ftrace: Use hash instead for FTRACE_FL_FILTER

When multiple users are allowed to have their own set of functions
to trace, having the FTRACE_FL_FILTER flag will not be enough to
handle the accounting of those users. Each user will need their own
set of functions.

Replace the FTRACE_FL_FILTER with a filter_hash instead. This is
temporary until the rest of the function filtering accounting
gets in.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index fe0a90a..52fc5d4 100644 (file)
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -147,8 +147,7 @@ extern int ftrace_text_reserved(void *start, void *end);
 
 enum {
        FTRACE_FL_FREE          = (1 << 0),
-       FTRACE_FL_FILTER        = (1 << 1),
-       FTRACE_FL_ENABLED       = (1 << 2),
+       FTRACE_FL_ENABLED       = (1 << 1),
 };
 
 struct dyn_ftrace {

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 04c002a..222eca4 100644 (file)
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -883,7 +883,11 @@ static struct ftrace_hash notrace_hash = {
        .buckets = notrace_buckets,
 };
 
-static int ftrace_filtered;
+static struct hlist_head filter_buckets[1 << FTRACE_HASH_MAX_BITS];
+static struct ftrace_hash filter_hash = {
+       .size_bits = FTRACE_HASH_MAX_BITS,
+       .buckets = filter_buckets,
+};
 
 static struct dyn_ftrace *ftrace_new_addrs;
 
@@ -1123,7 +1127,7 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
         * it's filtered
         */
        if (enable && !ftrace_lookup_ip(&notrace_hash, rec->ip)) {
-               if (!ftrace_filtered || (rec->flags & FTRACE_FL_FILTER))
+               if (!filter_hash.count || ftrace_lookup_ip(&filter_hash, rec->ip))
                        flag = FTRACE_FL_ENABLED;
        }
 
@@ -1430,6 +1434,7 @@ struct ftrace_iterator {
        struct dyn_ftrace               *func;
        struct ftrace_func_probe        *probe;
        struct trace_parser             parser;
+       struct ftrace_hash              *hash;
        int                             hidx;
        int                             idx;
        unsigned                        flags;
@@ -1552,7 +1557,7 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
                if ((rec->flags & FTRACE_FL_FREE) ||
 
                    ((iter->flags & FTRACE_ITER_FILTER) &&
-                    !(rec->flags & FTRACE_FL_FILTER)) ||
+                    !(ftrace_lookup_ip(&filter_hash, rec->ip))) ||
 
                    ((iter->flags & FTRACE_ITER_NOTRACE) &&
                     !ftrace_lookup_ip(&notrace_hash, rec->ip))) {
@@ -1598,7 +1603,7 @@ static void *t_start(struct seq_file *m, loff_t *pos)
         * off, we can short cut and just print out that all
         * functions are enabled.
         */
-       if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) {
+       if (iter->flags & FTRACE_ITER_FILTER && !filter_hash.count) {
                if (*pos > 0)
                        return t_hash_start(m, pos);
                iter->flags |= FTRACE_ITER_PRINTALL;
@@ -1695,24 +1700,16 @@ ftrace_avail_open(struct inode *inode, struct file *file)
        return ret;
 }
 
-static void ftrace_filter_reset(int enable)
+static void ftrace_filter_reset(struct ftrace_hash *hash)
 {
-       struct ftrace_page *pg;
-       struct dyn_ftrace *rec;
-
        mutex_lock(&ftrace_lock);
-       if (enable) {
-               ftrace_filtered = 0;
-               do_for_each_ftrace_rec(pg, rec) {
-                       rec->flags &= ~FTRACE_FL_FILTER;
-               } while_for_each_ftrace_rec();
-       } else
-               ftrace_hash_clear(&notrace_hash);
+       ftrace_hash_clear(hash);
        mutex_unlock(&ftrace_lock);
 }
 
 static int
-ftrace_regex_open(struct inode *inode, struct file *file, int enable)
+ftrace_regex_open(struct ftrace_hash *hash, int flag,
+                 struct inode *inode, struct file *file)
 {
        struct ftrace_iterator *iter;
        int ret = 0;
@@ -1729,15 +1726,16 @@ ftrace_regex_open(struct inode *inode, struct file *file, int enable)
                return -ENOMEM;
        }
 
