[PATCH 04/15] ftrace: break up ftrace_match_records into smaller components

Steven Rostedt
2009-02-17T05:19:12Z

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From: Steven Rostedt <srostedt@redhat.com>

Impact: clean up

ftrace_match_records does a lot of things that other features
can use. This patch breaks up ftrace_match_records and pulls
out ftrace_setup_glob and ftrace_match_record.

ftrace_setup_glob prepares a simple glob expression for use with
ftrace_match_record. ftrace_match_record compares a single record
with a glob type.

Breaking this up will allow for more features to run on individual
records.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
---
kernel/trace/ftrace.c | 115 ++++++++++++++++++++++++++++++++-----------------
1 files changed, 75 insertions(+), 40 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index f397d7a..fcec313 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1053,79 +1053,114 @@ enum {
MATCH_END_ONLY,
};

-static void
-ftrace_match_records(unsigned char *buff, int len, int enable)
+/*
+ * (static function - no need for kernel doc)
+ *
+ * Pass in a buffer containing a glob and this function will
+ * set search to point to the search part of the buffer and
+ * return the type of search it is (see enum above).
+ * This does modify buff.
+ *
+ * Returns enum type.
+ * search returns the pointer to use for comparison.
+ * not returns 1 if buff started with a '!'
+ * 0 otherwise.
+ */
+static int
+ftrace_setup_glob(unsigned char *buff, int len, char **search, int *not)
{
- char str[KSYM_SYMBOL_LEN];
- char *search = NULL;
- struct ftrace_page *pg;
- struct dyn_ftrace *rec;
int type = MATCH_FULL;
- unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
- unsigned i, match = 0, search_len = 0;
- int not = 0;
+ int i;

if (buff[0] == '!') {
- not = 1;
+ *not = 1;
buff++;
len--;
- }
+ } else
+ *not = 0;
+
+ *search = buff;

for (i = 0; i < len; i++) {
if (buff[i] == '*') {
if (!i) {
- search = buff + i + 1;
+ *search = buff + 1;
type = MATCH_END_ONLY;
- search_len = len - (i + 1);
} else {
- if (type == MATCH_END_ONLY) {
+ if (type == MATCH_END_ONLY)
type = MATCH_MIDDLE_ONLY;
- } else {
- match = i;
+ else
type = MATCH_FRONT_ONLY;
- }
buff[i] = 0;
break;
}
}
}

+ return type;
+}
+
+static int
+ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type)
+{
+ char str[KSYM_SYMBOL_LEN];
+ int matched = 0;
+ char *ptr;
+
+ kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
+ switch (type) {
+ case MATCH_FULL:
+ if (strcmp(str, regex) == 0)
+ matched = 1;
+ break;
+ case MATCH_FRONT_ONLY:
+ if (strncmp(str, regex, len) == 0)
+ matched = 1;
+ break;
+ case MATCH_MIDDLE_ONLY:
+ if (strstr(str, regex))
+ matched = 1;
+ break;
+ case MATCH_END_ONLY:
+ ptr = strstr(str, regex);
+ if (ptr && (ptr[len] == 0))
+ matched = 1;
+ break;
+ }
+
+ return matched;
+}
+
+static void ftrace_match_records(char *buff, int len, int enable)
+{
+ char *search;
+ struct ftrace_page *pg;
+ struct dyn_ftrace *rec;
+ int type;
+ unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
+ unsigned search_len;
+ int not;
+
+ type = ftrace_setup_glob(buff, len, &search, &not);
+
+ search_len = strlen(search);
+
/* should not be called from interrupt context */
spin_lock(&ftrace_lock);
if (enable)
ftrace_filtered = 1;
do_for_each_ftrace_rec(pg, rec) {
- int matched = 0;
- char *ptr;

if (rec->flags & FTRACE_FL_FAILED)
continue;
- kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
- switch (type) {
- case MATCH_FULL:
- if (strcmp(str, buff) == 0)
- matched = 1;
- break;
- case MATCH_FRONT_ONLY:
- if (memcmp(str, buff, match) == 0)
- matched = 1;
- break;
- case MATCH_MIDDLE_ONLY:
- if (strstr(str, search))
- matched = 1;
- break;
- case MATCH_END_ONLY:
- ptr = strstr(str, search);
- if (ptr && (ptr[search_len] == 0))
- matched = 1;
- break;
- }
- if (matched) {
+
+ if (ftrace_match_record(rec, search, search_len, type)) {
if (not)
rec->flags &= ~flag;
else
rec->flags |= flag;
}
+
} while_for_each_ftrace_rec();
spin_unlock(&ftrace_lock);
}
--
1.5.6.5

--