From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f43.google.com (mail-ej1-f43.google.com [209.85.218.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3473A15749F; Tue, 9 Jul 2024 14:27:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.43 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720535240; cv=none; b=KfhwWn/+tH8+1XQS9PKYQCtLpKe3iWTk7bpQHf77hCYjN73J4hj4zoCFlS6Kk9FQ6OMjRfgjFr5at2m92LpiOTPKJh36+buO8d8pv2TM0o/WQUW/lVLnpNjkRhLKhPdE7gFut6EGi+DmE91m8iPDLwq0sL3JjDhqyr6IsupGklA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720535240; c=relaxed/simple; bh=a5wfalHAVGimjhym+BEhPFIfP/IfIqtQ3vq9UUG4wYE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Pwsycs0EZFPYGRsXazSRg7wa+T3ZS3ogRNQrycTPROAGchkKHjC2V6rpczLNPxeVuwE+3Gr+pNrCWZnKIXvUwLsRRIxJEAOtkdGNUd4z2d+WEKX9kPUbYkTBLbBerM8blVLgbW5H61R4j4PLxbAJNrziTMd5eqXStRm8jZ4sPVk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=bviWYE9l; arc=none smtp.client-ip=209.85.218.43 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bviWYE9l" Received: by mail-ej1-f43.google.com with SMTP id a640c23a62f3a-a77e6dd7f72so349236166b.3; Tue, 09 Jul 2024 07:27:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1720535237; x=1721140037; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=viZ30E1hmv8p2AGmlt9wLyrt+Ui8LZLR4LApZyGXPD0=; b=bviWYE9lwny0UillwQeXbDbFq2ioso+cludnrdSJm5vfnPWkjWgofcVwkdWDudzm0G h7hyiLIbYSljAD24aLGSVNJHqHpGZMjawW8JBX60GuaQbmwL89ZlRFOlmlPgTy+MArp4 HS0yWwYmfjCSxU/0EVouLFz1BhJAponqo4qZY6nTY4n23UKDG8DzYo7eqSEKMDJq1tRt oGATreh3PDxcr0fKF4l7a382+ytLtd9IBxy3ipRdUsPDlHtHPhxjCUXRPFD/pzxBooQ5 D+pHvoizm0s0lS63cgNhti+//sLVkoWNb714YFNOWs8/+ixJ/cEMCTD7zIYvVXs4IRZ/ WZFA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1720535237; x=1721140037; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=viZ30E1hmv8p2AGmlt9wLyrt+Ui8LZLR4LApZyGXPD0=; b=II+YKaNYjLIWtP5KW7ocDKKY4DM5UYvgTff/R+z4NpJVB3H1Ov2lyN/RBYMeJI8fY5 T/17AMEE/or/EHwe8siahlvHqKM5BplZmyPcwDq1lVXiQHdTHxjSGD8FcjATBB4IxOuB KOXTXDWCeyDDnVk+XLKALBR7g+4R8Ai9jJkc2+naYR6Z0Sfc1MeLrB9I/cn/ga+prH0M Xd1wprRV9aJKyLK/DOrSsbIB/woeWa+FIPhm5/0BrnBF77mx2vQt9Cu0PCOi67c3GnXl BXMlXbT0BIIzBvahJUevJwdAO2i4f0Akj71iS4Jei4Y9IXUNbrC88+a3Hu2CZsSaUXL9 mrUQ== X-Forwarded-Encrypted: i=1; AJvYcCUrb+WrUWLyLRq8H/7gwHVIL4I1pliEN+uf7eMOCriCYxohgAMg9kiwtPLUBIj7gNKTKti8X1YElrJA6ZQBKKaazxWzdwSwwKjdjE8A X-Gm-Message-State: AOJu0YxeLXPfypdhDq78GT6uJ0tg5QpYEEgsHRGGAav1XJAcDl9haAVk BTAxsioAWSHX4Fv+Sd7+ZrzAkq/Bc/AqgDa/PPmd57zlnP/b+JY+mO0rqA== X-Google-Smtp-Source: AGHT+IGV2zjagwFScIaii8oEBTXuSEkflfr03lA7nPMekPBzQqC61H7lwsUbothjZVZc8YCRRCr4ng== X-Received: by 2002:a17:906:3416:b0:a72:88e2:c327 with SMTP id a640c23a62f3a-a780b6fef62mr170714266b.38.1720535237035; Tue, 09 Jul 2024 07:27:17 -0700 (PDT) Received: from 127.0.0.1localhost ([163.114.131.193]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a780a7ff21esm80649966b.135.2024.07.09.07.27.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 09 Jul 2024 07:27:16 -0700 (PDT) From: Pavel Begunkov To: io-uring@vger.kernel.org Cc: Jens Axboe , asml.silence@gmail.com, Oleg Nesterov , Andrew Morton , Christian Brauner , Tycho Andersen , Thomas Gleixner , linux-kernel@vger.kernel.org, Julian Orth , Peter Zijlstra , Tejun Heo Subject: [PATCH v2 2/2] kernel: rerun task_work while freezing in get_signal() Date: Tue, 9 Jul 2024 15:27:19 +0100 Message-ID: <149ff5a762997c723880751e8a4019907a0b6457.1720534425.git.asml.silence@gmail.com> X-Mailer: git-send-email 2.44.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit io_uring can asynchronously add a task_work while the task is getting freezed. TIF_NOTIFY_SIGNAL will prevent the task from sleeping in do_freezer_trap(), and since the get_signal()'s relock loop doesn't retry task_work, the task will spin there not being able to sleep until the freezing is cancelled / the task is killed / etc. Cc: stable@vger.kernel.org Link: https://github.com/systemd/systemd/issues/33626 Fixes: 12db8b690010c ("entry: Add support for TIF_NOTIFY_SIGNAL") Reported-by: Julian Orth Signed-off-by: Pavel Begunkov --- kernel/signal.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/kernel/signal.c b/kernel/signal.c index 1f9dd41c04be..60c737e423a1 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2600,6 +2600,14 @@ static void do_freezer_trap(void) spin_unlock_irq(¤t->sighand->siglock); cgroup_enter_frozen(); schedule(); + + /* + * We could've been woken by task_work, run it to clear + * TIF_NOTIFY_SIGNAL. The caller will retry if necessary. + */ + clear_notify_signal(); + if (unlikely(task_work_pending(current))) + task_work_run(); } static int ptrace_signal(int signr, kernel_siginfo_t *info, enum pid_type type) -- 2.44.0