+       iter->hash = hash;
+
        mutex_lock(&ftrace_regex_lock);
        if ((file->f_mode & FMODE_WRITE) &&
            (file->f_flags & O_TRUNC))
-               ftrace_filter_reset(enable);
+               ftrace_filter_reset(hash);
 
        if (file->f_mode & FMODE_READ) {
                iter->pg = ftrace_pages_start;
-               iter->flags = enable ? FTRACE_ITER_FILTER :
-                       FTRACE_ITER_NOTRACE;
+               iter->flags = flag;
 
                ret = seq_open(file, &show_ftrace_seq_ops);
                if (!ret) {
@@ -1757,13 +1755,15 @@ ftrace_regex_open(struct inode *inode, struct file *file, int enable)
 static int
 ftrace_filter_open(struct inode *inode, struct file *file)
 {
-       return ftrace_regex_open(inode, file, 1);
+       return ftrace_regex_open(&filter_hash, FTRACE_ITER_FILTER,
+                                inode, file);
 }
 
 static int
 ftrace_notrace_open(struct inode *inode, struct file *file)
 {
-       return ftrace_regex_open(inode, file, 0);
+       return ftrace_regex_open(&notrace_hash, FTRACE_ITER_NOTRACE,
+                                inode, file);
 }
 
 static loff_t
@@ -1808,33 +1808,24 @@ static int ftrace_match(char *str, char *regex, int len, int type)
 }
 
 static int
-update_record(struct dyn_ftrace *rec, int enable, int not)
+enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not)
 {
        struct ftrace_func_entry *entry;
-       struct ftrace_hash *hash = &notrace_hash;
        int ret = 0;
 
-       if (enable) {
-               if (not)
-                       rec->flags &= ~FTRACE_FL_FILTER;
-               else
-                       rec->flags |= FTRACE_FL_FILTER;
-       } else {
-               if (not) {
-                       /* Do nothing if it doesn't exist */
-                       entry = ftrace_lookup_ip(hash, rec->ip);
-                       if (!entry)
-                               return 0;
+       entry = ftrace_lookup_ip(hash, rec->ip);
+       if (not) {
+               /* Do nothing if it doesn't exist */
+               if (!entry)
+                       return 0;
 
-                       remove_hash_entry(hash, entry);
-               } else {
-                       /* Do nothing if it exists */
-                       entry = ftrace_lookup_ip(hash, rec->ip);
-                       if (entry)
-                               return 0;
+               remove_hash_entry(hash, entry);
+       } else {
+               /* Do nothing if it exists */
+               if (entry)
+                       return 0;
 
-                       ret = add_hash_entry(hash, rec->ip);
-               }
+               ret = add_hash_entry(hash, rec->ip);
        }
        return ret;
 }
@@ -1861,7 +1852,9 @@ ftrace_match_record(struct dyn_ftrace *rec, char *mod,
        return ftrace_match(str, regex, len, type);
 }
 
-static int match_records(char *buff, int len, char *mod, int enable, int not)
+static int
+match_records(struct ftrace_hash *hash, char *buff,
+             int len, char *mod, int not)
 {
        unsigned search_len = 0;
        struct ftrace_page *pg;
@@ -1884,20 +1877,13 @@ static int match_records(char *buff, int len, char *mod, int enable, int not)
        do_for_each_ftrace_rec(pg, rec) {
 
                if (ftrace_match_record(rec, mod, search, search_len, type)) {
-                       ret = update_record(rec, enable, not);
+                       ret = enter_record(hash, rec, not);
                        if (ret < 0) {
                                found = ret;
                                goto out_unlock;
                        }
                        found = 1;
                }
-               /*
-                * Only enable filtering if we have a function that
-                * is filtered on.
-                */
-               if (enable && (rec->flags & FTRACE_FL_FILTER))
-                       ftrace_filtered = 1;
-
        } while_for_each_ftrace_rec();
  out_unlock:
        mutex_unlock(&ftrace_lock);
@@ -1906,12 +1892,13 @@ static int match_records(char *buff, int len, char *mod, int enable, int not)
 }
 
 static int
-ftrace_match_records(char *buff, int len, int enable)
+ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
 {
-       return match_records(buff, len, NULL, enable, 0);
+       return match_records(hash, buff, len, NULL, 0);
 }
 
-static int ftrace_match_module_records(char *buff, char *mod, int enable)
+static int
+ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod)
 {
        int not = 0;
 
@@ -1925,7 +1912,7 @@ static int ftrace_match_module_records(char *buff, char *mod, int enable)
                not = 1;
        }
 
-       return match_records(buff, strlen(buff), mod, enable, not);
+       return match_records(hash, buff, strlen(buff), mod, not);
 }
 
 /*
@@ -1936,6 +1923,7 @@ static int ftrace_match_module_records(char *buff, char *mod, int enable)
 static int
 ftrace_mod_callback(char *func, char *cmd, char *param, int enable)
 {
+       struct ftrace_hash *hash;
        char *mod;
        int ret = -EINVAL;
 
@@ -1955,7 +1943,12 @@ ftrace_mod_callback(char *func, char *cmd, char *param, int enable)
        if (!strlen(mod))
                return ret;
 
-       ret = ftrace_match_module_records(func, mod, enable);
+       if (enable)
+               hash = &filter_hash;
+       else
+               hash = &notrace_hash;
+
+       ret = ftrace_match_module_records(hash, func, mod);
        if (!ret)
                ret = -EINVAL;
        if (ret < 0)
@@ -2253,12 +2246,18 @@ static int ftrace_process_regex(char *buff, int len, int enable)
 {
        char *func, *command, *next = buff;
        struct ftrace_func_command *p;
+       struct ftrace_hash *hash;
        int ret;
 
