diff options
Diffstat (limited to 'tools/perf/builtin-probe.c')
-rw-r--r-- | tools/perf/builtin-probe.c | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c new file mode 100644 index 00000000000..a58e11b7ea8 --- /dev/null +++ b/tools/perf/builtin-probe.c @@ -0,0 +1,242 @@ +/* + * 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/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 3 +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 */ +}; + +#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]; +} 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 int opt_add_probe_event(const struct option *opt __used, + const char *str, int unset __used) +{ + if (str) + parse_probe_event(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 --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 probes"), + 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, j, 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); + for (i = 0; i < argc; i++) + parse_probe_event(argv[i]); + + if ((session.nr_probe == 0 && !listing) || + (session.nr_probe != 0 && listing)) + usage_with_options(probe_usage, options); + + if (listing) { + show_perf_probe_events(); + 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) + fd = open(session.vmlinux, O_RDONLY); + else + fd = open_default_vmlinux(); + if (fd < 0) { + if (session.need_dwarf) + die("Could not open vmlinux/module file."); + + pr_warning("Could not open vmlinux/module file." + " Try to use symbols.\n"); + goto end_dwarf; + } + + /* Searching probe points */ + for (j = 0; j < session.nr_probe; j++) { + pp = &session.probes[j]; + 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 (j = 0; j < session.nr_probe; j++) { + pp = &session.probes[j]; + 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; +} + |