From nobody Tue Oct 7 22:51:44 2025 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 8AE672D9783 for ; Fri, 4 Jul 2025 12:35:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751632515; cv=none; b=YBca9mqvqDRn4pXLHGnT6s15tjVMUx8YSOugpnfxgeKqYusrQHHOyQ4VVe9HPZ/SePoiATRKQZxjk3d+UiHhluqWh/HfnqGMGvN1S2r8l1A7BWkquOmy0udIUkl42dP91kwc8kpCYyml8UpuwgXNAayAy8HslRRXC+7YIQF4A6g= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751632515; c=relaxed/simple; bh=1EEsk3CakOIK6uLy9xJ0+8ZrzcRqWqydDglc717WYjg=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=QZp6nMQAOxWgBW45OZUnZ6nE1obCdCa5DW1HS3YP1oh+wlxYGkP20PIZ3jwaAyMxUh6yQhDvrxQKNWnuEd7LnTI7obwHnqEADRx11kjYU9es7u4azdEBcZcU21Iew3rysHr7G/InZaKKZG7tC+mfqIOu8rWhH0SMMqSPSw0xe2s= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=Sb3dBoLN; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=S4duA70Q; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="Sb3dBoLN"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="S4duA70Q" From: =?utf-8?q?Thomas_Wei=C3=9Fschuh?= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1751632511; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=MQ8S2P6tr58+gxioMqiPvqUsLz1lP2Wb0NQnRQjJAB8=; b=Sb3dBoLNnSkyajIhodo7cj/Di50cmVQJQ6QziMvNOtfU4fjiN2J3auhKj3Taq8Ab1bYFDL lVZJL6QeCpwvKZDMOnRHODSVICPS5MXo8WpX0IoK+H9pmonNPvj1JB9BzevTq3ORgSHmba r1KAI7GDu1G9yh9D/lzTqmTfKPvAFiVd8cvBLP/XGTDWIqY+KqD4yPQgsoyCl4l9hP5ukf wz99pIa0ZLC4dTHJYDSarIs4nEIqTViJMpGfsDQLTyGauvelgntWjjFygOLricvKifAJAG NO8+RL1VU5JaqBrYo/XP3zj/flThqccCypUuGKBA96/jOHwsyO59Pe/m3+4mcg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1751632511; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=MQ8S2P6tr58+gxioMqiPvqUsLz1lP2Wb0NQnRQjJAB8=; b=S4duA70QNhQb/AOlTDxvtZ36FBu7BcQF9mVE8vZZtFhBz6yi98lXkm4DArhqMekcQRpxHI cVP3cfIZpURydDDQ== Date: Fri, 04 Jul 2025 14:34:47 +0200 Subject: [PATCH] um: Re-evaluate thread flags repeatedly Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250704-uml-thread_flags-v1-1-0e293fd8d627@linutronix.de> X-B4-Tracking: v=1; b=H4sIAGbKZ2gC/6tWKk4tykwtVrJSqFYqSi3LLM7MzwNyDHUUlJIzE vPSU3UzU4B8JSMDI1MDcwNj3dLcHN2SjKLUxJT4tJzE9GLdlDRDCxNTY9Mks2RzJaC2gqLUtMw KsJHRsbW1ANeAsBBiAAAA X-Change-ID: 20250703-uml-thread_flags-df184535b6c7 To: Richard Weinberger , Anton Ivanov , Johannes Berg Cc: linux-um@lists.infradead.org, linux-kernel@vger.kernel.org, =?utf-8?q?Thomas_Wei=C3=9Fschuh?= , Nam Cao X-Developer-Signature: v=1; a=ed25519-sha256; t=1751632510; l=2500; i=thomas.weissschuh@linutronix.de; s=20240209; h=from:subject:message-id; bh=1EEsk3CakOIK6uLy9xJ0+8ZrzcRqWqydDglc717WYjg=; b=Ncey8gWeakla09DCNmGT3PSI/G9tKWkGd/DZxzcF5ZZH1bZxFJDEx048UdBMeaa0DqoGYlR1t ct4Kep8B/9eASY5WMF/EJkgJgvAHZBnfvjcn7P6Hmx4XQCrxM5QjLzg X-Developer-Key: i=thomas.weissschuh@linutronix.de; a=ed25519; pk=pfvxvpFUDJV2h2nY0FidLUml22uGLSjByFbM6aqQQws= The thread flags may change during their processing. For example a task_work can queue a new signal to be sent. This signal should be delivered before returning to usespace again. Evaluate the flags repeatedly similar to other architectures. Signed-off-by: Thomas Wei=C3=9Fschuh Reviewed-by: Nam Cao --- arch/um/include/asm/thread_info.h | 4 ++++ arch/um/kernel/process.c | 20 ++++++++++++-------- 2 files changed, 16 insertions(+), 8 deletions(-) diff --git a/arch/um/include/asm/thread_info.h b/arch/um/include/asm/thread= _info.h index f9ad06fcc991a2b10e2aa6059880b993e3d60a2d..eb9b3a6d99e84751a0b48ba516a= af25752e90873 100644 --- a/arch/um/include/asm/thread_info.h +++ b/arch/um/include/asm/thread_info.h @@ -50,7 +50,11 @@ struct thread_info { #define _TIF_NOTIFY_SIGNAL (1 << TIF_NOTIFY_SIGNAL) #define _TIF_MEMDIE (1 << TIF_MEMDIE) #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) +#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) #define _TIF_SECCOMP (1 << TIF_SECCOMP) #define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP) =20 +#define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | _TIF_NOTIFY= _SIGNAL | \ + _TIF_NOTIFY_RESUME) + #endif diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c index 0cd6fad3d908d43e84ebc821676e05377ec641e9..1be644de9e41ecdb94d379760ee= 8790c1d0657c6 100644 --- a/arch/um/kernel/process.c +++ b/arch/um/kernel/process.c @@ -82,14 +82,18 @@ struct task_struct *__switch_to(struct task_struct *fro= m, struct task_struct *to void interrupt_end(void) { struct pt_regs *regs =3D ¤t->thread.regs; - - if (need_resched()) - schedule(); - if (test_thread_flag(TIF_SIGPENDING) || - test_thread_flag(TIF_NOTIFY_SIGNAL)) - do_signal(regs); - if (test_thread_flag(TIF_NOTIFY_RESUME)) - resume_user_mode_work(regs); + unsigned long thread_flags; + + thread_flags =3D read_thread_flags(); + while (thread_flags & _TIF_WORK_MASK) { + if (thread_flags & _TIF_NEED_RESCHED) + schedule(); + if (thread_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) + do_signal(regs); + if (thread_flags & _TIF_NOTIFY_RESUME) + resume_user_mode_work(regs); + thread_flags =3D read_thread_flags(); + } } =20 int get_current_pid(void) --- base-commit: 19272b37aa4f83ca52bdf9c16d5d81bdd1354494 change-id: 20250703-uml-thread_flags-df184535b6c7 Best regards, --=20 Thomas Wei=C3=9Fschuh