/* * 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/parse-options.h" #include "util/parse-events.h" /* For debugfs_path */ #include "util/probe-finder.h" #include "util/probe-event.h" /* Default vmlinux search paths */ #define NR_SEARCH_PATH 4 const char *default_search_path[NR_SEARCH_PATH] = { "/lib/modules/%s/build/vmlinux", /* Custom build kernel */ "/usr/lib/debug/lib/modules/%s/vmlinux", /* Red Hat debuginfo */ "/boot/vmlinux-debug-%s", /* Ubuntu */ "./vmlinux", /* CWD */ }; #define MAX_PATH_LEN 256 #define MAX_PROBES 128 /* Session management structure */ static struct { char *vmlinux; char *release; int need_dwarf; int nr_probe; struct probe_point probes[MAX_PROBES]; struct strlist *dellist; } session; static bool listing; /* 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 */ session.need_dwarf = parse_perf_probe_event(str, pp); 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; } #ifndef NO_LIBDWARF static int open_default_vmlinux(void) { struct utsname uts; char fname[MAX_PATH_LEN]; int fd, ret, i; ret = uname(&uts); if (ret) { pr_debug("uname() failed.\n"); return -errno; } session.release = uts.release; for (i = 0; i < NR_SEARCH_PATH; i++) { ret = snprintf(fname, MAX_PATH_LEN, default_search_path[i], session.release); if (ret >= MAX_PATH_LEN || ret < 0) { pr_debug("Filename(%d,%s) is too long.\n", i, uts.release); errno = E2BIG; return -E2BIG; } pr_debug("try to open %s\n", fname); fd = open(fname, O_RDONLY); if (fd >= 0) break; } return fd; } #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", NULL }; static const struct option options[] = { OPT_BOOLEAN('v', "verbose", &verbose, "be more verbose (show parsed arguments, etc)"), #ifndef NO_LIBDWARF OPT_STRING('k', "vmlinux", &session.vmlinux, "file", "vmlinux/module pathname"), #endif OPT_BOOLEAN('l', "list", &listing, "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_LIBDWARF "FUNC[+OFFS|%return] [ARG ...]", #else "FUNC[+OFFS|%return|:RLN][@SRC]|SRC:ALN [ARG ...]", #endif "probe point definition, where\n" "\t\tGRP:\tGroup name (optional)\n" "\t\tNAME:\tEvent name\n" "\t\tFUNC:\tFunction name\n" "\t\tOFFS:\tOffset from function entry (in byte)\n" "\t\t%return:\tPut the probe at function return\n" #ifdef NO_LIBDWARF "\t\tARG:\tProbe argument (only \n" #else "\t\tSRC:\tSource code path\n" "\t\tRLN:\tRelative line number from function entry.\n" "\t\tALN:\tAbsolute line number in file.\n" "\t\tARG:\tProbe argument (local variable name or\n" #endif "\t\t\tkprobe-tracer argument format.)\n", opt_add_probe_event), OPT_END() }; int cmd_probe(int argc, const char **argv, const char *prefix __used) { int i, ret; #ifndef NO_LIBDWARF int fd; #endif struct probe_point *pp; argc = parse_options(argc, argv, options, probe_usage, PARSE_OPT_STOP_AT_NON_OPTION); if (argc > 0) parse_probe_event_argv(argc, argv); if ((session.nr_probe == 0 && !session.dellist && !listing)) usage_with_options(probe_usage, options); if (listing) { if (session.nr_probe != 0 || session.dellist) { pr_warning(" Error: Don't use --list with" " --add/--del.\n"); usage_with_options(probe_usage, options); } show_perf_probe_events(); return 0; } if (session.dellist) { del_trace_kprobe_events(session.dellist); strlist__delete(session.dellist); if (session.nr_probe == 0) return 0; } if (session.need_dwarf) #ifdef NO_LIBDWARF die("Debuginfo-analysis is not supported"); #else /* !NO_LIBDWARF */ pr_debug("Some probes require debuginfo.\n"); if (session.vmlinux) { pr_debug("Try to open %s.", session.vmlinux); fd = open(session.vmlinux, O_RDONLY); } else fd = open_default_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_probepoint(fd, pp); if (ret < 0) { if (session.need_dwarf) die("Could not analyze debuginfo."); pr_warning("An error occurred in debuginfo analysis. Try to use symbols.\n"); break; } if (ret == 0) /* No error but failed to find probe point. */ die("No probe point found."); } close(fd); end_dwarf: #endif /* !NO_LIBDWARF */ /* 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; 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); return 0; }