tracing: Add hist trigger error messages for sort specification

Add error codes and messages for all the error paths leading to sort
specification parsing errors.

Link: http://lkml.kernel.org/r/237830dc05e583fbb53664d817a784297bf961be.1561743018.git.zanussi@kernel.org
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index bf2bcb8d7725eb4ccab66948bf167899e3bac3ef..23458ba9e5f52a8df4fd0c880cd202ceba1a48a0 100644 (file)
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -66,7 +66,12 @@
        C(INVALID_SUBSYS_EVENT, "Invalid subsystem or event name"),     \
        C(INVALID_REF_KEY,      "Using variable references in keys not supported"), \
        C(VAR_NOT_FOUND,        "Couldn't find variable"),              \
-       C(FIELD_NOT_FOUND,      "Couldn't find field"),
+       C(FIELD_NOT_FOUND,      "Couldn't find field"),                 \
+       C(EMPTY_ASSIGNMENT,     "Empty assignment"),                    \
+       C(INVALID_SORT_MODIFIER,"Invalid sort modifier"),               \
+       C(EMPTY_SORT_FIELD,     "Empty sort field"),                    \
+       C(TOO_MANY_SORT_FIELDS, "Too many sort fields (Max = 2)"),      \
+       C(INVALID_SORT_FIELD,   "Sort field must be a key or a val"),
 
 #undef C
 #define C(a, b)                HIST_ERR_##a
@@ -2183,6 +2188,7 @@ parse_hist_trigger_attrs(struct trace_array *tr, char *trigger_str)
                if (rhs) {
                        if (!strlen(++rhs)) {
                                ret = -EINVAL;
+                               hist_err(tr, HIST_ERR_EMPTY_ASSIGNMENT, errpos(str));
                                goto free;
                        }
                        ret = parse_assignment(tr, str, attrs);
@@ -4743,7 +4749,7 @@ static int create_hist_fields(struct hist_trigger_data *hist_data,
        return ret;
 }
 
-static int is_descending(const char *str)
+static int is_descending(struct trace_array *tr, const char *str)
 {
        if (!str)
                return 0;
@@ -4754,11 +4760,14 @@ static int is_descending(const char *str)
        if (strcmp(str, "ascending") == 0)
                return 0;
 
+       hist_err(tr, HIST_ERR_INVALID_SORT_MODIFIER, errpos((char *)str));
+
        return -EINVAL;
 }
 
 static int create_sort_keys(struct hist_trigger_data *hist_data)
 {
+       struct trace_array *tr = hist_data->event_file->tr;
        char *fields_str = hist_data->attrs->sort_key_str;
        struct tracing_map_sort_key *sort_key;
        int descending, ret = 0;
@@ -4782,10 +4791,12 @@ static int create_sort_keys(struct hist_trigger_data *hist_data)
 
                if (!*field_str) {
                        ret = -EINVAL;
+                       hist_err(tr, HIST_ERR_EMPTY_SORT_FIELD, errpos("sort="));
                        break;
                }
 
                if ((i == TRACING_MAP_SORT_KEYS_MAX - 1) && fields_str) {
+                       hist_err(tr, HIST_ERR_TOO_MANY_SORT_FIELDS, errpos("sort="));
                        ret = -EINVAL;
                        break;
                }
@@ -4793,11 +4804,12 @@ static int create_sort_keys(struct hist_trigger_data *hist_data)
                field_name = strsep(&field_str, ".");
                if (!field_name || !*field_name) {
                        ret = -EINVAL;
+                       hist_err(tr, HIST_ERR_EMPTY_SORT_FIELD, errpos("sort="));
                        break;
                }
 
                if (strcmp(field_name, "hitcount") == 0) {
-                       descending = is_descending(field_str);
+                       descending = is_descending(tr, field_str);
                        if (descending < 0) {
                                ret = descending;
                                break;
@@ -4819,7 +4831,7 @@ static int create_sort_keys(struct hist_trigger_data *hist_data)
 
                        if (strcmp(field_name, test_name) == 0) {
                                sort_key->field_idx = idx;
-                               descending = is_descending(field_str);
+                               descending = is_descending(tr, field_str);
                                if (descending < 0) {
                                        ret = descending;
                                        goto out;
@@ -4830,6 +4842,7 @@ static int create_sort_keys(struct hist_trigger_data *hist_data)
                }
                if (j == hist_data->n_fields) {
                        ret = -EINVAL;
+                       hist_err(tr, HIST_ERR_INVALID_SORT_FIELD, errpos(field_name));
                        break;
                }
        }