[PATCH 2/2] tracing: fprobe: Fix to remove recorded module addresses from filter

Masami Hiramatsu (Google)
2025-09-24T00:26:42Z

From: Masami Hiramatsu (Google) <mhiramat@kernel.org>

Even if there is a memory allocation failure in fprobe_addr_list_add(),
there is a partial list of module addresses. So remove the recorded
addresses from filter if exists.
This also removes the redundant ret local variable.

Fixes: a3dc2983ca7b ("tracing: fprobe: Cleanup fprobe hash when module unloading")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
kernel/trace/fprobe.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
index 12ec194fdfed..95e43814b85b 100644
--- a/kernel/trace/fprobe.c
+++ b/kernel/trace/fprobe.c
@@ -434,8 +434,9 @@ static int fprobe_addr_list_add(struct fprobe_addr_list *alist, unsigned long ad
{
unsigned long *addrs;

- if (alist->index >= alist->size)
- return -ENOMEM;
+ /* Previously we failed to expand the list. */
+ if (alist->index == alist->size)
+ return -ENOSPC;

alist->addrs[alist->index++] = addr;
if (alist->index < alist->size)
@@ -497,7 +498,7 @@ static int fprobe_module_callback(struct notifier_block *nb,
} while (node == ERR_PTR(-EAGAIN));
rhashtable_walk_exit(&iter);

- if (alist.index < alist.size && alist.index > 0)
+ if (alist.index > 0)
ftrace_set_filter_ips(&fprobe_graph_ops.ops,
alist.addrs, alist.index, 1, 0);
mutex_unlock(&fprobe_mutex);