[for-next][PATCH 5/9] ftrace: Introduce ftrace_glob structure

From: Steven Rostedt
Date: Wed Oct 21 2015 - 09:38:03 EST


From: Dmitry Safonov <0x7f454c46@xxxxxxxxx>

ftrace_match parameters are very related and I reduce the number of local
variables & parameters with it.
This is also preparation for module globbing as it would introduce more
realated variables & parameters.

Link: http://lkml.kernel.org/r/1443545176-3215-3-git-send-email-0x7f454c46@xxxxxxxxx

Signed-off-by: Dmitry Safonov <0x7f454c46@xxxxxxxxx>
[ Made some formatting changes ]
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
kernel/trace/ftrace.c | 84 ++++++++++++++++++++++++++++-----------------------
1 file changed, 46 insertions(+), 38 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index fc755a49704f..450a5f5676ae 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3425,27 +3425,35 @@ ftrace_notrace_open(struct inode *inode, struct file *file)
inode, file);
}

-static int ftrace_match(char *str, char *regex, int len, int type)
+/* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
+struct ftrace_glob {
+ char *search;
+ unsigned len;
+ int type;
+};
+
+static int ftrace_match(char *str, struct ftrace_glob *g)
{
int matched = 0;
int slen;

- switch (type) {
+ switch (g->type) {
case MATCH_FULL:
- if (strcmp(str, regex) == 0)
+ if (strcmp(str, g->search) == 0)
matched = 1;
break;
case MATCH_FRONT_ONLY:
- if (strncmp(str, regex, len) == 0)
+ if (strncmp(str, g->search, g->len) == 0)
matched = 1;
break;
case MATCH_MIDDLE_ONLY:
- if (strstr(str, regex))
+ if (strstr(str, g->search))
matched = 1;
break;
case MATCH_END_ONLY:
slen = strlen(str);
- if (slen >= len && memcmp(str + slen - len, regex, len) == 0)
+ if (slen >= g->len &&
+ memcmp(str + slen - g->len, g->search, g->len) == 0)
matched = 1;
break;
}
@@ -3477,8 +3485,8 @@ enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter)
}

static int
-ftrace_match_record(struct dyn_ftrace *rec, char *mod,
- char *regex, int len, int type)
+ftrace_match_record(struct dyn_ftrace *rec,
+ char *mod, struct ftrace_glob *func_g)
{
char str[KSYM_SYMBOL_LEN];
char *modname;
@@ -3491,28 +3499,27 @@ ftrace_match_record(struct dyn_ftrace *rec, char *mod,
return 0;

/* blank search means to match all funcs in the mod */
- if (!len)
+ if (!func_g->len)
return 1;
}

- return ftrace_match(str, regex, len, type);
+ return ftrace_match(str, func_g);
}

static int
-match_records(struct ftrace_hash *hash, char *buff, int len, char *mod)
+match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
{
- unsigned search_len = 0;
struct ftrace_page *pg;
struct dyn_ftrace *rec;
- int type = MATCH_FULL;
- char *search = buff;
+ struct ftrace_glob func_g = { .type = MATCH_FULL };
int found = 0;
int ret;
int clear_filter;

if (len) {
- type = filter_parse_regex(buff, len, &search, &clear_filter);
- search_len = strlen(search);
+ func_g.type = filter_parse_regex(func, len, &func_g.search,
+ &clear_filter);
+ func_g.len = strlen(func_g.search);
}

mutex_lock(&ftrace_lock);
@@ -3521,7 +3528,7 @@ match_records(struct ftrace_hash *hash, char *buff, int len, char *mod)
goto out_unlock;

do_for_each_ftrace_rec(pg, rec) {
- if (ftrace_match_record(rec, mod, search, search_len, type)) {
+ if (ftrace_match_record(rec, mod, &func_g)) {
ret = enter_record(hash, rec, clear_filter);
if (ret < 0) {
found = ret;
@@ -3682,19 +3689,20 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
{
struct ftrace_ops_hash old_hash_ops;
struct ftrace_func_probe *entry;
+ struct ftrace_glob func_g;
struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash;
struct ftrace_hash *old_hash = *orig_hash;
struct ftrace_hash *hash;
struct ftrace_page *pg;
struct dyn_ftrace *rec;
- int type, len, not;
+ int not;
unsigned long key;
int count = 0;
- char *search;
int ret;

- type = filter_parse_regex(glob, strlen(glob), &search, &not);
- len = strlen(search);
+ func_g.type = filter_parse_regex(glob, strlen(glob),
+ &func_g.search, &not);
+ func_g.len = strlen(func_g.search);

/* we do not support '!' for function probes */
if (WARN_ON(not))
@@ -3721,7 +3729,7 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,

do_for_each_ftrace_rec(pg, rec) {

- if (!ftrace_match_record(rec, NULL, search, len, type))
+ if (!ftrace_match_record(rec, NULL, &func_g))
continue;

entry = kmalloc(sizeof(*entry), GFP_KERNEL);
@@ -3794,24 +3802,24 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
struct ftrace_func_entry *rec_entry;
struct ftrace_func_probe *entry;
struct ftrace_func_probe *p;
+ struct ftrace_glob func_g;
struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash;
struct ftrace_hash *old_hash = *orig_hash;
struct list_head free_list;
struct ftrace_hash *hash;
struct hlist_node *tmp;
char str[KSYM_SYMBOL_LEN];
- int type = MATCH_FULL;
- int i, len = 0;
- char *search;
- int ret;
+ int i, ret;

if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))
- glob = NULL;
+ func_g.search = NULL;
else if (glob) {
int not;

- type = filter_parse_regex(glob, strlen(glob), &search, &not);
- len = strlen(search);
+ func_g.type = filter_parse_regex(glob, strlen(glob),
+ &func_g.search, &not);
+ func_g.len = strlen(func_g.search);
+ func_g.search = glob;

/* we do not support '!' for function probes */
if (WARN_ON(not))
@@ -3840,10 +3848,10 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
continue;

/* do this last, since it is the most expensive */
- if (glob) {
+ if (func_g.search) {
kallsyms_lookup(entry->ip, NULL, NULL,
NULL, str);
- if (!ftrace_match(str, glob, len, type))
+ if (!ftrace_match(str, &func_g))
continue;
}

@@ -3872,7 +3880,7 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
ftrace_free_entry(entry);
}
mutex_unlock(&ftrace_lock);
-
+
out_unlock:
mutex_unlock(&trace_probe_ops.func_hash->regex_lock);
free_ftrace_hash(hash);
@@ -4588,21 +4596,21 @@ ftrace_graph_release(struct inode *inode, struct file *file)
static int
ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer)
{
+ struct ftrace_glob func_g;
struct dyn_ftrace *rec;
struct ftrace_page *pg;
- int search_len;
int fail = 1;
- int type, not;
- char *search;
+ int not;
bool exists;
int i;

/* decode regex */
- type = filter_parse_regex(buffer, strlen(buffer), &search, &not);
+ func_g.type = filter_parse_regex(buffer, strlen(buffer),
+ &func_g.search, &not);
if (!not && *idx >= size)
return -EBUSY;

- search_len = strlen(search);
+ func_g.len = strlen(func_g.search);

mutex_lock(&ftrace_lock);

@@ -4613,7 +4621,7 @@ ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer)

do_for_each_ftrace_rec(pg, rec) {

- if (ftrace_match_record(rec, NULL, search, search_len, type)) {
+ if (ftrace_match_record(rec, NULL, &func_g)) {
/* if it is in the array */
exists = false;
for (i = 0; i < *idx; i++) {
--
2.6.1


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