From: Andy Chiu <andybnac@gmail.com>
Date: Tue, 8 Apr 2025 16:02:57 +0000 (+0800)
Subject: ftrace: Properly merge notrace hashes
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=04a80a34c22f4db245f553d8696d1318d1c00ece;p=users%2Fhch%2Fmisc.git

ftrace: Properly merge notrace hashes

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

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/20250408160258.48563-1-andybnac@gmail.com
Fixes: 5fccc7552ccb ("ftrace: Add subops logic to allow one ops to manage many")
Signed-off-by: Andy Chiu <andybnac@gmail.com>
[ fixed removing of freeing of filter_hash ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 1a48aedb5255..8939eeebb02e 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);
 			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);