+       if (enable)
+               hash = &filter_hash;
+       else
+               hash = &notrace_hash;
+
        func = strsep(&next, ":");
 
        if (!next) {
-               ret = ftrace_match_records(func, len, enable);
+               ret = ftrace_match_records(hash, func, len);
                if (!ret)
                        ret = -EINVAL;
                if (ret < 0)
@@ -2340,16 +2339,16 @@ ftrace_notrace_write(struct file *file, const char __user *ubuf,
 }
 
 static void
-ftrace_set_regex(unsigned char *buf, int len, int reset, int enable)
+ftrace_set_regex(struct ftrace_hash *hash, unsigned char *buf, int len, int reset)
 {
        if (unlikely(ftrace_disabled))
                return;
 
        mutex_lock(&ftrace_regex_lock);
        if (reset)
-               ftrace_filter_reset(enable);
+               ftrace_filter_reset(hash);
        if (buf)
-               ftrace_match_records(buf, len, enable);
+               ftrace_match_records(hash, buf, len);
        mutex_unlock(&ftrace_regex_lock);
 }
 
@@ -2364,7 +2363,7 @@ ftrace_set_regex(unsigned char *buf, int len, int reset, int enable)
  */
 void ftrace_set_filter(unsigned char *buf, int len, int reset)
 {
-       ftrace_set_regex(buf, len, reset, 1);
+       ftrace_set_regex(&filter_hash, buf, len, reset);
 }
 
 /**
@@ -2379,7 +2378,7 @@ void ftrace_set_filter(unsigned char *buf, int len, int reset)
  */
 void ftrace_set_notrace(unsigned char *buf, int len, int reset)
 {
-       ftrace_set_regex(buf, len, reset, 0);
+       ftrace_set_regex(&notrace_hash, buf, len, reset);
 }
 
 /*
@@ -2431,22 +2430,22 @@ static void __init set_ftrace_early_graph(char *buf)
 }
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 
-static void __init set_ftrace_early_filter(char *buf, int enable)
+static void __init set_ftrace_early_filter(struct ftrace_hash *hash, char *buf)
 {
        char *func;
 
        while (buf) {
                func = strsep(&buf, ",");
-               ftrace_set_regex(func, strlen(func), 0, enable);
+               ftrace_set_regex(hash, func, strlen(func), 0);
        }
 }
 
 static void __init set_ftrace_early_filters(void)
 {
        if (ftrace_filter_buf[0])
-               set_ftrace_early_filter(ftrace_filter_buf, 1);
+               set_ftrace_early_filter(&filter_hash, ftrace_filter_buf);
        if (ftrace_notrace_buf[0])
-               set_ftrace_early_filter(ftrace_notrace_buf, 0);
+               set_ftrace_early_filter(&notrace_hash, ftrace_notrace_buf);
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
        if (ftrace_graph_buf[0])
                set_ftrace_early_graph(ftrace_graph_buf);
@@ -2454,7 +2453,7 @@ static void __init set_ftrace_early_filters(void)
 }
 
 static int
-ftrace_regex_release(struct inode *inode, struct file *file, int enable)
+ftrace_regex_release(struct inode *inode, struct file *file)
 {
        struct seq_file *m = (struct seq_file *)file->private_data;
        struct ftrace_iterator *iter;
@@ -2471,7 +2470,7 @@ ftrace_regex_release(struct inode *inode, struct file *file, int enable)
        parser = &iter->parser;
        if (trace_parser_loaded(parser)) {
                parser->buffer[parser->idx] = 0;
-               ftrace_match_records(parser->buffer, parser->idx, enable);
+               ftrace_match_records(iter->hash, parser->buffer, parser->idx);
        }
 
        trace_parser_put(parser);
@@ -2488,18 +2487,6 @@ ftrace_regex_release(struct inode *inode, struct file *file, int enable)
        return 0;
 }
 
-static int
-ftrace_filter_release(struct inode *inode, struct file *file)
-{
-       return ftrace_regex_release(inode, file, 1);
-}
-
-static int
-ftrace_notrace_release(struct inode *inode, struct file *file)
-{
-       return ftrace_regex_release(inode, file, 0);
-}
-
 static const struct file_operations ftrace_avail_fops = {
        .open = ftrace_avail_open,
        .read = seq_read,
@@ -2512,7 +2499,7 @@ static const struct file_operations ftrace_filter_fops = {
        .read = seq_read,
        .write = ftrace_filter_write,
        .llseek = ftrace_regex_lseek,
-       .release = ftrace_filter_release,
+       .release = ftrace_regex_release,
 };
 
 static const struct file_operations ftrace_notrace_fops = {
@@ -2520,7 +2507,7 @@ static const struct file_operations ftrace_notrace_fops = {
        .read = seq_read,
        .write = ftrace_notrace_write,
        .llseek = ftrace_regex_lseek,
-       .release = ftrace_notrace_release,
+       .release = ftrace_regex_release,
 };
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER