| /* |
| * 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, ...) |
| __attribute__((format(printf, 3, 4))); |
| |
| 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", 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)); |
| } |
| |
| /* Show an event */ |
| static void show_perf_probe_event(const char *group, const char *event, |
| const char *place, struct probe_point *pp) |
| { |
| int i; |
| char buf[128]; |
| |
| e_snprintf(buf, 128, "%s:%s", group, event); |
| printf(" %-40s (on %s", buf, place); |
| |
| if (pp->nr_args > 0) { |
| printf(" with"); |
| for (i = 0; i < pp->nr_args; i++) |
| printf(" %s", pp->args[i]); |
| } |
| printf(")\n"); |
| } |
| |
| /* List up current perf-probe events */ |
| void show_perf_probe_events(void) |
| { |
| unsigned int i; |
| int fd, nr; |
| 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 only event probe point */ |
| nr = pp.nr_args; |
| pp.nr_args = 0; |
| synthesize_perf_probe_event(&pp); |
| pp.nr_args = nr; |
| /* Show an event */ |
| show_perf_probe_event(group, event, pp.probes[0], &pp); |
| 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(true, 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); |
| free(event); |
| } |
| |
| strlist__delete(rawlist); |
| |
| return sl; |
| } |
| |
| static void 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."); |
| } |
| |
| static void get_new_event_name(char *buf, size_t len, const char *base, |
| struct strlist *namelist) |
| { |
| int i, ret; |
| |
| /* Try no suffix */ |
| ret = e_snprintf(buf, len, "%s", base); |
| if (ret < 0) |
| die("snprintf() failed: %s", strerror(-ret)); |
| if (!strlist__has_entry(namelist, buf)) |
| return; |
| |
| /* Try to add suffix */ |
| for (i = 1; 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); |
| printf("Added new event:\n"); |
| /* Get the first parameter (probe-point) */ |
| sscanf(pp->probes[i], "%s", buf); |
| show_perf_probe_event(PERFPROBE_GROUP, event, |
| buf, pp); |
| /* Add added event name to namelist */ |
| strlist__add(namelist, event); |
| } |
| } |
| /* Show how to use the event. */ |
| printf("\nYou can now use it on all perf tools, such as:\n\n"); |
| printf("\tperf record -e %s:%s -a sleep 1\n\n", PERFPROBE_GROUP, event); |
| |
| strlist__delete(namelist); |
| close(fd); |
| } |