tracing: Use tracing error_log with trace event filters

Use tracing_log_err() from the new tracing error_log mechanism to send
filter parse errors to tracing/error_log.

With this change, users will be able to see filter errors by looking
at tracing/error_log.

The same errors will also be available in the filter file, as
expected.

Link: http://lkml.kernel.org/r/1d942c419941539a11d78a6810fc5740a99b2974.1554072478.git.tom.zanussi@linux.intel.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 05a6649..290d42c 100644 (file)
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -66,7 +66,8 @@ static const char * ops[] = { OPS };
        C(INVALID_FILTER,       "Meaningless filter expression"),       \
        C(IP_FIELD_ONLY,        "Only 'ip' field is supported for function trace"), \
        C(INVALID_VALUE,        "Invalid value (did you forget quotes)?"), \
-       C(NO_FILTER,            "No filter found"),
+       C(ERRNO,                "Error"),                               \
+       C(NO_FILTER,            "No filter found")
 
 #undef C
 #define C(a, b)                FILT_ERR_##a
@@ -76,7 +77,7 @@ enum { ERRORS };
 #undef C
 #define C(a, b)                b
 
-static char *err_text[] = { ERRORS };
+static const char *err_text[] = { ERRORS };
 
 /* Called after a '!' character but "!=" and "!~" are not "not"s */
 static bool is_not(const char *str)
@@ -947,8 +948,14 @@ static void append_filter_err(struct filter_parse_error *pe,
        if (pe->lasterr > 0) {
                trace_seq_printf(s, "\n%*s", pos, "^");
                trace_seq_printf(s, "\nparse_error: %s\n", err_text[pe->lasterr]);
+               tracing_log_err("event filter parse error",
+                               filter->filter_string, err_text,
+                               pe->lasterr, pe->lasterr_pos);
        } else {
                trace_seq_printf(s, "\nError: (%d)\n", pe->lasterr);
+               tracing_log_err("event filter parse error",
+                               filter->filter_string, err_text,
+                               FILT_ERR_ERRNO, 0);
        }
        trace_seq_putc(s, 0);
        buf = kmemdup_nul(s->buffer, s->seq.len, GFP_KERNEL);