1 files changed, 484 insertions, 0 deletions

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
new file mode 100644
index 000000000000..cd7fbda5e2a5
--- /dev/null
+++ b/tools/perf/util/probe-event.c
@@ -0,0 +1,484 @@
+/*
+ * probe-event.c : perf-probe definition to kprobe_events format converter
+ *
+ * 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>
+#include <stdarg.h>
+#include <limits.h>
+
+#undef _GNU_SOURCE
+#include "event.h"
+#include "string.h"
+#include "strlist.h"
+#include "debug.h"
+#include "parse-events.h"  /* For debugfs_path */
+#include "probe-event.h"
+
+#define MAX_CMDLEN 256
+#define MAX_PROBE_ARGS 128
+#define PERFPROBE_GROUP "probe"
+
+#define semantic_error(msg ...) die("Semantic error :" msg)
+
+/* If there is no space to write, returns -E2BIG. */
+static int e_snprintf(char *str, size_t size, const char *format, ...)
+{
+        int ret;
+        va_list ap;
+        va_start(ap, format);
+        ret = vsnprintf(str, size, format, ap);
+        va_end(ap);
+        if (ret >= (int)size)
+                ret = -E2BIG;
+        return ret;
+}
+
+/* Parse probepoint definition. */
+static void parse_perf_probe_probepoint(char *arg, struct probe_point *pp)
+{
+        char *ptr, *tmp;
+        char c, nc = 0;
+        /*
+         * <Syntax>
+         * perf probe SRC:LN
+         * perf probe FUNC[+OFFS|%return][@SRC]
+         */
+
+        ptr = strpbrk(arg, ":+@%");
+        if (ptr) {
+                nc = *ptr;
+                *ptr++ = '\0';
+        }
+
+        /* Check arg is function or file and copy it */
+        if (strchr(arg, '.'))   /* File */
+                pp->file = strdup(arg);
+        else                    /* Function */
+                pp->function = strdup(arg);
+        DIE_IF(pp->file == NULL && pp->function == NULL);
+
+        /* Parse other options */
+        while (ptr) {
+                arg = ptr;
+                c = nc;
+                ptr = strpbrk(arg, ":+@%");
+                if (ptr) {
+                        nc = *ptr;
+                        *ptr++ = '\0';
+                }
+                switch (c) {
+                case ':':       /* Line number */
+                        pp->line = strtoul(arg, &tmp, 0);
+                        if (*tmp != '\0')
+                                semantic_error("There is non-digit charactor"
+                                                " in line number.");
+                        break;
+                case '+':       /* Byte offset from a symbol */
+                        pp->offset = strtoul(arg, &tmp, 0);
+                        if (*tmp != '\0')
+                                semantic_error("There is non-digit charactor"
+                                                " in offset.");
+                        break;
+                case '@':       /* File name */
+                        if (pp->file)
+                                semantic_error("SRC@SRC is not allowed.");
+                        pp->file = strdup(arg);
+                        DIE_IF(pp->file == NULL);
+                        if (ptr)
+                                semantic_error("@SRC must be the last "
+                                               "option.");
+                        break;
+                case '%':       /* Probe places */
+                        if (strcmp(arg, "return") == 0) {
+                                pp->retprobe = 1;
+                        } else  /* Others not supported yet */
+                                semantic_error("%%%s is not supported.", arg);
+                        break;
+                default:
+                        DIE_IF("Program has a bug.");
+                        break;
+                }
+        }
+
+        /* Exclusion check */
+        if (pp->line && pp->offset)
+                semantic_error("Offset can't be used with line number.");
+
+        if (!pp->line && pp->file && !pp->function)
+                semantic_error("File always requires line number.");
+
+        if (pp->offset && !pp->function)
+                semantic_error("Offset requires an entry function.");
+
+        if (pp->retprobe && !pp->function)
+                semantic_error("Return probe requires an entry function.");
+
+        if ((pp->offset || pp->line) && pp->retprobe)
+                semantic_error("Offset/Line can't be used with return probe.");
+
+        pr_debug("symbol:%s file:%s line:%d offset:%d, return:%d\n",
+                 pp->function, pp->file, pp->line, pp->offset, pp->retprobe);
+}
+
+/* Parse perf-probe event definition */
+int parse_perf_probe_event(const char *str, struct probe_point *pp)
+{
+        char **argv;
+        int argc, i, need_dwarf = 0;
+
+        argv = argv_split(str, &argc);
+        if (!argv)
+                die("argv_split failed.");
+        if (argc > MAX_PROBE_ARGS + 1)
+                semantic_error("Too many arguments");
+
+        /* Parse probe point */
+        parse_perf_probe_probepoint(argv[0], pp);
+        if (pp->file || pp->line)
