Add lazy line matching support for specifying new probes. This also changes the syntax of perf probe a bit. Now perf probe accepts one of below probe event definitions. 1) Define event based on function name [EVENT=]FUNC[@SRC][:RLN|+OFF|%return|;PTN] [ARG ...] 2) Define event based on source file with line number [EVENT=]SRC:ALN [ARG ...] 3) Define event based on source file with lazy pattern [EVENT=]SRC;PTN [ARG ...] - New lazy matching pattern(PTN) follows ';' (semicolon). And it must be put the end of the definition. - So, @SRC is no longer the part which must be put at the end of the definition. Note that ';' (semicolon) can be interpreted as the end of a command by the shell. This means that you need to quote it. (anyway you will need to quote the lazy pattern itself too, because it may contains other sensitive characters, like '[',']' etc.). Lazy matching ------------- The lazy line matching is similar to glob matching except ignoring spaces in both of pattern and target. e.g. 'a=*' can matches 'a=b', 'a = b', 'a == b' and so on. This provides some sort of flexibility and robustness to probe point definitions against minor code changes. (for example, actual 10th line of schedule() can be changed easily by modifying schedule(), but the same line matching 'rq=cpu_rq*' may still exist.) Changes in v3: - Cast Dwarf_Addr to uintmax_t for printf-formats. Changes in v2: - Cast Dwarf_Addr to unsigned long long for printf-formats. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: systemtap <systemtap@sources.redhat.com> Cc: DLE <dle-develop@lists.sourceforge.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: K.Prasad <prasad@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> LKML-Reference: <20100225133611.6725.45078.stgit@localhost6.localdomain6> Signed-off-by: Ingo Molnar <mingo@elte.hu>
362 lines
9.6 KiB
C
362 lines
9.6 KiB
C
/*
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* builtin-probe.c
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*
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* Builtin probe command: Set up probe events by C expression
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*
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* Written by Masami Hiramatsu <mhiramat@redhat.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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*/
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#define _GNU_SOURCE
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#include <sys/utsname.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <errno.h>
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#include <stdio.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <string.h>
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#undef _GNU_SOURCE
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#include "perf.h"
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#include "builtin.h"
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#include "util/util.h"
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#include "util/strlist.h"
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#include "util/event.h"
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#include "util/debug.h"
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#include "util/debugfs.h"
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#include "util/symbol.h"
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#include "util/thread.h"
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#include "util/parse-options.h"
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#include "util/parse-events.h" /* For debugfs_path */
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#include "util/probe-finder.h"
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#include "util/probe-event.h"
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#define MAX_PATH_LEN 256
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#define MAX_PROBES 128
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/* Session management structure */
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static struct {
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bool need_dwarf;
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bool list_events;
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bool force_add;
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bool show_lines;
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int nr_probe;
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struct probe_point probes[MAX_PROBES];
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struct strlist *dellist;
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struct map_groups kmap_groups;
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struct map *kmaps[MAP__NR_TYPES];
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struct line_range line_range;
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} session;
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/* Parse an event definition. Note that any error must die. */
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static void parse_probe_event(const char *str)
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{
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struct probe_point *pp = &session.probes[session.nr_probe];
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pr_debug("probe-definition(%d): %s\n", session.nr_probe, str);
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if (++session.nr_probe == MAX_PROBES)
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die("Too many probes (> %d) are specified.", MAX_PROBES);
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/* Parse perf-probe event into probe_point */
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parse_perf_probe_event(str, pp, &session.need_dwarf);
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pr_debug("%d arguments\n", pp->nr_args);
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}
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static void parse_probe_event_argv(int argc, const char **argv)
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{
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int i, len;
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char *buf;
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/* Bind up rest arguments */
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len = 0;
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for (i = 0; i < argc; i++)
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len += strlen(argv[i]) + 1;
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buf = zalloc(len + 1);
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if (!buf)
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die("Failed to allocate memory for binding arguments.");
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len = 0;
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for (i = 0; i < argc; i++)
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len += sprintf(&buf[len], "%s ", argv[i]);
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parse_probe_event(buf);
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free(buf);
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}
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static int opt_add_probe_event(const struct option *opt __used,
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const char *str, int unset __used)
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{
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if (str)
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parse_probe_event(str);
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return 0;
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}
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static int opt_del_probe_event(const struct option *opt __used,
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const char *str, int unset __used)
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{
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if (str) {
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if (!session.dellist)
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session.dellist = strlist__new(true, NULL);
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strlist__add(session.dellist, str);
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}
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return 0;
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}
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/* Currently just checking function name from symbol map */
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static void evaluate_probe_point(struct probe_point *pp)
