[PATCH bpf-next v4 2/2] bpf: expose bpf_d_path helper to vfs_* and security_* functions

From: Hengqi Chen <hengqi.chen@gmail.com>
To: bpf@vger.kernel.org
Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
	yhs@fb.com, john.fastabend@gmail.com, jolsa@kernel.org,
	yanivagman@gmail.com, hengqi.chen@gmail.com
Subject: [PATCH bpf-next v4 2/2] bpf: expose bpf_d_path helper to vfs_* and security_* functions
Date: Mon, 26 Jul 2021 22:10:13 +0800	[thread overview]
Message-ID: <20210726141013.2239765-3-hengqi.chen@gmail.com> (raw)
In-Reply-To: <20210726141013.2239765-1-hengqi.chen@gmail.com>

Add vfs_* and security_* to bpf_d_path allowlist, so that we can use
bpf_d_path helper to extract full file path from these functions' arguments.
This will help tools like BCC's filetop[1]/filelife to get full file path.

[1] https://github.com/iovisor/bcc/issues/3527

Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
---
 kernel/trace/bpf_trace.c | 60 +++++++++++++++++++++++++++++++++++++---
 1 file changed, 56 insertions(+), 4 deletions(-)

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index c5e0b6a64091..e7b24abcf3bf 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -849,18 +849,70 @@ BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
 
 BTF_SET_START(btf_allowlist_d_path)
 #ifdef CONFIG_SECURITY
+BTF_ID(func, security_bprm_check)
+BTF_ID(func, security_bprm_committed_creds)
+BTF_ID(func, security_bprm_committing_creds)
+BTF_ID(func, security_bprm_creds_for_exec)
+BTF_ID(func, security_bprm_creds_from_file)
+BTF_ID(func, security_file_alloc)
+BTF_ID(func, security_file_fcntl)
+BTF_ID(func, security_file_free)
+BTF_ID(func, security_file_ioctl)
+BTF_ID(func, security_file_lock)
+BTF_ID(func, security_file_open)
 BTF_ID(func, security_file_permission)
+BTF_ID(func, security_file_receive)
+BTF_ID(func, security_file_set_fowner)
 BTF_ID(func, security_inode_getattr)
-BTF_ID(func, security_file_open)
+BTF_ID(func, security_sb_mount)
 #endif
 #ifdef CONFIG_SECURITY_PATH
+BTF_ID(func, security_path_chmod)
+BTF_ID(func, security_path_chown)
+BTF_ID(func, security_path_chroot)
+BTF_ID(func, security_path_link)
+BTF_ID(func, security_path_mkdir)
+BTF_ID(func, security_path_mknod)
+BTF_ID(func, security_path_notify)
+BTF_ID(func, security_path_rename)
+BTF_ID(func, security_path_rmdir)
+BTF_ID(func, security_path_symlink)
 BTF_ID(func, security_path_truncate)
+BTF_ID(func, security_path_unlink)
 #endif
-BTF_ID(func, vfs_truncate)
-BTF_ID(func, vfs_fallocate)
 BTF_ID(func, dentry_open)
-BTF_ID(func, vfs_getattr)
 BTF_ID(func, filp_close)
+BTF_ID(func, vfs_cancel_lock)
+BTF_ID(func, vfs_clone_file_range)
+BTF_ID(func, vfs_copy_file_range)
+BTF_ID(func, vfs_dedupe_file_range)
+BTF_ID(func, vfs_dedupe_file_range_one)
+BTF_ID(func, vfs_fadvise)
+BTF_ID(func, vfs_fallocate)
+BTF_ID(func, vfs_fchmod)
+BTF_ID(func, vfs_fchown)
+BTF_ID(func, vfs_fsync)
+BTF_ID(func, vfs_fsync_range)
+BTF_ID(func, vfs_getattr)
+BTF_ID(func, vfs_getattr_nosec)
+BTF_ID(func, vfs_iocb_iter_read)
+BTF_ID(func, vfs_iocb_iter_write)
+BTF_ID(func, vfs_ioctl)
+BTF_ID(func, vfs_iter_read)
+BTF_ID(func, vfs_iter_write)
+BTF_ID(func, vfs_llseek)
+BTF_ID(func, vfs_lock_file)
+BTF_ID(func, vfs_open)
+BTF_ID(func, vfs_read)
+BTF_ID(func, vfs_readv)
+BTF_ID(func, vfs_setlease)
+BTF_ID(func, vfs_setpos)
+BTF_ID(func, vfs_statfs)
+BTF_ID(func, vfs_test_lock)
+BTF_ID(func, vfs_truncate)
+BTF_ID(func, vfs_utimes)
+BTF_ID(func, vfs_write)
+BTF_ID(func, vfs_writev)
 BTF_SET_END(btf_allowlist_d_path)
 
 static bool bpf_d_path_allowed(const struct bpf_prog *prog)
-- 
2.25.1

