1 files changed, 360 insertions, 0 deletions

diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
new file mode 100644
index 000000000000..152d6c9b1fa4
--- /dev/null
+++ b/tools/perf/builtin-probe.c
@@ -0,0 +1,360 @@
+/*
+ * 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
+
+/* 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;
+}
+