From: Rong Tao rongtao@cestc.cn

Since commit 1b8abbb12128 ("bpf...d_path(): constify path argument"), the first parameter of the bpf_d_path() has been changed to a const constant. We need to modify the header file and bpf_doc.py.

The two error messages are as follows:

linux/tools/testing/selftests/bpf$ make

CLNG-BPF [test_progs] bpf_iter_task_vmas.bpf.o progs/bpf_iter_task_vmas.c:52:14: error: passing 'const struct path *' to parameter of type 'struct path *' discards qualifiers [-Werror,-Wincompatible-pointer-types-discards-qualifiers] 52 | bpf_d_path(&file->f_path, d_path_buf, D_PATH_BUF_SIZE); | ^~~~~~~~~~~~~ 1 error generated. .... progs/verifier_vfs_accept.c:80:7: error: assigning to 'struct path *' from 'const struct path *' discards qualifiers [-Werror,-Wincompatible-pointer-types-discards-qualifiers] 80 | path = &file->f_path; | ^ ~~~~~~~~~~~~~ 1 error generated.

Fixes: 1b8abbb12128 ("bpf...d_path(): constify path argument") Signed-off-by: Rong Tao rongtao@cestc.cn --- include/uapi/linux/bpf.h | 2 +- scripts/bpf_doc.py | 1 + tools/include/uapi/linux/bpf.h | 2 +- tools/testing/selftests/bpf/progs/verifier_vfs_accept.c | 2 +- 4 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index ae83d8649ef1..6829936d33f5 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -4891,7 +4891,7 @@ union bpf_attr { * * **-ENOENT** if the bpf_local_storage cannot be found. * - * long bpf_d_path(struct path *path, char *buf, u32 sz) + * long bpf_d_path(const struct path *path, char *buf, u32 sz) * Description * Return full path for given **struct path** object, which * needs to be the kernel BTF *path* object. The path is diff --git a/scripts/bpf_doc.py b/scripts/bpf_doc.py index c77dc40f7689..15d113a1bc1d 100755 --- a/scripts/bpf_doc.py +++ b/scripts/bpf_doc.py @@ -788,6 +788,7 @@ class PrinterHelpersHeader(Printer): 'struct task_struct', 'struct cgroup', 'struct path', + 'const struct path', 'struct btf_ptr', 'struct inode', 'struct socket', diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index ae83d8649ef1..6829936d33f5 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -4891,7 +4891,7 @@ union bpf_attr { * * **-ENOENT** if the bpf_local_storage cannot be found. * - * long bpf_d_path(struct path *path, char *buf, u32 sz) + * long bpf_d_path(const struct path *path, char *buf, u32 sz) * Description * Return full path for given **struct path** object, which * needs to be the kernel BTF *path* object. The path is diff --git a/tools/testing/selftests/bpf/progs/verifier_vfs_accept.c b/tools/testing/selftests/bpf/progs/verifier_vfs_accept.c index 3e2d76ee8050..55398c04290a 100644 --- a/tools/testing/selftests/bpf/progs/verifier_vfs_accept.c +++ b/tools/testing/selftests/bpf/progs/verifier_vfs_accept.c @@ -70,7 +70,7 @@ __success int BPF_PROG(path_d_path_from_file_argument, struct file *file) { int ret; - struct path *path; + const struct path *path;

/* The f_path member is a path which is embedded directly within a * file. Therefore, a pointer to such embedded members are still