linux/tools/perf/util/evsel.h
Wang Nan 1f45b1d490 perf bpf: Attach eBPF filter to perf event
This is the final patch which makes basic BPF filter work. After
applying this patch, users are allowed to use BPF filter like:

 # perf record --event ./hello_world.o ls

A bpf_fd field is appended to 'struct evsel', and setup during the
callback function add_bpf_event() for each 'probe_trace_event'.

PERF_EVENT_IOC_SET_BPF ioctl is used to attach eBPF program to a newly
created perf event. The file descriptor of the eBPF program is passed to
perf record using previous patches, and stored into evsel->bpf_fd.

It is possible that different perf event are created for one kprobe
events for different CPUs. In this case, when trying to call the ioctl,
EEXIST will be return. This patch doesn't treat it as an error.

Committer note:

The bpf proggie used so far:

  __attribute__((section("fork=_do_fork"), used))
  int fork(void *ctx)
  {
	  return 0;
  }

  char _license[] __attribute__((section("license"), used)) = "GPL";
  int _version __attribute__((section("version"), used)) = 0x40300;

failed to produce any samples, even with forks happening and it being
running in system wide mode.

That is because now the filter is being associated, and the code above
always returns zero, meaning that all forks will be probed but filtered
away ;-/

Change it to 'return 1;' instead and after that:

  # trace --no-syscalls --event /tmp/foo.o
     0.000 perf_bpf_probe:fork:(ffffffff8109be30))
     2.333 perf_bpf_probe:fork:(ffffffff8109be30))
     3.725 perf_bpf_probe:fork:(ffffffff8109be30))
     4.550 perf_bpf_probe:fork:(ffffffff8109be30))
  ^C#

And it works with all tools, including 'perf trace'.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1444826502-49291-8-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-10-29 17:16:22 -03:00

