On 7/3/25 5:43 AM, Tao Chen wrote:
No logic change, just use bpf_copy_to_user to clean code.
Signed-off-by: Tao Chen <chen.dylane@xxxxxxxxx>
---
kernel/bpf/syscall.c | 17 +++--------------
1 file changed, 3 insertions(+), 14 deletions(-)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index e6eea594f1c..ca152d36312 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -5208,21 +5208,10 @@ static int bpf_task_fd_query_copy(const union bpf_attr *attr,
if (put_user(zero, ubuf))
return -EFAULT;
- } else if (input_len >= len + 1) {
- /* ubuf can hold the string with NULL terminator */
- if (copy_to_user(ubuf, buf, len + 1))
- return -EFAULT;
} else {
- /* ubuf cannot hold the string with NULL terminator,
- * do a partial copy with NULL terminator.
- */
- char zero = '\0';
-
- err = -ENOSPC;
- if (copy_to_user(ubuf, buf, input_len - 1))
- return -EFAULT;
- if (put_user(zero, ubuf + input_len - 1))
- return -EFAULT;
+ err = bpf_copy_to_user(ubuf, buf, input_len, len);
+ if (err)
+ return err;
}
}
Actually, there is a return value change with this patch.
bpf_copy_to_user() return returns -ENOSPC while the original
implementation may return -EFAULT due to following code.
if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
put_user(fd_type, &uattr->task_fd_query.fd_type) ||
put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
put_user(probe_addr, &uattr->task_fd_query.probe_addr))
return -EFAULT;
return err;
