From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) (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 A4D2122A817; Tue, 9 Sep 2025 21:51:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.14 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757454719; cv=none; b=VijKM8N7f5E1a2OGPL6/ZN724WMb/cfn5DyepTp4ahkAFpipObjAsVMUnlpnqoYan9cywm1SXTZeLA1Pf3Qwt94Wzj7DJAwLwX6LBb00TORmFiznMqPTgO7bSHQcYn82GSmoU8zxkZg8ZPtgLx3HaH6EEP2qxlb2xq9xDMaYofY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757454719; c=relaxed/simple; bh=bjUkjTH9OdxS0DCNUZKqxku7vJbh17gd1/TPchE6Ctg=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Xr7L3+0l3cQhN1CGp6oXzrTlWvb0HKBGNn9osKgOdHHn0/KY7Pg5z41XpLpCWFG0RREHFTeOFkAS72bsCS25LsCAgEpkzTRqhtVmIZCdQ59cAKyiY7hbB5t8ZTt7D5+MWDHR+fVdUMJoPrznSn1P1MFp82P6DHnaeZAYn3nri8E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org; spf=pass smtp.mailfrom=goodmis.org; arc=none smtp.client-ip=216.40.44.14 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=goodmis.org Received: from omf20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 37F7411AC15; Tue, 9 Sep 2025 21:51:55 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf20.hostedemail.com (Postfix) with ESMTPA id B3CED20025; Tue, 9 Sep 2025 21:51:51 +0000 (UTC) Date: Tue, 9 Sep 2025 17:52:40 -0400 From: Steven Rostedt To: Vincent Donnefort Cc: mhiramat@kernel.org, mathieu.desnoyers@efficios.com, linux-trace-kernel@vger.kernel.org, maz@kernel.org, oliver.upton@linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, jstultz@google.com, qperret@google.com, will@kernel.org, aneesh.kumar@kernel.org, kernel-team@android.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v6 07/24] tracing: Add events/ root files to trace remotes Message-ID: <20250909175240.4db7c0eb@gandalf.local.home> In-Reply-To: <20250821081412.1008261-8-vdonnefort@google.com> References: <20250821081412.1008261-1-vdonnefort@google.com> <20250821081412.1008261-8-vdonnefort@google.com> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) 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-Transfer-Encoding: 7bit X-Stat-Signature: a6dhj43w5f1j4i5ea6e1kz1oidpsfdiz X-Rspamd-Server: rspamout03 X-Rspamd-Queue-Id: B3CED20025 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX19NE8UX9pout0gmp8nK4qQdOWNA+46veZ8= X-HE-Tag: 1757454711-688199 X-HE-Meta: U2FsdGVkX1+5T2tCPQ+moXus8fA3OM8acJeM+WEPmFi/qhIBWOI3c1MIrGa8HCGVuEPNTJpPFnstSsHWuAqGhXNajKOEStbjgqTlnZzV/TGwuesdpTEnH/czE+NNgquHlm6dtXATZx3Ygwq3Ay3ZH2ovgcIxKBk5xyiyIAO31TrYvniPp/wSl2JSupBAhRGenJEdGZ6RLnX6LTapu3t5pEqVwyIfG0Y6oBvF4w8lI5adQVgM/ZDhHkx6yFiV+1aOk0521araOy7Rc5SDUxEzZxgrGaxDaxU1Ko+DPWVghsinHexkE24dcer7txlzXEnZBK0ctKUzoE9rmB/+jnGhiIx7KKmW664l On Thu, 21 Aug 2025 09:13:55 +0100 Vincent Donnefort wrote: > diff --git a/kernel/trace/trace_remote.c b/kernel/trace/trace_remote.c > index 822cdd76e334..5065b162c8ef 100644 > --- a/kernel/trace/trace_remote.c > +++ b/kernel/trace/trace_remote.c > @@ -710,10 +710,118 @@ static int remote_event_callback(const char *name, umode_t *mode, void **data, > return 0; > } > > +static ssize_t remote_events_dir_enable_write(struct file *filp, const char __user *ubuf, > + size_t count, loff_t *ppos) > +{ > + struct trace_remote *remote = file_inode(filp)->i_private; > + u8 enable; > + int i, ret; > + > + ret = kstrtou8_from_user(ubuf, count, 10, &enable); > + if (ret) > + return ret; > + > + guard(mutex)(&remote->lock); > + > + for (i = 0; i < remote->nr_events; i++) { > + struct remote_event *evt = &remote->events[i]; > + > + trace_remote_enable_event(remote, evt, enable); > + } > + > + return count; > +} > + > +static const struct file_operations remote_events_dir_enable_fops = { > + .write = remote_events_dir_enable_write, Hmm, why not a read as well? Or is it too difficult to figure out what is enabled and what isn't. For the main trace buffer, it's: 0 - all disabled 1 - all enabled X - some disabled some enabled > +}; > + > +static ssize_t > +remote_events_dir_header_page_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) > +{ > + struct trace_seq *s; > + int ret; > + > + s = kmalloc(sizeof(*s), GFP_KERNEL); > + if (!s) > + return -ENOMEM; > + > + trace_seq_init(s); > + > + ring_buffer_print_page_header(NULL, s); > + ret = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, trace_seq_used(s)); > + kfree(s); > + > + return ret; > +} > + > +static const struct file_operations remote_events_dir_header_page_fops = { > + .read = remote_events_dir_header_page_read, > +}; > + > +static ssize_t > +remote_events_dir_header_event_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) > +{ > + struct trace_seq *s; > + int ret; > + > + s = kmalloc(sizeof(*s), GFP_KERNEL); > + if (!s) > + return -ENOMEM; > + > + trace_seq_init(s); > + > + ring_buffer_print_entry_header(s); > + ret = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, trace_seq_used(s)); > + kfree(s); > + > + return ret; > +} > + > +static const struct file_operations remote_events_dir_header_event_fops = { > + .read = remote_events_dir_header_event_read, > +}; > + > +static int remote_events_dir_callback(const char *name, umode_t *mode, void **data, > + const struct file_operations **fops) > +{ > + if (!strcmp(name, "enable")) { > + *mode = 0200; As 0200 is a bit strange. -- Steve > + *fops = &remote_events_dir_enable_fops; > + return 1; > + } > + > + if (!strcmp(name, "header_page")) { > + *mode = TRACEFS_MODE_READ; > + *fops = &remote_events_dir_header_page_fops; > + return 1; > + } > + > + if (!strcmp(name, "header_event")) { > + *mode = TRACEFS_MODE_READ; > + *fops = &remote_events_dir_header_event_fops; > + return 1; > + } > + > + return 0; > +} > + > static int trace_remote_init_eventfs(const char *remote_name, struct trace_remote *remote, > struct remote_event *evt) > { > struct eventfs_inode *eventfs = remote->eventfs; > + static struct eventfs_entry dir_entries[] = { > + { > + .name = "enable", > + .callback = remote_events_dir_callback, > + }, { > + .name = "header_page", > + .callback = remote_events_dir_callback, > + }, { > + .name = "header_event", > + .callback = remote_events_dir_callback, > + } > + }; > static struct eventfs_entry entries[] = { > { > .name = "enable", > @@ -729,7 +837,8 @@ static int trace_remote_init_eventfs(const char *remote_name, struct trace_remot > bool eventfs_create = false; > > if (!eventfs) { > - eventfs = eventfs_create_events_dir("events", remote->dentry, NULL, 0, NULL); > + eventfs = eventfs_create_events_dir("events", remote->dentry, dir_entries, > + ARRAY_SIZE(dir_entries), remote); > if (IS_ERR(eventfs)) > return PTR_ERR(eventfs); >