bpf...d_path(): constify path argument

Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Author: Al Viro

fs/bpf_fs_kfuncs.c

@@ -79,7 +79,7 @@ __bpf_kfunc void bpf_put_file(struct file *file)
  * pathname in *buf*, including the NUL termination character. On error, a
  * negative integer is returned.
  */
-__bpf_kfunc int bpf_path_d_path(struct path *path, char *buf, size_t buf__sz)
+__bpf_kfunc int bpf_path_d_path(const struct path *path, char *buf, size_t buf__sz)
 {
 	int len;
 	char *ret;

kernel/trace/bpf_trace.c

@@ -900,7 +900,7 @@ const struct bpf_func_proto bpf_send_signal_thread_proto = {
 	.arg1_type	= ARG_ANYTHING,
 };
 
-BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
+BPF_CALL_3(bpf_d_path, const struct path *, path, char *, buf, u32, sz)
 {
 	struct path copy;
 	long len;

tools/testing/selftests/bpf/bpf_experimental.h

@@ -219,7 +219,7 @@ extern void bpf_put_file(struct file *file) __ksym;
  *	including the NULL termination character, stored in the supplied
  *	buffer. On error, a negative integer is returned.
  */
-extern int bpf_path_d_path(struct path *path, char *buf, size_t buf__sz) __ksym;
+extern int bpf_path_d_path(const struct path *path, char *buf, size_t buf__sz) __ksym;
 
 /* This macro must be used to mark the exception callback corresponding to the
  * main program. For example: