ftrace: Separate out functionality from ftrace_location_range()

Create a new function called lookup_rec() from the functionality of
ftrace_location_range(). The difference between lookup_rec() is that it
returns the record that it finds, where as ftrace_location_range() returns
only if it found a match or not.

The lookup_rec() is static, and can be used for new functionality where
ftrace needs to find a record of a specific address.

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

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 76e5de8c78220baac622a7d213779bb57fd86515..b0e7f03919de9f42d6485b10780b625d525ec796 100644 (file)
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1541,6 +1541,26 @@ static int ftrace_cmp_recs(const void *a, const void *b)
        return 0;
 }
 
+static struct dyn_ftrace *lookup_rec(unsigned long start, unsigned long end)
+{
+       struct ftrace_page *pg;
+       struct dyn_ftrace *rec = NULL;
+       struct dyn_ftrace key;
+
+       key.ip = start;
+       key.flags = end;        /* overload flags, as it is unsigned long */
+
+       for (pg = ftrace_pages_start; pg; pg = pg->next) {
+               if (end < pg->records[0].ip ||
+                   start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
+                       continue;
+               rec = bsearch(&key, pg->records, pg->index,
+                             sizeof(struct dyn_ftrace),
+                             ftrace_cmp_recs);
+       }
+       return rec;
+}
+
 /**
  * ftrace_location_range - return the first address of a traced location
  *     if it touches the given ip range
@@ -1555,23 +1575,11 @@ static int ftrace_cmp_recs(const void *a, const void *b)
  */
 unsigned long ftrace_location_range(unsigned long start, unsigned long end)
 {
-       struct ftrace_page *pg;
        struct dyn_ftrace *rec;
-       struct dyn_ftrace key;
 
-       key.ip = start;
-       key.flags = end;        /* overload flags, as it is unsigned long */
-
-       for (pg = ftrace_pages_start; pg; pg = pg->next) {
-               if (end < pg->records[0].ip ||
-                   start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
-                       continue;
-               rec = bsearch(&key, pg->records, pg->index,
-                             sizeof(struct dyn_ftrace),
-                             ftrace_cmp_recs);
-               if (rec)
-                       return rec->ip;
-       }
+       rec = lookup_rec(start, end);
+       if (rec)
+               return rec->ip;
 
        return 0;
 }