From c9e759b1e8456a460f258fcfe9682003fcf03938 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Mon, 1 Feb 2021 13:48:12 -0600 Subject: tracing: Rework synthetic event command parsing Now that command parsing has been delegated to the create functions and we're no longer constrained by argv_split(), we can modify the synthetic event command parser to better match the higher-level structure of the synthetic event commands, which is basically an event name followed by a set of semicolon-separated fields. Since we're also now passed the raw command, we can also save it directly and can get rid of save_cmdstr(). Link: https://lkml.kernel.org/r/cb9e2be92d992ce59f2b4f132264a5d467f3933f.1612208610.git.zanussi@kernel.org Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_events_synth.c | 245 ++++++++++++++++++++++---------------- 1 file changed, 143 insertions(+), 102 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c index b2588a5650c9..4f6c5a104ee2 100644 --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -48,7 +48,7 @@ static int errpos(const char *str) return err_pos(last_cmd, str); } -static void last_cmd_set(char *str) +static void last_cmd_set(const char *str) { if (!str) return; @@ -579,18 +579,14 @@ static void free_synth_field(struct synth_field *field) kfree(field); } -static struct synth_field *parse_synth_field(int argc, const char **argv, - int *consumed) +static struct synth_field *parse_synth_field(int argc, char **argv) { - struct synth_field *field; const char *prefix = NULL, *field_type = argv[0], *field_name, *array; - int len, ret = -ENOMEM; + int len, consumed, ret = -ENOMEM; + struct synth_field *field; struct seq_buf s; ssize_t size; - if (field_type[0] == ';') - field_type++; - if (!strcmp(field_type, "unsigned")) { if (argc < 3) { synth_err(SYNTH_ERR_INCOMPLETE_TYPE, errpos(field_type)); @@ -599,10 +595,20 @@ static struct synth_field *parse_synth_field(int argc, const char **argv, prefix = "unsigned "; field_type = argv[1]; field_name = argv[2]; - *consumed = 3; + consumed = 3; } else { field_name = argv[1]; - *consumed = 2; + consumed = 2; + } + + if (consumed < argc) { + synth_err(SYNTH_ERR_INVALID_FIELD, errpos(field_type)); + return ERR_PTR(-EINVAL); + } + + if (!field_name) { + synth_err(SYNTH_ERR_INVALID_FIELD, errpos(field_type)); + return ERR_PTR(-EINVAL); } field = kzalloc(sizeof(*field), GFP_KERNEL); @@ -613,8 +619,6 @@ static struct synth_field *parse_synth_field(int argc, const char **argv, array = strchr(field_name, '['); if (array) len -= strlen(array); - else if (field_name[len - 1] == ';') - len--; field->name = kmemdup_nul(field_name, len, GFP_KERNEL); if (!field->name) @@ -626,8 +630,6 @@ static struct synth_field *parse_synth_field(int argc, const char **argv, goto free; } - if (field_type[0] == ';') - field_type++; len = strlen(field_type) + 1; if (array) @@ -644,11 +646,8 @@ static struct synth_field *parse_synth_field(int argc, const char **argv, if (prefix) seq_buf_puts(&s, prefix); seq_buf_puts(&s, field_type); - if (array) { + if (array) seq_buf_puts(&s, array); - if (s.buffer[s.len - 1] == ';') - s.len--; - } if (WARN_ON_ONCE(!seq_buf_buffer_left(&s))) goto free; @@ -1160,46 +1159,12 @@ int synth_event_gen_cmd_array_start(struct dynevent_cmd *cmd, const char *name, } EXPORT_SYMBOL_GPL(synth_event_gen_cmd_array_start); -static int save_cmdstr(int argc, const char *name, const char **argv) -{ - struct seq_buf s; - char *buf; - int i; - - buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL); - if (!buf) - return -ENOMEM; - - seq_buf_init(&s, buf, MAX_DYNEVENT_CMD_LEN); - - seq_buf_puts(&s, name); - - for (i = 0; i < argc; i++) { - seq_buf_putc(&s, ' '); - seq_buf_puts(&s, argv[i]); - } - - if (!seq_buf_buffer_left(&s)) { - synth_err(SYNTH_ERR_CMD_TOO_LONG, 0); - kfree(buf); - return -EINVAL; - } - buf[s.len] = 0; - last_cmd_set(buf); - - kfree(buf); - return 0; -} - -static int __create_synth_event(int argc, const char *name, const char **argv) +static int __create_synth_event(const char *name, const char *raw_fields) { + char **argv, *field_str, *tmp_fields, *saved_fields = NULL; struct synth_field *field, *fields[SYNTH_FIELDS_MAX]; + int i, argc, n_fields = 0, ret = 0; struct synth_event *event = NULL; - int i, consumed = 0, n_fields = 0, ret = 0; - - ret = save_cmdstr(argc, name, argv); - if (ret) - return ret; /* * Argument syntax: @@ -1208,46 +1173,60 @@ static int __create_synth_event(int argc, const char *name, const char **argv) * where 'field' = type field_name */ - if (name[0] == '\0' || argc < 1) { + if (name[0] == '\0') { synth_err(SYNTH_ERR_CMD_INCOMPLETE, 0); return -EINVAL; } - mutex_lock(&event_mutex); - if (!is_good_name(name)) { synth_err(SYNTH_ERR_BAD_NAME, errpos(name)); - ret = -EINVAL; - goto