diff options
Diffstat (limited to 'tools/perf/util/probe-event.c')
| -rw-r--r-- | tools/perf/util/probe-event.c | 484 |
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 00000000000..cd7fbda5e2a --- /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); +} |