| /* |
| * builtin-ftrace.c |
| * |
| * Copyright (c) 2013 LG Electronics, Namhyung Kim <namhyung@kernel.org> |
| * |
| * Released under the GPL v2. |
| */ |
| |
| #include "builtin.h" |
| #include "perf.h" |
| |
| #include <errno.h> |
| #include <unistd.h> |
| #include <signal.h> |
| #include <fcntl.h> |
| #include <poll.h> |
| |
| #include "debug.h" |
| #include <subcmd/parse-options.h> |
| #include <api/fs/tracing_path.h> |
| #include "evlist.h" |
| #include "target.h" |
| #include "cpumap.h" |
| #include "thread_map.h" |
| #include "util/config.h" |
| |
| |
| #define DEFAULT_TRACER "function_graph" |
| |
| struct perf_ftrace { |
| struct perf_evlist *evlist; |
| struct target target; |
| const char *tracer; |
| struct list_head filters; |
| struct list_head notrace; |
| struct list_head graph_funcs; |
| struct list_head nograph_funcs; |
| }; |
| |
| struct filter_entry { |
| struct list_head list; |
| char name[]; |
| }; |
| |
| static bool done; |
| |
| static void sig_handler(int sig __maybe_unused) |
| { |
| done = true; |
| } |
| |
| /* |
| * perf_evlist__prepare_workload will send a SIGUSR1 if the fork fails, since |
| * we asked by setting its exec_error to the function below, |
| * ftrace__workload_exec_failed_signal. |
| * |
| * XXX We need to handle this more appropriately, emitting an error, etc. |
| */ |
| static void ftrace__workload_exec_failed_signal(int signo __maybe_unused, |
| siginfo_t *info __maybe_unused, |
| void *ucontext __maybe_unused) |
| { |
| /* workload_exec_errno = info->si_value.sival_int; */ |
| done = true; |
| } |
| |
| static int __write_tracing_file(const char *name, const char *val, bool append) |
| { |
| char *file; |
| int fd, ret = -1; |
| ssize_t size = strlen(val); |
| int flags = O_WRONLY; |
| char errbuf[512]; |
| |
| file = get_tracing_file(name); |
| if (!file) { |
| pr_debug("cannot get tracing file: %s\n", name); |
| return -1; |
| } |
| |
| if (append) |
| flags |= O_APPEND; |
| else |
| flags |= O_TRUNC; |
| |
| fd = open(file, flags); |
| if (fd < 0) { |
| pr_debug("cannot open tracing file: %s: %s\n", |
| name, str_error_r(errno, errbuf, sizeof(errbuf))); |
| goto out; |
| } |
| |
| if (write(fd, val, size) == size) |
| ret = 0; |
| else |
| pr_debug("write '%s' to tracing/%s failed: %s\n", |
| val, name, str_error_r(errno, errbuf, sizeof(errbuf))); |
| |
| close(fd); |
| out: |
| put_tracing_file(file); |
| return ret; |
| } |
| |
| static int write_tracing_file(const char *name, const char *val) |
| { |
| return __write_tracing_file(name, val, false); |
| } |
| |
| static int append_tracing_file(const char *name, const char *val) |
| { |
| return __write_tracing_file(name, val, true); |
| } |
| |
| static int reset_tracing_cpu(void); |
| static void reset_tracing_filters(void); |
| |
| static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused) |
| { |
| if (write_tracing_file("tracing_on", "0") < 0) |
| return -1; |
| |
| if (write_tracing_file("current_tracer", "nop") < 0) |
| return -1; |
| |
| if (write_tracing_file("set_ftrace_pid", " ") < 0) |
| return -1; |
| |
| if (reset_tracing_cpu() < 0) |
| return -1; |
| |
| reset_tracing_filters(); |
| return 0; |
| } |
| |
| static int set_tracing_pid(struct perf_ftrace *ftrace) |
| { |
| int i; |
| char buf[16]; |
| |
| if (target__has_cpu(&ftrace->target)) |
| return 0; |
| |
| for (i = 0; i < thread_map__nr(ftrace->evlist->threads); i++) { |
| scnprintf(buf, sizeof(buf), "%d", |
| ftrace->evlist->threads->map[i]); |
| if (append_tracing_file("set_ftrace_pid", buf) < 0) |
| return -1; |
| } |
| return 0; |
| } |
| |
| static int set_tracing_cpumask(struct cpu_map *cpumap) |
| { |
| char *cpumask; |
| size_t mask_size; |
| int ret; |
| int last_cpu; |
| |
| last_cpu = cpu_map__cpu(cpumap, cpumap->nr - 1); |
| mask_size = (last_cpu + 3) / 4 + 1; |
| mask_size += last_cpu / 32; /* ',' is needed for every 32th cpus */ |
| |
| cpumask = malloc(mask_size); |
| if (cpumask == NULL) { |
