From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f52.google.com (mail-wr1-f52.google.com [209.85.221.52]) (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 005D730BB8A for ; Sat, 5 Sep 2026 13:04:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.52 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788613490; cv=none; b=HB3M0WUWZbOUc6r/Z/lam6EIDUZQNJnosyo++MUOOfhjBpZpCVH8hZL3U5g/oKb/XyQPHLqPowM0TdCilsqmk2Lz1Uo5bc+2WdUrU7TbMQQqthbSMy9AKHYLiL3KCigxAQYwTw1GZrbUBqzUQStV5qUX1EuQacFDXLOLT/3NwsE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788613490; c=relaxed/simple; bh=J+rRKtgAlEjfqxSZXZsYqEuQQycmsbgN57qptwdUxp0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=m9j4ggHBjr4yCUc4rAcjtCWbHhTTw+DaeHz8YQrlXuEQEFBgmo1wS5KpoNzodvatrxTAvGK1CZqZQ/qkTZuIKE77d5YfOM3BPfJo0fpnqOGlO7zl/Vijja6GbMZcSM7VGK/6QeNM//h7OCUQFETetN86kg+QLuBddKIO/NChkyE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=ivtYRXoi; arc=none smtp.client-ip=209.85.221.52 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ivtYRXoi" Received: by mail-wr1-f52.google.com with SMTP id ffacd0b85a97d-48436251906so2172323f8f.0 for ; Sat, 05 Sep 2026 06:04:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1788613487; x=1789218287; darn=vger.kernel.org; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:from:to:cc:subject :date:message-id:reply-to:content-type; bh=FKCYHYnz4LwrqJmGzipTMr7mOO6sdij85Eh/KU1PCWk=; b=ivtYRXoiaYM7B9UTPrd+eVTrrCDQnDSLfmsSy+C3419e5vcI6OhLDd+syjsZ+oPqMZ EUAyOcycB9SrD5B0Jzn1pfB0g4f/5JPp7SXFIeZT9pJkmZEWy2i81I//bPxlbdRFikyc lpB9vjJLR0jexhk39dffFSC5g3ogpu4p8Spw58Uajnhu10ZOf0+T9BbIbcW2+XP7fMx6 0uvYqTgBnTMhfAXAWisIVox2lqcJ+NZW/4lNma9vAq7PT6nx9hqEbVoY+v1IiNlkQ4Xn omKhZwQn0+1szquHSFwKlIGEuq3wACM7SjoBPSv6uGXRRDmG23UcRwc3bJ7nDUBBZ7eT jbbg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788613487; x=1789218287; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=FKCYHYnz4LwrqJmGzipTMr7mOO6sdij85Eh/KU1PCWk=; b=Bw3YwQ6JWOgFmmD3R8tWaEREJ2jA6Eh4iAryzjM5WmcqTyhtfCt1/oVrVUQHZemn7G 5wmTTdzwWzss1vA9nRE7wzUi+9j4Pehqmezi3XqVD9gsNi+Xh9UbqBpzFvIMTCVDG5OH Fa/2jNbLITnPy9ZYHTILxY1t69qQ5Tm7iToJCR3Fu+Hcs4GlaMsTD0AIKnL2WUaAbfSh bWnWlzaSonRx84lDdG9Of11F+5w4PecR2tRtYaFgY1F02erU0ejC/k9MGwj6lbK77OiQ Vr6Ou3pIuRTlEb+9pjsnUkQOErJl9sl9CHQ10e6PyWwACjoh/GBKfsAlMLikNLVUpWzb xgeA== X-Forwarded-Encrypted: i=1; AKwUvBwunqk4tO6aCf5f6W0ifG3FFjjIMJAXOtv8zWsPijoHhm3meE/0AwK0bsSJVrj0j8GXvk4E8y6OpTI8p5e7isBFziE=@vger.kernel.org X-Gm-Message-State: AFuF++lZ4kyCzQAOJ4RHeN7oe8kMxYPSO5NVCMW5Ud/ZoPW2t00zfp7q bzc1g50QKq46f/F4GYUofJIT+ZcmUicek9IL73uaG+AWoTRAFiUSGcYWgwIVnZq7/w== X-Gm-Gg: AYBFou0uZSDkgt3GBi+9z46WW3EcXiN6wUySfPv2KHs6TDUen+p7xFCFvYFahk9Haj2 vF/sMB0Rhq7QZVhnMG1fsNoGbxvx6pm5EsmJ/4EaAfJeYrciDL9nhbToaroC+cw3066WYuZzBlt Qa+gd7Z9p9PtfR02BoSHEV5u7P66SiBjpytmGGSp6mywvnqgX0JphF/dC11tCFKLPyQg8bk+xuB