From patchwork Fri Dec 6 10:17:37 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jinjie Ruan X-Patchwork-Id: 13896835 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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 86B5AE7717B for ; Fri, 6 Dec 2024 10:18:36 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.850004.1264566 (Exim 4.92) (envelope-from ) id 1tJVPs-0005TQ-7E; Fri, 06 Dec 2024 10:18:32 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 850004.1264566; Fri, 06 Dec 2024 10:18:32 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1tJVPr-0005QM-Qq; Fri, 06 Dec 2024 10:18:31 +0000 Received: by outflank-mailman (input) for mailman id 850004; Fri, 06 Dec 2024 10:18:30 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1tJVPq-0001of-D7 for xen-devel@lists.xenproject.org; Fri, 06 Dec 2024 10:18:30 +0000 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 6e5c0c36-b3bb-11ef-a0d5-8be0dac302b0; Fri, 06 Dec 2024 11:18:28 +0100 (CET) Received: from mail.maildlp.com (unknown [172.19.163.48]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4Y4RwQ3XBKzgZ8D; Fri, 6 Dec 2024 18:15:34 +0800 (CST) Received: from kwepemg200008.china.huawei.com (unknown [7.202.181.35]) by mail.maildlp.com (Postfix) with ESMTPS id 41FA418009B; Fri, 6 Dec 2024 18:18:25 +0800 (CST) Received: from huawei.com (10.90.53.73) by kwepemg200008.china.huawei.com (7.202.181.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Fri, 6 Dec 2024 18:18:23 +0800 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 6e5c0c36-b3bb-11ef-a0d5-8be0dac302b0 From: Jinjie Ruan To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH -next v5 15/22] arm64/ptrace: Refator el0_svc_common() Date: Fri, 6 Dec 2024 18:17:37 +0800 Message-ID: <20241206101744.4161990-16-ruanjinjie@huawei.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241206101744.4161990-1-ruanjinjie@huawei.com> References: <20241206101744.4161990-1-ruanjinjie@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.90.53.73] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To kwepemg200008.china.huawei.com (7.202.181.35) As the generic entry, before report_syscall_exit(), it terminate the process if the syscall is issued within a restartable sequence. In preparation for moving arm64 over to the generic entry code, refator el0_svc_common() as below: - Extract syscall_exit_to_user_mode_prepare() helper to replace the the combination of read_thread_flags() and syscall_trace_exit(), also move the syscall exit check logic into it. - Move rseq_syscall() ahead, so the CONFIG_DEBUG_RSEQ check is not needed. - Move has_syscall_work() helper into asm/syscall.h to be reused for ptrace.c. Signed-off-by: Jinjie Ruan --- arch/arm64/include/asm/syscall.h | 7 ++++++- arch/arm64/kernel/ptrace.c | 10 +++++++++- arch/arm64/kernel/syscall.c | 26 +++++--------------------- 3 files changed, 20 insertions(+), 23 deletions(-) diff --git a/arch/arm64/include/asm/syscall.h b/arch/arm64/include/asm/syscall.h index 925a257145f9..6eeb1e7b033f 100644 --- a/arch/arm64/include/asm/syscall.h +++ b/arch/arm64/include/asm/syscall.h @@ -85,7 +85,12 @@ 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, 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); #endif /* __ASM_SYSCALL_H */ diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index bb994d668d74..23df2e558fe9 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -2384,7 +2384,7 @@ int syscall_trace_enter(struct pt_regs *regs, long syscall, unsigned long flags) return regs->syscallno; } -void syscall_trace_exit(struct pt_regs *regs, unsigned long flags) +static void syscall_trace_exit(struct pt_regs *regs, unsigned long flags) { audit_syscall_exit(regs); @@ -2393,8 +2393,16 @@ void syscall_trace_exit(struct pt_regs *regs, unsigned long flags) if (flags & (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP)) report_syscall_exit(regs); +} + +void syscall_exit_to_user_mode_prepare(struct pt_regs *regs) +{ + unsigned long flags = read_thread_flags(); rseq_syscall(regs); + + if (has_syscall_work(flags) || flags & _TIF_SINGLESTEP) + syscall_trace_exit(regs, flags); } /* diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c index 064dc114fb9b..a50db885fc34 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, unsigned int scno, choose_random_kstack_offset(get_random_u16()); } -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[]) { @@ -125,26 +120,15 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr, if (scno == NO_SYSCALL) syscall_set_return_value(current, regs, -ENOSYS, 0); scno = syscall_trace_enter(regs, regs->syscallno, flags); - if (scno == NO_SYSCALL) - goto trace_exit; + if (scno == NO_SYSCALL) { + syscall_exit_to_user_mode_prepare(regs); + return; + } } 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 = read_thread_flags(); - if (!has_syscall_work(flags) && !(flags & _TIF_SINGLESTEP)) - return; - } - -trace_exit: - flags = read_thread_flags(); - syscall_trace_exit(regs, flags); + syscall_exit_to_user_mode_prepare(regs); } void do_el0_svc(struct pt_regs *regs)