[PATCH BlueZ v2] monitor: Add support for -K/--kernel

[PATCH BlueZ v2] monitor: Add support for -K/--kernel

[Luiz Augusto von Dentz]

From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

This adds support for -K/--kernel that open /proc/kmsg and attempts
to print messages starting with 'Kernel:':

> monitor/btmon -K
= Note: Kernel: BNEP (Ethernet Emulation) ver 1.3
= Note: Kernel: BNEP filters: protocol multicast
= Note: Kernel: BNEP socket layer initialized
= Note: Kernel: MGMT ver 1.23
= Note: Kernel: RFCOMM TTY layer initialized
= Note: Kernel: RFCOMM socket layer initialized
= Note: Kernel: RFCOMM ver 1.11
---
 monitor/btmon.rst |  2 ++
 monitor/control.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++
 monitor/main.c    |  7 +++++-
 monitor/packet.h  |  1 +
 4 files changed, 68 insertions(+), 1 deletion(-)

diff --git a/monitor/btmon.rst b/monitor/btmon.rst
index eb5e25182f0f..39c185fd5e41 100644
--- a/monitor/btmon.rst
+++ b/monitor/btmon.rst
@@ -77,6 +77,8 @@ OPTIONS
 
 -M, --mgmt                  Open channel for mgmt events.
 
+-K, --kernel                Open kmsg for kernel messages.
+
 -t, --time                  Show a time instead of time offset.
 
 -T, --date                  Show a time and date information instead of
diff --git a/monitor/control.c b/monitor/control.c
index cb8e9fe731fb..83347d5dbc3e 100644
--- a/monitor/control.c
+++ b/monitor/control.c
@@ -1081,6 +1081,62 @@ static int open_channel(uint16_t channel)
 	return 0;
 }
 
+static void kmsg_callback(int fd, uint32_t events, void *user_data)
+{
+	char buf[1024], *msg;
+	ssize_t len;
+	struct timeval tv;
+
+	if (events & (EPOLLERR | EPOLLHUP)) {
+		mainloop_remove_fd(fd);
+		return;
+	}
+
+	memset(buf, 0, sizeof(buf));
+
+	len = read(fd, buf, sizeof(buf));
+	if (len < 0)
+		return;
+
+	/* Check if the kernel message is from Bluetooth */
+	msg = strcasestr(buf, "Bluetooth:");
+	if (!msg)
+		return;
+
+	/* Replace Bluetooth with Kernel to avoid possible confusions */
+	msg += 3;
+	memcpy(msg, "Kernel", 6);
+
+	/* Adjust the actual length since part of the message is skipped and
+	 * replace the \n with \0 at the end.
+	 */
+	len = len - (msg - buf);
+	msg[len - 1] = '\0';
+
+	gettimeofday(&tv, NULL);
+
+	btsnoop_write_hci(btsnoop_file, &tv, HCI_DEV_NONE,
+				BTSNOOP_OPCODE_SYSTEM_NOTE, 0, msg, len);
+	packet_monitor(&tv, NULL, HCI_DEV_NONE,
+				BTSNOOP_OPCODE_SYSTEM_NOTE, msg, len);
+}
+
+static int open_kmsg(void)
+{
+	int fd;
+
+	fd = open("/dev/kmsg", O_RDONLY);
+	if (fd < 0)
+		return -1;
+
+	if (mainloop_add_fd(fd, EPOLLIN, kmsg_callback, NULL, NULL) < 0) {
+		close(fd);
+		return -1;
+	}
+
+	return 0;
+}
+
 static void client_callback(int fd, uint32_t events, void *user_data)
 {
 	struct control_data *data = user_data;
@@ -1556,6 +1612,9 @@ int control_tracing(void)
 	if (packet_has_filter(PACKET_FILTER_SHOW_MGMT_SOCKET))
 		open_channel(HCI_CHANNEL_CONTROL);
 
+	if (packet_has_filter(PACKET_FILTER_SHOW_KMSG))
+		open_kmsg();
+
 	return 0;
 }
 
