linux-kernel - [PATCH v2 02/15] blktrace: factor out recording a blktrace event

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250925150231.67342-3-johannes.thumshirn@wdc.com>
Date: Thu, 25 Sep 2025 17:02:18 +0200
From: Johannes Thumshirn <johannes.thumshirn@....com>
To: Jens Axboe <axboe@...nel.dk>
Cc: Steven Rostedt <rostedt@...dmis.org>,
	Masami Hiramatsu <mhiramat@...nel.org>,
	Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
	linux-block@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	linux-trace-kernel@...r.kernel.org,
	linux-btrace@...r.kernel.org,
	John Garry <john.g.garry@...cle.com>,
	Hannes Reinecke <hare@...e.de>,
	Damien Le Moal <dlemoal@...nel.org>,
	Christoph Hellwig <hch@....de>,
	Naohiro Aota <naohiro.aota@....com>,
	Shinichiro Kawasaki <shinichiro.kawasaki@....com>,
	Chaitanya Kulkarni <chaitanyak@...dia.com>,
	"Martin K . Petersen" <martin.petersen@...cle.com>,
	Johannes Thumshirn <johannes.thumshirn@....com>
Subject: [PATCH v2 02/15] blktrace: factor out recording a blktrace event

Factor out the recording of a blktrace event into its own function,
deduplicating the code.

This also enables recording different versions of the blktrace protocol
later on.

Reviewed-by: Christoph Hellwig <hch@....de>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@....com>
---
 kernel/trace/blktrace.c | 89 +++++++++++++++++++++++------------------
 1 file changed, 49 insertions(+), 40 deletions(-)

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index bc4b885f2cec..25a0a1b09747 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -63,6 +63,34 @@ static int blk_probes_ref;
 static void blk_register_tracepoints(void);
 static void blk_unregister_tracepoints(void);
 
+static void record_blktrace_event(struct blk_io_trace *t, pid_t pid, int cpu,
+				  sector_t sector, int bytes, u32 what,
+				  dev_t dev, int error, u64 cgid,
+				  ssize_t cgid_len, void *pdu_data, int pdu_len)
+
+{
+	/*
+	 * These two are not needed in ftrace as they are in the
+	 * generic trace_entry, filled by tracing_generic_entry_update,
+	 * but for the trace_event->bin() synthesizer benefit we do it
+	 * here too.
+	 */
+	t->cpu = cpu;
+	t->pid = pid;
+
+	t->sector = sector;
+	t->bytes = bytes;
+	t->action = what;
+	t->device = dev;
+	t->error = error;
+	t->pdu_len = pdu_len + cgid_len;
+
+	if (cgid_len)
+		memcpy((void *)t + sizeof(*t), &cgid, cgid_len);
+	if (pdu_len)
+		memcpy((void *)t + sizeof(*t) + cgid_len, pdu_data, pdu_len);
+}
+
 /*
  * Send out a notify message.
  */
@@ -87,7 +115,12 @@ static void trace_note(struct blk_trace *bt, pid_t pid, int action,
 		if (!event)
 			return;
 		t = ring_buffer_event_data(event);
-		goto record_it;
+		record_blktrace_event(t, pid, cpu, 0, 0,
+				      action | (cgid ? __BLK_TN_CGROUP : 0),
+				      bt->dev, 0, cgid, cgid_len, (void *)data,
+				      len);
+		trace_buffer_unlock_commit(blk_tr, buffer, event, trace_ctx);
+		return;
 	}
 
 	if (!bt->rchan)
@@ -97,18 +130,11 @@ static void trace_note(struct blk_trace *bt, pid_t pid, int action,
 	if (t) {
 		t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
 		t->time = ktime_to_ns(ktime_get());
-record_it:
-		t->device = bt->dev;
-		t->action = action | (cgid ? __BLK_TN_CGROUP : 0);
-		t->pid = pid;
-		t->cpu = cpu;
-		t->pdu_len = len + cgid_len;
-		if (cgid_len)
-			memcpy((void *)t + sizeof(*t), &cgid, cgid_len);
-		memcpy((void *) t + sizeof(*t) + cgid_len, data, len);
-
-		if (blk_tracer)
-			trace_buffer_unlock_commit(blk_tr, buffer, event, trace_ctx);
+
+		record_blktrace_event(t, pid, cpu, 0, 0,
+				      action | (cgid ? __BLK_TN_CGROUP : 0),
+				      bt->dev, 0, cgid, cgid_len, (void *)data,
+				      len);
 	}
 }
 
@@ -263,7 +289,12 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
 		if (!event)
 			return;
 		t = ring_buffer_event_data(event);
-		goto record_it;
+
+		record_blktrace_event(t, pid, cpu, sector, bytes, what, bt->dev,
+				      error, cgid, cgid_len, pdu_data, pdu_len);
+
+		trace_buffer_unlock_commit(blk_tr, buffer, event, trace_ctx);
+		return;
 	}
 
 	if (unlikely(tsk->btrace_seq != blktrace_seq))
@@ -282,32 +313,10 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
 		t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
 		t->sequence = ++(*sequence);
 		t->time = ktime_to_ns(ktime_get());
-record_it:
-		/*
-		 * These two are not needed in ftrace as they are in the
-		 * generic trace_entry, filled by tracing_generic_entry_update,
-		 * but for the trace_event->bin() synthesizer benefit we do it
-		 * here too.
-		 */
-		t->cpu = cpu;
-		t->pid = pid;
-
-		t->sector = sector;
-		t->bytes = bytes;
-		t->action = what;
-		t->device = bt->dev;
-		t->error = error;
-		t->pdu_len = pdu_len + cgid_len;
-
-		if (cgid_len)
-			memcpy((void *)t + sizeof(*t), &cgid, cgid_len);
-		if (pdu_len)
-			memcpy((void *)t + sizeof(*t) + cgid_len, pdu_data, pdu_len);
-
-		if (blk_tracer) {
-			trace_buffer_unlock_commit(blk_tr, buffer, event, trace_ctx);
-			return;
-		}
+
+		record_blktrace_event(t, pid, cpu, sector, bytes, what,
+				      bt->dev, error, cgid, cgid_len,
+				      pdu_data, pdu_len);
 	}
 
 	local_irq_restore(flags);
-- 
2.51.0