[PATCH bpf-next 01/29] ftrace: Use direct_ops hash in unregister_ftrace_direct
From: Jiri Olsa <hidden>
Date: 2021-11-18 11:26:08
Also in:
bpf
Subsystem:
function hooks (ftrace), the rest, tracing · Maintainers:
Steven Rostedt, Masami Hiramatsu, Linus Torvalds
Now when we have *direct_multi interface the direct_functions
hash is no longer owned just by direct_ops. It's also used by
any other ftrace_ops passed to *direct_multi interface.
Thus to find out that we are unregistering the last function
from direct_ops, we need to check directly direct_ops's hash.
Cc: Steven Rostedt <redacted>
Fixes: f64dd4627ec6 ("ftrace: Add multi direct register/unregister interface")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
kernel/trace/ftrace.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 30bc880c3849..7f0594e28226 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c@@ -5217,6 +5217,7 @@ int unregister_ftrace_direct(unsigned long ip, unsigned long addr) { struct ftrace_direct_func *direct; struct ftrace_func_entry *entry; + struct ftrace_hash *hash; int ret = -ENODEV; mutex_lock(&direct_mutex);
@@ -5225,7 +5226,8 @@ int unregister_ftrace_direct(unsigned long ip, unsigned long addr) if (!entry) goto out_unlock; - if (direct_functions->count == 1) + hash = direct_ops.func_hash->filter_hash; + if (hash->count == 1) unregister_ftrace_function(&direct_ops); ret = ftrace_set_filter_ip(&direct_ops, ip, 1, 0);
--
2.31.1