From nobody Thu Apr 2 17:23:46 2026 Received: from mail-wr1-f74.google.com (mail-wr1-f74.google.com [209.85.221.74]) (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 830AD3E9F7D for ; Mon, 9 Mar 2026 16:26:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773073575; cv=none; b=ex72Tw+LBAD31O7s3C20Iyw0EcGIiX7TRTh0WRNaTxm43sm0JdvU5FnEvLvCUye2J4s01/m9GUDpC2BlkU8QFmEJ2LNbDHGZwT3lCZCMJroJu74cGV8oGbHcK9zXlFbEkMx7BN6nbb8GaN+of7ula0HnaeSyQYL1LzZ1nzIMd/s= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773073575; c=relaxed/simple; bh=OXoAPQaz1JofYbdbTf0qijBb8NJIxVFt2UTMjH3mbAg=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=svXpXOk9yV+1CIHDHoNy4WC5RznmYLScIRoHNyvcUGM2vkMff3edffi9X3xaYadvsDhXjjhewu7KRhZaoxSqfd0h8VQuny+AGqo+CmzqPLkU2f8KYm0b6xZ5rvncehQxGA1bS+gGCGerl8bbmuKR1dnwCaAYyiYFTZhy+1ANFlA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--vdonnefort.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=KdTwpfJy; arc=none smtp.client-ip=209.85.221.74 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=flex--vdonnefort.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="KdTwpfJy" Received: by mail-wr1-f74.google.com with SMTP id ffacd0b85a97d-439c4bde453so4273197f8f.0 for ; Mon, 09 Mar 2026 09:26:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1773073571; x=1773678371; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=61Jen8I7dV/ehx9kpoBtCUAlE55w0+kXOtk88vzQsJw=; b=KdTwpfJy2bgbXLSmOjbx+ZP9T+g4QNUdzsHxzwFDjyYYfh+pJ0caFwJQLhWiUjrh+8 gK3X8ogII/ugfagGjUG6I1nyCjm5l04NM5yeXW/rvOc4RlS2FoPVo18WyZtLGCVYy+5E GNf8Q+wXERaVZLe2oPrGzgWHil+Aju0o8f8saBTJC0lkgwn1IQxzma74VWHDSHtIj+ij gXY5HESN8Z/1Nl9Wtl1XFUZnJcXHdTqZ1QqKBrkPvoOYbSQjwzX91nAXNNKaTCLkZ7wC +8hglLPlLgcYOy/mVc3QqnvLNL1GpDvcM8BikTauNIP3fMBfXFZNrHTZrXrOAAeaAEw/ 9T4g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1773073571; x=1773678371; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=61Jen8I7dV/ehx9kpoBtCUAlE55w0+kXOtk88vzQsJw=; b=XzOlu1OXy2z0elKQkag01ItXTAi81/s6QH3nJ9VeMaJD2dsJ5VSFKmZVpOgojhmFBv djhoQM3tyKLPbe6Es2jqS3gh7HZvEsj9X2fYVEk52h8jX4CafKV3ZoGXtx/bxj5qRfEc vUUoaVanQcSuG+dpFZq+95d9lbuNwX6CCQK++9Z9NtZF1Xu6ua8MZ6aSK42lAqgEiFFo rA+uwM9TCQCXoJAbiJ+f8Z3y7jV/nqiFWxceS4xs3Qe3EO1uQUsUJ7jLImKhAKR3+I+J S4XDUc/NDQIuMjGrICSisfDn6YRwv2BEDsibzdZd6tUdTfeq3vHesIT0/NNgYEJ+36/m F/eA== X-Forwarded-Encrypted: i=1; AJvYcCUDk0lG7d0xj8jojoAPHlYox4jeYcHWTpTc29rCNn/wB43XPUh2OL9N3F+do19wU6CMp4q8V5opJ+kNV14=@vger.kernel.org X-Gm-Message-State: AOJu0YzxljC6zrSs/drrUG6oziw8/bpUrx6yXB6gdslNPnEbLUE5Tl+n zBePGC3pAiezl8x5rYkcrUkBwDG6ygSo71zxeTmK68ygnfhCKKVI2cljFvpaByOB71lQ8L2XyA1 8bFyjOvuWKo4cDnxnPyLaZw== X-Received: from wrwq12.prod.google.com ([2002:a5d:574c:0:b0:439:d11d:950c]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6000:2891:b0:439:d935:87c0 with SMTP id ffacd0b85a97d-439da65d71emr21352305f8f.17.1773073570088; Mon, 09 Mar 2026 09:26:10 -0700 (PDT) Date: Mon, 9 Mar 2026 16:24:56 +0000 In-Reply-To: <20260309162516.2623589-1-vdonnefort@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260309162516.2623589-1-vdonnefort@google.com> X-Mailer: git-send-email 2.53.0.473.g4a7958ca14-goog Message-ID: <20260309162516.2623589-11-vdonnefort@google.com> Subject: [PATCH v14 10/30] tracing: Add events/ root files to trace remotes From: Vincent Donnefort To: rostedt@goodmis.org, 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 Cc: 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, Vincent Donnefort Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Just like for the kernel events directory, add 'enable', 'header_page' and 'header_event' at the root of the trace remote events/ directory. Reviewed-by: Steven Rostedt (Google) Signed-off-by: Vincent Donnefort 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 2.53.0.473.g4a7958ca14-goog