From nobody Tue Dec 2 00:05:06 2025 Received: from canpmsgout01.his.huawei.com (canpmsgout01.his.huawei.com [113.46.200.216]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A8FB928DF07; Wed, 26 Nov 2025 07:15:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.216 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764141306; cv=none; b=lWsruCculzsjl0HapAKWyAIkYypRL0yPEV8ZJ9L80ZCVRsJBAl9Jja4u/nRXw8iaskuZY6ssQJp+uQLvb7D6+6QXbY3ocw1yCKfPAUUZuXwBlKjQkqJ8hYdy6OlFOt1x2DYiA3Id80fhI6jWWoRL4DNQyR95M4st6YZkWv17vP0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764141306; c=relaxed/simple; bh=iMf2S5tmP9dOHVKzng2sI4rZFEkn103DhGMPUAyHEGE=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=rSCipumU0vaTSfs6Ly6TVtKjoQz0kB2X4FleaHCk6lJkhTbcn/3FShGpZxbzhOvecka9j5FAa+7pKDhxV0sLwkeKlrvWiX/jpjFx5EZq4LB4RyO5xQ5zgZQqfa4tqLZ0mbF2bnylfwsvh1n6LpqaAJutzBI6erkssvdbFQx3tno= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=pgEdQviy; arc=none smtp.client-ip=113.46.200.216 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="pgEdQviy" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=3xA2sNuV0/hiav7h7IG8jXOzdUfLNPwMwSOaHlFQaQ0=; b=pgEdQviyuX5uZyYrn09RFkLNjFqaPis/hWKSTBN/altVMSpYNjzb1xeeyhJVkZ2NKelbaA7Jz YgXraJ8l3Iog95nURqKMXbjPF24jA+RQnJahIGobgjMoK1o9SGLcb9mE3b/VAFujDcPDZA94K2X Qc+OteH1pjlmeJxsrPyQjVo= Received: from mail.maildlp.com (unknown [172.19.163.48]) by canpmsgout01.his.huawei.com (SkyGuard) with ESMTPS id 4dGW4G20gPz1T4FZ; Wed, 26 Nov 2025 15:13:18 +0800 (CST) Received: from dggpemf500011.china.huawei.com (unknown [7.185.36.131]) by mail.maildlp.com (Postfix) with ESMTPS id E27B1180483; Wed, 26 Nov 2025 15:15:00 +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; Wed, 26 Nov 2025 15:14:59 +0800 From: Jinjie Ruan To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , CC: Subject: [PATCH v8 05/12] arm64: syscall: Rework el0_svc_common() Date: Wed, 26 Nov 2025 15:14:39 +0800 Message-ID: <20251126071446.3234218-6-ruanjinjie@huawei.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20251126071446.3234218-1-ruanjinjie@huawei.com> References: <20251126071446.3234218-1-ruanjinjie@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: kwepems500002.china.huawei.com (7.221.188.17) To dggpemf500011.china.huawei.com (7.185.36.131) Content-Type: text/plain; charset="utf-8" The generic syscall syscall_exit_work() has the following content: | audit_syscall_exit(regs) | trace_sys_exit(regs, ...) | ptrace_report_syscall_exit(regs, step) The generic syscall syscall_exit_to_user_mode_work() has the following form: | unsigned long work =3D READ_ONCE(current_thread_info()->syscall_work) | rseq_syscall() | if (unlikely(work & SYSCALL_WORK_EXIT)) | syscall_exit_work(regs, work) In preparation for moving arm64 over to the generic entry code, rework el0_svc_common() as below: - Rename syscall_trace_exit() to syscall_exit_work(). - Add syscall_exit_to_user_mode_prepare() function to replace the combination of read_thread_flags() and syscall_exit_work(), also move the syscall exit check logic into it. Move has_syscall_work() helper into asm/syscall.h for reuse. - As currently rseq_syscall() is always called and itself is controlled by the CONFIG_DEBUG_RSEQ macro, so the