// SPDX-License-Identifier: GPL-2.0-only /* * builtin-ftrace.c * * Copyright (c) 2013 LG Electronics, Namhyung Kim * Copyright (c) 2020 Changbin Du , significant enhancement. */ #include "builtin.h" #include #include #include #include #include #include #include #include #include "debug.h" #include #include #include #include "evlist.h" #include "target.h" #include "cpumap.h" #include "thread_map.h" #include "strfilter.h" #include "util/cap.h" #include "util/config.h" #include "util/units.h" #include "util/parse-sublevel-options.h" #define DEFAULT_TRACER "function_graph" struct perf_ftrace { struct 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; int graph_depth; unsigned long percpu_buffer_size; bool inherit; int func_stack_trace; int func_irq_info; int graph_nosleep_time; int graph_noirqs; int graph_verbose; int graph_thresh; unsigned int initial_delay; }; struct filter_entry { struct list_head list; char name[]; }; static volatile int workload_exec_errno; static bool done; static void sig_handler(int sig __maybe_unused) { done = true; } /* * 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]; char *val_copy; 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; } /* * Copy the original value and append a '\n'. Without this, * the kernel can hide possible errors. */ val_copy = strdup(val); if (!val_copy) goto out_close; val_copy[size] = '\n'; if (write(fd, val_copy, size + 1) == size + 1) ret = 0; else pr_debug("write '%s' to tracing/%s failed: %s\n", val, name, str_error_r(errno, errbuf, sizeof(errbuf))); free(val_copy); out_close: 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 read_tracing_file_to_stdout(const char *name) { char buf[4096]; char *file; int fd; int ret = -1; file = get_tracing_file(name); if (!file) { pr_debug("cannot get tracing file: %s\n", name); return -1; } fd = open(file, O_RDONLY); if (fd < 0) { pr_debug("cannot open tracing file: %s: %s\n", name, str_error_r(errno, buf, sizeof(buf))); goto out; } /* read contents to stdout */ while (true) { int n = read(fd, buf, sizeof(buf)); if (n == 0) break; else if (n < 0) goto out_close; if (fwrite(buf, n, 1, stdout) != 1) goto out_close; } ret = 0; out_close: close(fd); out: put_tracing_file(file); return ret; } static int read_tracing_file_by_line(const char *name, void (*cb)(char *str, void *arg), void *cb_arg) { char *line = NULL; size_t len = 0; char *file; FILE *fp; file = get_tracing_file(name); if (!file) { pr_debug("cannot get tracing file: %s\n", name); return -1; } fp = fopen(file, "r"); if (fp == NULL) { pr_debug("cannot open tracing file: %s\n", name); put_tracing_file(file); return -1; } while (getline(&line, &len, fp) != -1) { cb(line, cb_arg); } if (line) free(line); fclose(fp); put_tracing_file(file); return 0; } static int write_tracing_file_int(const char *name, int value) { char buf[16]; snprintf(buf, sizeof(buf), "%d", value); if (write_tracing_file(name, buf) < 0) return -1; return 0; } static int write_tracing_option_file(const char *name, const char *val) { char *file; int ret; if (asprintf(&file, "options/%s", name) < 0) return -1; ret = __write_tracing_file(file, val, false); free(file); return ret; } static int reset_tracing_cpu(void); static void reset_tracing_filters(void); static void reset_tracing_options(struct perf_ftrace *ftrace __maybe_unused) { write_tracing_option_file("function-fork", "0"); write_tracing_option_file("func_stack_trace", "0"); write_tracing_option_file("sleep-time", "1"); write_tracing_option_file("funcgraph-irqs", "1"); write_tracing_option_file("funcgraph-proc", "0"); write_tracing_option_file("funcgraph-abstime", "0"); write_tracing_option_file("latency-format", "0"); write_tracing_option_file("irq-info", "0"); } 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; if (write_tracing_file("max_graph_depth", "0") < 0) return -1; if (write_tracing_file("tracing_thresh", "0") < 0) return -1; reset_tracing_filters(); reset_tracing_options(ftrace); 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 < perf_thread_map__nr(ftrace->evlist->core.threads); i++) { scnprintf(buf, sizeof(buf), "%d", perf_thread_map__pid(ftrace->evlist->core.threads, i)); if (append_tracing_file("set_ftrace_pid", buf) < 0) return -1; } return 0; } static int set_tracing_cpumask(struct perf_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 / 4 + 2; /* one more byte for EOS */ 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 perf_cpu_map *cpumap = ftrace->evlist->core.cpus; if (!target__has_cpu(&ftrace->target)) return 0; return set_tracing_cpumask(cpumap); } static int set_tracing_func_stack_trace(struct perf_ftrace *ftrace) { if (!ftrace->func_stack_trace) return 0; if (write_tracing_option_file("func_stack_trace", "1") < 0) return -1; return 0; } static int set_tracing_func_irqinfo(struct perf_ftrace *ftrace) { if (!ftrace->func_irq_info) return 0; if (write_tracing_option_file("irq-info", "1") < 0) return -1; return 0; } static int reset_tracing_cpu(void) { struct perf_cpu_map *cpumap = perf_cpu_map__new(NULL); int ret; ret = set_tracing_cpumask(cpumap); perf_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 set_tracing_depth(struct perf_ftrace *ftrace) { if (ftrace->graph_depth == 0) return 0; if (ftrace->graph_depth < 0) { pr_err("invalid graph depth: %d\n", ftrace->graph_depth); return -1; } if (write_tracing_file_int("max_graph_depth", ftrace->graph_depth) < 0) return -1; return 0; } static int set_tracing_percpu_buffer_size(struct perf_ftrace *ftrace) { int ret; if (ftrace->percpu_buffer_size == 0) return 0; ret = write_tracing_file_int("buffer_size_kb", ftrace->percpu_buffer_size / 1024); if (ret < 0) return ret; return 0; } static int set_tracing_trace_inherit(struct perf_ftrace *ftrace) { if (!ftrace->inherit) return 0; if (write_tracing_option_file("function-fork", "1") < 0) return -1; return 0; } static int set_tracing_sleep_time(struct perf_ftrace *ftrace) { if (!ftrace->graph_nosleep_time) return 0; if (write_tracing_option_file("sleep-time", "0") < 0) return -1; return 0; } static int set_tracing_funcgraph_irqs(struct perf_ftrace *ftrace) { if (!ftrace->graph_noirqs) return 0; if (write_tracing_option_file("funcgraph-irqs", "0") < 0) return -1; return 0; } static int set_tracing_funcgraph_verbose(struct perf_ftrace *ftrace) { if (!ftrace->graph_verbose) return 0; if (write_tracing_option_file("funcgraph-proc", "1") < 0) return -1; if (write_tracing_option_file("funcgraph-abstime", "1") < 0) return -1; if (write_tracing_option_file("latency-format", "1") < 0) return -1; return 0; } static int set_tracing_thresh(struct perf_ftrace *ftrace) { int ret; if (ftrace->graph_thresh == 0) return 0; ret = write_tracing_file_int("tracing_thresh", ftrace->graph_thresh); if (ret < 0) return ret; return 0; } static int set_tracing_options(struct perf_ftrace *ftrace) { if (set_tracing_pid(ftrace) < 0) { pr_err("failed to set ftrace pid\n"); return -1; } if (set_tracing_cpu(ftrace) < 0) { pr_err("failed to set tracing cpumask\n"); return -1; } if (set_tracing_func_stack_trace(ftrace) < 0) { pr_err("failed to set tracing option func_stack_trace\n"); return -1; } if (set_tracing_func_irqinfo(ftrace) < 0) { pr_err("failed to set tracing option irq-info\n"); return -1; } if (set_tracing_filters(ftrace) < 0) { pr_err("failed to set tracing filters\n"); return -1; } if (set_tracing_depth(ftrace) < 0) { pr_err("failed to set graph depth\n"); return -1; } if (set_tracing_percpu_buffer_size(ftrace) < 0) { pr_err("failed to set tracing per-cpu buffer size\n"); return -1; } if (set_tracing_trace_inherit(ftrace) < 0) { pr_err("failed to set tracing option function-fork\n"); return -1; } if (set_tracing_sleep_time(ftrace) < 0) { pr_err("failed to set tracing option sleep-time\n"); return -1; } if (set_tracing_funcgraph_irqs(ftrace) < 0) { pr_err("failed to set tracing option funcgraph-irqs\n"); return -1; } if (set_tracing_funcgraph_verbose(ftrace) < 0) { pr_err("failed to set tracing option funcgraph-proc/funcgraph-abstime\n"); return -1; } if (set_tracing_thresh(ftrace) < 0) { pr_err("failed to set tracing thresh\n"); return -1; } return 0; } static void select_tracer(struct perf_ftrace *ftrace) { bool graph = !list_empty(&ftrace->graph_funcs) || !list_empty(&ftrace->nograph_funcs); bool func = !list_empty(&ftrace->filters) || !list_empty(&ftrace->notrace); /* The function_graph has priority over function tracer. */ if (graph) ftrace->tracer = "function_graph"; else if (func) ftrace->tracer = "function"; /* Otherwise, the default tracer is used. */ pr_debug("%s tracer is used\n", ftrace->tracer); } static int __cmd_ftrace(struct perf_ftrace *ftrace) { char *trace_file; int trace_fd; char buf[4096]; struct pollfd pollfd = { .events = POLLIN, }; if (!(perf_cap__capable(CAP_PERFMON) || perf_cap__capable(CAP_SYS_ADMIN))) { pr_err("ftrace only works for %s!\n", #ifdef HAVE_LIBCAP_SUPPORT "users with the CAP_PERFMON or CAP_SYS_ADMIN capability" #else "root" #endif ); return -1; } select_tracer(ftrace); if (reset_tracing_files(ftrace) < 0) { pr_err("failed to reset ftrace\n"); goto out; } /* reset ftrace buffer */ if (write_tracing_file("trace", "0") < 0) goto out; if (set_tracing_options(ftrace) < 0) 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; /* display column headers */ read_tracing_file_to_stdout("trace"); if (!ftrace->initial_delay) { if (write_tracing_file("tracing_on", "1") < 0) { pr_err("can't enable tracing\n"); goto out_close_fd; } } evlist__start_workload(ftrace->evlist); if (ftrace->initial_delay) { usleep(ftrace->initial_delay * 1000); if (write_tracing_file("tracing_on", "1") < 0) { pr_err("can't enable tracing\n"); goto out_close_fd; } } 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"); if (workload_exec_errno) { const char *emsg = str_error_r(workload_exec_errno, buf, sizeof(buf)); /* flush stdout first so below error msg appears at the end. */ fflush(stdout); pr_err("workload failed: %s\n", emsg); goto out_close_fd; } /* 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 && !workload_exec_errno) ? 0 : -1; } static int perf_ftrace_config(const char *var, const char *value, void *cb) { struct perf_ftrace *ftrace = cb; if (!strstarts(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 void list_function_cb(char *str, void *arg) { struct strfilter *filter = (struct strfilter *)arg; if (strfilter__compare(filter, str)) printf("%s", str); } static int opt_list_avail_functions(const struct option *opt __maybe_unused, const char *str, int unset) { struct strfilter *filter; const char *err = NULL; int ret; if (unset || !str) return -1; filter = strfilter__new(str, &err); if (!filter) return err ? -EINVAL : -ENOMEM; ret = strfilter__or(filter, str, &err); if (ret == -EINVAL) { pr_err("Filter parse error at %td.\n", err - str + 1); pr_err("Source: \"%s\"\n", str); pr_err(" %*c\n", (int)(err - str + 1), '^'); strfilter__delete(filter); return ret; } ret = read_tracing_file_by_line("available_filter_functions", list_function_cb, filter); strfilter__delete(filter); if (ret < 0) return ret; exit(0); } 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_init(&pos->list); free(pos); } } static int parse_buffer_size(const struct option *opt, const char *str, int unset) { unsigned long *s = (unsigned long *)opt->value; static struct parse_tag tags_size[] = { { .tag = 'B', .mult = 1 }, { .tag = 'K', .mult = 1 << 10 }, { .tag = 'M', .mult = 1 << 20 }, { .tag = 'G', .mult = 1 << 30 }, { .tag = 0 }, }; unsigned long val; if (unset) { *s = 0; return 0; } val = parse_tag_value(str, tags_size); if (val != (unsigned long) -1) { if (val < 1024) { pr_err("buffer size too small, must larger than 1KB."); return -1; } *s = val; return 0; } return -1; } static int parse_func_tracer_opts(const struct option *opt, const char *str, int unset) { int ret; struct perf_ftrace *ftrace = (struct perf_ftrace *) opt->value; struct sublevel_option func_tracer_opts[] = { { .name = "call-graph", .value_ptr = &ftrace->func_stack_trace }, { .name = "irq-info", .value_ptr = &ftrace->func_irq_info }, { .name = NULL, } }; if (unset) return 0; ret = perf_parse_sublevel_options(str, func_tracer_opts); if (ret) return ret; return 0; } static int parse_graph_tracer_opts(const struct option *opt, const char *str, int unset) { int ret; struct perf_ftrace *ftrace = (struct perf_ftrace *) opt->value; struct sublevel_option graph_tracer_opts[] = { { .name = "nosleep-time", .value_ptr = &ftrace->graph_nosleep_time }, { .name = "noirqs", .value_ptr = &ftrace->graph_noirqs }, { .name = "verbose", .value_ptr = &ftrace->graph_verbose }, { .name = "thresh", .value_ptr = &ftrace->graph_thresh }, { .name = "depth", .value_ptr = &ftrace->graph_depth }, { .name = NULL, } }; if (unset) return 0; ret = perf_parse_sublevel_options(str, graph_tracer_opts); if (ret) return ret; return 0; } int cmd_ftrace(int argc, const char **argv) { int ret; struct perf_ftrace ftrace = { .tracer = DEFAULT_TRACER, .target = { .uid = UINT_MAX, }, }; const struct option common_options[] = { OPT_STRING('p', "pid", &ftrace.target.pid, "pid", "Trace on existing process id"), /* TODO: Add short option -t after -t/--tracer can be removed. */ OPT_STRING(0, "tid", &ftrace.target.tid, "tid", "Trace on existing thread id (exclusive to --pid)"), 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_END() }; const struct option ftrace_options[] = { OPT_STRING('t', "tracer", &ftrace.tracer, "tracer", "Tracer to use: function_graph(default) or function"), OPT_CALLBACK_DEFAULT('F', "funcs", NULL, "[FILTER]", "Show available functions to filter", opt_list_avail_functions, "*"), OPT_CALLBACK('T', "trace-funcs", &ftrace.filters, "func", "Trace given functions using function tracer", parse_filter_func), OPT_CALLBACK('N', "notrace-funcs", &ftrace.notrace, "func", "Do not trace given functions", parse_filter_func), OPT_CALLBACK(0, "func-opts", &ftrace, "options", "Function tracer options, available options: call-graph,irq-info", parse_func_tracer_opts), OPT_CALLBACK('G', "graph-funcs", &ftrace.graph_funcs, "func", "Trace given functions using function_graph tracer", parse_filter_func), OPT_CALLBACK('g', "nograph-funcs", &ftrace.nograph_funcs, "func", "Set nograph filter on given functions", parse_filter_func), OPT_CALLBACK(0, "graph-opts", &ftrace, "options", "Graph tracer options, available options: nosleep-time,noirqs,verbose,thresh=,depth=", parse_graph_tracer_opts), OPT_CALLBACK('m', "buffer-size", &ftrace.percpu_buffer_size, "size", "Size of per cpu buffer, needs to use a B, K, M or G suffix.", parse_buffer_size), OPT_BOOLEAN(0, "inherit", &ftrace.inherit, "Trace children processes"), OPT_UINTEGER('D', "delay", &ftrace.initial_delay, "Number of milliseconds to wait before starting tracing after program start"), OPT_PARENT(common_options), }; const char * const ftrace_usage[] = { "perf ftrace [] []", "perf ftrace [] -- [] []", "perf ftrace trace [] []", "perf ftrace trace [] -- [] []", NULL }; INIT_LIST_HEAD(&ftrace.filters); INIT_LIST_HEAD(&ftrace.notrace); INIT_LIST_HEAD(&ftrace.graph_funcs); INIT_LIST_HEAD(&ftrace.nograph_funcs); signal(SIGINT, sig_handler); signal(SIGUSR1, sig_handler); signal(SIGCHLD, sig_handler); signal(SIGPIPE, sig_handler); ret = perf_config(perf_ftrace_config, &ftrace); if (ret < 0) return -1; if (argc > 1 && !strcmp(argv[1], "trace")) { argc--; argv++; } argc = parse_options(argc, argv, ftrace_options, ftrace_usage, PARSE_OPT_STOP_AT_NON_OPTION); if (!argc && target__none(&ftrace.target)) ftrace.target.system_wide = true; 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 = evlist__new(); if (ftrace.evlist == NULL) { ret = -ENOMEM; goto out_delete_filters; } ret = evlist__create_maps(ftrace.evlist, &ftrace.target); if (ret < 0) goto out_delete_evlist; if (argc) { ret = evlist__prepare_workload(ftrace.evlist, &ftrace.target, argv, false, ftrace__workload_exec_failed_signal); if (ret < 0) goto out_delete_evlist; } ret = __cmd_ftrace(&ftrace); out_delete_evlist: 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; }