From nobody Thu Apr 9 07:12:20 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 6FE71301718 for ; Tue, 10 Mar 2026 14:35:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773153354; cv=none; b=cviqU5cGdcuVRy4mIff6ueuY3Dcg9o5OlzQXi2f0+KVX6aB3Lzg7/FRd5OQbswVTc/nCXqXJOyZYpd7ZKYmWT9BFIZaAsH6iu9yzz48cdj7rFMm6VNB91nt/JjYGBFJpUya7dzsHnRoHTIZYHc4lVoXhtUUgOCnO72rcdMcQjnU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773153354; c=relaxed/simple; bh=cZ0GbeEILCLfY9kn7aiNLDZvIrK0bpvAUy2i+xVxSDM=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=In6VO8M0No37rHUOiQwXyzHFhW0V9XEnZ+Y2ZNfOUnpD3TNUXvSHPO/8rri0HqjCxM+UBlBRshNrkCa+vtHh1pb1HAZ0muXBRlXSgEU00iy54Pw6RS5RCahzLiTE36RMjDzx+C0e9tn6L5KtmROOJYosqHqdy/j0VCFfFvnj9RY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EygMjcbW; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="EygMjcbW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4941BC2BCB1; Tue, 10 Mar 2026 14:35:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773153354; bh=cZ0GbeEILCLfY9kn7aiNLDZvIrK0bpvAUy2i+xVxSDM=; h=Date:From:To:Cc:Subject:References:From; b=EygMjcbWlVPJivMegY36jUXLlAmW1hm3TzcYrLUtvR8uNkQFr5pe1vBTkPonghCCm OgWkZmP+O2at7OQLKOwCIxIQrAsynmN8EV4sO4AOV8NQsEVkDFx0nE036wgzTiqQjM hocM1r9u/YY2zYHx5lNt3e470POU/AqChNT8MOriheggFo6o4dh2VwGM7PIZcQInOt ezRa5xw4zIgx8/iitaUk9zQN9Vy6Lj/c+Wmz6lQilb+6MYjFSs+9Xg/QZXuNwrzeTi Nf2c7ivyvou72EX5Xaez+yoFQEdVXui3UNTu+JKI/hvL6rC9KFE3nlQnKoqvtoCjnp iLbwYlMlU3irQ== Received: from rostedt by gandalf with local (Exim 4.99.1) (envelope-from ) id 1vzyBo-00000002ZeH-1AiW; Tue, 10 Mar 2026 10:36:04 -0400 Message-ID: <20260310143604.136215492@kernel.org> User-Agent: quilt/0.69 Date: Tue, 10 Mar 2026 10:35:25 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Vincent Donnefort Subject: [for-next][PATCH 10/18] tracing: Add events/ root files to trace remotes References: <20260310143515.132579088@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Vincent Donnefort Just like for the kernel events directory, add 'enable', 'header_page' and 'header_event' at the root of the trace remote events/ directory. Link: https://patch.msgid.link/20260309162516.2623589-11-vdonnefort@google.= com Reviewed-by: Steven Rostedt (Google) Signed-off-by: Vincent Donnefort Signed-off-by: Steven Rostedt (Google) --- kernel/trace/ring_buffer.c | 3 +- kernel/trace/trace_remote.c | 138 +++++++++++++++++++++++++++++++++++- 2 files changed, 139 insertions(+), 2 deletions(-) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index fb39dd43e00b..605142e06863 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -640,7 +640,8 @@ int ring_buffer_print_page_header(struct trace_buffer *= buffer, struct trace_seq trace_seq_printf(s, "\tfield: char data;\t" "offset:%u;\tsize:%u;\tsigned:%u;\n", (unsigned int)offsetof(typeof(field), data), - (unsigned int)buffer->subbuf_size, + (unsigned int)(buffer ? buffer->subbuf_size : + PAGE_SIZE - BUF_PAGE_HDR_SIZE), (unsigned int)is_signed_type(char)); =20 return !trace_seq_has_overflowed(s); diff --git a/kernel/trace/trace_remote.c b/kernel/trace/trace_remote.c index 0d0af53c0ce9..0d78e5f5fe98 100644 --- a/kernel/trace/trace_remote.c +++ b/kernel/trace/trace_remote.c @@ -1125,10 +1125,145 @@ static int remote_event_callback(const char *name,= umode_t *mode, void **data, return 0; } =20 +static ssize_t remote_events_dir_enable_write(struct file *filp, const cha= r __user *ubuf, + size_t count, loff_t *ppos) +{ + struct trace_remote *remote =3D