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-rw-r--r--include/linux/ftrace_event.h627
1 files changed, 627 insertions, 0 deletions
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
new file mode 100644
index 000000000..f9ecf63d4
--- /dev/null
+++ b/include/linux/ftrace_event.h
@@ -0,0 +1,627 @@
+
+#ifndef _LINUX_FTRACE_EVENT_H
+#define _LINUX_FTRACE_EVENT_H
+
+#include <linux/ring_buffer.h>
+#include <linux/trace_seq.h>
+#include <linux/percpu.h>
+#include <linux/hardirq.h>
+#include <linux/perf_event.h>
+#include <linux/tracepoint.h>
+
+struct trace_array;
+struct trace_buffer;
+struct tracer;
+struct dentry;
+struct bpf_prog;
+
+struct trace_print_flags {
+ unsigned long mask;
+ const char *name;
+};
+
+struct trace_print_flags_u64 {
+ unsigned long long mask;
+ const char *name;
+};
+
+const char *ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
+ unsigned long flags,
+ const struct trace_print_flags *flag_array);
+
+const char *ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
+ const struct trace_print_flags *symbol_array);
+
+#if BITS_PER_LONG == 32
+const char *ftrace_print_symbols_seq_u64(struct trace_seq *p,
+ unsigned long long val,
+ const struct trace_print_flags_u64
+ *symbol_array);
+#endif
+
+const char *ftrace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
+ unsigned int bitmask_size);
+
+const char *ftrace_print_hex_seq(struct trace_seq *p,
+ const unsigned char *buf, int len);
+
+const char *ftrace_print_array_seq(struct trace_seq *p,
+ const void *buf, int count,
+ size_t el_size);
+
+struct trace_iterator;
+struct trace_event;
+
+int ftrace_raw_output_prep(struct trace_iterator *iter,
+ struct trace_event *event);
+
+/*
+ * The trace entry - the most basic unit of tracing. This is what
+ * is printed in the end as a single line in the trace output, such as:
+ *
+ * bash-15816 [01] 235.197585: idle_cpu <- irq_enter
+ */
+struct trace_entry {
+ unsigned short type;
+ unsigned char flags;
+ unsigned char preempt_count;
+ int pid;
+};
+
+#define FTRACE_MAX_EVENT \
+ ((1 << (sizeof(((struct trace_entry *)0)->type) * 8)) - 1)
+
+/*
+ * Trace iterator - used by printout routines who present trace
+ * results to users and which routines might sleep, etc:
+ */
+struct trace_iterator {
+ struct trace_array *tr;
+ struct tracer *trace;
+ struct trace_buffer *trace_buffer;
+ void *private;
+ int cpu_file;
+ struct mutex mutex;
+ struct ring_buffer_iter **buffer_iter;
+ unsigned long iter_flags;
+
+ /* trace_seq for __print_flags() and __print_symbolic() etc. */
+ struct trace_seq tmp_seq;
+
+ cpumask_var_t started;
+
+ /* it's true when current open file is snapshot */
+ bool snapshot;
+
+ /* The below is zeroed out in pipe_read */
+ struct trace_seq seq;
+ struct trace_entry *ent;
+ unsigned long lost_events;
+ int leftover;
+ int ent_size;
+ int cpu;
+ u64 ts;
+
+ loff_t pos;
+ long idx;
+
+ /* All new field here will be zeroed out in pipe_read */
+};
+
+enum trace_iter_flags {
+ TRACE_FILE_LAT_FMT = 1,
+ TRACE_FILE_ANNOTATE = 2,
+ TRACE_FILE_TIME_IN_NS = 4,
+};
+
+
+typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter,
+ int flags, struct trace_event *event);
+
+struct trace_event_functions {
+ trace_print_func trace;
+ trace_print_func raw;
+ trace_print_func hex;
+ trace_print_func binary;
+};
+
+struct trace_event {
+ struct hlist_node node;
+ struct list_head list;
+ int type;
+ struct trace_event_functions *funcs;
+};
+
+extern int register_ftrace_event(struct trace_event *event);
+extern int unregister_ftrace_event(struct trace_event *event);
+
+/* Return values for print_line callback */
+enum print_line_t {
+ TRACE_TYPE_PARTIAL_LINE = 0, /* Retry after flushing the seq */
+ TRACE_TYPE_HANDLED = 1,
+ TRACE_TYPE_UNHANDLED = 2, /* Relay to other output functions */
+ TRACE_TYPE_NO_CONSUME = 3 /* Handled but ask to not consume */
+};
+
+/*
+ * Several functions return TRACE_TYPE_PARTIAL_LINE if the trace_seq
+ * overflowed, and TRACE_TYPE_HANDLED otherwise. This helper function
+ * simplifies those functions and keeps them in sync.