402 lines
12 KiB
C

#ifndef __PERF_EVSEL_H
#define __PERF_EVSEL_H 1
#include <linux/list.h>
#include <stdbool.h>
#include <stddef.h>
#include <linux/perf_event.h>
#include <linux/types.h>
#include "xyarray.h"
#include "symbol.h"
#include "cpumap.h"
#include "counts.h"
struct perf_evsel;
/*
* Per fd, to map back from PERF_SAMPLE_ID to evsel, only used when there are
* more than one entry in the evlist.
*/
struct perf_sample_id {
struct hlist_node node;
u64 id;
struct perf_evsel *evsel;
int idx;
int cpu;
pid_t tid;
/* Holds total ID period value for PERF_SAMPLE_READ processing. */
u64 period;
};
struct cgroup_sel;
/*
* The 'struct perf_evsel_config_term' is used to pass event
* specific configuration data to perf_evsel__config routine.
* It is allocated within event parsing and attached to
* perf_evsel::config_terms list head.
*/
enum {
PERF_EVSEL__CONFIG_TERM_PERIOD,
PERF_EVSEL__CONFIG_TERM_FREQ,
PERF_EVSEL__CONFIG_TERM_TIME,
PERF_EVSEL__CONFIG_TERM_CALLGRAPH,
PERF_EVSEL__CONFIG_TERM_STACK_USER,
PERF_EVSEL__CONFIG_TERM_INHERIT,
PERF_EVSEL__CONFIG_TERM_MAX,
};
struct perf_evsel_config_term {
struct list_head list;
int type;
union {
u64 period;
u64 freq;
bool time;
char *callgraph;
u64 stack_user;
bool inherit;
} val;
};
/** struct perf_evsel - event selector
*
* @evlist - evlist this evsel is in, if it is in one.
* @node - To insert it into evlist->entries or in other list_heads, say in
* the event parsing routines.
* @name - Can be set to retain the original event name passed by the user,
* so that when showing results in tools such as 'perf stat', we
* show the name used, not some alias.
* @id_pos: the position of the event id (PERF_SAMPLE_ID or
* PERF_SAMPLE_IDENTIFIER) in a sample event i.e. in the array of
* struct sample_event
* @is_pos: the position (counting backwards) of the event id (PERF_SAMPLE_ID or
* PERF_SAMPLE_IDENTIFIER) in a non-sample event i.e. if sample_id_all
* is used there is an id sample appended to non-sample events
* @priv: And what is in its containing unnamed union are tool specific
*/
struct perf_evsel {
struct list_head node;
struct perf_evlist *evlist;
struct perf_event_attr attr;
char *filter;
struct xyarray *fd;
struct xyarray *sample_id;
u64 *id;
struct perf_counts *counts;
struct perf_counts *prev_raw_counts;
int idx;
u32 ids;
char *name;
double scale;
const char *unit;
struct event_format *tp_format;
off_t id_offset;
union {
void *priv;
u64 db_id;
};
struct cgroup_sel *cgrp;
void *handler;
struct cpu_map *cpus;
struct cpu_map *own_cpus;
struct thread_map *threads;
unsigned int sample_size;
int id_pos;
int is_pos;
bool snapshot;
bool supported;
bool needs_swap;
bool no_aux_samples;
bool immediate;
bool system_wide;
bool tracking;
bool per_pkg;
bool precise_max;
/* parse modifier helper */
int exclude_GH;
int nr_members;
int sample_read;
unsigned long *per_pkg_mask;
struct perf_evsel *leader;
char *group_name;
bool cmdline_group_boundary;
struct list_head config_terms;
int bpf_fd;
};
union u64_swap {
u64 val64;
u32 val32[2];
};
struct cpu_map;
struct target;
struct thread_map;
struct record_opts;
static inline struct cpu_map *perf_evsel__cpus(struct perf_evsel *evsel)
{
return evsel->cpus;
}
static inline int perf_evsel__nr_cpus(struct perf_evsel *evsel)
{
return perf_evsel__cpus(evsel)->nr;
}
void perf_counts_values__scale(struct perf_counts_values *count,
bool scale, s8 *pscaled);
void perf_evsel__compute_deltas(struct perf_evsel *evsel, int cpu, int thread,
struct perf_counts_values *count);
int perf_evsel__object_config(size_t object_size,
int (*init)(struct perf_evsel *evsel),
void (*fini)(struct perf_evsel *evsel));
struct perf_evsel *perf_evsel__new_idx(struct perf_event_attr *attr, int idx);
static inline struct perf_evsel *perf_evsel__new(struct perf_event_attr *attr)
{
return perf_evsel__new_idx(attr, 0);
}
struct perf_evsel *perf_evsel__newtp_idx(const char *sys, const char *name, int idx);
/*
* Returns pointer with encoded error via <linux/err.h> interface.
*/
static inline struct perf_evsel *perf_evsel__newtp(const char *sys, const char *name)
{
return perf_evsel__newtp_idx(sys, name, 0);
}
struct event_format *event_format__new(const char *sys, const char *name);
void perf_evsel__init(struct perf_evsel *evsel,
struct perf_event_attr *attr, int idx);
void perf_evsel__exit(struct perf_evsel *evsel);
void perf_evsel__delete(struct perf_evsel *evsel);
void perf_evsel__config(struct perf_evsel *evsel,
struct record_opts *opts);
int __perf_evsel__sample_size(u64 sample_type);
void perf_evsel__calc_id_pos(struct perf_evsel *evsel);
bool perf_evsel__is_cache_op_valid(u8 type, u8 op);
#define PERF_EVSEL__MAX_ALIASES 8
extern const char *perf_evsel__hw_cache[PERF_COUNT_HW_CACHE_MAX]
[PERF_EVSEL__MAX_ALIASES];
extern const char *perf_evsel__hw_cache_op[PERF_COUNT_HW_CACHE_OP_MAX]
[PERF_EVSEL__MAX_ALIASES];
extern const char *perf_evsel__hw_cache_result[PERF_COUNT_HW_CACHE_RESULT_MAX]
[PERF_EVSEL__MAX_ALIASES];
extern const char *perf_evsel__hw_names[PERF_COUNT_HW_MAX];
extern const char *perf_evsel__sw_names[PERF_COUNT_SW_MAX];
int __perf_evsel__hw_cache_type_op_res_name(u8 type, u8 op, u8 result,
char *bf, size_t size);
const char *perf_evsel__name(struct perf_evsel *evsel);
const char *perf_evsel__group_name(struct perf_evsel *evsel);
int perf_evsel__group_desc(struct perf_evsel *evsel, char *buf, size_t size);
int perf_evsel__alloc_id(struct perf_evsel *evsel, int ncpus, int nthreads);
void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads);
void __perf_evsel__set_sample_bit(struct perf_evsel *evsel,
