Messages in this thread Patch in this message | | | From | Shunsuke Nakamura <> | Subject | [RFC PATCH v2 4/7] libperf: Introduce perf_{evsel, evlist}__open_opt with extensible struct opts | Date | Fri, 25 Mar 2022 13:38:26 +0900 |
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Introduce perf_{evsel, evlist}__open_opt with extensible structure opts. The mechanism of the extensible structure opts imitates tools/lib/bpf/libbpf.h. This allows the user to set the open_flags specified in perf_event_open and a signal handler to receive overflow notifications for sampling events.
Signed-off-by: Shunsuke Nakamura <nakamura.shun@fujitsu.com> --- tools/lib/perf/Documentation/libperf.txt | 14 +++ tools/lib/perf/evlist.c | 20 +++++ tools/lib/perf/evsel.c | 105 +++++++++++++++++++++++ tools/lib/perf/include/perf/evlist.h | 3 + tools/lib/perf/include/perf/evsel.h | 26 ++++++ tools/lib/perf/internal.h | 44 ++++++++++ tools/lib/perf/libperf.map | 2 + 7 files changed, 214 insertions(+)
diff --git a/tools/lib/perf/Documentation/libperf.txt b/tools/lib/perf/Documentation/libperf.txt index ae55e62fc4ce..700c1ce15159 100644 --- a/tools/lib/perf/Documentation/libperf.txt +++ b/tools/lib/perf/Documentation/libperf.txt @@ -131,6 +131,20 @@ SYNOPSIS }; }; + struct perf_evsel_open_opts { + /* size of this struct, for forward/backward compatibility */ + size_t sz; + + unsigned long open_flags; /* perf_event_open flags */ + int flags; /* fcntl flags */ + unsigned int signal; + int owner_type; + struct sigaction *sig; + }; + #define perf_evsel_open_opts__last_field sig + + #define LIBPERF_OPTS(TYPE, NAME, ...) + struct perf_evsel *perf_evsel__new(struct perf_event_attr *attr); void perf_evsel__delete(struct perf_evsel *evsel); int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map *cpus, diff --git a/tools/lib/perf/evlist.c b/tools/lib/perf/evlist.c index 9a770bfdc804..6f136905d249 100644 --- a/tools/lib/perf/evlist.c +++ b/tools/lib/perf/evlist.c @@ -666,3 +666,23 @@ void perf_evlist__set_leader(struct perf_evlist *evlist) __perf_evlist__set_leader(&evlist->entries, first); } } + +int perf_evlist__open_opts(struct perf_evlist *evlist, + struct perf_evsel_open_opts *opts) +{ + struct perf_evsel *evsel; + int err; + + perf_evlist__for_each_entry(evlist, evsel) { + err = perf_evsel__open_opts(evsel, evsel->cpus, + evsel->threads, opts); + if (err < 0) + goto out_err; + } + + return 0; + +out_err: + perf_evlist__close(evlist); + return err; +} diff --git a/tools/lib/perf/evsel.c b/tools/lib/perf/evsel.c index b17842581dea..db9b7274feb5 100644 --- a/tools/lib/perf/evsel.c +++ b/tools/lib/perf/evsel.c @@ -1,4 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 +#ifndef _GNU_SOURCE +#define _GNU_SOURCE +#endif #include <errno.h> #include <unistd.h> #include <sys/syscall.h> @@ -16,8 +19,12 @@ #include <internal/lib.h> #include <linux/string.h> #include <sys/ioctl.h> +#include <signal.h> +#include <fcntl.h> +#include <sys/types.h> #include <sys/mman.h> #include <asm/bug.h> +#include "internal.h" void perf_evsel__init(struct perf_evsel *evsel, struct perf_event_attr *attr, int idx) @@ -511,3 +518,101 @@ void perf_counts_values__scale(struct perf_counts_values *count, if (pscaled) *pscaled = scaled; } + +static int perf_evsel__run_fcntl(struct