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{
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struct symbol *sym;
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sym = map__find_symbol_by_name(session.kmaps[MAP__FUNCTION],
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pp->function, NULL);
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if (!sym)
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die("Kernel symbol \'%s\' not found - probe not added.",
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pp->function);
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}
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#ifndef NO_DWARF_SUPPORT
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static int open_vmlinux(void)
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{
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if (map__load(session.kmaps[MAP__FUNCTION], NULL) < 0) {
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pr_debug("Failed to load kernel map.\n");
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return -EINVAL;
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}
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pr_debug("Try to open %s\n",
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session.kmaps[MAP__FUNCTION]->dso->long_name);
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return open(session.kmaps[MAP__FUNCTION]->dso->long_name, O_RDONLY);
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}
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static int opt_show_lines(const struct option *opt __used,
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const char *str, int unset __used)
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{
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if (str)
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parse_line_range_desc(str, &session.line_range);
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INIT_LIST_HEAD(&session.line_range.line_list);
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session.show_lines = true;
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return 0;
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}
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#endif
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static const char * const probe_usage[] = {
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"perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
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"perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
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"perf probe [<options>] --del '[GROUP:]EVENT' ...",
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"perf probe --list",
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#ifndef NO_DWARF_SUPPORT
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"perf probe --line 'LINEDESC'",
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#endif
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NULL
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};
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static const struct option options[] = {
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OPT_BOOLEAN('v', "verbose", &verbose,
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"be more verbose (show parsed arguments, etc)"),
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#ifndef NO_DWARF_SUPPORT
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OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
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"file", "vmlinux pathname"),
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#endif
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OPT_BOOLEAN('l', "list", &session.list_events,
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"list up current probe events"),
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OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
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opt_del_probe_event),
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OPT_CALLBACK('a', "add", NULL,
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#ifdef NO_DWARF_SUPPORT
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"[EVENT=]FUNC[+OFF|%return] [ARG ...]",
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#else
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"[EVENT=]FUNC[+OFF|%return|:RL|;PT][@SRC]|SRC:AL|SRC;PT"
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" [ARG ...]",
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#endif
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"probe point definition, where\n"
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"\t\tGROUP:\tGroup name (optional)\n"
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"\t\tEVENT:\tEvent name\n"
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"\t\tFUNC:\tFunction name\n"
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"\t\tOFF:\tOffset from function entry (in byte)\n"
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"\t\t%return:\tPut the probe at function return\n"
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#ifdef NO_DWARF_SUPPORT
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"\t\tARG:\tProbe argument (only \n"
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#else
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"\t\tSRC:\tSource code path\n"
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"\t\tRL:\tRelative line number from function entry.\n"
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"\t\tAL:\tAbsolute line number in file.\n"
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"\t\tPT:\tLazy expression of line code.\n"
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"\t\tARG:\tProbe argument (local variable name or\n"
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#endif
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"\t\t\tkprobe-tracer argument format.)\n",
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opt_add_probe_event),
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OPT_BOOLEAN('f', "force", &session.force_add, "forcibly add events"
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" with existing name"),
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#ifndef NO_DWARF_SUPPORT
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OPT_CALLBACK('L', "line", NULL,
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"FUNC[:RLN[+NUM|:RLN2]]|SRC:ALN[+NUM|:ALN2]",
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"Show source code lines.", opt_show_lines),
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#endif
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OPT_END()
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};
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/* Initialize symbol maps for vmlinux */
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static void init_vmlinux(void)
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{
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symbol_conf.sort_by_name = true;
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if (symbol_conf.vmlinux_name == NULL)
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symbol_conf.try_vmlinux_path = true;
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else
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pr_debug("Use vmlinux: %s\n", symbol_conf.vmlinux_name);
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if (symbol__init() < 0)
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die("Failed to init symbol map.");
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map_groups__init(&session.kmap_groups);
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if (map_groups__create_kernel_maps(&session.kmap_groups,
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session.kmaps) < 0)
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die("Failed to create kernel maps.");
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}
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int cmd_probe(int argc, const char **argv, const char *prefix __used)
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{
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int i, ret;
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#ifndef NO_DWARF_SUPPORT
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int fd;
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#endif
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struct probe_point *pp;
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argc = parse_options(argc, argv, options, probe_usage,
