Hi Masami,
On Sat, 2020-10-10 at 23:57 +0900, Masami Hiramatsu wrote:
> On Fri, 9 Oct 2020 10:17:10 -0500
> Tom Zanussi <zanu...@kernel.org> wrote:
>
> > 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.
>
> Thanks for fixing this. But it seems that the INVALID_TYPE error
> position is not correct.
>
> /sys/kernel/debug/tracing # echo "myevent chr arg" >>
> synthetic_events
> sh: write error: Invalid argument
> /sys/kernel/debug/tracing # cat error_log
> [ 1354.611660] synthetic_events: error: Invalid type
> Command: myevent chr arg
> ^
>
> If the type is invalid, it should point "chr" instead of "arg".
> If you add a syntax error testcase as same as kprobe_events, you can
> check the error position too.
>
Right, it's using name where it should be using type. Will fix in the
next version.
Thanks,
Tom
> Thank you,
>
> >
> > Signed-off-by: Tom Zanussi <zanu...@kernel.org>
> > ---
> > kernel/trace/trace_events_synth.c | 114
> > +++++++++++++++++++++++++++++-
> > 1 file changed, 112 insertions(+), 2 deletions(-)
> >
> > diff --git a/kernel/trace/trace_events_synth.c
> > b/kernel/trace/trace_events_synth.c
> > index 8c9d6e464da0..ce4cae5cfd47 100644
> > --- a/kernel/trace/trace_events_synth.c
> > +++ b/kernel/trace/trace_events_synth.c
> > @@ -20,6 +20,53 @@
> >
> > #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;
> > +
> > + strncat(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 void synth_err_clear(void)
> > +{
> > + last_cmd[0] = '\0';
> > +}
> > +
> > 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 +592,10 @@ 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 +622,7 @@ 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 +651,7 @@ 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->name));
> > ret = -EINVAL;
> > goto free;
> > } else if (size == 0) {
> > @@ -621,6 +672,7 @@ 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-
> > >name));
> > ret = -EINVAL;
> > goto free;
> > }
> > @@ -1098,12 +1150,64 @@ 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 cmdstr_append(char *buf, const char *str, int
> > *remaining)
> > +{
> > + int len = strlen(str);
> > +
> > + if (len + 1 >= *remaining) {
> > + synth_err(SYNTH_ERR_CMD_TOO_LONG, 0);
> > + return -EINVAL;
> > + }
> > +
> > + strcat(buf, str);
> > + strcat(buf, " ");
> > + *remaining -= len + 1;
> > +
> > + return 0;
> > +}
> > +
> > +static int save_cmdstr(int argc, const char *name, const char
> > **argv)
> > +{
> > + int i, ret, remaining = MAX_DYNEVENT_CMD_LEN;
> > + char *buf;
> > +
> > + synth_err_clear();
> > +
> > + buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL);
> > + if (!buf)
> > + return -ENOMEM;
> > +
> > + ret = cmdstr_append(buf, name, &remaining);
> > + if (ret) {
> > + kfree(buf);
> > + return ret;
> > + }
> > +
> > + for (i = 0; i < argc; i++) {
> > + ret = cmdstr_append(buf, argv[i], &remaining);
> > + if (ret) {
> > + kfree(buf);
> > + return ret;
> > + }
> > + }
> > +
> > + last_cmd_set(buf);
> > +
> > + kfree(buf);
> > +
> > + return ret;
> > +}
> > +
> > 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 +1215,22 @@ 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 +1239,7 @@ 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 +1254,7 @@ 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;
> > }
> > --
> > 2.17.1
> >
>
>
