From: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Date: Mon, 23 Mar 2020 21:03:37 +0000 (-0400)
Subject: kernel: event notifier: kernel-ctl interface
X-Git-Tag: v2.13.0-rc1~370
X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=cfb1c9bcab7801380b6ffbab9e505b861072254c;ds=sidebyside

kernel: event notifier: kernel-ctl interface

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Idd3983c594ffecff0a20b71b7cd3d297e77446a1
Depends-on: lttng-ust: I5a800fc92e588c2a6a0e26282b0ad5f31c044479
---

diff --git a/src/common/kernel-ctl/kernel-ctl.c b/src/common/kernel-ctl/kernel-ctl.c
index 4470e7717..f7b92f045 100644
--- a/src/common/kernel-ctl/kernel-ctl.c
+++ b/src/common/kernel-ctl/kernel-ctl.c
@@ -418,6 +418,25 @@ int kernctl_stop_session(int fd)
 			LTTNG_KERNEL_SESSION_STOP);
 }
 
+int kernctl_create_event_notifier_group(int fd)
+{
+	return LTTNG_IOCTL_NO_CHECK(fd,
+			LTTNG_KERNEL_EVENT_NOTIFIER_GROUP_CREATE);
+}
+
+int kernctl_create_event_notifier_group_notification_fd(int group_fd)
+{
+	return LTTNG_IOCTL_NO_CHECK(group_fd,
+			LTTNG_KERNEL_EVENT_NOTIFIER_GROUP_NOTIFICATION_FD);
+}
+
+int kernctl_create_event_notifier(int group_fd,
+		const struct lttng_kernel_event_notifier *event_notifier)
+{
+	return LTTNG_IOCTL_NO_CHECK(group_fd,
+			LTTNG_KERNEL_EVENT_NOTIFIER_CREATE, event_notifier);
+}
+
 int kernctl_filter(int fd, struct lttng_filter_bytecode *filter)
 {
 	struct lttng_kernel_filter_bytecode *kb;
diff --git a/src/common/kernel-ctl/kernel-ctl.h b/src/common/kernel-ctl/kernel-ctl.h
index 49925ea6c..b73a1d68e 100644
--- a/src/common/kernel-ctl/kernel-ctl.h
+++ b/src/common/kernel-ctl/kernel-ctl.h
@@ -28,7 +28,14 @@ int kernctl_disable(int fd);
 int kernctl_start_session(int fd);
 int kernctl_stop_session(int fd);
 
-/* Apply on event FD */
+int kernctl_create_event_notifier_group(int fd);
+
+/* Apply on event notifier_group file descriptor. */
+int kernctl_create_event_notifier_group_notification_fd(int fd);
+int kernctl_create_event_notifier(int fd,
+		const struct lttng_kernel_event_notifier *event_notifier);
+
+/* Apply on event file descriptor. */
 int kernctl_filter(int fd, struct lttng_filter_bytecode *filter);
 int kernctl_add_callsite(int fd, struct lttng_kernel_event_callsite *callsite);
 
@@ -39,7 +46,8 @@ int kernctl_tracer_abi_version(int fd, struct lttng_kernel_tracer_abi_version *v
 int kernctl_wait_quiescent(int fd);
 
 /*
- * kernctl_syscall_mask - Get syscall mask associated to a channel FD.
+ * kernctl_syscall_mask - Get syscall mask associated to a channel file
+ * descriptor.
  *
  * The parameter @syscall_mask should initially be either NULL or point
  * to memory allocated with malloc(3) or realloc(3). When the function
@@ -52,7 +60,7 @@ int kernctl_wait_quiescent(int fd);
 int kernctl_syscall_mask(int fd, char **syscall_mask,
 		uint32_t *nr_bits);
 
-/* Process ID tracking can be applied to session FD */
+/* Process ID tracking can be applied to session file descriptor. */
 int kernctl_track_pid(int fd, int pid);
 int kernctl_untrack_pid(int fd, int pid);
 int kernctl_list_tracker_pids(int fd);
diff --git a/src/common/kernel-ctl/kernel-ioctl.h b/src/common/kernel-ctl/kernel-ioctl.h
index ed6555e10..8fa0a7d10 100644
--- a/src/common/kernel-ctl/kernel-ioctl.h
+++ b/src/common/kernel-ctl/kernel-ioctl.h
@@ -117,6 +117,8 @@
 #define LTTNG_KERNEL_SYSCALL_LIST		_IO(0xF6, 0x4A)
 #define LTTNG_KERNEL_TRACER_ABI_VERSION		\
 	_IOR(0xF6, 0x4B, struct lttng_kernel_tracer_abi_version)
+#define LTTNG_KERNEL_EVENT_NOTIFIER_GROUP_CREATE \
+	_IO(0xF6, 0x4C)
 
 /* Session FD ioctl */
 #define LTTNG_KERNEL_METADATA			\
@@ -154,11 +156,11 @@
 #define LTTNG_KERNEL_CONTEXT			\
 	_IOW(0xF6, 0x71, struct lttng_kernel_context)
 
-/* Event, Channel and Session ioctl */
+/* Event, event notifier, Channel and Session ioctl */
 #define LTTNG_KERNEL_ENABLE			_IO(0xF6, 0x82)
 #define LTTNG_KERNEL_DISABLE			_IO(0xF6, 0x83)
 
-/* Event FD ioctl */
+/* Event and event notifier FD ioctl */
 #define LTTNG_KERNEL_FILTER			_IO(0xF6, 0x90)
 #define LTTNG_KERNEL_ADD_CALLSITE	_IO(0xF6, 0x91)
 
@@ -170,4 +172,10 @@
 #define LTTNG_KERNEL_SESSION_UNTRACK_ID		\
 	_IOR(0xF6, 0xA2, struct lttng_kernel_tracker_args)
 
+/* Event notifier group file descriptor ioctl */
+#define LTTNG_KERNEL_EVENT_NOTIFIER_CREATE			\
+	_IOW(0xF6, 0xB0, struct lttng_kernel_event_notifier)
+#define LTTNG_KERNEL_EVENT_NOTIFIER_GROUP_NOTIFICATION_FD	\
+	_IO(0xF6, 0xB1)
+
 #endif /* _LTT_KERNEL_IOCTL_H */
diff --git a/src/common/lttng-kernel.h b/src/common/lttng-kernel.h
index 3dd866c75..cd343bb76 100644
--- a/src/common/lttng-kernel.h
+++ b/src/common/lttng-kernel.h
@@ -178,6 +178,18 @@ struct lttng_kernel_event {
 	} u;
 } LTTNG_PACKED;
 
+#define LTTNG_KERNEL_EVENT_NOTIFIER_PADDING	40
+struct lttng_kernel_event_notifier {
+	struct lttng_kernel_event event;
+	char padding[LTTNG_KERNEL_EVENT_NOTIFIER_PADDING];
+} LTTNG_PACKED;
+
+#define LTTNG_KERNEL_EVENT_NOTIFIER_NOTIFICATION_PADDING 34
+struct lttng_kernel_event_notifier_notification {
+	uint64_t token;
+	char padding[LTTNG_KERNEL_EVENT_NOTIFIER_NOTIFICATION_PADDING];
+} LTTNG_PACKED;
+
 struct lttng_kernel_tracer_version {
 	uint32_t major;
 	uint32_t minor;