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Diffstat (limited to 'include/linux/marker.h')
| -rw-r--r-- | include/linux/marker.h | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/include/linux/marker.h b/include/linux/marker.h new file mode 100644 index 00000000000..c50c66d09f0 --- /dev/null +++ b/include/linux/marker.h @@ -0,0 +1,273 @@ +#ifndef _LINUX_MARKER_H +#define _LINUX_MARKER_H + +/* + * Code markup for dynamic and static tracing. + * + * See Documentation/marker.txt. + * + * (C) Copyright 2006 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> + * + * This file is released under the GPLv2. + * See the file COPYING for more details. + */ + +#include <stdarg.h> +#include <linux/types.h> +#include <linux/immediate.h> + +struct module; +struct marker; +struct marker_probe_array; + +/** + * marker_probe_func - Type of a marker probe function + * @mdata: marker data + * @probe_private: probe private data + * @call_private: call site private data + * @fmt: format string + * @args: variable argument list pointer. Use a pointer to overcome C's + * inability to pass this around as a pointer in a portable manner in + * the callee otherwise. + * + * Type of marker probe functions. They receive the mdata and need to parse the + * format string to recover the variable argument list. + */ +typedef void marker_probe_func(const struct marker *mdata, + void *probe_private, void *call_private, + const char *fmt, va_list *args); + +struct marker_probe_closure { + marker_probe_func *func; /* Callback */ + void *probe_private; /* Private probe data */ +}; + +struct marker { + const char *channel; /* Name of channel where to send data */ + const char *name; /* Marker name */ + const char *format; /* Marker format string, describing the + * variable argument list. + */ + DEFINE_IMV(char, state);/* Immediate value state. */ + char ptype; /* probe type : 0 : single, 1 : multi */ + /* Probe wrapper */ + u16 channel_id; /* Numeric channel identifier, dynamic */ + u16 event_id; /* Numeric event identifier, dynamic */ + void (*call)(const struct marker *mdata, void *call_private, ...); + struct marker_probe_closure single; + struct marker_probe_array *multi; + const char *tp_name; /* Optional tracepoint name */ + void *tp_cb; /* Optional tracepoint callback */ +} __attribute__((aligned(128))); /* + * Aligned on 128 bytes because it is + * globally visible and gcc happily + * align these on the structure size. + * Keep in sync with vmlinux.lds.h. + */ + +#ifdef CONFIG_MARKERS + +#define _DEFINE_MARKER(channel, name, tp_name_str, tp_cb, format) \ + static const char __mstrtab_##channel##_##name[] \ + __attribute__((section("__markers_strings"))) \ + = #channel "\0" #name "\0" format; \ + static struct marker __mark_##channel##_##name \ + __attribute__((section("__markers"), aligned(128))) = \ + { __mstrtab_##channel##_##name, \ + &__mstrtab_##channel##_##name[sizeof(#channel)], \ + &__mstrtab_##channel##_##name[sizeof(#channel) + \ + sizeof(#name)], \ + 0, 0, 0, 0, marker_probe_cb, \ + { __mark_empty_function, NULL}, \ + NULL, tp_name_str, tp_cb } + +#define DEFINE_MARKER(channel, name, format) \ + _DEFINE_MARKER(channel, name, NULL, NULL, format) + +#define DEFINE_MARKER_TP(channel, name, tp_name, tp_cb, format) \ + _DEFINE_MARKER(channel, name, #tp_name, tp_cb, format) + +/* + * Make sure the alignment of the structure in the __markers section will + * not add unwanted padding between the beginning of the section and the + * structure. Force alignment to the same alignment as the section start. + * + * The "generic" argument controls which marker enabling mechanism must be used. + * If generic is true, a variable read is used. + * If generic is false, immediate values are used. + */ +#define __trace_mark(generic, channel, name, call_private, format, args...) \ + do { \ + DEFINE_MARKER(channel, name, format); \ + __mark_check_format(format, ## args); \ + if (!generic) { \ + if (unlikely(imv_read( \ + __mark_##channel##_##name.state))) \ + (*__mark_##channel##_##name.call) \ + (&__mark_##channel##_##name, \ + call_private, ## args); \ + } else { \ + if (unlikely(_imv_read( \ + __mark_##channel##_##name.state))) \ + (*__mark_##channel##_##name.call) \ + (&__mark_##channel##_##name, \ + call_private, ## args); \ + } \ + } while (0) + +#define __trace_mark_tp(channel, name, call_private, tp_name, tp_cb, \ + format, args...) \ + do { \ + void __check_tp_type(void) \ + { \ + register_trace_##tp_name(tp_cb, NULL); \ + } \ + DEFINE_MARKER_TP(channel, name, tp_name, tp_cb, format);\ + __mark_check_format(format, ## args); \ + (*__mark_##channel##_##name.call)(&__mark_##channel##_##name, \ + call_private, ## args); \ + } while (0) + +extern void marker_update_probe_range(struct marker *begin, + struct marker *end); + +#define GET_MARKER(channel, name) (__mark_##channel##_##name) + +#else /* !CONFIG_MARKERS */ +#define DEFINE_MARKER(channel, name, tp_name, tp_cb, format) +#define __trace_mark(generic, channel, name, call_private, format, args...) \ + __mark_check_format(format, ## args) +#define __trace_mark_tp(channel, name, call_private, tp_name, tp_cb, \ + format, args...) \ + do { \ + void __check_tp_type(void) \ + { \ + register_trace_##tp_name(tp_cb, NULL); \ + } \ + __mark_check_format(format, ## args); \ + } while (0) +static inline void marker_update_probe_range(struct marker *begin, + struct marker *end) +{ } +#define GET_MARKER(channel, name) +#endif /* CONFIG_MARKERS */ + +/** + * trace_mark - Marker using code patching + * @channel: marker channel (where to send the data), not quoted. + * @name: marker name, not quoted. + * @format: format string + * @args...: variable argument list + * + * Places a marker using optimized code patching technique (imv_read()) + * to be enabled when immediate values are present. + */ +#define trace_mark(channel, name, format, args...) \ + __trace_mark(0, channel, name, NULL, format, ## args) + +/** + * _trace_mark - Marker using variable read + * @channel: marker channel (where to send the data), not quoted. + * @name: marker name, not quoted. + * @format: format string + * @args...: variable argument list + * + * Places a marker using a standard memory read (_imv_read()) to be + * enabled. Should be used for markers in code paths where instruction + * modification based enabling is not welcome. (__init and __exit functions, + * lockdep, some traps, printk). + */ +#define _trace_mark(channel, name, format, args...) \ + __trace_mark(1, channel, name, NULL, format, ## args) + +/** + * trace_mark_tp - Marker in a tracepoint callback + * @channel: marker channel (where to send the data), not quoted. + * @name: marker name, not quoted. + * @tp_name: tracepoint name, not quoted. + * @tp_cb: tracepoint callback. Should have an associated global symbol so it + * is not optimized away by the compiler (should not be static). + * @format: format string + * @args...: variable argument list + * + * Places a marker in a tracepoint callback. + */ +#define trace_mark_tp(channel, name, tp_name, tp_cb, format, args...) \ + __trace_mark_tp(channel, name, NULL, tp_name, tp_cb, format, ## args) + +/** + * MARK_NOARGS - Format string for a marker with no argument. + */ +#define MARK_NOARGS " " + +extern void lock_markers(void); +extern void unlock_markers(void); + +extern void markers_compact_event_ids(void); + +/* To be used for string format validity checking with gcc */ +static inline void __printf(1, 2) ___mark_check_format(const char *fmt, ...) +{ +} + +#define __mark_check_format(format, args...) \ + do { \ + if (0) \ + ___mark_check_format(format, ## args); \ + } while (0) + +extern marker_probe_func __mark_empty_function; + +extern void marker_probe_cb(const struct marker *mdata, + void *call_private, ...); + +/* + * Connect a probe to a marker. + * private data pointer must be a valid allocated memory address, or NULL. + */ +extern int marker_probe_register(const char *channel, const char *name, + const char *format, marker_probe_func *probe, void *probe_private); + +/* + * Returns the private data given to marker_probe_register. + */ +extern int marker_probe_unregister(const char *channel, const char *name, + marker_probe_func *probe, void *probe_private); +/* + * Unregister a marker by providing the registered private data. + */ +extern int marker_probe_unregister_private_data(marker_probe_func *probe, + void *probe_private); + +extern void *marker_get_private_data(const char *channel, const char *name, + marker_probe_func *probe, int num); + +const char *marker_get_name_from_id(u16 channel_id, u16 event_id); +const char *marker_get_fmt_from_id(u16 channel_id, u16 event_id); + +/* + * marker_synchronize_unregister must be called between the last marker probe + * unregistration and the first one of + * - the end of module exit function + * - the free of any resource used by the probes + * to ensure the code and data are valid for any possibly running probes. + */ +#define marker_synchronize_unregister() synchronize_sched() + +struct marker_iter { + struct module *module; + struct marker *marker; +}; + +extern void marker_iter_start(struct marker_iter *iter); +extern void marker_iter_next(struct marker_iter *iter); +extern void marker_iter_stop(struct marker_iter *iter); +extern void marker_iter_reset(struct marker_iter *iter); +extern int marker_get_iter_range(struct marker **marker, struct marker *begin, + struct marker *end); +extern int _is_marker_enabled(const char *channel, const char *name); +extern int is_marker_enabled(const char *channel, const char *name); +extern int is_marker_present(const char *channel, const char *name); +extern void marker_update_probes(void); + +#endif |