2 * Copyright (C) 2005,2006,2008 Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca)
4 * This contains the definitions for the Linux Trace Toolkit tracer.
6 * Dual LGPL v2.1/GPL v2 license.
12 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
13 /* Align data on its natural alignment */
14 #define RING_BUFFER_ALIGN
17 #include <linux/ringbuffer/config.h>
20 #include <linux/types.h>
21 #include <linux/limits.h>
22 #include <linux/list.h>
23 #include <linux/cache.h>
24 #include <linux/kernel.h>
25 #include <linux/timex.h>
26 #include <linux/wait.h>
27 #include <linux/trace-clock.h>
28 #include <asm/atomic.h>
29 #include <asm/local.h>
31 #include "ltt-tracer-core.h"
33 /* Number of bytes to log with a read/write event */
34 #define LTT_LOG_RW_SIZE 32L
36 /* Maximum number of callbacks per marker */
37 #define LTT_NR_CALLBACKS 10
39 struct ltt_serialize_closure
;
41 /* Serialization callback */
42 typedef size_t (*ltt_serialize_cb
)(struct lib_ring_buffer
*buf
,
44 struct ltt_serialize_closure
*closure
,
45 void *serialize_private
,
46 unsigned int stack_pos_ctx
,
48 const char *fmt
, va_list *args
);
50 struct ltt_serialize_closure
{
51 ltt_serialize_cb
*callbacks
;
52 long cb_args
[LTT_NR_CALLBACKS
];
56 size_t ltt_serialize_data(struct lib_ring_buffer
*buf
, size_t buf_offset
,
57 struct ltt_serialize_closure
*closure
,
58 void *serialize_private
, unsigned int stack_pos_ctx
,
59 int *largest_align
, const char *fmt
, va_list *args
);
64 LTT_CHANNEL_GLOBAL_STATE
,
65 LTT_CHANNEL_IRQ_STATE
,
66 LTT_CHANNEL_MODULE_STATE
,
67 LTT_CHANNEL_NETIF_STATE
,
68 LTT_CHANNEL_SOFTIRQ_STATE
,
69 LTT_CHANNEL_SWAP_STATE
,
70 LTT_CHANNEL_SYSCALL_STATE
,
71 LTT_CHANNEL_TASK_STATE
,
83 size_t ltt_serialize_printf(struct lib_ring_buffer
*buf
, unsigned long buf_offset
,
84 size_t *msg_size
, char *output
, size_t outlen
,
88 * Unique ID assigned to each registered probe.
91 MARKER_ID_SET_MARKER_ID
= 0, /* Static IDs available (range 0-7) */
92 MARKER_ID_SET_MARKER_FORMAT
,
93 MARKER_ID_COMPACT
, /* Compact IDs (range: 8-127) */
94 MARKER_ID_DYNAMIC
, /* Dynamic IDs (range: 128-65535) */
97 /* static ids 0-1 reserved for internal use. */
98 #define MARKER_CORE_IDS 2
99 static __inline__
enum marker_id
marker_id_type(uint16_t id
)
101 if (id
< MARKER_CORE_IDS
)
102 return (enum marker_id
)id
;
104 return MARKER_ID_DYNAMIC
;
107 struct user_dbg_data
{
108 unsigned long avail_size
;
113 enum trace_mode
{ LTT_TRACE_NORMAL
, LTT_TRACE_FLIGHT
, LTT_TRACE_HYBRID
};
115 #define CHANNEL_FLAG_ENABLE (1U<<0)
116 #define CHANNEL_FLAG_OVERWRITE (1U<<1)
120 /* Per-trace information - each trace/flight recorder represented by one */
122 /* First 32 bytes cache-hot cacheline */
123 struct list_head list
;
124 struct ltt_chan
**channels
;
125 unsigned int nr_channels
;
127 /* Second 32 bytes cache-hot cacheline */
128 struct ltt_trace_ops
*ops
;
132 unsigned long long start_monotonic
;
133 struct timeval start_time
;
134 struct ltt_channel_setting
*settings
;
136 struct dentry
*trace_root
;
137 struct dentry
*ascii_root
;
139 struct kref kref
; /* Each channel has a kref of the trace struct */
140 struct ltt_transport
*transport
;
141 struct kref ltt_transport_kref
;
142 wait_queue_head_t kref_wq
; /* Place for ltt_trace_destroy to sleep */
143 char trace_name
[NAME_MAX
];
144 } ____cacheline_aligned
;
148 * Hardcoded event headers
150 * event header for a trace with active heartbeat : 27 bits timestamps
152 * headers are 32-bits aligned. In order to insure such alignment, a dynamic per
153 * trace alignment value must be done.
