[for-next][PATCH 04/33] ftrace: Separate out the copying of a ftrace_hash from __ftrace_hash_move()

From: Steven Rostedt
Date: Thu Nov 14 2019 - 13:19:33 EST


From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>

Most of the functionality of __ftrace_hash_move() can be reused, but not all
of it. That is, __ftrace_hash_move() is used to simply make a new hash from
an existing one, using the same size as the original. Creating a dup_hash(),
where we can specify a new size will be useful when we want to create a hash
with a default size, or simply copy the old one.

Signed-off-by: Steven Rostedt (VMWare) <rostedt@xxxxxxxxxxx>
---
kernel/trace/ftrace.c | 29 +++++++++++++++++------------
1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 89e9128652ef..76e5de8c7822 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1372,23 +1372,15 @@ ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);
static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
struct ftrace_hash *new_hash);

-static struct ftrace_hash *
-__ftrace_hash_move(struct ftrace_hash *src)
+static struct ftrace_hash *dup_hash(struct ftrace_hash *src, int size)
{
struct ftrace_func_entry *entry;
- struct hlist_node *tn;
- struct hlist_head *hhd;
struct ftrace_hash *new_hash;
- int size = src->count;
+ struct hlist_head *hhd;
+ struct hlist_node *tn;
int bits = 0;
int i;

- /*
- * If the new source is empty, just return the empty_hash.
- */
- if (ftrace_hash_empty(src))
- return EMPTY_HASH;
-
/*
* Make the hash size about 1/2 the # found
*/
@@ -1413,10 +1405,23 @@ __ftrace_hash_move(struct ftrace_hash *src)
__add_hash_entry(new_hash, entry);
}
}
-
return new_hash;
}

+static struct ftrace_hash *
+__ftrace_hash_move(struct ftrace_hash *src)
+{
+ int size = src->count;
+
+ /*
+ * If the new source is empty, just return the empty_hash.
+ */
+ if (ftrace_hash_empty(src))
+ return EMPTY_HASH;
+
+ return dup_hash(src, size);
+}
+
static int
ftrace_hash_move(struct ftrace_ops *ops, int enable,
struct ftrace_hash **dst, struct ftrace_hash *src)
--
2.23.0