| pr_debug("failed to allocate cpu mask\n"); |
| return -1; |
| } |
| |
| cpu_map__snprint_mask(cpumap, cpumask, mask_size); |
| |
| ret = write_tracing_file("tracing_cpumask", cpumask); |
| |
| free(cpumask); |
| return ret; |
| } |
| |
| static int set_tracing_cpu(struct perf_ftrace *ftrace) |
| { |
| struct cpu_map *cpumap = ftrace->evlist->cpus; |
| |
| if (!target__has_cpu(&ftrace->target)) |
| return 0; |
| |
| return set_tracing_cpumask(cpumap); |
| } |
| |
| static int reset_tracing_cpu(void) |
| { |
| struct cpu_map *cpumap = cpu_map__new(NULL); |
| int ret; |
| |
| ret = set_tracing_cpumask(cpumap); |
| cpu_map__put(cpumap); |
| return ret; |
| } |
| |
| static int __set_tracing_filter(const char *filter_file, struct list_head *funcs) |
| { |
| struct filter_entry *pos; |
| |
| list_for_each_entry(pos, funcs, list) { |
| if (append_tracing_file(filter_file, pos->name) < 0) |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| static int set_tracing_filters(struct perf_ftrace *ftrace) |
| { |
| int ret; |
| |
| ret = __set_tracing_filter("set_ftrace_filter", &ftrace->filters); |
| if (ret < 0) |
| return ret; |
| |
| ret = __set_tracing_filter("set_ftrace_notrace", &ftrace->notrace); |
| if (ret < 0) |
| return ret; |
| |
| ret = __set_tracing_filter("set_graph_function", &ftrace->graph_funcs); |
| if (ret < 0) |
| return ret; |
| |
| /* old kernels do not have this filter */ |
| __set_tracing_filter("set_graph_notrace", &ftrace->nograph_funcs); |
| |
| return ret; |
| } |
| |
| static void reset_tracing_filters(void) |
| { |
| write_tracing_file("set_ftrace_filter", " "); |
| write_tracing_file("set_ftrace_notrace", " "); |
| write_tracing_file("set_graph_function", " "); |
| write_tracing_file("set_graph_notrace", " "); |
| } |
| |
| static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv) |
| { |
| char *trace_file; |
| int trace_fd; |
| char buf[4096]; |
| struct pollfd pollfd = { |
| .events = POLLIN, |
| }; |
| |
| if (geteuid() != 0) { |
| pr_err("ftrace only works for root!\n"); |
| return -1; |
| } |
| |
| signal(SIGINT, sig_handler); |
| signal(SIGUSR1, sig_handler); |
| signal(SIGCHLD, sig_handler); |
| signal(SIGPIPE, sig_handler); |
| |
| if (reset_tracing_files(ftrace) < 0) |
| goto out; |
| |
| /* reset ftrace buffer */ |
| if (write_tracing_file("trace", "0") < 0) |
| goto out; |
| |
| if (argc && perf_evlist__prepare_workload(ftrace->evlist, |
| &ftrace->target, argv, false, |
| ftrace__workload_exec_failed_signal) < 0) { |
| goto out; |
| } |
| |
| if (set_tracing_pid(ftrace) < 0) { |
| pr_err("failed to set ftrace pid\n"); |
| goto out_reset; |
| } |
| |
| if (set_tracing_cpu(ftrace) < 0) { |
| pr_err("failed to set tracing cpumask\n"); |
| goto out_reset; |
| } |
| |
| if (set_tracing_filters(ftrace) < 0) { |
| pr_err("failed to set tracing filters\n"); |
| goto out_reset; |
| } |
| |
| if (write_tracing_file("current_tracer", ftrace->tracer) < 0) { |
| pr_err("failed to set current_tracer to %s\n", ftrace->tracer); |
| goto out_reset; |
| } |
| |
| setup_pager(); |
| |
| trace_file = get_tracing_file("trace_pipe"); |
| if (!trace_file) { |
| pr_err("failed to open trace_pipe\n"); |
| goto out_reset; |
| } |
| |
| trace_fd = open(trace_file, O_RDONLY); |
| |
| put_tracing_file(trace_file); |
| |
| if (trace_fd < 0) { |
| pr_err("failed to open trace_pipe\n"); |
| goto out_reset; |
| } |
| |
| fcntl(trace_fd, F_SETFL, O_NONBLOCK); |
| pollfd.fd = trace_fd; |
| |
| if (write_tracing_file("tracing_on", "1") < 0) { |
| pr_err("can't enable tracing\n"); |
| goto out_close_fd; |
| } |
| |
| perf_evlist__start_workload(ftrace->evlist); |
| |
| while (!done) { |
| if (poll(&pollfd, 1, -1) < 0) |
| break; |
| |
| if (pollfd.revents & POLLIN) { |
| int n = read(trace_fd, buf, sizeof(buf)); |
| if (n < 0) |
| break; |
| if (fwrite(buf, n, 1, stdout) != 1) |
| break; |
| } |
| } |
| |
| write_tracing_file("tracing_on", "0"); |
| |
| /* read remaining buffer contents */ |
