[PATCH 08/25] dynamic_debug: warn when >1 of each type of match-spec is given

Jim Cromie
2011-07-25T21:43:39Z

Issue warning when a match-spec is given multiple times in a rule.
Previous code kept last one, but was silent about it. Docs imply only
one is allowed by saying match-specs are ANDed together, given that
module M cannot match both A and B.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
lib/dynamic_debug.c | 20 ++++++++++++++++----
1 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 8ce941a..6746439 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -280,6 +280,14 @@ static char *unescape(char *str)
return str;
}

+static inline void check_set(const char **dest, char *src, char *name)
+{
+ if (*dest)
+ pr_warn("match-spec:%s val:%s overridden by %s",
+ name, *dest, src);
+ *dest = src;
+}
+
/*
* Parse words[] as a ddebug query specification, which is a series
* of (keyword, value) pairs chosen from these possibilities:
@@ -291,6 +299,9 @@ static char *unescape(char *str)
* format <escaped-string-to-find-in-format>
* line <lineno>
* line <first-lineno>-<last-lineno> // where either may be empty
+ *
+ * only 1 pair of each type is expected, subsequent ones elicit a
+ * warning, and override the setting.
*/
static int ddebug_parse_query(char *words[], int nwords,
struct ddebug_query *query)
@@ -304,13 +315,14 @@ static int ddebug_parse_query(char *words[], int nwords,

for (i = 0 ; i < nwords ; i += 2) {
if (!strcmp(words[i], "func"))
- query->function = words[i+1];
+ check_set(&query->function, words[i+1], "func");
else if (!strcmp(words[i], "file"))
- query->filename = words[i+1];
+ check_set(&query->filename, words[i+1], "file");
else if (!strcmp(words[i], "module"))
- query->module = words[i+1];
+ check_set(&query->module, words[i+1], "module");
else if (!strcmp(words[i], "format"))
- query->format = unescape(words[i+1]);
+ check_set(&query->format, unescape(words[i+1]),
+ "format");
else if (!strcmp(words[i], "line")) {
char *first = words[i+1];
char *last = strchr(first, '-');
--
1.7.4.1