+ */
+static inline enum print_line_t trace_handle_return(struct trace_seq *s)
+{
+ return trace_seq_has_overflowed(s) ?
+ TRACE_TYPE_PARTIAL_LINE : TRACE_TYPE_HANDLED;
+}
+
+void tracing_generic_entry_update(struct trace_entry *entry,
+ unsigned long flags,
+ int pc);
+struct ftrace_event_file;
+
+struct ring_buffer_event *
+trace_event_buffer_lock_reserve(struct ring_buffer **current_buffer,
+ struct ftrace_event_file *ftrace_file,
+ int type, unsigned long len,
+ unsigned long flags, int pc);
+struct ring_buffer_event *
+trace_current_buffer_lock_reserve(struct ring_buffer **current_buffer,
+ int type, unsigned long len,
+ unsigned long flags, int pc);
+void trace_current_buffer_unlock_commit(struct ring_buffer *buffer,
+ struct ring_buffer_event *event,
+ unsigned long flags, int pc);
+void trace_buffer_unlock_commit(struct ring_buffer *buffer,
+ struct ring_buffer_event *event,
+ unsigned long flags, int pc);
+void trace_buffer_unlock_commit_regs(struct ring_buffer *buffer,
+ struct ring_buffer_event *event,
+ unsigned long flags, int pc,
+ struct pt_regs *regs);
+void trace_current_buffer_discard_commit(struct ring_buffer *buffer,
+ struct ring_buffer_event *event);
+
+void tracing_record_cmdline(struct task_struct *tsk);
+
+int ftrace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...);
+
+struct event_filter;
+
+enum trace_reg {
+ TRACE_REG_REGISTER,
+ TRACE_REG_UNREGISTER,
+#ifdef CONFIG_PERF_EVENTS
+ TRACE_REG_PERF_REGISTER,
+ TRACE_REG_PERF_UNREGISTER,
+ TRACE_REG_PERF_OPEN,
+ TRACE_REG_PERF_CLOSE,
+ TRACE_REG_PERF_ADD,
+ TRACE_REG_PERF_DEL,
+#endif
+};
+
+struct ftrace_event_call;
+
+struct ftrace_event_class {
+ const char *system;
+ void *probe;
+#ifdef CONFIG_PERF_EVENTS
+ void *perf_probe;
+#endif
+ int (*reg)(struct ftrace_event_call *event,
+ enum trace_reg type, void *data);
+ int (*define_fields)(struct ftrace_event_call *);
+ struct list_head *(*get_fields)(struct ftrace_event_call *);
+ struct list_head fields;
+ int (*raw_init)(struct ftrace_event_call *);
+};
+
+extern int ftrace_event_reg(struct ftrace_event_call *event,
+ enum trace_reg type, void *data);
+
+int ftrace_output_event(struct trace_iterator *iter, struct ftrace_event_call *event,
+ char *fmt, ...);
+
+int ftrace_event_define_field(struct ftrace_event_call *call,
+ char *type, int len, char *item, int offset,
+ int field_size, int sign, int filter);
+
+struct ftrace_event_buffer {
+ struct ring_buffer *buffer;
+ struct ring_buffer_event *event;
+ struct ftrace_event_file *ftrace_file;
+ void *entry;
+ unsigned long flags;
+ int pc;
+};
+
+void *ftrace_event_buffer_reserve(struct ftrace_event_buffer *fbuffer,
+ struct ftrace_event_file *ftrace_file,
+ unsigned long len);
+
+void ftrace_event_buffer_commit(struct ftrace_event_buffer *fbuffer);
+
+int ftrace_event_define_field(struct ftrace_event_call *call,
+ char *type, int len, char *item, int offset,
+ int field_size, int sign, int filter);
+
+enum {
+ TRACE_EVENT_FL_FILTERED_BIT,
+ TRACE_EVENT_FL_CAP_ANY_BIT,
+ TRACE_EVENT_FL_NO_SET_FILTER_BIT,
+ TRACE_EVENT_FL_IGNORE_ENABLE_BIT,
+ TRACE_EVENT_FL_WAS_ENABLED_BIT,
+ TRACE_EVENT_FL_USE_CALL_FILTER_BIT,