155 * Remember that the C compiler does align each member on the boundary
156 * equivalent to their own size.
158 * As relay subbuffers are aligned on pages, we are sure that they are 4 and 8
159 * bytes aligned, so the buffer header and trace header are aligned.
161 * Event headers are aligned depending on the trace alignment option.
163 * Note using C structure bitfields for cross-endianness and portability
167 #define LTT_RESERVED_EVENTS 3
168 #define LTT_EVENT_BITS 5
169 #define LTT_FREE_EVENTS ((1 << LTT_EVENT_BITS) - LTT_RESERVED_EVENTS)
170 #define LTT_TSC_BITS 27
171 #define LTT_TSC_MASK ((1 << LTT_TSC_BITS) - 1)
173 struct event_header
{
174 u32 id_time
; /* 5 bits event id (MSB); 27 bits time (LSB) */
177 /* Reservation flags */
178 #define LTT_RFLAG_ID (1 << 0)
179 #define LTT_RFLAG_ID_SIZE (1 << 1)
180 #define LTT_RFLAG_ID_SIZE_TSC (1 << 2)
182 #define LTT_MAX_SMALL_SIZE 0xFFFFU
185 * We use asm/timex.h : cpu_khz/HZ variable in here : we might have to deal
186 * specifically with CPU frequency scaling someday, so using an interpolation
187 * between the start and end of buffer values is not flexible enough. Using an
188 * immediate frequency value permits to calculate directly the times for parts
189 * of a buffer that would be before a frequency change.
191 * Keep the natural field alignment for _each field_ within this structure if
192 * you ever add/remove a field from this header. Packed attribute is not used
193 * because gcc generates poor code on at least powerpc and mips. Don't ever
194 * let gcc add padding between the structure elements.
196 struct subbuffer_header
{
197 uint64_t cycle_count_begin
; /* Cycle count at subbuffer start */
198 uint64_t cycle_count_end
; /* Cycle count at subbuffer end */
199 uint32_t magic_number
; /*
200 * Trace magic number.
201 * contains endianness information.
203 uint8_t major_version
;
204 uint8_t minor_version
;
205 uint8_t arch_size
; /* Architecture pointer size */
206 uint8_t alignment
; /* LTT data alignment */
207 uint64_t start_time_sec
; /* NTP-corrected start time */
208 uint64_t start_time_usec
;
209 uint64_t start_freq
; /*
210 * Frequency at trace start,
211 * used all along the trace.
213 uint32_t freq_scale
; /* Frequency scaling (divisor) */
214 uint32_t data_size
; /* Size of data in subbuffer */
215 uint32_t sb_size
; /* Subbuffer size (include padding) */
216 uint32_t events_lost
; /*
217 * Events lost in this subbuffer since
218 * the beginning of the trace.
221 uint32_t subbuf_corrupt
; /*
222 * Corrupted (lost) subbuffers since
223 * the begginig of the trace.
226 uint8_t header_end
[0]; /* End of header */
229 static inline notrace u64
lib_ring_buffer_clock_read(struct channel
*chan
)
231 return trace_clock_read64();
235 * record_header_size - Calculate the header size and padding necessary.
236 * @config: ring buffer instance configuration
238 * @offset: offset in the write buffer
239 * @data_size: size of the payload
240 * @pre_header_padding: padding to add before the header (output)
241 * @rflags: reservation flags
242 * @ctx: reservation context
244 * Returns the event header size (including padding).
247 * The event header must be 32-bits. The total offset calculated here :
249 * Alignment of header struct on 32 bits (min arch size, header size)
250 * + sizeof(header struct) (32-bits)
251 * + (opt) u16 (ext. event id)
252 * + (opt) u16 (event_size)
253 * (if event_size == LTT_MAX_SMALL_SIZE, has ext. event size)
254 * + (opt) u32 (ext. event size)
255 * + (opt) u64 full TSC (aligned on min(64-bits, arch size))
257 * The payload must itself determine its own alignment from the biggest type it
261 unsigned char record_header_size(const struct lib_ring_buffer_config
*config
,
262 struct channel
*chan
, size_t offset
,
263 size_t data_size
, size_t *pre_header_padding
,
265 struct lib_ring_buffer_ctx
*ctx
)
267 size_t orig_offset
= offset
;
270 BUILD_BUG_ON(sizeof(struct event_header
) != sizeof(u32
));
272 padding
= lib_ring_buffer_align(config
, offset
,
273 sizeof(struct event_header
));
275 offset
+= sizeof(struct event_header
);
277 if (unlikely(rflags
)) {
279 case LTT_RFLAG_ID_SIZE_TSC
:
280 offset
+= sizeof(u16
) + sizeof(u16
);
281 if (data_size
>= LTT_MAX_SMALL_SIZE
)
282 offset
+= sizeof(u32
);
283 offset
+= ltt_align(offset
, sizeof(u64
));
284 offset
+= sizeof(u64
);
286 case LTT_RFLAG_ID_SIZE
:
287 offset
+= sizeof(u16
) + sizeof(u16
);
288 if (data_size
>= LTT_MAX_SMALL_SIZE
)
289 offset
+= sizeof(u32
);
292 offset
+= sizeof(u16
);
297 *pre_header_padding
= padding
;
298 return offset
- orig_offset
;
301 #include <linux/ringbuffer/api.h>
304 size_t ltt_write_event_header_slow(const struct lib_ring_buffer_config
*config
,
305 struct lib_ring_buffer_ctx
*ctx
,
306 u16 eID
, u32 event_size
);
309 * ltt_write_event_header
311 * Writes the event header to the offset (already aligned on 32-bits).