enum perf_event_sample_format bit);
void __perf_evsel__reset_sample_bit(struct perf_evsel *evsel,
enum perf_event_sample_format bit);
#define perf_evsel__set_sample_bit(evsel, bit) \
__perf_evsel__set_sample_bit(evsel, PERF_SAMPLE_##bit)
#define perf_evsel__reset_sample_bit(evsel, bit) \
__perf_evsel__reset_sample_bit(evsel, PERF_SAMPLE_##bit)
void perf_evsel__set_sample_id(struct perf_evsel *evsel,
bool use_sample_identifier);
int perf_evsel__set_filter(struct perf_evsel *evsel, const char *filter);
int perf_evsel__append_filter(struct perf_evsel *evsel,
const char *op, const char *filter);
int perf_evsel__apply_filter(struct perf_evsel *evsel, int ncpus, int nthreads,
const char *filter);
int perf_evsel__enable(struct perf_evsel *evsel, int ncpus, int nthreads);
int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
struct cpu_map *cpus);
int perf_evsel__open_per_thread(struct perf_evsel *evsel,
struct thread_map *threads);
int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
struct thread_map *threads);
void perf_evsel__close(struct perf_evsel *evsel, int ncpus, int nthreads);
struct perf_sample;
void *perf_evsel__rawptr(struct perf_evsel *evsel, struct perf_sample *sample,
const char *name);
u64 perf_evsel__intval(struct perf_evsel *evsel, struct perf_sample *sample,
const char *name);
static inline char *perf_evsel__strval(struct perf_evsel *evsel,
struct perf_sample *sample,
const char *name)
{
return perf_evsel__rawptr(evsel, sample, name);
}
struct format_field;
struct format_field *perf_evsel__field(struct perf_evsel *evsel, const char *name);
#define perf_evsel__match(evsel, t, c) \
(evsel->attr.type == PERF_TYPE_##t && \
evsel->attr.config == PERF_COUNT_##c)
static inline bool perf_evsel__match2(struct perf_evsel *e1,
struct perf_evsel *e2)
{
return (e1->attr.type == e2->attr.type) &&
(e1->attr.config == e2->attr.config);
}
#define perf_evsel__cmp(a, b) \
((a) && \
(b) && \
(a)->attr.type == (b)->attr.type && \
(a)->attr.config == (b)->attr.config)
int perf_evsel__read(struct perf_evsel *evsel, int cpu, int thread,
struct perf_counts_values *count);
int __perf_evsel__read_on_cpu(struct perf_evsel *evsel,
int cpu, int thread, bool scale);
/**
* perf_evsel__read_on_cpu - Read out the results on a CPU and thread
*
* @evsel - event selector to read value
* @cpu - CPU of interest
* @thread - thread of interest
*/
static inline int perf_evsel__read_on_cpu(struct perf_evsel *evsel,
int cpu, int thread)
{
return __perf_evsel__read_on_cpu(evsel, cpu, thread, false);
}
/**
* perf_evsel__read_on_cpu_scaled - Read out the results on a CPU and thread, scaled
*
* @evsel - event selector to read value
* @cpu - CPU of interest
* @thread - thread of interest
*/
static inline int perf_evsel__read_on_cpu_scaled(struct perf_evsel *evsel,
int cpu, int thread)
{
return __perf_evsel__read_on_cpu(evsel, cpu, thread, true);
}
int perf_evsel__parse_sample(struct perf_evsel *evsel, union perf_event *event,
struct perf_sample *sample);
static inline struct perf_evsel *perf_evsel__next(struct perf_evsel *evsel)
{
return list_entry(evsel->node.next, struct perf_evsel, node);
}
static inline struct perf_evsel *perf_evsel__prev(struct perf_evsel *evsel)
{
return list_entry(evsel->node.prev, struct perf_evsel, node);
}
/**
* perf_evsel__is_group_leader - Return whether given evsel is a leader event
*
* @evsel - evsel selector to be tested
*
* Return %true if @evsel is a group leader or a stand-alone event
*/
static inline bool perf_evsel__is_group_leader(const struct perf_evsel *evsel)
{
return evsel->leader == evsel;
}
/**
* perf_evsel__is_group_event - Return whether given evsel is a group event
*
* @evsel - evsel selector to be tested
*
* Return %true iff event group view is enabled and @evsel is a actual group
* leader which has other members in the group
*/
static inline bool perf_evsel__is_group_event(struct perf_evsel *evsel)
{
if (!symbol_conf.event_group)
return false;
return perf_evsel__is_group_leader(evsel) && evsel->nr_members > 1;
}
/**
* perf_evsel__is_function_event - Return whether given evsel is a function
* trace event
*
* @evsel - evsel selector to be tested
*
* Return %true if event is function trace event
*/
static inline bool perf_evsel__is_function_event(struct perf_evsel *evsel)
{
#define FUNCTION_EVENT "ftrace:function"
return evsel->name &&
!strncmp(FUNCTION_EVENT, evsel->name, sizeof(FUNCTION_EVENT));
#undef FUNCTION_EVENT
}
struct perf_attr_details {
bool freq;
bool verbose;
bool event_group;
bool force;
};
int perf_evsel__fprintf(struct perf_evsel *evsel,
struct perf_attr_details *details, FILE *fp);
bool perf_evsel__fallback(struct perf_evsel *evsel, int err,
char *msg, size_t msgsize);
int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target,
int err, char *msg, size_t size);
static inline int perf_evsel__group_idx(struct perf_evsel *evsel)
{
return evsel->idx - evsel->leader->idx;
}
#define for_each_group_member(_evsel, _leader) \
for ((_evsel) = list_entry((_leader)->node.next, struct perf_evsel, node); \
(_evsel) && (_evsel)->leader == (_leader); \
(_evsel) = list_entry((_evsel)->node.next, struct perf_evsel, node))
static inline bool has_branch_callstack(struct perf_evsel *evsel)
{
return evsel->attr.branch_sample_type & PERF_SAMPLE_BRANCH_CALL_STACK;
}
typedef int (*attr__fprintf_f)(FILE *, const char *, const char *, void *);
int perf_event_attr__fprintf(FILE *fp, struct perf_event_attr *attr,
attr__fprintf_f attr__fprintf, void *priv);
#endif /* __PERF_EVSEL_H */