+ TRACE_EVENT_FL_TRACEPOINT_BIT,
+ TRACE_EVENT_FL_KPROBE_BIT,
+};
+
+/*
+ * Event flags:
+ * FILTERED - The event has a filter attached
+ * CAP_ANY - Any user can enable for perf
+ * NO_SET_FILTER - Set when filter has error and is to be ignored
+ * IGNORE_ENABLE - For ftrace internal events, do not enable with debugfs file
+ * WAS_ENABLED - Set and stays set when an event was ever enabled
+ * (used for module unloading, if a module event is enabled,
+ * it is best to clear the buffers that used it).
+ * USE_CALL_FILTER - For ftrace internal events, don't use file filter
+ * TRACEPOINT - Event is a tracepoint
+ * KPROBE - Event is a kprobe
+ */
+enum {
+ TRACE_EVENT_FL_FILTERED = (1 << TRACE_EVENT_FL_FILTERED_BIT),
+ TRACE_EVENT_FL_CAP_ANY = (1 << TRACE_EVENT_FL_CAP_ANY_BIT),
+ TRACE_EVENT_FL_NO_SET_FILTER = (1 << TRACE_EVENT_FL_NO_SET_FILTER_BIT),
+ TRACE_EVENT_FL_IGNORE_ENABLE = (1 << TRACE_EVENT_FL_IGNORE_ENABLE_BIT),
+ TRACE_EVENT_FL_WAS_ENABLED = (1 << TRACE_EVENT_FL_WAS_ENABLED_BIT),
+ TRACE_EVENT_FL_USE_CALL_FILTER = (1 << TRACE_EVENT_FL_USE_CALL_FILTER_BIT),
+ TRACE_EVENT_FL_TRACEPOINT = (1 << TRACE_EVENT_FL_TRACEPOINT_BIT),
+ TRACE_EVENT_FL_KPROBE = (1 << TRACE_EVENT_FL_KPROBE_BIT),
+};
+
+struct ftrace_event_call {
+ struct list_head list;
+ struct ftrace_event_class *class;
+ union {
+ char *name;
+ /* Set TRACE_EVENT_FL_TRACEPOINT flag when using "tp" */
+ struct tracepoint *tp;
+ };
+ struct trace_event event;
+ char *print_fmt;
+ struct event_filter *filter;
+ void *mod;
+ void *data;
+ /*
+ * bit 0: filter_active
+ * bit 1: allow trace by non root (cap any)
+ * bit 2: failed to apply filter
+ * bit 3: ftrace internal event (do not enable)
+ * bit 4: Event was enabled by module
+ * bit 5: use call filter rather than file filter
+ * bit 6: Event is a tracepoint
+ */
+ int flags; /* static flags of different events */
+
+#ifdef CONFIG_PERF_EVENTS
+ int perf_refcount;
+ struct hlist_head __percpu *perf_events;
+ struct bpf_prog *prog;
+
+ int (*perf_perm)(struct ftrace_event_call *,
+ struct perf_event *);
+#endif
+};
+
+static inline const char *
+ftrace_event_name(struct ftrace_event_call *call)
+{
+ if (call->flags & TRACE_EVENT_FL_TRACEPOINT)
+ return call->tp ? call->tp->name : NULL;
+ else
+ return call->name;
+}
+
+struct trace_array;
+struct ftrace_subsystem_dir;
+
+enum {
+ FTRACE_EVENT_FL_ENABLED_BIT,
+ FTRACE_EVENT_FL_RECORDED_CMD_BIT,
+ FTRACE_EVENT_FL_FILTERED_BIT,
+ FTRACE_EVENT_FL_NO_SET_FILTER_BIT,
+ FTRACE_EVENT_FL_SOFT_MODE_BIT,
+ FTRACE_EVENT_FL_SOFT_DISABLED_BIT,
+ FTRACE_EVENT_FL_TRIGGER_MODE_BIT,
+ FTRACE_EVENT_FL_TRIGGER_COND_BIT,
+};
+
+/*
+ * Ftrace event file flags:
+ * ENABLED - The event is enabled
+ * RECORDED_CMD - The comms should be recorded at sched_switch
+ * FILTERED - The event has a filter attached
+ * NO_SET_FILTER - Set when filter has error and is to be ignored
+ * SOFT_MODE - The event is enabled/disabled by SOFT_DISABLED
+ * SOFT_DISABLED - When set, do not trace the event (even though its
+ * tracepoint may be enabled)
+ * TRIGGER_MODE - When set, invoke the triggers associated with the event
+ * TRIGGER_COND - When set, one or more triggers has an associated filter
+ */
+enum {
+ FTRACE_EVENT_FL_ENABLED = (1 << FTRACE_EVENT_FL_ENABLED_BIT),
+ FTRACE_EVENT_FL_RECORDED_CMD = (1 << FTRACE_EVENT_FL_RECORDED_CMD_BIT),
+ FTRACE_EVENT_FL_FILTERED = (1 << FTRACE_EVENT_FL_FILTERED_BIT),
+ FTRACE_EVENT_FL_NO_SET_FILTER = (1 << FTRACE_EVENT_FL_NO_SET_FILTER_BIT),
+ FTRACE_EVENT_FL_SOFT_MODE = (1 << FTRACE_EVENT_FL_SOFT_MODE_BIT),
+ FTRACE_EVENT_FL_SOFT_DISABLED = (1 << FTRACE_EVENT_FL_SOFT_DISABLED_BIT),
+ FTRACE_EVENT_FL_TRIGGER_MODE = (1 << FTRACE_EVENT_FL_TRIGGER_MODE_BIT),
+ FTRACE_EVENT_FL_TRIGGER_COND = (1 << FTRACE_EVENT_FL_TRIGGER_COND_BIT),
+};
+
+struct ftrace_event_file {
+ struct list_head list;
+ struct ftrace_event_call *event_call;
+ struct event_filter *filter;
+ struct dentry *dir;
+ struct trace_array *tr;
+ struct ftrace_subsystem_dir *system;
+ struct list_head triggers;
+
+ /*
+ * 32 bit flags:
+ * bit 0: enabled
+ * bit 1: enabled cmd record
+ * bit 2: enable/disable with the soft disable bit
+ * bit 3: soft disabled
+ * bit 4: trigger enabled
+ *
+ * Note: The bits must be set atomically to prevent races
+ * from other writers. Reads of flags do not need to be in
+ * sync as they occur in critical sections. But the way flags
+ * is currently used, these changes do not affect the code
+ * except that when a change is made, it may have a slight
+ * delay in propagating the changes to other CPUs due to
+ * caching and such. Which is mostly OK ;-)
+ */
+ unsigned long flags;
+ atomic_t sm_ref; /* soft-mode reference counter */
+ atomic_t tm_ref; /* trigger-mode reference counter */
+};
+
+#define __TRACE_EVENT_FLAGS(name, value) \
+ static int __init trace_init_flags_##name(void) \
+ { \
+ event_##name.flags |= value; \
+ return 0; \
+ } \
+ early_initcall(trace_init_flags_##name);
+
+#define __TRACE_EVENT_PERF_PERM(name, expr...) \
+ static int perf_perm_##name(struct ftrace_event_call *tp_event, \
+ struct perf_event *p_event) \
+ { \
+ return ({ expr; }); \
+ } \
+ static int __init trace_init_perf_perm_##name(void) \
+ { \
+ event_##name.perf_perm = &perf_perm_##name; \
+ return 0; \
+ } \
+ early_initcall(trace_init_perf_perm_##name);
+
+#define PERF_MAX_TRACE_SIZE 2048
+
+#define MAX_FILTER_STR_VAL 256 /* Should handle KSYM_SYMBOL_LEN */
+
+enum event_trigger_type {
+ ETT_NONE = (0),
+ ETT_TRACE_ONOFF = (1 << 0),
+ ETT_SNAPSHOT = (1 << 1),
+ ETT_STACKTRACE = (1 << 2),
+ ETT_EVENT_ENABLE = (1 << 3),
+};
+
+extern int filter_match_preds(struct event_filter *filter, void *rec);
+
+extern int filter_check_discard(struct ftrace_event_file *file, void *rec,
+ struct ring_buffer *buffer,
+ struct ring_buffer_event *event);
+extern int call_filter_check_discard(struct ftrace_event_call *call, void *rec,
+ struct ring_buffer *buffer,
+ struct ring_buffer_event *event);
+extern enum event_trigger_type event_triggers_call(struct ftrace_event_file *file,
+ void *rec);
+extern void event_triggers_post_call(struct ftrace_event_file *file,
+ enum event_trigger_type tt);
+
+/**
+ * ftrace_trigger_soft_disabled - do triggers and test if soft disabled
+ * @file: The file pointer of the event to test
+ *
+ * If any triggers without filters are attached to this event, they