+                need_dwarf = 1;
+
+        /* Copy arguments and ensure return probe has no C argument */
+        pp->nr_args = argc - 1;
+        pp->args = zalloc(sizeof(char *) * pp->nr_args);
+        for (i = 0; i < pp->nr_args; i++) {
+                pp->args[i] = strdup(argv[i + 1]);
+                if (!pp->args[i])
+                        die("Failed to copy argument.");
+                if (is_c_varname(pp->args[i])) {
+                        if (pp->retprobe)
+                                semantic_error("You can't specify local"
+                                                " variable for kretprobe");
+                        need_dwarf = 1;
+                }
+        }
+
+        argv_free(argv);
+        return need_dwarf;
+}
+
+/* Parse kprobe_events event into struct probe_point */
+void parse_trace_kprobe_event(const char *str, char **group, char **event,
+                              struct probe_point *pp)
+{
+        char pr;
+        char *p;
+        int ret, i, argc;
+        char **argv;
+
+        pr_debug("Parsing kprobe_events: %s\n", str);
+        argv = argv_split(str, &argc);
+        if (!argv)
+                die("argv_split failed.");
+        if (argc < 2)
+                semantic_error("Too less arguments.");
+
+        /* Scan event and group name. */
+        ret = sscanf(argv[0], "%c:%a[^/ \t]/%a[^ \t]",
+                     &pr, (float *)(void *)group, (float *)(void *)event);
+        if (ret != 3)
+                semantic_error("Failed to parse event name: %s", argv[0]);
+        pr_debug("Group:%s Event:%s probe:%c\n", *group, *event, pr);
+
+        if (!pp)
+                goto end;
+
+        pp->retprobe = (pr == 'r');
+
+        /* Scan function name and offset */
+        ret = sscanf(argv[1], "%a[^+]+%d", (float *)(void *)&pp->function, &pp->offset);
+        if (ret == 1)
+                pp->offset = 0;
+
+        /* kprobe_events doesn't have this information */
+        pp->line = 0;
+        pp->file = NULL;
+
+        pp->nr_args = argc - 2;
+        pp->args = zalloc(sizeof(char *) * pp->nr_args);
+        for (i = 0; i < pp->nr_args; i++) {
+                p = strchr(argv[i + 2], '=');
+                if (p)  /* We don't need which register is assigned. */
+                        *p = '\0';
+                pp->args[i] = strdup(argv[i + 2]);
+                if (!pp->args[i])
+                        die("Failed to copy argument.");
+        }
+
+end:
+        argv_free(argv);
+}
+
+int synthesize_perf_probe_event(struct probe_point *pp)
+{
+        char *buf;
+        char offs[64] = "", line[64] = "";
+        int i, len, ret;
+
+        pp->probes[0] = buf = zalloc(MAX_CMDLEN);
+        if (!buf)
+                die("Failed to allocate memory by zalloc.");
+        if (pp->offset) {
+                ret = e_snprintf(offs, 64, "+%d", pp->offset);
+                if (ret <= 0)
+                        goto error;
+        }
+        if (pp->line) {
+                ret = e_snprintf(line, 64, ":%d", pp->line);
+                if (ret <= 0)
+                        goto error;
+        }
+
+        if (pp->function)
+                ret = e_snprintf(buf, MAX_CMDLEN, "%s%s%s%s", pp->function,
+                                 offs, pp->retprobe ? "%return" : "", line);
+        else
+                ret = e_snprintf(buf, MAX_CMDLEN, "%s%s%s%s", pp->file, line);
+        if (ret <= 0)
+                goto error;
+        len = ret;
+
+        for (i = 0; i < pp->nr_args; i++) {
+                ret = e_snprintf(&buf[len], MAX_CMDLEN - len, " %s",
+                                 pp->args[i]);
+                if (ret <= 0)
+                        goto error;
+                len += ret;
+        }
+        pp->found = 1;
+
+        return pp->found;
+error:
+        free(pp->probes[0]);
+
+        return ret;
+}
+
+int synthesize_trace_kprobe_event(struct probe_point *pp)
+{
+        char *buf;
+        int i, len, ret;
+
+        pp->probes[0] = buf = zalloc(MAX_CMDLEN);
+        if (!buf)
+                die("Failed to allocate memory by zalloc.");
+        ret = e_snprintf(buf, MAX_CMDLEN, "%s+%d", pp->function, pp->offset);
+        if (ret <= 0)
+                goto error;
+        len = ret;
+
+        for (i = 0; i < pp->nr_args; i++) {
+                ret = e_snprintf(&buf[len], MAX_CMDLEN - len, " %s",
+                                 pp->args[i]);
+                if (ret <= 0)
+                        goto error;
+                len += ret;
+        }
+        pp->found = 1;
+
+        return pp->found;
+error:
+        free(pp->probes[0]);
+
+        return ret;
+}
+
+static int open_kprobe_events(int flags, int mode)
+{
+        char buf[PATH_MAX];
+        int ret;
+
+        ret = e_snprintf(buf, PATH_MAX, "%s/../kprobe_events", debugfs_path);
+        if (ret < 0)
+                die("Failed to make kprobe_events path.");
+
+        ret = open(buf, flags, mode);
+        if (ret < 0) {
+                if (errno == ENOENT)