diff --git a/monitor/main.c b/monitor/main.c
index fa56fcb29f38..cc947af1ffc4 100644
--- a/monitor/main.c
+++ b/monitor/main.c
@@ -61,6 +61,7 @@ static void usage(void)
 		"\t-B, --tty-speed <rate> Set TTY speed (default 115200)\n"
 		"\t-V, --vendor <compid>  Set default company identifier\n"
 		"\t-M, --mgmt             Open channel for mgmt events\n"
+		"\t-K, --kernel           Open kmsg for kernel messages\n"
 		"\t-t, --time             Show time instead of time offset\n"
 		"\t-T, --date             Show time and date information\n"
 		"\t-S, --sco              Dump SCO traffic\n"
@@ -88,6 +89,7 @@ static const struct option main_options[] = {
 	{ "tty-speed", required_argument, NULL, 'B' },
 	{ "vendor",    required_argument, NULL, 'V' },
 	{ "mgmt",      no_argument,       NULL, 'M' },
+	{ "kernel",    no_argument,       NULL, 'K' },
 	{ "no-time",   no_argument,       NULL, 'N' },
 	{ "time",      no_argument,       NULL, 't' },
 	{ "date",      no_argument,       NULL, 'T' },
@@ -131,7 +133,7 @@ int main(int argc, char *argv[])
 		struct sockaddr_un addr;
 
 		opt = getopt_long(argc, argv,
-				"r:w:a:s:p:i:d:B:V:MNtTSAIE:PJ:R:C:c:vh",
+				"r:w:a:s:p:i:d:B:V:MKNtTSAIE:PJ:R:C:c:vh",
 				main_options, NULL);
 		if (opt < 0)
 			break;
@@ -184,6 +186,9 @@ int main(int argc, char *argv[])
 		case 'M':
 			filter_mask |= PACKET_FILTER_SHOW_MGMT_SOCKET;
 			break;
+		case 'K':
+			filter_mask |= PACKET_FILTER_SHOW_KMSG;
+			break;
 		case 'N':
 			filter_mask &= ~PACKET_FILTER_SHOW_TIME_OFFSET;
 			break;
diff --git a/monitor/packet.h b/monitor/packet.h
index 964b9a7219fa..154a08efacc5 100644
--- a/monitor/packet.h
+++ b/monitor/packet.h
@@ -23,6 +23,7 @@
 #define PACKET_FILTER_SHOW_A2DP_STREAM	(1 << 6)
 #define PACKET_FILTER_SHOW_MGMT_SOCKET	(1 << 7)
 #define PACKET_FILTER_SHOW_ISO_DATA	(1 << 8)
+#define PACKET_FILTER_SHOW_KMSG		(1 << 9)
 #define TV_MSEC(_tv) (long long)((_tv).tv_sec * 1000 + (_tv).tv_usec / 1000)
 
 struct packet_latency {
-- 
2.50.1

RE: [BlueZ,v2] monitor: Add support for -K/--kernel

[bluez.test.bot]

[-- Attachment #1: Type: text/plain, Size: 1261 bytes --]

This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=994059

---Test result---

Test Summary:
CheckPatch                    PENDING   0.28 seconds
GitLint                       PENDING   0.31 seconds
BuildEll                      PASS      19.94 seconds
BluezMake                     PASS      2593.48 seconds
MakeCheck                     PASS      20.22 seconds
MakeDistcheck                 PASS      184.32 seconds
CheckValgrind                 PASS      235.72 seconds
CheckSmatch                   PASS      305.53 seconds
bluezmakeextell               PASS      128.02 seconds
IncrementalBuild              PENDING   0.23 seconds
ScanBuild                     PASS      905.89 seconds

Details
##############################
Test: CheckPatch - PENDING
Desc: Run checkpatch.pl script
Output:

##############################
Test: GitLint - PENDING
Desc: Run gitlint
Output:

##############################
Test: IncrementalBuild - PENDING
Desc: Incremental build with the patches in the series
Output:



---
Regards,
Linux Bluetooth

Re: [PATCH BlueZ v2] monitor: Add support for -K/--kernel

[patchwork-bot+bluetooth]

Hello:

This patch was applied to bluetooth/bluez.git (master)
by Luiz Augusto von Dentz <luiz.von.dentz@intel.com>:

On Thu, 21 Aug 2025 09:50:31 -0400 you wrote:
> From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
> 
> This adds support for -K/--kernel that open /proc/kmsg and attempts
> to print messages starting with 'Kernel:':
> 
> > monitor/btmon -K
> = Note: Kernel: BNEP (Ethernet Emulation) ver 1.3
> = Note: Kernel: BNEP filters: protocol multicast
> = Note: Kernel: BNEP socket layer initialized
> = Note: Kernel: MGMT ver 1.23
> = Note: Kernel: RFCOMM TTY layer initialized
> = Note: Kernel: RFCOMM socket layer initialized
> = Note: Kernel: RFCOMM ver 1.11
> 
> [...]

Here is the summary with links:
  - [BlueZ,v2] monitor: Add support for -K/--kernel
    https://git.kernel.org/pub/scm/bluetooth/bluez.git/?id=90a490569cb8

You are awesome, thank you!
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