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PARSE_OPT_STOP_AT_NON_OPTION);
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if (argc > 0) {
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if (strcmp(argv[0], "-") == 0) {
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pr_warning(" Error: '-' is not supported.\n");
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usage_with_options(probe_usage, options);
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}
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parse_probe_event_argv(argc, argv);
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}
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if ((!session.nr_probe && !session.dellist && !session.list_events &&
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!session.show_lines))
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usage_with_options(probe_usage, options);
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if (debugfs_valid_mountpoint(debugfs_path) < 0)
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die("Failed to find debugfs path.");
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if (session.list_events) {
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if (session.nr_probe != 0 || session.dellist) {
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pr_warning(" Error: Don't use --list with"
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" --add/--del.\n");
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usage_with_options(probe_usage, options);
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}
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if (session.show_lines) {
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pr_warning(" Error: Don't use --list with --line.\n");
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usage_with_options(probe_usage, options);
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}
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show_perf_probe_events();
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return 0;
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}
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#ifndef NO_DWARF_SUPPORT
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if (session.show_lines) {
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if (session.nr_probe != 0 || session.dellist) {
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pr_warning(" Error: Don't use --line with"
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" --add/--del.\n");
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usage_with_options(probe_usage, options);
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}
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init_vmlinux();
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fd = open_vmlinux();
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if (fd < 0)
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die("Could not open debuginfo file.");
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ret = find_line_range(fd, &session.line_range);
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if (ret <= 0)
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die("Source line is not found.\n");
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close(fd);
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show_line_range(&session.line_range);
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return 0;
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}
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#endif
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if (session.dellist) {
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del_trace_kprobe_events(session.dellist);
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strlist__delete(session.dellist);
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if (session.nr_probe == 0)
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return 0;
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}
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/* Add probes */
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init_vmlinux();
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if (session.need_dwarf)
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#ifdef NO_DWARF_SUPPORT
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die("Debuginfo-analysis is not supported");
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#else /* !NO_DWARF_SUPPORT */
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pr_debug("Some probes require debuginfo.\n");
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fd = open_vmlinux();
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if (fd < 0) {
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if (session.need_dwarf)
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die("Could not open debuginfo file.");
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pr_debug("Could not open vmlinux/module file."
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" Try to use symbols.\n");
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goto end_dwarf;
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}
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/* Searching probe points */
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for (i = 0; i < session.nr_probe; i++) {
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pp = &session.probes[i];
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if (pp->found)
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continue;
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lseek(fd, SEEK_SET, 0);
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ret = find_probe_point(fd, pp);
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if (ret > 0)
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continue;
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if (ret == 0) { /* No error but failed to find probe point. */
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synthesize_perf_probe_point(pp);
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die("Probe point '%s' not found. - probe not added.",
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pp->probes[0]);
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}
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/* Error path */
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if (session.need_dwarf) {
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if (ret == -ENOENT)
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pr_warning("No dwarf info found in the vmlinux - please rebuild with CONFIG_DEBUG_INFO=y.\n");
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die("Could not analyze debuginfo.");
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}
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pr_debug("An error occurred in debuginfo analysis."
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" Try to use symbols.\n");
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break;
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}
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close(fd);
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end_dwarf:
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#endif /* !NO_DWARF_SUPPORT */
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/* Synthesize probes without dwarf */
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for (i = 0; i < session.nr_probe; i++) {
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pp = &session.probes[i];
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if (pp->found) /* This probe is already found. */
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continue;
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evaluate_probe_point(pp);
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ret = synthesize_trace_kprobe_event(pp);
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if (ret == -E2BIG)
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die("probe point definition becomes too long.");
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else if (ret < 0)
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die("Failed to synthesize a probe point.");
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}
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/* Settng up probe points */
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add_trace_kprobe_events(session.probes, session.nr_probe,
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session.force_add);
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return 0;
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}
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