313 * @config: ring buffer instance configuration
314 * @ctx: reservation context
316 * @event_size : size of the event, excluding the event header.
319 void ltt_write_event_header(const struct lib_ring_buffer_config
*config
,
320 struct lib_ring_buffer_ctx
*ctx
,
321 u16 eID
, u32 event_size
)
323 struct event_header header
;
325 if (unlikely(ctx
->rflags
))
328 header
.id_time
= eID
<< LTT_TSC_BITS
;
329 header
.id_time
|= (u32
)ctx
->tsc
& LTT_TSC_MASK
;
330 lib_ring_buffer_write(config
, ctx
, &header
, sizeof(header
));
333 ltt_write_event_header_slow(config
, ctx
, eID
, event_size
);
338 * ltt_read_event_header
339 * buf_offset must aligned on 32 bits
342 size_t ltt_read_event_header(struct ltt_chanbuf_alloc
*bufa
, long buf_offset
,
343 u64
*tsc
, u32
*event_size
, u16
*eID
,
344 unsigned int *rflags
)
346 struct ltt_event_header header
;
349 ltt_relay_read(bufa
, buf_offset
, &header
, sizeof(header
));
350 buf_offset
+= sizeof(header
);
352 *event_size
= INT_MAX
;
353 *eID
= header
.id_time
>> LTT_TSC_BITS
;
354 *tsc
= header
.id_time
& LTT_TSC_MASK
;
358 *rflags
= LTT_RFLAG_ID_SIZE_TSC
;
359 ltt_relay_read(bufa
, buf_offset
, eID
, sizeof(u16
));
360 buf_offset
+= sizeof(u16
);
361 ltt_relay_read(bufa
, buf_offset
, &small_size
, sizeof(u16
));
362 buf_offset
+= sizeof(u16
);
363 if (small_size
== LTT_MAX_SMALL_SIZE
) {
364 ltt_relay_read(bufa
, buf_offset
, event_size
,
366 buf_offset
+= sizeof(u32
);
368 *event_size
= small_size
;
369 buf_offset
+= ltt_align(buf_offset
, sizeof(u64
));
370 ltt_relay_read(bufa
, buf_offset
, tsc
, sizeof(u64
));
371 buf_offset
+= sizeof(u64
);
374 *rflags
= LTT_RFLAG_ID_SIZE
;
375 ltt_relay_read(bufa
, buf_offset
, eID
, sizeof(u16
));
376 buf_offset
+= sizeof(u16
);
377 ltt_relay_read(bufa
, buf_offset
, &small_size
, sizeof(u16
));
378 buf_offset
+= sizeof(u16
);
379 if (small_size
== LTT_MAX_SMALL_SIZE
) {
380 ltt_relay_read(bufa
, buf_offset
, event_size
,
382 buf_offset
+= sizeof(u32
);
384 *event_size
= small_size
;
387 *rflags
= LTT_RFLAG_ID
;
388 ltt_relay_read(bufa
, buf_offset
, eID
, sizeof(u16
));
389 buf_offset
+= sizeof(u16
);
409 #define LTT_RELAY_ROOT "ltt"
411 #define LTT_METADATA_CHANNEL "metadata_state"
412 #define LTT_FD_STATE_CHANNEL "fd_state"
413 #define LTT_GLOBAL_STATE_CHANNEL "global_state"
414 #define LTT_IRQ_STATE_CHANNEL "irq_state"
415 #define LTT_MODULE_STATE_CHANNEL "module_state"
416 #define LTT_NETIF_STATE_CHANNEL "netif_state"
417 #define LTT_SOFTIRQ_STATE_CHANNEL "softirq_state"
418 #define LTT_SWAP_STATE_CHANNEL "swap_state"
419 #define LTT_SYSCALL_STATE_CHANNEL "syscall_state"
420 #define LTT_TASK_STATE_CHANNEL "task_state"
421 #define LTT_VM_STATE_CHANNEL "vm_state"
422 #define LTT_FS_CHANNEL "fs"
423 #define LTT_INPUT_CHANNEL "input"
424 #define LTT_IPC_CHANNEL "ipc"
425 #define LTT_KERNEL_CHANNEL "kernel"
426 #define LTT_MM_CHANNEL "mm"
427 #define LTT_RCU_CHANNEL "rcu"
429 #define LTT_FLIGHT_PREFIX "flight-"
431 #define LTT_ASCII "ascii"
433 /* Tracer properties */
434 #define LTT_DEFAULT_SUBBUF_SIZE_LOW 65536