Rv5BXzIQ/qT0XkbUyvA0qxzWQ0ZxUgoSadYPubVSsyPu/bGvUx/M9igEkMIIbjQ4Pr0MO6Eqg1M 82DHt0zDWP+VF52HH2z1Lub4M4QXQ662FzqomFzaqYAQWImVv4MO0vy40gnjxOHMP217IUuyXrb dvo4kfaU7m3cz5VY/jGX8qh/iRwz3IhZk4/dAhnQxzfun35KdhXJsgwFrIftFNOb/hl2GzpivvX Cc/0KzurQRDs9SbYVeulCEqGz8SOCTq44+VJfcOgg92OxNtIhIkFAOL9qrvAc6Okz3awfbhLi5u nTU+F6T6SVf5ngHH9i1PVrLlR+10zx9 X-Received: by 2002:a05:6000:26d3:b0:485:8393:2176 with SMTP id ffacd0b85a97d-485870902eamr22317816f8f.21.1788613486296; Sat, 05 Sep 2026 06:04:46 -0700 (PDT) Received: from google.com (135.91.155.104.bc.googleusercontent.com. [104.155.91.135]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-485883927a3sm10315802f8f.11.2026.09.05.06.04.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 05 Sep 2026 06:04:45 -0700 (PDT) Date: Sat, 5 Sep 2026 14:04:42 +0100 From: Vincent Donnefort To: Steven Rostedt Cc: LKML , Linux Trace Kernel , Masami Hiramatsu , Mathieu Desnoyers Subject: Re: [PATCH] tracing: Fix comment in tracing_buffers_splice_read() Message-ID: References: <20260904144902.506862a1@gandalf.local.home> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260904144902.506862a1@gandalf.local.home> On Fri, Sep 04, 2026 at 02:49:02PM -0400, Steven Rostedt wrote: > From: Steven Rostedt > > The comment about returning an error if the read fails on the first > iteration is slightly incorrect. It makes it sound like the only reason it > could fail on a later iteration is if the subbuf order changed. That is > incorrect, it could also fail if the length passed in was not a multiple > of the subbuf size. Fix the comment. > > Link: https://lore.kernel.org/all/20260904143527.40e73d36@gandalf.local.home/ > Fixes: TBD > Signed-off-by: Steven Rostedt > --- > kernel/trace/trace.c | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index b26c4c277ce5..8658cad53cb5 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -7296,11 +7296,13 @@ ssize_t tracing_buffers_splice_read(struct file *file, loff_t *ppos, > r = ring_buffer_read_page(ref->buffer, ref->rpage, len, iter->cpu_file, 1); > } else if (!i) { > /* > - * We failed to read because the length is too small > - * or unaligned. If this is the first iteration, it's > - * an invalid userspace input. Otherwise, this is due > - * to a subbuf order change. Do not report an error > - * and just finish the read. > + * If this fails to read on the first iteration, it > + * means the length was too small and an error should > + * be returned to user space. Otherwise, at least > + * one sub-buffer was successfully read but this failed > + * due to either the length was unaligned or the > + * subbuf order changed. Either case, do not report > + * an error. > */ > ret = -EINVAL; > } > -- > 2.53.0 > Ha yes, I see the missing case you were refering to now. Reviewed-by: Vincent Donnefort -- Vincent