On Thu, 21 Jan 2021 11:01:05 -0600 Tom Zanussi <zanu...@kernel.org> wrote:
> 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(). > This looks good to me. Reviewed-by: Masami Hiramatsu <mhira...@kernel.org> Thank you, > Signed-off-by: Tom Zanussi <zanu...@kernel.org> > --- > kernel/trace/trace_events_synth.c | 198 +++++++++++++++--------------- > 1 file changed, 98 insertions(+), 100 deletions(-) > > diff --git a/kernel/trace/trace_events_synth.c > b/kernel/trace/trace_events_synth.c > index b2588a5650c9..a79c17b97add 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: > @@ -1208,13 +1173,14 @@ static int __create_synth_event(int argc, const char > *name, const char **argv) > * where 'field' = type field_name > */ > > - if (name[0] == '\0' || argc < 1) { > + mutex_lock(&event_mutex); > + > + if (name[0] == '\0') { > synth_err(SYNTH_ERR_CMD_INCOMPLETE, 0); > - return -EINVAL; > + ret = -EINVAL; > + goto out; > } > > - mutex_lock(&event_mutex); > - > if (!is_good_name(name)) { > synth_err(SYNTH_ERR_BAD_NAME, errpos(name)); > ret = -EINVAL; > @@ -1228,26 +1194,41 @@ static int __create_synth_event(int argc, const char > *name, const char **argv) > goto out; > } > > - 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 out; > + } > + > + 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 +1247,8 @@ 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++) > @@ -1385,29 +1368,38 @@ EXPORT_SYMBOL_GPL(synth_event_delete); > > static int create_or_delete_synth_event(const char *raw_command) > { > - char **argv, *name = NULL; > - int argc = 0, ret = 0; > + char *name = NULL, *fields, *p; > + int ret = 0; > > - argv = argv_split(GFP_KERNEL, raw_command, &argc); > - if (!argv) > - return -ENOMEM; > + raw_command = skip_spaces(raw_command); > + if (raw_command[0] == '\0') > + return ret; > + > + last_cmd_set(raw_command); > > - if (!argc) > + p = strpbrk(raw_command, " \t"); > + if (!p && raw_command[0] != '!') { > + synth_err(SYNTH_ERR_CMD_INCOMPLETE, 0); > + ret = -EINVAL; > goto free; > + } > > - name = argv[0]; > + 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 +1945,45 @@ 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; > + > + 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; > } > -- > 2.17.1 > -- Masami Hiramatsu <mhira...@kernel.org>