-by: Arnd Bergmann --- arch/arm/include/asm/syscall.h | 5 ++++- arch/arm/kernel/asm-offsets.c | 1 + arch/arm/kernel/entry-common.S | 8 ++++++-- arch/arm/kernel/ptrace.c | 9 +++++---- 4 files changed, 16 insertions(+), 7 deletions(-) diff --git a/arch/arm/include/asm/syscall.h b/arch/arm/include/asm/syscall.h index fd02761ba06c..89898497edd6 100644 --- a/arch/arm/include/asm/syscall.h +++ b/arch/arm/include/asm/syscall.h @@ -22,7 +22,10 @@ extern const unsigned long sys_call_table[]; static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) { - return task_thread_info(task)->syscall; + if (IS_ENABLED(CONFIG_AEABI) && !IS_ENABLED(CONFIG_OABI_COMPAT)) + return task_thread_info(task)->syscall; + + return task_thread_info(task)->syscall & ~__NR_OABI_SYSCALL_BASE; } static inline void syscall_rollback(struct task_struct *task, diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c index a1570c8bab25..97af6735172b 100644 --- a/arch/arm/kernel/asm-offsets.c +++ b/arch/arm/kernel/asm-offsets.c @@ -46,6 +46,7 @@ int main(void) DEFINE(TI_CPU, offsetof(struct thread_info, cpu)); DEFINE(TI_CPU_DOMAIN, offsetof(struct thread_info, cpu_domain)); DEFINE(TI_CPU_SAVE, offsetof(struct thread_info, cpu_context)); + DEFINE(TI_SYSCALL, offsetof(struct thread_info, syscall)); DEFINE(TI_USED_CP, offsetof(struct thread_info, used_cp)); DEFINE(TI_TP_VALUE, offsetof(struct thread_info, tp_value)); DEFINE(TI_FPSTATE, offsetof(struct thread_info, fpstate)); diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 271cb8a1eba1..9a76467bbb47 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -223,6 +223,7 @@ ENTRY(vector_swi) /* saved_psr and saved_pc are now dead */ uaccess_disable tbl + get_thread_info tsk adr tbl, sys_call_table @ load syscall table pointer @@ -234,13 +235,17 @@ ENTRY(vector_swi) * get the old ABI syscall table address. */ bics r10, r10, #0xff000000 + strne r10, [tsk, #TI_SYSCALL] + streq scno, [tsk, #TI_SYSCALL] eorne scno, r10, #__NR_OABI_SYSCALL_BASE ldrne tbl, =sys_oabi_call_table #elif !defined(CONFIG_AEABI) bic scno, scno, #0xff000000 @ mask off SWI op-code + str scno, [tsk, #TI_SYSCALL] eor scno, scno, #__NR_SYSCALL_BASE @ check OS number +#else + str scno, [tsk, #TI_SYSCALL] #endif - get_thread_info tsk /* * Reload the registers that may have been corrupted on entry to * the syscall assembly (by tracing or context tracking.) @@ -285,7 +290,6 @@ ENDPROC(vector_swi) * context switches, and waiting for our parent to respond. */ __sys_trace: - mov r1, scno add r0, sp, #S_OFF bl syscall_trace_enter mov scno, r0 diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c index 2771e682220b..683edb8b627d 100644 --- a/arch/arm/kernel/ptrace.c +++ b/arch/arm/kernel/ptrace.c @@ -25,6 +25,7 @@ #include #include +#include #include #define CREATE_TRACE_POINTS @@ -885,9 +886,9 @@ static void tracehook_report_syscall(struct pt_regs *regs, regs->ARM_ip = ip; } -asmlinkage int syscall_trace_enter(struct pt_regs *regs, int scno) +asmlinkage int syscall_trace_enter(struct pt_regs *regs) { - current_thread_info()->syscall = scno; + int scno; if (test_thread_flag(TIF_SYSCALL_TRACE)) tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER); @@ -898,11 +899,11 @@ asmlinkage int syscall_trace_enter(struct pt_regs *regs, int scno) return -1; #else /* XXX: remove this once OABI gets fixed */ - secure_computing_strict(current_thread_info()->syscall); + secure_computing_strict(syscall_get_nr(current, regs)); #endif /* Tracer or seccomp may have changed syscall. */ - scno = current_thread_info()->syscall; + scno = syscall_get_nr(current, regs); if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) trace_sys_enter(regs, scno); -- 2.27.0