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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1A8D0108B8EC for ; Fri, 20 Mar 2026 10:25:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-ID:Date :Subject:To:From:Reply-To:Cc:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=u0Y9GjiSl5vX2OXva1joM1TwRoFmzfgD12kzkGLos7o=; b=F3Kdy6XBHS7GMOABN/zI24APpC wTfJZsDTzNjdnNWQmxhRLpk2GN5Z0vYESJFVgj8VzF8A2vT5pynT9E0aLx2nE6esRfvsmWiJyMPz5 d7A/rHt0t2hkItwSEJFv71uV+jAtT7UteiqWctntH6YxKLvvrDs2QHhY8sHwFfBl2w1st+NorO5Ly d07ngX9JxYh+2FUQDGVGP2YNPjzvT2YbA1Wj9HBTAzuYuCtYra3JzG/IC87Wnjlkqg8uAMQjVw3nJ 40KWCkplvWHCU7KVh3XOolacElcn8aDzNYRCydertNRuA1weUC/5u5zoha9PLzcp5wk0mx3uJhZ7u jK7hoOMQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w3X3A-0000000CaOL-3uJE; Fri, 20 Mar 2026 10:25:52 +0000 Received: from canpmsgout03.his.huawei.com ([113.46.200.218]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1w3X2r-0000000CaEP-3Jvi for linux-arm-kernel@lists.infradead.org; Fri, 20 Mar 2026 10:25:35 +0000 dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=u0Y9GjiSl5vX2OXva1joM1TwRoFmzfgD12kzkGLos7o=; b=wvCCb99qnk/E6uggaxbZGtgltFV5oSfcIa+o1su0Qd0s9XTRU6PiOCBCSTX67X1Bp/MQFit8k kv9VDSNBW59mjiJRrqWFHY2ualvf7U8LW13f4hLZ9Q84mpielSmhQPvyRczvR7CJRid2A6SCbJ0 xt/vN0nPIl18QnyISuD16EE= Received: from mail.maildlp.com (unknown [172.19.162.144]) by canpmsgout03.his.huawei.com (SkyGuard) with ESMTPS id 4fcdq61LfmzpSv8; Fri, 20 Mar 2026 18:20:02 +0800 (CST) Received: from dggpemf500011.china.huawei.com (unknown [7.185.36.131]) by mail.maildlp.com (Postfix) with ESMTPS id 64AD340567; Fri, 20 Mar 2026 18:25:29 +0800 (CST) Received: from huawei.com (10.90.53.73) by dggpemf500011.china.huawei.com (7.185.36.131) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Fri, 20 Mar 2026 18:25:28 +0800 From: Jinjie Ruan To: , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v14 07/10] arm64/ptrace: Define and use _TIF_SYSCALL_EXIT_WORK Date: Fri, 20 Mar 2026 18:26:17 +0800 Message-ID: <20260320102620.1336796-8-ruanjinjie@huawei.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260320102620.1336796-1-ruanjinjie@huawei.com> References: <20260320102620.1336796-1-ruanjinjie@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.90.53.73] X-ClientProxiedBy: kwepems100002.china.huawei.com (7.221.188.206) To dggpemf500011.china.huawei.com (7.185.36.131) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260320_032534_240175_B6176379 X-CRM114-Status: GOOD ( 14.31 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Introduce _TIF_SYSCALL_EXIT_WORK to filter out entry-only flags during the syscall exit path. This aligns arm64 with the generic entry framework's SYSCALL_WORK_EXIT semantics. [Rationale] The current syscall exit path uses _TIF_SYSCALL_WORK to decide whether to invoke syscall_exit_work(). However, _TIF_SYSCALL_WORK includes flags that are only relevant during syscall entry: 1. _TIF_SECCOMP: Seccomp filtering (__secure_computing) only runs on entry. There is no seccomp callback for syscall exit. 2. _TIF_SYSCALL_EMU: In PTRACE_SYSEMU mode, the syscall is intercepted and skipped on entry. Since the syscall is never executed, reporting a syscall exit stop is unnecessary. [Changes] - Define _TIF_SYSCALL_EXIT_WORK: A new mask containing only flags requiring exit processing: _TIF_SYSCALL_TRACE, _TIF_SYSCALL_AUDIT, and _TIF_SYSCALL_TRACEPOINT. - Update exit path: Use _TIF_SYSCALL_EXIT_WORK in syscall_exit_to_user_mode_work() to avoid redundant calls to audit and ptrace reporting when only entry-flags are set. - Cleanup: Remove the has_syscall_work() helper as it is no longer needed. Direct flag comparison is now used to distinguish between entry and exit work requirements. [Impact] audit_syscall_exit() and report_syscall_exit() will no longer be triggered for seccomp-only or emu-only syscalls. This matches the generic entry behavior and improves efficiency by skipping unnecessary exit processing. Cc: Will Deacon Cc: Catalin Marinas Reviewed-by: Linus Walleij Reviewed-by: Yeoreum Yun Signed-off-by: Jinjie Ruan --- arch/arm64/include/asm/syscall.h | 5 ----- arch/arm64/include/asm/thread_info.h | 3 +++ arch/arm64/kernel/ptrace.c | 2 +- arch/arm64/kernel/syscall.c | 2 +- 4 files changed, 5 insertions(+), 7 deletions(-) diff --git a/arch/arm64/include/asm/syscall.h b/arch/arm64/include/asm/syscall.h index c469d09a7964..dea392c081ca 100644 --- a/arch/arm64/include/asm/syscall.h +++ b/arch/arm64/include/asm/syscall.h @@ -120,11 +120,6 @@ static inline int syscall_get_arch(struct task_struct *task) return AUDIT_ARCH_AARCH64; } -static inline bool has_syscall_work(unsigned long flags) -{ - return unlikely(flags & _TIF_SYSCALL_WORK); -} - int syscall_trace_enter(struct pt_regs *regs, unsigned long flags); void syscall_exit_to_user_mode_work(struct pt_regs *regs); diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h index 7942478e4065..4ae83cb620bb 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -109,6 +109,9 @@ void arch_setup_new_exec(void); _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP | \ _TIF_SYSCALL_EMU) +#define _TIF_SYSCALL_EXIT_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \ + _TIF_SYSCALL_TRACEPOINT) + #ifdef CONFIG_SHADOW_CALL_STACK #define INIT_SCS \ .scs_base = init_shadow_call_stack, \ diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 2c97de8a097c..c494fec68e35 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -2471,7 +2471,7 @@ void syscall_exit_to_user_mode_work(struct pt_regs *regs) rseq_syscall(regs); - if (has_syscall_work(flags) || flags & _TIF_SINGLESTEP) + if (unlikely(flags & _TIF_SYSCALL_EXIT_WORK) || flags & _TIF_SINGLESTEP) syscall_exit_work(regs, flags); } diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c index 66d4da641d97..ec478fc37a9f 100644 --- a/arch/arm64/kernel/syscall.c +++ b/arch/arm64/kernel/syscall.c @@ -101,7 +101,7 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr, return; } - if (has_syscall_work(flags)) { + if (unlikely(flags & _TIF_SYSCALL_WORK)) { /* * The de-facto standard way to skip a system call using ptrace * is to set the system call to -1 (NO_SYSCALL) and set x0 to a -- 2.34.1