| while (true) { |
| int n = read(trace_fd, buf, sizeof(buf)); |
| if (n <= 0) |
| break; |
| if (fwrite(buf, n, 1, stdout) != 1) |
| break; |
| } |
| |
| out_close_fd: |
| close(trace_fd); |
| out_reset: |
| reset_tracing_files(ftrace); |
| out: |
| return done ? 0 : -1; |
| } |
| |
| static int perf_ftrace_config(const char *var, const char *value, void *cb) |
| { |
| struct perf_ftrace *ftrace = cb; |
| |
| if (prefixcmp(var, "ftrace.")) |
| return 0; |
| |
| if (strcmp(var, "ftrace.tracer")) |
| return -1; |
| |
| if (!strcmp(value, "function_graph") || |
| !strcmp(value, "function")) { |
| ftrace->tracer = value; |
| return 0; |
| } |
| |
| pr_err("Please select \"function_graph\" (default) or \"function\"\n"); |
| return -1; |
| } |
| |
| static int parse_filter_func(const struct option *opt, const char *str, |
| int unset __maybe_unused) |
| { |
| struct list_head *head = opt->value; |
| struct filter_entry *entry; |
| |
| entry = malloc(sizeof(*entry) + strlen(str) + 1); |
| if (entry == NULL) |
| return -ENOMEM; |
| |
| strcpy(entry->name, str); |
| list_add_tail(&entry->list, head); |
| |
| return 0; |
| } |
| |
| static void delete_filter_func(struct list_head *head) |
| { |
| struct filter_entry *pos, *tmp; |
| |
| list_for_each_entry_safe(pos, tmp, head, list) { |
| list_del(&pos->list); |
| free(pos); |
| } |
| } |
| |
| int cmd_ftrace(int argc, const char **argv) |
| { |
| int ret; |
| struct perf_ftrace ftrace = { |
| .tracer = DEFAULT_TRACER, |
| .target = { .uid = UINT_MAX, }, |
| }; |
| const char * const ftrace_usage[] = { |
| "perf ftrace [<options>] [<command>]", |
| "perf ftrace [<options>] -- <command> [<options>]", |
| NULL |
| }; |
| const struct option ftrace_options[] = { |
| OPT_STRING('t', "tracer", &ftrace.tracer, "tracer", |
| "tracer to use: function_graph(default) or function"), |
| OPT_STRING('p', "pid", &ftrace.target.pid, "pid", |
| "trace on existing process id"), |
| OPT_INCR('v', "verbose", &verbose, |
| "be more verbose"), |
| OPT_BOOLEAN('a', "all-cpus", &ftrace.target.system_wide, |
| "system-wide collection from all CPUs"), |
| OPT_STRING('C', "cpu", &ftrace.target.cpu_list, "cpu", |
| "list of cpus to monitor"), |
| OPT_CALLBACK('T', "trace-funcs", &ftrace.filters, "func", |
| "trace given functions only", parse_filter_func), |
| OPT_CALLBACK('N', "notrace-funcs", &ftrace.notrace, "func", |
| "do not trace given functions", parse_filter_func), |
| OPT_CALLBACK('G', "graph-funcs", &ftrace.graph_funcs, "func", |
| "Set graph filter on given functions", parse_filter_func), |
| OPT_CALLBACK('g', "nograph-funcs", &ftrace.nograph_funcs, "func", |
| "Set nograph filter on given functions", parse_filter_func), |
| OPT_END() |
| }; |
| |
| INIT_LIST_HEAD(&ftrace.filters); |
| INIT_LIST_HEAD(&ftrace.notrace); |
| INIT_LIST_HEAD(&ftrace.graph_funcs); |
| INIT_LIST_HEAD(&ftrace.nograph_funcs); |
| |
| ret = perf_config(perf_ftrace_config, &ftrace); |
| if (ret < 0) |
| return -1; |
| |
| argc = parse_options(argc, argv, ftrace_options, ftrace_usage, |
| PARSE_OPT_STOP_AT_NON_OPTION); |
| if (!argc && target__none(&ftrace.target)) |
| usage_with_options(ftrace_usage, ftrace_options); |
| |
| ret = target__validate(&ftrace.target); |
| if (ret) { |
| char errbuf[512]; |
| |
| target__strerror(&ftrace.target, ret, errbuf, 512); |
| pr_err("%s\n", errbuf); |
| goto out_delete_filters; |
| } |
| |
| ftrace.evlist = perf_evlist__new(); |
| if (ftrace.evlist == NULL) { |
| ret = -ENOMEM; |
| goto out_delete_filters; |
| } |
| |
| ret = perf_evlist__create_maps(ftrace.evlist, &ftrace.target); |
| if (ret < 0) |
| goto out_delete_evlist; |
| |
| ret = __cmd_ftrace(&ftrace, argc, argv); |
| |
| out_delete_evlist: |
| perf_evlist__delete(ftrace.evlist); |
| |
| out_delete_filters: |
| delete_filter_func(&ftrace.filters); |
| delete_filter_func(&ftrace.notrace); |
| delete_filter_func(&ftrace.graph_funcs); |
| delete_filter_func(&ftrace.nograph_funcs); |
| |
| return ret; |
| } |