/* * builtin-probe.c * * Builtin probe command: Set up probe events by C expression * * Written by Masami Hiramatsu <mhiramat@redhat.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * */ #define _GNU_SOURCE #include <sys/utsname.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <errno.h> #include <stdio.h> #include <unistd.h> #include <stdlib.h> #include <string.h> #undef _GNU_SOURCE #include "perf.h" #include "builtin.h" #include "util/util.h" #include "util/strlist.h" #include "util/event.h" #include "util/debug.h" #include "util/debugfs.h" #include "util/symbol.h" #include "util/thread.h" #include "util/parse-options.h" #include "util/parse-events.h" /* For debugfs_path */ #include "util/probe-finder.h" #include "util/probe-event.h" #define MAX_PATH_LEN 256 #define MAX_PROBES 128 /* Session management structure */ static struct { bool need_dwarf; bool list_events; bool force_add; bool show_lines; int nr_probe; struct probe_point probes[MAX_PROBES]; struct strlist *dellist; struct map_groups kmap_groups; struct map *kmaps[MAP__NR_TYPES]; struct line_range line_range; } session; /* Parse an event definition. Note that any error must die. */ static void parse_probe_event(const char *str) { struct probe_point *pp = &session.probes[session.nr_probe]; pr_debug("probe-definition(%d): %s\n", session.nr_probe, str); if (++session.nr_probe == MAX_PROBES) die("Too many probes (> %d) are specified.", MAX_PROBES); /* Parse perf-probe event into probe_point */ parse_perf_probe_event(str, pp, &session.need_dwarf); pr_debug("%d arguments\n", pp->nr_args); } static void parse_probe_event_argv(int argc, const char **argv) { int i, len; char *buf; /* Bind up rest arguments */ len = 0; for (i = 0; i < argc; i++) len += strlen(argv[i]) + 1; buf = zalloc(len + 1); if (!buf) die("Failed to allocate memory for binding arguments."); len = 0; for (i = 0; i < argc; i++) len += sprintf(&buf[len], "%s ", argv[i]); parse_probe_event(buf); free(buf); } static int opt_add_probe_event(const struct option *opt __used, const char *str, int unset __used) { if (str) parse_probe_event(str); return 0; } static int opt_del_probe_event(const struct option *opt __used, const char *str, int unset __used) { if (str) { if (!session.dellist) session.dellist = strlist__new(true, NULL); strlist__add(session.dellist, str); } return 0; } /* Currently just checking function name from symbol map */ static void evaluate_probe_point(struct probe_point *pp) { struct symbol *sym; sym = map__find_symbol_by_name(session.kmaps[MAP__FUNCTION], pp->function, NULL); if (!sym) die("Kernel symbol \'%s\' not found - probe not added.", pp->function); } #ifndef NO_DWARF_SUPPORT static int open_vmlinux(void) { if (map__load(session.kmaps[MAP__FUNCTION], NULL) < 0) { pr_debug("Failed to load kernel map.\n"); return -EINVAL; } pr_debug("Try to open %s\n", session.kmaps[MAP__FUNCTION]->dso->long_name); return open(session.kmaps[MAP__FUNCTION]->dso->long_name, O_RDONLY); } static int opt_show_lines(const struct option *opt __used, const char *str, int unset __used) { if (str) parse_line_range_desc(str, &session.line_range); INIT_LIST_HEAD(&session.line_range.line_list); session.show_lines = true; return 0; } #endif static const char * const probe_usage[] = { "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]", "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]", "perf probe [<options>] --del '[GROUP:]EVENT' ...", "perf probe --list", #ifndef NO_DWARF_SUPPORT "perf probe --line 'LINEDESC'", #endif NULL }; static const struct option options[] = { OPT_BOOLEAN('v', "verbose", &verbose, "be more verbose (show parsed arguments, etc)"), #ifndef NO_DWARF_SUPPORT OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name, "file", "vmlinux pathname"), #endif OPT_BOOLEAN('l', "list", &session.list_events, "list up current probe events"), OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.", opt_del_probe_event), OPT_CALLBACK('a', "add", NULL, #ifdef NO_DWARF_SUPPORT "[EVENT=]FUNC[+OFF|%return] [ARG ...]", #else "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT" " [ARG ...]", #endif "probe point definition, where\n" "\t\tGROUP:\tGroup name (optional)\n" "\t\tEVENT:\tEvent name\n" "\t\tFUNC:\tFunction name\n" "\t\tOFF:\tOffset from function entry (in byte)\n" "\t\t%return:\tPut the probe at function return\n" #ifdef NO_DWARF_SUPPORT "\t\tARG:\tProbe argument (only \n" #else "\t\tSRC:\tSource code path\n" "\t\tRL:\tRelative line number from function entry.