+ * will be called here. If the event is soft disabled and has no
+ * triggers that require testing the fields, it will return true,
+ * otherwise false.
+ */
+static inline bool
+ftrace_trigger_soft_disabled(struct ftrace_event_file *file)
+{
+ unsigned long eflags = file->flags;
+
+ if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
+ if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
+ event_triggers_call(file, NULL);
+ if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
+ return true;
+ }
+ return false;
+}
+
+/*
+ * Helper function for event_trigger_unlock_commit{_regs}().
+ * If there are event triggers attached to this event that requires
+ * filtering against its fields, then they wil be called as the
+ * entry already holds the field information of the current event.
+ *
+ * It also checks if the event should be discarded or not.
+ * It is to be discarded if the event is soft disabled and the
+ * event was only recorded to process triggers, or if the event
+ * filter is active and this event did not match the filters.
+ *
+ * Returns true if the event is discarded, false otherwise.
+ */
+static inline bool
+__event_trigger_test_discard(struct ftrace_event_file *file,
+ struct ring_buffer *buffer,
+ struct ring_buffer_event *event,
+ void *entry,
+ enum event_trigger_type *tt)
+{
+ unsigned long eflags = file->flags;
+
+ if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
+ *tt = event_triggers_call(file, entry);
+
+ if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags))
+ ring_buffer_discard_commit(buffer, event);
+ else if (!filter_check_discard(file, entry, buffer, event))
+ return false;
+
+ return true;
+}
+
+/**
+ * event_trigger_unlock_commit - handle triggers and finish event commit
+ * @file: The file pointer assoctiated to the event
+ * @buffer: The ring buffer that the event is being written to
+ * @event: The event meta data in the ring buffer
+ * @entry: The event itself
+ * @irq_flags: The state of the interrupts at the start of the event
+ * @pc: The state of the preempt count at the start of the event.
+ *
+ * This is a helper function to handle triggers that require data
+ * from the event itself. It also tests the event against filters and
+ * if the event is soft disabled and should be discarded.
+ */
+static inline void
+event_trigger_unlock_commit(struct ftrace_event_file *file,
+ struct ring_buffer *buffer,
+ struct ring_buffer_event *event,
+ void *entry, unsigned long irq_flags, int pc)
+{
+ enum event_trigger_type tt = ETT_NONE;
+
+ if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
+ trace_buffer_unlock_commit(buffer, event, irq_flags, pc);
+
+ if (tt)
+ event_triggers_post_call(file, tt);
+}
+
+/**
+ * event_trigger_unlock_commit_regs - handle triggers and finish event commit
+ * @file: The file pointer assoctiated to the event
+ * @buffer: The ring buffer that the event is being written to
+ * @event: The event meta data in the ring buffer
+ * @entry: The event itself
+ * @irq_flags: The state of the interrupts at the start of the event
+ * @pc: The state of the preempt count at the start of the event.