out; + return -EINVAL; } + mutex_lock(&event_mutex); + event = find_synth_event(name); if (event) { synth_err(SYNTH_ERR_EVENT_EXISTS, errpos(name)); ret = -EEXIST; - goto out; + goto err; } - for (i = 0; i < argc - 1; i++) { - if (strcmp(argv[i], ";") == 0) - continue; - if (n_fields == SYNTH_FIELDS_MAX) { - synth_err(SYNTH_ERR_TOO_MANY_FIELDS, 0); - ret = -EINVAL; + tmp_fields = saved_fields = kstrdup(raw_fields, GFP_KERNEL); + if (!tmp_fields) { + ret = -ENOMEM; + goto err; + } + + while ((field_str = strsep(&tmp_fields, ";")) != NULL) { + argv = argv_split(GFP_KERNEL, field_str, &argc); + if (!argv) { + ret = -ENOMEM; goto err; } - field = parse_synth_field(argc - i, &argv[i], &consumed); + if (!argc) + continue; + + field = parse_synth_field(argc, argv); if (IS_ERR(field)) { + argv_free(argv); ret = PTR_ERR(field); goto err; } + + argv_free(argv); + fields[n_fields++] = field; - i += consumed - 1; + if (n_fields == SYNTH_FIELDS_MAX) { + synth_err(SYNTH_ERR_TOO_MANY_FIELDS, 0); + ret = -EINVAL; + goto err; + } } - if (i < argc && strcmp(argv[i], ";") != 0) { - synth_err(SYNTH_ERR_INVALID_FIELD, errpos(argv[i])); + if (n_fields == 0) { + synth_err(SYNTH_ERR_CMD_INCOMPLETE, 0); ret = -EINVAL; goto err; } @@ -1266,6 +1245,8 @@ static int __create_synth_event(int argc, const char *name, const char **argv) out: mutex_unlock(&event_mutex); + kfree(saved_fields); + return ret; err: for (i = 0; i < n_fields; i++) @@ -1383,31 +1364,79 @@ int synth_event_delete(const char *event_name) } EXPORT_SYMBOL_GPL(synth_event_delete); -static int create_or_delete_synth_event(const char *raw_command) +static int check_command(const char *raw_command) { - char **argv, *name = NULL; - int argc = 0, ret = 0; + char **argv = NULL, *cmd, *saved_cmd, *name_and_field; + int argc, ret = 0; - argv = argv_split(GFP_KERNEL, raw_command, &argc); - if (!argv) + cmd = saved_cmd = kstrdup(raw_command, GFP_KERNEL); + if (!cmd) return -ENOMEM; - if (!argc) + name_and_field = strsep(&cmd, ";"); + if (!name_and_field) { + ret = -EINVAL; + goto free; + } + + if (name_and_field[0] == '!') + goto free; + + argv = argv_split(GFP_KERNEL, name_and_field, &argc); + if (!argv) { + ret = -ENOMEM; goto free; + } + argv_free(argv); + + if (argc < 3) + ret = -EINVAL; +free: + kfree(saved_cmd); - name = argv[0]; + return ret; +} + +static int create_or_delete_synth_event(const char *raw_command) +{ + char *name = NULL, *fields, *p; + int ret = 0; + + raw_command = skip_spaces(raw_command); + if (raw_command[0] == '\0') + return ret; + + last_cmd_set(raw_command); + + ret = check_command(raw_command); + if (ret) { + synth_err(SYNTH_ERR_CMD_INCOMPLETE, 0); + return ret; + } + + p = strpbrk(raw_command, " \t"); + if (!p && raw_command[0] != '!') { + synth_err(SYNTH_ERR_CMD_INCOMPLETE, 0); + ret = -EINVAL; + goto free; + } + + name = kmemdup_nul(raw_command, p ? p - raw_command : strlen(raw_command), GFP_KERNEL); + if (!name) + return -ENOMEM; - /* trace_run_command() ensures argc != 0 */ if (name[0] == '!') { ret = synth_event_delete(name + 1); goto free; } - ret = __create_synth_event(argc - 1, name, (const char **)argv + 1); + fields = skip_spaces(p); + + ret = __create_synth_event(name, fields); free: - argv_free(argv); + kfree(name); - return ret == -ECANCELED ? -EINVAL : ret; + return ret; } static int synth_event_run_command(struct dynevent_cmd *cmd) @@ -1953,39 +1982,51 @@ EXPORT_SYMBOL_GPL(synth_event_trace_end); static int create_synth_event(const char *raw_command) { - char **argv, *name; - int len, argc = 0, ret = 0; + char *fields, *p; + const char *name; + int len, ret = 0; - argv = argv_split(GFP_KERNEL, raw_command, &argc); - if (!argv) { - ret = -ENOMEM; + raw_command = skip_spaces(raw_command); + if (raw_command[0] == '\0') return ret; - } - if (!argc) - goto free; + last_cmd_set(raw_command); - name = argv[0]; + p = strpbrk(raw_command, " \t"); + if (!p) + return -EINVAL; - if (name[0] != 's' || name[1] != ':') { - ret = -ECANCELED; - goto free; - } + fields = skip_spaces(p); + + name = raw_command; + + if (name[0] != 's' || name[1] != ':') + return -ECANCELED; name += 2; /* This interface accepts group name prefix */ if (strchr(name, '/')) { len = str_has_prefix(name, SYNTH_SYSTEM "/"); - if (len == 0) { - ret = -EINVAL; - goto free; - } + if (len == 0) + return -EINVAL; name += len; } - ret = __create_synth_event(argc - 1, name, (const char **)argv + 1); -free: - argv_free(argv); + len = name - raw_command; + + ret = check_command(raw_command + len); + if (ret) { + synth_err(SYNTH_ERR_CMD_INCOMPLETE, 0); + return ret; + } + + name = kmemdup_nul(raw_command + len, p - raw_command - len, GFP_KERNEL); + if (!name) + return -ENOMEM; + + ret = __create_synth_event(name, fields); + + kfree(name); return ret; } -- cgit