perf_evsel *evsel, + unsigned int cmd, unsigned long arg, + int cpu_map_idx) +{ + int thread; + + for (thread = 0; thread < xyarray__max_y(evsel->fd); thread++) { + int err; + int *fd = FD(evsel, cpu_map_idx, thread); + + if (!fd || *fd < 0) + return -1; + + err = fcntl(*fd, cmd, arg); + + if (err) + return err; + } + + return 0; +} + +static int perf_evsel__set_signal_handler(struct perf_evsel *evsel, + struct perf_evsel_open_opts *opts) +{ + unsigned int flags; + unsigned int signal; + struct f_owner_ex owner; + struct sigaction *sig; + int cpu_map_idx; + int err = 0; + + flags = OPTS_GET(opts, flags, (O_RDWR | O_NONBLOCK | O_ASYNC)); + signal = OPTS_GET(opts, signal, SIGIO); + owner.type = OPTS_GET(opts, owner_type, F_OWNER_PID); + sig = OPTS_GET(opts, sig, NULL); + + if (flags == 0 && signal == 0 && !owner.type == 0 && sig == 0) + return err; + + err = sigaction(signal, sig, NULL); + if (err) + return err; + + switch (owner.type) { + case F_OWNER_PID: + owner.pid = getpid(); + break; + case F_OWNER_TID: + owner.pid = syscall(SYS_gettid); + break; + case F_OWNER_PGRP: + default: + return -1; + } + + for (cpu_map_idx = 0; cpu_map_idx < xyarray__max_x(evsel->fd); cpu_map_idx++) { + err = perf_evsel__run_fcntl(evsel, F_SETFL, flags, cpu_map_idx); + if (err) + return err; + + err = perf_evsel__run_fcntl(evsel, F_SETSIG, signal, cpu_map_idx); + if (err) + return err; + + err = perf_evsel__run_fcntl(evsel, F_SETOWN_EX, + (unsigned long)&owner, cpu_map_idx); + if (err) + return err; + } + + return err; +} + +int perf_evsel__open_opts(struct perf_evsel *evsel, struct perf_cpu_map *cpus, + struct perf_thread_map *threads, + struct perf_evsel_open_opts *opts) +{ + int err = 0; + + if (!OPTS_VALID(opts, perf_evsel_open_opts)) { + err = -EINVAL; + return err; + } + + evsel->open_flags = OPTS_GET(opts, open_flags, 0); + + err = perf_evsel__open(evsel, cpus, threads); + if (err) + return err; + + err = perf_evsel__set_signal_handler(evsel, opts); + if (err) + return err; + + return err; +} diff --git a/tools/lib/perf/include/perf/evlist.h b/tools/lib/perf/include/perf/evlist.h index 9ca399d49bb4..6eff1e9b3481 100644 --- a/tools/lib/perf/include/perf/evlist.h +++ b/tools/lib/perf/include/perf/evlist.h @@ -9,6 +9,7 @@ struct perf_evlist; struct perf_evsel; struct perf_cpu_map; struct perf_thread_map; +struct perf_evsel_open_opts; LIBPERF_API void perf_evlist__add(struct perf_evlist *evlist, struct perf_evsel *evsel); @@ -47,4 +48,6 @@ LIBPERF_API struct perf_mmap *perf_evlist__next_mmap(struct perf_evlist *evlist, (pos) = perf_evlist__next_mmap((evlist), (pos), overwrite)) LIBPERF_API void perf_evlist__set_leader(struct perf_evlist *evlist); +LIBPERF_API int perf_evlist__open_opts(struct perf_evlist *evlist, + struct perf_evsel_open_opts *opts); #endif /* __LIBPERF_EVLIST_H */ diff --git a/tools/lib/perf/include/perf/evsel.h b/tools/lib/perf/include/perf/evsel.h index 360ced734add..ecf30bc6303f 100644 --- a/tools/lib/perf/include/perf/evsel.h +++ b/tools/lib/perf/include/perf/evsel.h @@ -5,6 +5,7 @@ #include <stdint.h> #include <perf/core.h> #include <stdbool.h> +#include <signal.h> #include <linux/types.h> struct perf_evsel; @@ -23,6 +24,27 @@ struct perf_counts_values { }; }; +struct perf_evsel_open_opts { + /* size of this struct, for