+ *
+ * This is a helper function to handle triggers that require data
+ * from the event itself. It also tests the event against filters and
+ * if the event is soft disabled and should be discarded.
+ *
+ * Same as event_trigger_unlock_commit() but calls
+ * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
+ */
+static inline void
+event_trigger_unlock_commit_regs(struct ftrace_event_file *file,
+ struct ring_buffer *buffer,
+ struct ring_buffer_event *event,
+ void *entry, unsigned long irq_flags, int pc,
+ struct pt_regs *regs)
+{
+ enum event_trigger_type tt = ETT_NONE;
+
+ if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
+ trace_buffer_unlock_commit_regs(buffer, event,
+ irq_flags, pc, regs);
+
+ if (tt)
+ event_triggers_post_call(file, tt);
+}
+
+#ifdef CONFIG_BPF_SYSCALL
+unsigned int trace_call_bpf(struct bpf_prog *prog, void *ctx);
+#else
+static inline unsigned int trace_call_bpf(struct bpf_prog *prog, void *ctx)
+{
+ return 1;
+}
+#endif
+
+enum {
+ FILTER_OTHER = 0,
+ FILTER_STATIC_STRING,
+ FILTER_DYN_STRING,
+ FILTER_PTR_STRING,
+ FILTER_TRACE_FN,
+};
+
+extern int trace_event_raw_init(struct ftrace_event_call *call);
+extern int trace_define_field(struct ftrace_event_call *call, const char *type,
+ const char *name, int offset, int size,
+ int is_signed, int filter_type);
+extern int trace_add_event_call(struct ftrace_event_call *call);
+extern int trace_remove_event_call(struct ftrace_event_call *call);
+
+#define is_signed_type(type) (((type)(-1)) < (type)1)
+
+int trace_set_clr_event(const char *system, const char *event, int set);
+
+/*
+ * The double __builtin_constant_p is because gcc will give us an error
+ * if we try to allocate the static variable to fmt if it is not a
+ * constant. Even with the outer if statement optimizing out.
+ */
+#define event_trace_printk(ip, fmt, args...) \
+do { \
+ __trace_printk_check_format(fmt, ##args); \
+ tracing_record_cmdline(current); \
+ if (__builtin_constant_p(fmt)) { \
+ static const char *trace_printk_fmt \
+ __attribute__((section("__trace_printk_fmt"))) = \
+ __builtin_constant_p(fmt) ? fmt : NULL; \
+ \
+ __trace_bprintk(ip, trace_printk_fmt, ##args); \
+ } else \
+ __trace_printk(ip, fmt, ##args); \
+} while (0)
+
+#ifdef CONFIG_PERF_EVENTS
+struct perf_event;
+
+DECLARE_PER_CPU(struct pt_regs, perf_trace_regs);
+
+extern int perf_trace_init(struct perf_event *event);
+extern void perf_trace_destroy(struct perf_event *event);
+extern int perf_trace_add(struct perf_event *event, int flags);
+extern void perf_trace_del(struct perf_event *event, int flags);
+extern int ftrace_profile_set_filter(struct perf_event *event, int event_id,
+ char *filter_str);
+extern void ftrace_profile_free_filter(struct perf_event *event);
+extern void *perf_trace_buf_prepare(int size, unsigned short type,
+ struct pt_regs **regs, int *rctxp);
+
+static inline void
+perf_trace_buf_submit(void *raw_data, int size, int rctx, u64 addr,
+ u64 count, struct pt_regs *regs, void *head,
+ struct task_struct *task)
+{
+ perf_tp_event(addr, count, raw_data, size, regs, head, rctx, task);
+}
+#endif
+
+#endif /* _LINUX_FTRACE_EVENT_H */