CONFIG_DEBUG_RSEQ check is removed. Signed-off-by: Jinjie Ruan Reviewed-by: Kevin Brodsky --- arch/arm64/include/asm/syscall.h | 7 ++++++- arch/arm64/kernel/ptrace.c | 14 +++++++++++--- arch/arm64/kernel/syscall.c | 20 +------------------- 3 files changed, 18 insertions(+), 23 deletions(-) diff --git a/arch/arm64/include/asm/syscall.h b/arch/arm64/include/asm/sysc= all.h index d69f590a989b..6225981fbbdb 100644 --- a/arch/arm64/include/asm/syscall.h +++ b/arch/arm64/include/asm/syscall.h @@ -114,7 +114,12 @@ static inline int syscall_get_arch(struct task_struct = *task) return AUDIT_ARCH_AARCH64; } =20 +static inline bool has_syscall_work(unsigned long flags) +{ + return unlikely(flags & _TIF_SYSCALL_WORK); +} + int syscall_trace_enter(struct pt_regs *regs, long syscall, unsigned long = flags); -void syscall_trace_exit(struct pt_regs *regs, unsigned long flags); +void syscall_exit_to_user_mode_prepare(struct pt_regs *regs); =20 #endif /* __ASM_SYSCALL_H */ diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index dfdd886dc0a9..233a7688ac94 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -2409,10 +2409,8 @@ int syscall_trace_enter(struct pt_regs *regs, long s= yscall, unsigned long flags) return syscall; } =20 -void syscall_trace_exit(struct pt_regs *regs, unsigned long flags) +static void syscall_exit_work(struct pt_regs *regs, unsigned long flags) { - rseq_syscall(regs); - audit_syscall_exit(regs); =20 if (flags & _TIF_SYSCALL_TRACEPOINT) @@ -2422,6 +2420,16 @@ void syscall_trace_exit(struct pt_regs *regs, unsign= ed long flags) report_syscall_exit(regs); } =20 +void syscall_exit_to_user_mode_prepare(struct pt_regs *regs) +{ + unsigned long flags =3D read_thread_flags(); + + rseq_syscall(regs); + + if (has_syscall_work(flags) || flags & _TIF_SINGLESTEP) + syscall_exit_work(regs, flags); +} + /* * SPSR_ELx bits which are always architecturally RES0 per ARM DDI 0487D.a. * We permit userspace to set SSBS (AArch64 bit 12, AArch32 bit 23) which = is diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c index ec31f82d2e9f..65021d0f49e1 100644 --- a/arch/arm64/kernel/syscall.c +++ b/arch/arm64/kernel/syscall.c @@ -65,11 +65,6 @@ static void invoke_syscall(struct pt_regs *regs, unsigne= d int scno, choose_random_kstack_offset(get_random_u16()); } =20 -static inline bool has_syscall_work(unsigned long flags) -{ - return unlikely(flags & _TIF_SYSCALL_WORK); -} - static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr, const syscall_fn_t syscall_table[]) { @@ -130,21 +125,8 @@ static void el0_svc_common(struct pt_regs *regs, int s= cno, int sc_nr, } =20 invoke_syscall(regs, scno, sc_nr, syscall_table); - - /* - * The tracing status may have changed under our feet, so we have to - * check again. However, if we were tracing entry, then we always trace - * exit regardless, as the old entry assembly did. - */ - if (!has_syscall_work(flags) && !IS_ENABLED(CONFIG_DEBUG_RSEQ)) { - flags =3D read_thread_flags(); - if (!has_syscall_work(flags) && !(flags & _TIF_SINGLESTEP)) - return; - } - trace_exit: - flags =3D read_thread_flags(); - syscall_trace_exit(regs, flags); + syscall_exit_to_user_mode_prepare(regs); } =20 void do_el0_svc(struct pt_regs *regs) --=20 2.34.1