From: Tom Zanussi <zanu...@kernel.org> Add support for synthetic event error logging, which entails adding a logging function for it, a way to save the synthetic event command, and a set of specific synthetic event parse error strings and handling.
Link: https://lkml.kernel.org/r/ed099c66df13b40cfc633aaeb17f66c37a923066.1602598160.git.zanu...@kernel.org [ <rost...@goodmis.org>: wrote save_cmdstr() seq_buf implementation. ] Tested-by: Masami Hiramatsu <mhira...@kernel.org> Signed-off-by: Tom Zanussi <zanu...@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rost...@goodmis.org> --- kernel/trace/trace_events_synth.c | 92 ++++++++++++++++++++++++++++++- 1 file changed, 90 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c index 8c9d6e464da0..f77851018121 100644 --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -20,6 +20,48 @@ #include "trace_synth.h" +#undef ERRORS +#define ERRORS \ + C(BAD_NAME, "Illegal name"), \ + C(CMD_INCOMPLETE, "Incomplete command"), \ + C(EVENT_EXISTS, "Event already exists"), \ + C(TOO_MANY_FIELDS, "Too many fields"), \ + C(INCOMPLETE_TYPE, "Incomplete type"), \ + C(INVALID_TYPE, "Invalid type"), \ + C(INVALID_FIELD, "Invalid field"), \ + C(CMD_TOO_LONG, "Command too long"), + +#undef C +#define C(a, b) SYNTH_ERR_##a + +enum { ERRORS }; + +#undef C +#define C(a, b) b + +static const char *err_text[] = { ERRORS }; + +static char last_cmd[MAX_FILTER_STR_VAL]; + +static int errpos(const char *str) +{ + return err_pos(last_cmd, str); +} + +static void last_cmd_set(char *str) +{ + if (!str) + return; + + strncpy(last_cmd, str, MAX_FILTER_STR_VAL - 1); +} + +static void synth_err(u8 err_type, u8 err_pos) +{ + tracing_log_err(NULL, "synthetic_events", last_cmd, err_text, + err_type, err_pos); +} + static int create_synth_event(int argc, const char **argv); static int synth_event_show(struct seq_file *m, struct dyn_event *ev); static int synth_event_release(struct dyn_event *ev); @@ -545,8 +587,10 @@ static struct synth_field *parse_synth_field(int argc, const char **argv, field_type++; if (!strcmp(field_type, "unsigned")) { - if (argc < 3) + if (argc < 3) { + synth_err(SYNTH_ERR_INCOMPLETE_TYPE, errpos(field_type)); return ERR_PTR(-EINVAL); + } prefix = "unsigned "; field_type = argv[1]; field_name = argv[2]; @@ -573,6 +617,7 @@ static struct synth_field *parse_synth_field(int argc, const char **argv, goto free; } if (!is_good_name(field->name)) { + synth_err(SYNTH_ERR_BAD_NAME, errpos(field_name)); ret = -EINVAL; goto free; } @@ -601,6 +646,7 @@ static struct synth_field *parse_synth_field(int argc, const char **argv, size = synth_field_size(field->type); if (size < 0) { + synth_err(SYNTH_ERR_INVALID_TYPE, errpos(field_type)); ret = -EINVAL; goto free; } else if (size == 0) { @@ -621,6 +667,7 @@ static struct synth_field *parse_synth_field(int argc, const char **argv, field->is_dynamic = true; size = sizeof(u64); } else { + synth_err(SYNTH_ERR_INVALID_TYPE, errpos(field_type)); ret = -EINVAL; goto free; } @@ -1098,12 +1145,47 @@ 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) { struct synth_field *field, *fields[SYNTH_FIELDS_MAX]; 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: * - Add synthetic event: <event_name> field[;field] ... @@ -1111,18 +1193,22 @@ 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' || argc < 1) { + 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; } event = find_synth_event(name); if (event) { + synth_err(SYNTH_ERR_EVENT_EXISTS, errpos(name)); ret = -EEXIST; goto out; } @@ -1131,6 +1217,7 @@ static int __create_synth_event(int argc, const char *name, const char **argv) if (strcmp(argv[i], ";") == 0) continue; if (n_fields == SYNTH_FIELDS_MAX) { + synth_err(SYNTH_ERR_TOO_MANY_FIELDS, 0); ret = -EINVAL; goto err; } @@ -1145,6 +1232,7 @@ static int __create_synth_event(int argc, const char *name, const char **argv) } if (i < argc && strcmp(argv[i], ";") != 0) { + synth_err(SYNTH_ERR_INVALID_FIELD, errpos(argv[i])); ret = -EINVAL; goto err; } -- 2.28.0