435 #define LTT_DEFAULT_N_SUBBUFS_LOW 2
436 #define LTT_DEFAULT_SUBBUF_SIZE_MED 262144
437 #define LTT_DEFAULT_N_SUBBUFS_MED 2
438 #define LTT_DEFAULT_SUBBUF_SIZE_HIGH 1048576
439 #define LTT_DEFAULT_N_SUBBUFS_HIGH 2
440 #define LTT_TRACER_MAGIC_NUMBER 0x00D6B7ED
441 #define LTT_TRACER_VERSION_MAJOR 2
442 #define LTT_TRACER_VERSION_MINOR 6
445 * ltt_write_trace_header - Write trace header
446 * @priv: Private data (struct trace)
447 * @header: Memory address where the information must be written to
450 void ltt_write_trace_header(void *priv
,
451 struct subbuffer_header
*header
)
453 struct ltt_session
*session
= priv
;
455 header
->magic_number
= LTT_TRACER_MAGIC_NUMBER
;
456 header
->major_version
= LTT_TRACER_VERSION_MAJOR
;
457 header
->minor_version
= LTT_TRACER_VERSION_MINOR
;
458 header
->arch_size
= sizeof(void *);
459 header
->alignment
= lib_ring_buffer_get_alignment();
460 header
->start_time_sec
= session
->start_time
.tv_sec
;
461 header
->start_time_usec
= session
->start_time
.tv_usec
;
462 header
->start_freq
= session
->start_freq
;
463 header
->freq_scale
= session
->freq_scale
;
467 * Size reserved for high priority events (interrupts, NMI, BH) at the end of a
468 * nearly full buffer. User space won't use this last amount of space when in
469 * blocking mode. This space also includes the event header that would be
470 * written by this user space event.
472 #define LTT_RESERVE_CRITICAL 4096
474 /* Register and unregister function pointers */
476 enum ltt_module_function
{
477 LTT_FUNCTION_RUN_FILTER
,
478 LTT_FUNCTION_FILTER_CONTROL
,
479 LTT_FUNCTION_STATEDUMP
482 extern int ltt_module_register(enum ltt_module_function name
, void *function
,
483 struct module
*owner
);
484 extern void ltt_module_unregister(enum ltt_module_function name
);
486 /* Exported control function */
488 enum ltt_control_msg
{
491 LTT_CONTROL_CREATE_TRACE
,
492 LTT_CONTROL_DESTROY_TRACE
495 union ltt_control_args
{
497 enum trace_mode mode
;
498 unsigned int subbuf_size_low
;
499 unsigned int n_subbufs_low
;
500 unsigned int subbuf_size_med
;
501 unsigned int n_subbufs_med
;
502 unsigned int subbuf_size_high
;
503 unsigned int n_subbufs_high
;
507 void ltt_core_register(int (*function
)(u8
, void *));
509 void ltt_core_unregister(void);
511 extern int ltt_marker_connect(const char *channel
, const char *mname
,
513 extern int ltt_marker_disconnect(const char *channel
, const char *mname
,
515 extern void ltt_dump_marker_state(struct ltt_trace
*trace
);
518 void ltt_statedump_register_kprobes_dump(void (*callback
)(void *call_data
));
520 void ltt_statedump_unregister_kprobes_dump(void (*callback
)(void *call_data
));
522 extern void ltt_dump_softirq_vec(void *call_data
);
524 #ifdef CONFIG_HAVE_LTT_DUMP_TABLES
525 extern void ltt_dump_sys_call_table(void *call_data
);
526 extern void ltt_dump_idt_table(void *call_data
);
528 static inline void ltt_dump_sys_call_table(void *call_data
)
532 static inline void ltt_dump_idt_table(void *call_data
)
537 #endif /* _LTT_TRACER_H */