\n" "\t\tAL:\tAbsolute line number in file.\n" "\t\tPT:\tLazy expression of line code.\n" "\t\tARG:\tProbe argument (local variable name or\n" #endif "\t\t\tkprobe-tracer argument format.)\n", opt_add_probe_event), OPT_BOOLEAN('f', "force", &session.force_add, "forcibly add events" " with existing name"), #ifndef NO_DWARF_SUPPORT OPT_CALLBACK('L', "line", NULL, "FUNC[:RLN[+NUM|:RLN2]]|SRC:ALN[+NUM|:ALN2]", "Show source code lines.", opt_show_lines), #endif OPT_END() }; /* Initialize symbol maps for vmlinux */ static void init_vmlinux(void) { symbol_conf.sort_by_name = true; if (symbol_conf.vmlinux_name == NULL) symbol_conf.try_vmlinux_path = true; else pr_debug("Use vmlinux: %s\n", symbol_conf.vmlinux_name); if (symbol__init() < 0) die("Failed to init symbol map."); map_groups__init(&session.kmap_groups); if (map_groups__create_kernel_maps(&session.kmap_groups, session.kmaps) < 0) die("Failed to create kernel maps."); } int cmd_probe(int argc, const char **argv, const char *prefix __used) { int i, ret; #ifndef NO_DWARF_SUPPORT int fd; #endif struct probe_point *pp; argc = parse_options(argc, argv, options, probe_usage, PARSE_OPT_STOP_AT_NON_OPTION); if (argc > 0) { if (strcmp(argv[0], "-") == 0) { pr_warning(" Error: '-' is not supported.\n"); usage_with_options(probe_usage, options); } parse_probe_event_argv(argc, argv); } if ((!session.nr_probe && !session.dellist && !session.list_events && !session.show_lines)) usage_with_options(probe_usage, options); if (debugfs_valid_mountpoint(debugfs_path) < 0) die("Failed to find debugfs path."); if (session.list_events) { if (session.nr_probe != 0 || session.dellist) { pr_warning(" Error: Don't use --list with" " --add/--del.\n"); usage_with_options(probe_usage, options); } if (session.show_lines) { pr_warning(" Error: Don't use --list with --line.\n"); usage_with_options(probe_usage, options); } show_perf_probe_events(); return 0; } #ifndef NO_DWARF_SUPPORT if (session.show_lines) { if (session.nr_probe != 0 || session.dellist) { pr_warning(" Error: Don't use --line with" " --add/--del.\n"); usage_with_options(probe_usage, options); } init_vmlinux(); fd = open_vmlinux(); if (fd < 0) die("Could not open debuginfo file."); ret = find_line_range(fd, &session.line_range); if (ret <= 0) die("Source line is not found.\n"); close(fd); show_line_range(&session.line_range); return 0; } #endif if (session.dellist) { del_trace_kprobe_events(session.dellist); strlist__delete(session.dellist); if (session.nr_probe == 0) return 0; } /* Add probes */ init_vmlinux(); if (session.need_dwarf) #ifdef NO_DWARF_SUPPORT die("Debuginfo-analysis is not supported"); #else /* !NO_DWARF_SUPPORT */ pr_debug("Some probes require debuginfo.\n"); fd = open_vmlinux(); if (fd < 0) { if (session.need_dwarf) die("Could not open debuginfo file."); pr_debug("Could not open vmlinux/module file." " Try to use symbols.\n"); goto end_dwarf; } /* Searching probe points */ for (i = 0; i < session.nr_probe; i++) { pp = &session.probes[i]; if (pp->found) continue; lseek(fd, SEEK_SET, 0); ret = find_probe_point(fd, pp); if (ret > 0) continue; if (ret == 0) { /* No error but failed to find probe point. */ synthesize_perf_probe_point(pp); die("Probe point '%s' not found. - probe not added.", pp->probes[0]); } /* Error path */ if (session.need_dwarf) { if (ret == -ENOENT) pr_warning("No dwarf info found in the vmlinux - please rebuild with CONFIG_DEBUG_INFO=y.\n"); die("Could not analyze debuginfo."); } pr_debug("An error occurred in debuginfo analysis." " Try to use symbols.\n"); break; } close(fd); end_dwarf: #endif /* !NO_DWARF_SUPPORT */ /* Synthesize probes without dwarf */ for (i = 0; i < session.nr_probe; i++) { pp = &session.probes[i]; if (pp->found) /* This probe is already found. */ continue; evaluate_probe_point(pp); ret = synthesize_trace_kprobe_event(pp); if (ret == -E2BIG) die("probe point definition becomes too long."); else if (ret < 0) die("Failed to synthesize a probe point."); } /* Settng up probe points */ add_trace_kprobe_events(session.probes, session.nr_probe, session.force_add); return 0; }