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>

1 files changed, 69 insertions, 82 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 04c002a491fb..222eca4c3022 100644
--- 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