From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.214.173 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793834458; b=XmWCU/DGyOXbdXtOsAwf+EWzdd3u0UF7LNX5RiEDQQvwv/KKu3lGV4A99OWYAHfYXXSr ToCDCaTRmQD1rM7vrZOboOyH9rKilLbDep1QgJ3mwrf467ZmSpRuGyeDZap0lAk+k9ZvH 03vjbNVyTupuQuP73quJOzk+hZF86bMjMFP72LfRHT++pLS4I6TuBZH1j6/gywmzXss9i dnuV00XutDD0lsMNfRC4DeidSmeF5CDKWPlsWzfgO/iBer6HaYgwghXHpD+J+jCFxjeUT jBs2N+cXbaNDxWhGIx457F7M1HXP+ycmqK6k1pnsP3r9H45IVIA6LGslOfQizZz5LHQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793834458; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Forwarded-Encrypted:X-Gm-Message-State:X-Gm-Gg:X-Received:Received: From:To:Cc:Subject:Date:Message-ID:X-Mailer:In-Reply-To:References: MIME-Version:Content-Transfer-Encoding; bh=6pcpvaSe9ElEJt/G5lEejZAQ2sl+Ux6mleZlCU2LO+0=; b=i3AuH/0zEQMV2tZYDGDzi9IjJV3GVUeqKNl94i/UTN+bDFe7i/nUxYbMtiDI4havhv26 /pCzoEKyH73Imc3tondKCMy5XpGqUztLvPpeYNGYPFmquMOa37YoUD/X91DIWJQn16b5s SRwhuHrYVrXa25CDNTOgYLro6xnu1mEV9bAHmc81CYdSaHyEkpJ5bjYCYjF2CJ/omHKaJ haQ4fRwNJYwb7loe0tqxzt7LmhwLMunJhar+Pnm2uZyl0cPjDWhiyAEIgK2I9XIzwFO/I XrRv1yJ0D+9wIApfNvfvRrxHklK/LWTCVjgoiLr5JQiTEO3dkvkRzkhTsjDGMKmhhpg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b="D/kVshHl"; arc=none smtp.remote-ip=209.85.214.173 Received: from mail-pl1-f173.google.com (mail-pl1-f173.google.com [209.85.214.173]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2A1C0606A32C for ; Wed, 4 Nov 2026 23:20:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 2A1C0606A32C 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, unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=D/kVshHl Received: by mail-pl1-f173.google.com with SMTP id d9443c01a7336-2ea138a3497so8235215ad.2 for ; Wed, 04 Nov 2026 15:20:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20260707; t=1793834456; x=1794439256; 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:content-type; bh=6pcpvaSe9ElEJt/G5lEejZAQ2sl+Ux6mleZlCU2LO+0=; b=D/kVshHlSztePvRdaME0VrDfCaifENALUV5qVvoTlOqwXmIOoRDvM8d+e2KtZbsp6n MM4W7BmOwFnTIQTJV5mH+nKzcfaDfcklz4psWGxjZ5qxFEwt2QZ7sKJVdw0UY3jZj2fv WvZCJQucY/GpO87C1GyoYqwyZoalSi4YsUwRR7pRgN5NQNV5NvdT5ApTpBg7QTjAyf2N CEJOh5k2RQxA/sIUZLzpy+JXq+tcwClbhZFcrLP53Ro/1nbmU9majZlr+vxKyDkQdDoX 9ETPZ59lJPc8f9CcQ896HXzsNXUi3iujx/RpI2lBDkkIfSc0xdCdEVdycQERgRylhmwP 9vkA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1793834456; x=1794439256; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=6pcpvaSe9ElEJt/G5lEejZAQ2sl+Ux6mleZlCU2LO+0=; b=y3iwniiU62Rl25EHUJNYwt5v3kvIMkxsWN2yVcZeeiY4vxQ1LMrYU2jC9ITolYss9t pPPqOoUy4yKf3KRckkaIWCuXCTcN2xjutwKqD2uX/5QvPo/pMqF9A0jMyRD710eqENNO ++dWEVOwM3iMeu1PhxbxwyEIpL9gPDa+jnbo3iOuYF7B05FZo5lvRcvQjc5GQQAGAOMD QFf5/3ZS7IxgrVHfCBwRBB3Fl5N/DlF3lCq2HfcpFm+uyHcE2mNWIoVedkzKtoSF0hbw h5lf7IEN8gzbMZByYMfD3dMSNpuBvIEYdogbG44QgCDxTGeTeDQRdKtRTCJw2/huDplm TsBg== X-Forwarded-Encrypted: i=1; AKwUvBxdoSnvTWuZfHXEEIdtIn/F3dbM+EGsnBspmGey9mPJltSgYyAH3yhHIXDynjmT/TOpVSsDqhdFXLPBR7giBcAlTmc=@vger.kernel.org X-Gm-Message-State: APuU4Z/xWvR5F01N3VLFDjZhBI/qTfw3EuII0B74OIMFra5TtqJ0aj+L OfWuOma+++K9ksTXzggXiXG8psceHjHn5UGpFFqbpTZPCeABdkRBNnBB X-Gm-Gg: AYBFou0Y9jUbokCyf3vjpJWvBu/PWqiUDpb7m/8KWPf7I952naLTm60mKMMUQ6GMICP +0e41uzShsKsxoXYaYg0v+6xJwQ66hwFOo/BCNlrk2L8W362uoFjShJXPsDP6Y6GbZhSXbH4Njy Lnn226Um4+fuZ0tBGVxuG8ZwDW0znWiZQc6pbAHa2brl+ut1m4FWD+FYcECxeh5H9UArWm2iph3 