[PATCH v2] ftrace: properly merge notrace hash

From: Andy Chiu
Date: Tue Apr 08 2025 - 12:14:21 EST


The global notrace hash should be jointly decided by the intersection of
each subops's notrace hash, but not the filter hash.

Fixes: 5fccc7552ccb ("ftrace: Add subops logic to allow one ops to manage many")
Signed-off-by: Andy Chiu <andybnac@xxxxxxxxx>
---
Changelog v2:
- free both filter and notrace hash when intersect_hash() fails
---
kernel/trace/ftrace.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 1a48aedb5255..bb9e1bf4fe86 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3526,16 +3526,16 @@ int ftrace_startup_subops(struct ftrace_ops *ops, struct ftrace_ops *subops, int
ftrace_hash_empty(subops->func_hash->notrace_hash)) {
notrace_hash = EMPTY_HASH;
} else {
- size_bits = max(ops->func_hash->filter_hash->size_bits,
- subops->func_hash->filter_hash->size_bits);
+ size_bits = max(ops->func_hash->notrace_hash->size_bits,
+ subops->func_hash->notrace_hash->size_bits);
notrace_hash = alloc_ftrace_hash(size_bits);
if (!notrace_hash) {
- free_ftrace_hash(filter_hash);
+ free_ftrace_hash(notrace_hash);
return -ENOMEM;
}

- ret = intersect_hash(&notrace_hash, ops->func_hash->filter_hash,
- subops->func_hash->filter_hash);
+ ret = intersect_hash(&notrace_hash, ops->func_hash->notrace_hash,
+ subops->func_hash->notrace_hash);
if (ret < 0) {
free_ftrace_hash(filter_hash);
free_ftrace_hash(notrace_hash);
--
2.39.3 (Apple Git-145)