diff options
Diffstat (limited to 'samples')
| -rw-r--r-- | samples/Kconfig | 8 | ||||
| -rw-r--r-- | samples/Makefile | 1 | ||||
| -rw-r--r-- | samples/trace_events/Makefile | 2 | ||||
| -rw-r--r-- | samples/trace_events/trace_custom_sched.c | 60 | ||||
| -rw-r--r-- | samples/trace_events/trace_custom_sched.h | 96 | ||||
| -rw-r--r-- | samples/user_events/Makefile | 5 | ||||
| -rw-r--r-- | samples/user_events/example.c | 91 |
7 files changed, 262 insertions, 1 deletions
diff --git a/samples/Kconfig b/samples/Kconfig index 8415d60ea5f4..470ee3baf2e1 100644 --- a/samples/Kconfig +++ b/samples/Kconfig @@ -14,7 +14,13 @@ config SAMPLE_TRACE_EVENTS tristate "Build trace_events examples -- loadable modules only" depends on EVENT_TRACING && m help - This build trace event example modules. + This builds the trace event example module. + +config SAMPLE_TRACE_CUSTOM_EVENTS + tristate "Build custom trace event example -- loadable modules only" + depends on EVENT_TRACING && m + help + This builds the custom trace event example module. config SAMPLE_TRACE_PRINTK tristate "Build trace_printk module - tests various trace_printk formats" diff --git a/samples/Makefile b/samples/Makefile index 6d662965be5b..701e912ab5af 100644 --- a/samples/Makefile +++ b/samples/Makefile @@ -20,6 +20,7 @@ obj-$(CONFIG_SAMPLE_RPMSG_CLIENT) += rpmsg/ subdir-$(CONFIG_SAMPLE_SECCOMP) += seccomp subdir-$(CONFIG_SAMPLE_TIMER) += timers obj-$(CONFIG_SAMPLE_TRACE_EVENTS) += trace_events/ +obj-$(CONFIG_SAMPLE_TRACE_CUSTOM_EVENTS) += trace_events/ obj-$(CONFIG_SAMPLE_TRACE_PRINTK) += trace_printk/ obj-$(CONFIG_SAMPLE_FTRACE_DIRECT) += ftrace/ obj-$(CONFIG_SAMPLE_FTRACE_DIRECT_MULTI) += ftrace/ diff --git a/samples/trace_events/Makefile b/samples/trace_events/Makefile index b78344e7bbed..b3808bb4cf8b 100644 --- a/samples/trace_events/Makefile +++ b/samples/trace_events/Makefile @@ -11,5 +11,7 @@ # Here trace-events-sample.c does the CREATE_TRACE_POINTS. # CFLAGS_trace-events-sample.o := -I$(src) +CFLAGS_trace_custom_sched.o := -I$(src) obj-$(CONFIG_SAMPLE_TRACE_EVENTS) += trace-events-sample.o +obj-$(CONFIG_SAMPLE_TRACE_CUSTOM_EVENTS) += trace_custom_sched.o diff --git a/samples/trace_events/trace_custom_sched.c b/samples/trace_events/trace_custom_sched.c new file mode 100644 index 000000000000..b99d9ab7db85 --- /dev/null +++ b/samples/trace_events/trace_custom_sched.c @@ -0,0 +1,60 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * event tracer + * + * Copyright (C) 2022 Google Inc, Steven Rostedt <rostedt@goodmis.org> + */ + +#define pr_fmt(fmt) fmt + +#include <linux/trace_events.h> +#include <linux/version.h> +#include <linux/module.h> +#include <linux/sched.h> + +/* + * Must include the event header that the custom event will attach to, + * from the C file, and not in the custom header file. + */ +#include <trace/events/sched.h> + +/* Declare CREATE_CUSTOM_TRACE_EVENTS before including custom header */ +#define CREATE_CUSTOM_TRACE_EVENTS + +#include "trace_custom_sched.h" + +/* + * As the trace events are not exported to modules, the use of + * for_each_kernel_tracepoint() is needed to find the trace event + * to attach to. The fct() function below, is a callback that + * will be called for every event. + * + * Helper functions are created by the TRACE_CUSTOM_EVENT() macro + * update the event. Those are of the form: + * + * trace_custom_event_<event>_update() + * + * Where <event> is the event to attach. + */ +static void fct(struct tracepoint *tp, void *priv) +{ + trace_custom_event_sched_switch_update(tp); + trace_custom_event_sched_waking_update(tp); +} + +static int __init trace_sched_init(void) +{ + for_each_kernel_tracepoint(fct, NULL); + return 0; +} + +static void __exit trace_sched_exit(void) +{ +} + +module_init(trace_sched_init); +module_exit(trace_sched_exit); + +MODULE_AUTHOR("Steven Rostedt"); +MODULE_DESCRIPTION("Custom scheduling events"); +MODULE_LICENSE("GPL"); diff --git a/samples/trace_events/trace_custom_sched.h b/samples/trace_events/trace_custom_sched.h new file mode 100644 index 000000000000..9fdd8e7c2a45 --- /dev/null +++ b/samples/trace_events/trace_custom_sched.h @@ -0,0 +1,96 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * Like the headers that use TRACE_EVENT(), the TRACE_CUSTOM_EVENT() + * needs a header that allows for multiple inclusions. + * + * Test for a unique name (here we have _TRACE_CUSTOM_SCHED_H), + * also allowing to continue if TRACE_CUSTOM_MULTI_READ is defined. + */ +#if !defined(_TRACE_CUSTOM_SCHED_H) || defined(TRACE_CUSTOM_MULTI_READ) +#define _TRACE_CUSTOM_SCHED_H + +/* Include linux/trace_events.h for initial defines of TRACE_CUSTOM_EVENT() */ +#include <linux/trace_events.h> + +/* + * TRACE_CUSTOM_EVENT() is just like TRACE_EVENT(). The first parameter + * is the event name of an existing event where the TRACE_EVENT has been included + * in the C file before including this file. + */ +TRACE_CUSTOM_EVENT(sched_switch, + + /* + * The TP_PROTO() and TP_ARGS must match the trace event + * that the custom event is using. + */ + TP_PROTO(bool preempt, + unsigned int prev_state, + struct task_struct *prev, + struct task_struct *next), + + TP_ARGS(preempt, prev_state, prev, next), + + /* + * The next fields are where the customization happens. + * The TP_STRUCT__entry() defines what will be recorded + * in the ring buffer when the custom event triggers. + * + * The rest is just like the TRACE_EVENT() macro except that + * it uses the custom entry. + */ + TP_STRUCT__entry( + __field( unsigned short, prev_prio ) + __field( unsigned short, next_prio ) + __field( pid_t, next_pid ) + ), + + TP_fast_assign( + __entry->prev_prio = prev->prio; + __entry->next_pid = next->pid; + __entry->next_prio = next->prio; + ), + + TP_printk("prev_prio=%d next_pid=%d next_prio=%d", + __entry->prev_prio, __entry->next_pid, __entry->next_prio) +) + + +TRACE_CUSTOM_EVENT(sched_waking, + + TP_PROTO(struct task_struct *p), + + TP_ARGS(p), + + TP_STRUCT__entry( + __field( pid_t, pid ) + __field( unsigned short, prio ) + ), + + TP_fast_assign( + __entry->pid = p->pid; + __entry->prio = p->prio; + ), + + TP_printk("pid=%d prio=%d", __entry->pid, __entry->prio) +) +#endif +/* + * Just like the headers that create TRACE_EVENTs, the below must + * be outside the protection of the above #if block. + */ + +/* + * It is required that the Makefile includes: + * CFLAGS_<c_file>.o := -I$(src) + */ +#undef TRACE_INCLUDE_PATH +#undef TRACE_INCLUDE_FILE +#define TRACE_INCLUDE_PATH . + +/* + * It is requred that the TRACE_INCLUDE_FILE be the same + * as this file without the ".h". + */ +#define TRACE_INCLUDE_FILE trace_custom_sched +#include <trace/define_custom_trace.h> diff --git a/samples/user_events/Makefile b/samples/user_events/Makefile new file mode 100644 index 000000000000..7252b589db57 --- /dev/null +++ b/samples/user_events/Makefile @@ -0,0 +1,5 @@ +# SPDX-License-Identifier: GPL-2.0 +CFLAGS += -Wl,-no-as-needed -Wall -I../../usr/include + +example: example.o +example.o: example.c diff --git a/samples/user_events/example.c b/samples/user_events/example.c new file mode 100644 index 000000000000..4f5778e441c0 --- /dev/null +++ b/samples/user_events/example.c @@ -0,0 +1,91 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2021, Microsoft Corporation. + * + * Authors: + * Beau Belgrave <beaub@linux.microsoft.com> + */ + +#include <errno.h> +#include <sys/ioctl.h> +#include <sys/mman.h> +#include <fcntl.h> +#include <stdio.h> +#include <unistd.h> +#include <linux/user_events.h> + +/* Assumes debugfs is mounted */ +const char *data_file = "/sys/kernel/debug/tracing/user_events_data"; +const char *status_file = "/sys/kernel/debug/tracing/user_events_status"; + +static int event_status(char **status) +{ + int fd = open(status_file, O_RDONLY); + + *status = mmap(NULL, sysconf(_SC_PAGESIZE), PROT_READ, + MAP_SHARED, fd, 0); + + close(fd); + + if (*status == MAP_FAILED) + return -1; + + return 0; +} + +static int event_reg(int fd, const char *command, int *status, int *write) +{ + struct user_reg reg = {0}; + + reg.size = sizeof(reg); + reg.name_args = (__u64)command; + + if (ioctl(fd, DIAG_IOCSREG, ®) == -1) + return -1; + + *status = reg.status_index; + *write = reg.write_index; + + return 0; +} + +int main(int argc, char **argv) +{ + int data_fd, status, write; + char *status_page; + struct iovec io[2]; + __u32 count = 0; + + if (event_status(&status_page) == -1) + return errno; + + data_fd = open(data_file, O_RDWR); + + if (event_reg(data_fd, "test u32 count", &status, &write) == -1) + return errno; + + /* Setup iovec */ + io[0].iov_base = &write; + io[0].iov_len = sizeof(write); + io[1].iov_base = &count; + io[1].iov_len = sizeof(count); + +ask: + printf("Press enter to check status...\n"); + getchar(); + + /* Check if anyone is listening */ + if (status_page[status]) { + /* Yep, trace out our data */ + writev(data_fd, (const struct iovec *)io, 2); + + /* Increase the count */ + count++; + + printf("Something was attached, wrote data\n"); + } + + goto ask; + + return 0; +} |