ep4939vyUBXcVDJ2iroy1vcmZiw7t/c4y65KsMdwxAvOLkIdm5uvkODMu0AGOXh3iNEKWKXEdcT vb14p0L7mDJ3pQZSii6l7WdJ9yLhA2Z45bNh/8HMi/lwo//GhL/jUemVXiJnZYhwp4E0kyoYTmW rI3zIxLOYquaCssWMl1zuxPBHQakGuZxOdTQXmsoaEVjRqqxLqtuRio44f+yHDt1IQX1/rqysLx RkmI6keEY4YEUnupHWcVxd5EskfNGMuJey3Z1sNCYUcYJ1w15X8nXcziTeWOE/SgSF1wG4Pcuyg VB7pEzxUZ12bjjM9XxfzY2owubeIcmkg/BSm0LfgKPtxxQPx8BtX6bMSo5SHXb2OGmv2aD18Fsx 5YKZ6BAgEmCCfB5g/5Rrlxq3eHjm X-Received: by 2002:a17:90b:3811:b0:3b0:adba:45e9 with SMTP id 98e67ed59e1d1-3b0adc98d2emr1040635a91.58.1793834456448; Wed, 04 Nov 2026 15:20:56 -0800 (PST) Received: from localhost ([182.216.53.174]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3b094dec0e3sm2551500a91.1.2026.11.04.15.20.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Nov 2026 15:20:55 -0800 (PST) From: Jaewon Jung To: Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers Cc: sashiko-bot@kernel.org, sashiko-reviews@lists.linux.dev, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH v3] tracing: Keep copying markers when one instance is stopped Date: Thu, 5 Nov 2026 08:19:26 +0900 Message-ID: <20261104232046.32519-1-jaewon8868@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20261104085715.5838b869@gandalf.local.home> References: <20261103005219.3236380-1-jaewon8868@gmail.com> <20261103095019.6a88e783@gandalf.local.home> <20261104063552.28094-1-jaewon8868@gmail.com> <20261104085715.5838b869@gandalf.local.home> X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit When several instances enable copy_trace_marker, stopping one instance can prevent the remaining buffers from receiving markers. Continue copying text and raw markers even if one copy fails. Return the largest successful write length, or -ENODEV if no write succeeds. Fixes: 7b382efd5e8a ("tracing: Allow the top level trace_marker to write into another instances") Signed-off-by: Jaewon Jung --- Changes in v3: - Return the largest successful write length, as suggested by Steven. Tested on x86_64 QEMU: - Before: A failed copy prevents writes to later live buffers. - After: All buffers are tried, and the largest successful write length is returned. If no write succeeds, ENODEV is returned. - Existing text/raw marker and instance selftests: 6 PASS. kernel/trace/trace.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 08614af8fad1..164da1ea5e73 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -6329,9 +6329,10 @@ tracing_mark_write(struct file *filp, const char __user *ubuf, if (tr == &global_trace) { guard(rcu)(); list_for_each_entry_rcu(tr, &marker_copies, marker_list) { - written = write_marker_to_buffer(tr, buf, cnt, ip); - if (written < 0) - break; + ssize_t w = write_marker_to_buffer(tr, buf, cnt, ip); + + if (w >= 0 && w > written) + written = w; } } else { written = write_marker_to_buffer(tr, buf, cnt, ip); @@ -6408,9 +6409,10 @@ tracing_mark_raw_write(struct file *filp, const char __user *ubuf, if (tr == &global_trace) { guard(rcu)(); list_for_each_entry_rcu(tr, &marker_copies, marker_list) { - written = write_raw_marker_to_buffer(tr, buf, cnt); - if (written < 0) - break; + ssize_t w = write_raw_marker_to_buffer(tr, buf, cnt); + + if (w >= 0 && w > written) + written = w; } } else { written = write_raw_marker_to_buffer(tr, buf, cnt); base-commit: d7ff48d92a0f28bc0612da47c054efbc28c19562 -- 2.43.0