+                        die("kprobe_events file does not exist -"
+                            " please rebuild with CONFIG_KPROBE_TRACER.");
+                else
+                        die("Could not open kprobe_events file: %s",
+                            strerror(errno));
+        }
+        return ret;
+}
+
+/* Get raw string list of current kprobe_events */
+static struct strlist *get_trace_kprobe_event_rawlist(int fd)
+{
+        int ret, idx;
+        FILE *fp;
+        char buf[MAX_CMDLEN];
+        char *p;
+        struct strlist *sl;
+
+        sl = strlist__new(true, NULL);
+
+        fp = fdopen(dup(fd), "r");
+        while (!feof(fp)) {
+                p = fgets(buf, MAX_CMDLEN, fp);
+                if (!p)
+                        break;
+
+                idx = strlen(p) - 1;
+                if (p[idx] == '\n')
+                        p[idx] = '\0';
+                ret = strlist__add(sl, buf);
+                if (ret < 0)
+                        die("strlist__add failed: %s", strerror(-ret));
+        }
+        fclose(fp);
+
+        return sl;
+}
+
+/* Free and zero clear probe_point */
+static void clear_probe_point(struct probe_point *pp)
+{
+        int i;
+
+        if (pp->function)
+                free(pp->function);
+        if (pp->file)
+                free(pp->file);
+        for (i = 0; i < pp->nr_args; i++)
+                free(pp->args[i]);
+        if (pp->args)
+                free(pp->args);
+        for (i = 0; i < pp->found; i++)
+                free(pp->probes[i]);
+        memset(pp, 0, sizeof(pp));
+}
+
+/* List up current perf-probe events */
+void show_perf_probe_events(void)
+{
+        unsigned int i;
+        int fd;
+        char *group, *event;
+        struct probe_point pp;
+        struct strlist *rawlist;
+        struct str_node *ent;
+
+        fd = open_kprobe_events(O_RDONLY, 0);
+        rawlist = get_trace_kprobe_event_rawlist(fd);
+        close(fd);
+
+        for (i = 0; i < strlist__nr_entries(rawlist); i++) {
+                ent = strlist__entry(rawlist, i);
+                parse_trace_kprobe_event(ent->s, &group, &event, &pp);
+                synthesize_perf_probe_event(&pp);
+                printf("[%s:%s]\t%s\n", group, event, pp.probes[0]);
+                free(group);
+                free(event);
+                clear_probe_point(&pp);
+        }
+
+        strlist__delete(rawlist);
+}
+
+/* Get current perf-probe event names */
+static struct strlist *get_perf_event_names(int fd)
+{
+        unsigned int i;
+        char *group, *event;
+        struct strlist *sl, *rawlist;
+        struct str_node *ent;
+
+        rawlist = get_trace_kprobe_event_rawlist(fd);
+
+        sl = strlist__new(false, NULL);
+        for (i = 0; i < strlist__nr_entries(rawlist); i++) {
+                ent = strlist__entry(rawlist, i);
+                parse_trace_kprobe_event(ent->s, &group, &event, NULL);
+                strlist__add(sl, event);
+                free(group);
+        }
+
+        strlist__delete(rawlist);
+
+        return sl;
+}
+
+static int write_trace_kprobe_event(int fd, const char *buf)
+{
+        int ret;
+
+        ret = write(fd, buf, strlen(buf));
+        if (ret <= 0)
+                die("Failed to create event.");
+        else
+                printf("Added new event: %s\n", buf);
+
+        return ret;
+}
+
+static void get_new_event_name(char *buf, size_t len, const char *base,
+                               struct strlist *namelist)
+{
+        int i, ret;
+        for (i = 0; i < MAX_EVENT_INDEX; i++) {
+                ret = e_snprintf(buf, len, "%s_%d", base, i);
+                if (ret < 0)
+                        die("snprintf() failed: %s", strerror(-ret));
+                if (!strlist__has_entry(namelist, buf))
+                        break;
+        }
+        if (i == MAX_EVENT_INDEX)
+                die("Too many events are on the same function.");
+}
+
+void add_trace_kprobe_events(struct probe_point *probes, int nr_probes)
+{
+        int i, j, fd;
+        struct probe_point *pp;
+        char buf[MAX_CMDLEN];
+        char event[64];
+        struct strlist *namelist;
+
+        fd = open_kprobe_events(O_RDWR, O_APPEND);
+        /* Get current event names */
+        namelist = get_perf_event_names(fd);
+
+        for (j = 0; j < nr_probes; j++) {
+                pp = probes + j;
+                for (i = 0; i < pp->found; i++) {
+                        /* Get an unused new event name */
+                        get_new_event_name(event, 64, pp->function, namelist);
+                        snprintf(buf, MAX_CMDLEN, "%c:%s/%s %s\n",
+                                 pp->retprobe ? 'r' : 'p',
+                                 PERFPROBE_GROUP, event,
+                                 pp->probes[i]);
+                        write_trace_kprobe_event(fd, buf);
+                        /* Add added event name to namelist */
+                        strlist__add(namelist, event);
+                }
+        }
+        close(fd);
+}