From nobody Sat Feb 7 05:33:02 2026 Received: from canpmsgout07.his.huawei.com (canpmsgout07.his.huawei.com [113.46.200.222]) (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 7698B3A0B1B; Tue, 3 Feb 2026 13:37:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.222 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770125849; cv=none; b=uZihzDWmx3UXbEOXKi+eQnFP3yqks9RJPa4GLnhaowRpTaMI8OIrP2790XR0h7l9tZDpqzA6gJgtxwq+DNPg7qkT2MmI8clkbSEG5W0X7JnXtBjt071zhyB6blimEEGHw9zrAgecTUwbTJ/t2s0sZMYvREkNo0NiZXUXmFqsiiQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770125849; c=relaxed/simple; bh=YQxSdlMBptSCAi4OE7zpcGcqe2BLz4hSnhdN0B/dG9c=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=HgFblQaIc4gjTIR5oPUXw/+sBVPEJLPWSkdip7BL0MhZ0TybP7+XlyTs85cZMd/hwtATQ/kf6XiEC3Oe3A+G/rjK/MzFRaHM6flptmguvToGGR8/YJeOuy31TckWXOpuneY1mUCA1pZG0/WwlevUz4ZogtWUBynh/T1ZRjcfKP4= 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=0w4Ecgax; arc=none smtp.client-ip=113.46.200.222 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="0w4Ecgax" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=Ons0IhYAi+tEtZUFK+VtoCYghx5q1a+Q3OdvFvSt4HA=; b=0w4EcgaxjWXO4fx3WCpCxX5bgqbHY2Orz6MhI0dStAiNMe69vkFa7eMtJkrFlU9OkS/q8CrRd G2oyHfRDPxmBgUK5Y1N9uLOBQQCERW6gSillJ9Exev/JzmoBFwO2aCHW3EBRtQSH0BSqPRh4Dka tRlr6UdpRmasAjEEiWqInyU= Received: from mail.maildlp.com (unknown [172.19.163.163]) by canpmsgout07.his.huawei.com (SkyGuard) with ESMTPS id 4f54DH6SwdzLlwZ; Tue, 3 Feb 2026 21:32:47 +0800 (CST) Received: from dggpemf500011.china.huawei.com (unknown [7.185.36.131]) by mail.maildlp.com (Postfix) with ESMTPS id 625C640565; Tue, 3 Feb 2026 21:37:21 +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; Tue, 3 Feb 2026 21:37:19 +0800 From: Jinjie Ruan To: , , , , , , , , , , , , , , , , , , , , , , , , , , , CC: Subject: [PATCH v12 10/13] arm64/ptrace: Do not report_syscall_exit() for PTRACE_SYSEMU_SINGLESTEP Date: Tue, 3 Feb 2026 21:37:25 +0800 Message-ID: <20260203133728.848283-11-ruanjinjie@huawei.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260203133728.848283-1-ruanjinjie@huawei.com> References: <20260203133728.848283-1-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: kwepems200002.china.huawei.com (7.221.188.68) To dggpemf500011.china.huawei.com (7.185.36.131) Content-Type: text/plain; charset="utf-8" The generic report_single_step() always returns false if SYSCALL_EMU is set, but arm64 only checks _TIF_SINGLESTEP and does not check _TIF_SYSCALL_EMU, which means that if both _TIF_SINGLESTEP and _TIF_SYSCALL_EMU are set, the generic entry will not report a single-step, whereas arm64 will do it. As the man manual of PTRACE_SYSEMU and PTRACE_SYSEMU_SINGLESTEP said, "For PTRACE_SYSEMU, continue and stop on entry to the next system call, which will not be executed. For PTRACE_SYSEMU_SINGLESTEP, do the same but also singlestep if not a system call.". And as the generic entry report_single_step() comment said, If SYSCALL_EMU is set, then the only reason to report is when SINGLESTEP is set (i.e. PTRACE_SYSEMU_SINGLESTEP). Because this syscall instruction has been already reported in syscall_trace_enter(), there is no need to report the syscall again in syscall_exit_work(). In preparation for moving arm64 over to the generic entry code, - Add report_single_step() helper for arm64 to make it clear. - Do not report_syscall_exit() if both _TIF_SYSCALL_EMU and _TIF_SINGLESTEP set. Signed-off-by: Jinjie Ruan --- arch/arm64/kernel/ptrace.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index e68aa386ea48..6e86aec8d607 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -2453,14 +2453,25 @@ int syscall_trace_enter(struct pt_regs *regs, unsig= ned long flags) return ret ? : syscall; } =20 +static inline bool report_single_step(unsigned long flags) +{ + if (flags & _TIF_SYSCALL_EMU) + return false; + + return flags & _TIF_SINGLESTEP; +} + static void syscall_exit_work(struct pt_regs *regs, unsigned long flags) { + bool step; + audit_syscall_exit(regs); =20 if (flags & _TIF_SYSCALL_TRACEPOINT) trace_sys_exit(regs, syscall_get_return_value(current, regs)); =20 - if (flags & (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP)) + step =3D report_single_step(flags); + if (step || flags & _TIF_SYSCALL_TRACE) report_syscall_exit(regs); } =20 --=20 2.34.1