[PATCH 10/25] dynamic_debug: tighten up error checking on debug queries

From: jim . cromie
Date: Mon Dec 12 2011 - 18:13:32 EST


From: Jim Cromie <jim.cromie@xxxxxxxxx>

Issue error 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. Also error when last_line < 1st_line.

Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>
---
lib/dynamic_debug.c | 39 +++++++++++++++++++++++++++++++++------
1 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 6a170c3..f133e03 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -276,6 +276,19 @@ static char *unescape(char *str)
return str;
}

+static int check_set(const char **dest, char *src, char *name)
+{
+ int rc = 0;
+
+ if (*dest) {
+ rc = -EINVAL;
+ pr_err("match-spec:%s val:%s overridden by %s",
+ name, *dest, src);
+ }
+ *dest = src;
+ return rc;
+}
+
/*
* Parse words[] as a ddebug query specification, which is a series
* of (keyword, value) pairs chosen from these possibilities:
@@ -287,11 +300,15 @@ 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 of each type is allowed.
+ * Returns 0 on success, <0 on error.
*/
static int ddebug_parse_query(char *words[], int nwords,
struct ddebug_query *query)
{
unsigned int i;
+ int rc;

/* check we have an even number of words */
if (nwords % 2 != 0)
@@ -300,24 +317,32 @@ 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];
+ rc = check_set(&query->function, words[i+1], "func");
else if (!strcmp(words[i], "file"))
- query->filename = words[i+1];
+ rc = check_set(&query->filename, words[i+1], "file");
else if (!strcmp(words[i], "module"))
- query->module = words[i+1];
+ rc = check_set(&query->module, words[i+1], "module");
else if (!strcmp(words[i], "format"))
- query->format = unescape(words[i+1]);
+ rc = check_set(&query->format, unescape(words[i+1]),
+ "format");
else if (!strcmp(words[i], "line")) {
char *first = words[i+1];
char *last = strchr(first, '-');
+ if (query->first_lineno || query->last_lineno) {
+ pr_err("match-spec:line given 2 times\n");
+ return -EINVAL;
+ }
if (last)
*last++ = '\0';
if (parse_lineno(first, &query->first_lineno) < 0)
return -EINVAL;
- if (last != NULL) {
+ if (last) {
/* range <first>-<last> */
- if (parse_lineno(last, &query->last_lineno) < 0)
+ if (parse_lineno(last, &query->last_lineno)
+ < query->first_lineno) {
+ pr_err("last-line < 1st-line\n");
return -EINVAL;
+ }
} else {
query->last_lineno = query->first_lineno;
}
@@ -325,6 +350,8 @@ static int ddebug_parse_query(char *words[], int nwords,
pr_err("unknown keyword \"%s\"\n", words[i]);
return -EINVAL;
}
+ if (rc)
+ return rc;
}

if (verbose)
--
1.7.7.3

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