3.16-stable review patch. If anyone has any objections, please let me know.
------------------
From: "Steven Rostedt (Red Hat)" <rostedt@xxxxxxxxxxx>
commit 84261912ebee41269004e8a9f3614ba38ef6b206 upstream.
When updating what an ftrace_ops traces, if it is registered (that is,
actively tracing), and that ftrace_ops uses the shared global_ops
local_hash, then we need to update all tracers that are active and
also share the global_ops' ftrace_hash_ops.
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/trace/ftrace.c | 43 +++++++++++++++++++++++++++++++++++++++----
1 file changed, 39 insertions(+), 4 deletions(-)
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1298,9 +1298,9 @@ alloc_and_copy_ftrace_hash(int size_bits
}
static void
-ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash);
+ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash);
static void
-ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash);
+ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);
static int
ftrace_hash_move(struct ftrace_ops *ops, int enable,
@@ -1320,7 +1320,7 @@ ftrace_hash_move(struct ftrace_ops *ops,
* Remove the current set, update the hash and add
* them back.
*/
- ftrace_hash_rec_disable(ops, enable);
+ ftrace_hash_rec_disable_modify(ops, enable);
/*
* If the new source is empty, just free dst and assign it
@@ -1369,7 +1369,7 @@ ftrace_hash_move(struct ftrace_ops *ops,
* On success, we enable the new hash.
* On failure, we re-enable the original hash.
*/
- ftrace_hash_rec_enable(ops, enable);
+ ftrace_hash_rec_enable_modify(ops, enable);
return ret;
}
@@ -1613,6 +1613,41 @@ static void ftrace_hash_rec_enable(struc
__ftrace_hash_rec_update(ops, filter_hash, 1);
}
+static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops,
+ int filter_hash, int inc)
+{
+ struct ftrace_ops *op;
+
+ __ftrace_hash_rec_update(ops, filter_hash, inc);
+
+ if (ops->func_hash != &global_ops.local_hash)
+ return;
+
+ /*
+ * If the ops shares the global_ops hash, then we need to update
+ * all ops that are enabled and use this hash.
+ */
+ do_for_each_ftrace_op(op, ftrace_ops_list) {
+ /* Already done */
+ if (op == ops)
+ continue;
+ if (op->func_hash == &global_ops.local_hash)
+ __ftrace_hash_rec_update(op, filter_hash, inc);
+ } while_for_each_ftrace_op(op);
+}
+
+static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops,
+ int filter_hash)
+{
+ ftrace_hash_rec_update_modify(ops, filter_hash, 0);
+}
+
+static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops,
+ int filter_hash)
+{
+ ftrace_hash_rec_update_modify(ops, filter_hash, 1);
+}
+
static void print_ip_ins(const char *fmt, unsigned char *p)
{
int i;
--
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