forward/backward compatibility */ + size_t sz; + + unsigned long open_flags; /* perf_event_open flags */ + int flags; /* fcntl flags */ + unsigned int signal; + int owner_type; + struct sigaction *sig; +}; +#define perf_evsel_open_opts__last_field sig + +#define LIBPERF_OPTS(TYPE, NAME, ...) \ + struct TYPE NAME = ({ \ + memset(&NAME, 0, sizeof(struct TYPE)); \ + (struct TYPE) { \ + .sz = sizeof(struct TYPE), \ + __VA_ARGS__ \ + }; \ + }) + LIBPERF_API struct perf_evsel *perf_evsel__new(struct perf_event_attr *attr); LIBPERF_API void perf_evsel__delete(struct perf_evsel *evsel); LIBPERF_API int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map *cpus, @@ -48,5 +70,9 @@ LIBPERF_API struct perf_thread_map *perf_evsel__threads(struct perf_evsel *evsel LIBPERF_API struct perf_event_attr *perf_evsel__attr(struct perf_evsel *evsel); LIBPERF_API void perf_counts_values__scale(struct perf_counts_values *count, bool scale, __s8 *pscaled); +LIBPERF_API int perf_evsel__open_opts(struct perf_evsel *evsel, + struct perf_cpu_map *cpus, + struct perf_thread_map *threads, + struct perf_evsel_open_opts *opts); #endif /* __LIBPERF_EVSEL_H */ diff --git a/tools/lib/perf/internal.h b/tools/lib/perf/internal.h index 2c27e158de6b..637bf6793c26 100644 --- a/tools/lib/perf/internal.h +++ b/tools/lib/perf/internal.h @@ -20,4 +20,48 @@ do { \ #define pr_debug2(fmt, ...) __pr(LIBPERF_DEBUG2, fmt, ##__VA_ARGS__) #define pr_debug3(fmt, ...) __pr(LIBPERF_DEBUG3, fmt, ##__VA_ARGS__) +static inline bool libperf_is_mem_zeroed(const char *p, ssize_t len) +{ + while (len > 0) { + if (*p) + return false; + p++; + len--; + } + return true; +} + +static inline bool libperf_validate_opts(const char *opts, + size_t opts_sz, size_t user_sz, + const char *type_name) +{ + if (user_sz < sizeof(size_t)) { + pr_warning("%s size (%zu) is too small\n", type_name, user_sz); + return false; + } + if (!libperf_is_mem_zeroed(opts + opts_sz, (ssize_t)user_sz - opts_sz)) { + pr_warning("%s has non-zero extra bytes\n", type_name); + return false; + } + return true; +} + +# define offsetofend(TYPE, FIELD) \ + (offsetof(TYPE, FIELD) + sizeof(((TYPE *)0)->FIELD)) + +#define OPTS_VALID(opts, type) \ + (!(opts) || libperf_validate_opts((const char *)opts, \ + offsetofend(struct type, \ + type##__last_field), \ + (opts)->sz, #type)) +#define OPTS_HAS(opts, field) \ + ((opts) && opts->sz >= offsetofend(typeof(*(opts)), field)) +#define OPTS_GET(opts, field, fallback_value) \ + (OPTS_HAS(opts, field) ? (opts)->field : fallback_value) +#define OPTS_SET(opts, field, value) \ + do { \ + if (OPTS_HAS(opts, field)) \ + (opts)->field = value; \ + } while (0) + #endif /* __LIBPERF_INTERNAL_H */ diff --git a/tools/lib/perf/libperf.map b/tools/lib/perf/libperf.map index ab0f44e9bb57..534614fbbb26 100644 --- a/tools/lib/perf/libperf.map +++ b/tools/lib/perf/libperf.map @@ -24,6 +24,7 @@ LIBPERF_0.0.1 { perf_evsel__enable; perf_evsel__disable; perf_evsel__open; + perf_evsel__open_opts; perf_evsel__close; perf_evsel__mmap; perf_evsel__munmap; @@ -39,6 +40,7 @@ LIBPERF_0.0.1 { perf_evlist__new; perf_evlist__delete; perf_evlist__open; + perf_evlist__open_opts; perf_evlist__close; perf_evlist__enable; perf_evlist__disable; -- 2.25.1
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