file_inode(filp)->i_private; + int i, ret; + u8 enable; + + ret =3D kstrtou8_from_user(ubuf, count, 10, &enable); + if (ret) + return ret; + + guard(mutex)(&remote->lock); + + for (i =3D 0; i < remote->nr_events; i++) { + struct remote_event *evt =3D &remote->events[i]; + + trace_remote_enable_event(remote, evt, enable); + } + + return count; +} + +static ssize_t remote_events_dir_enable_read(struct file *filp, char __use= r *ubuf, size_t cnt, + loff_t *ppos) +{ + struct trace_remote *remote =3D file_inode(filp)->i_private; + const char enabled_char[] =3D {'0', '1', 'X'}; + char enabled_str[] =3D " \n"; + int i, enabled =3D -1; + + guard(mutex)(&remote->lock); + + for (i =3D 0; i < remote->nr_events; i++) { + struct remote_event *evt =3D &remote->events[i]; + + if (enabled =3D=3D -1) { + enabled =3D evt->enabled; + } else if (enabled !=3D evt->enabled) { + enabled =3D 2; + break; + } + } + + enabled_str[0] =3D enabled_char[enabled =3D=3D -1 ? 0 : enabled]; + + return simple_read_from_buffer(ubuf, cnt, ppos, enabled_str, 2); +} + +static const struct file_operations remote_events_dir_enable_fops =3D { + .write =3D remote_events_dir_enable_write, + .read =3D remote_events_dir_enable_read, +}; + +static ssize_t +remote_events_dir_header_page_read(struct file *filp, char __user *ubuf, s= ize_t cnt, loff_t *ppos) +{ + struct trace_seq *s; + int ret; + + s =3D kmalloc(sizeof(*s), GFP_KERNEL); + if (!s) + return -ENOMEM; + + trace_seq_init(s); + + ring_buffer_print_page_header(NULL, s); + ret =3D simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, trace_seq_use= d(s)); + kfree(s); + + return ret; +} + +static const struct file_operations remote_events_dir_header_page_fops =3D= { + .read =3D 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 =3D kmalloc(sizeof(*s), GFP_KERNEL); + if (!s) + return -ENOMEM; + + trace_seq_init(s); + + ring_buffer_print_entry_header(s); + ret =3D simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, trace_seq_use= d(s)); + kfree(s); + + return ret; +} + +static const struct file_operations remote_events_dir_header_event_fops = =3D { + .read =3D remote_events_dir_header_event_read, +}; + +static int remote_events_dir_callback(const char *name, umode_t *mode, voi= d **data, + const struct file_operations **fops) +{ + if (!strcmp(name, "enable")) { + *mode =3D TRACEFS_MODE_WRITE; + *fops =3D &remote_events_dir_enable_fops; + return 1; + } + + if (!strcmp(name, "header_page")) { + *mode =3D TRACEFS_MODE_READ; + *fops =3D &remote_events_dir_header_page_fops; + return 1; + } + + if (!strcmp(name, "header_event")) { + *mode =3D TRACEFS_MODE_READ; + *fops =3D &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 =3D remote->eventfs; + static struct eventfs_entry dir_entries[] =3D { + { + .name =3D "enable", + .callback =3D remote_events_dir_callback, + }, { + .name =3D "header_page", + .callback =3D remote_events_dir_callback, + }, { + .name =3D "header_event", + .callback =3D remote_events_dir_callback, + } + }; static struct eventfs_entry entries[] =3D { { .name =3D "enable", @@ -1144,7 +1279,8 @@ static int trace_remote_init_eventfs(const char *remo= te_name, struct trace_remot bool eventfs_create =3D false; =20 if (!eventfs) { - eventfs =3D eventfs_create_events_dir("events", remote->dentry, NULL, 0,= NULL); + eventfs =3D eventfs_create_events_dir("events", remote->dentry, dir_entr= ies, + ARRAY_SIZE(dir_entries), remote); if (IS_ERR(eventfs)) return PTR_ERR(eventfs); =20 --=20 2.51.0