diff mbox series

[bpf-next,v8,4/5] bpf: Make fs kfuncs available for SYSCALL program type

Message ID AM6PR03MB50800269747016757C7BA35D99E12@AM6PR03MB5080.eurprd03.prod.outlook.com (mailing list archive)
State New
Delegated to: BPF
Headers show
Series bpf: Add open-coded style process file iterator and bpf_fget_task() kfunc | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for bpf-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1 this patch: 1
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 2 maintainers not CCed: jack@suse.cz viro@zeniv.linux.org.uk
netdev/build_clang success Errors and warnings before: 2 this patch: 2
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 7 this patch: 7
netdev/checkpatch warning WARNING: line length of 90 exceeds 80 columns
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 1 this patch: 1
netdev/source_inline success Was 0 now: 0

Commit Message

Juntong Deng Jan. 22, 2025, 11:04 p.m. UTC 
Currently fs kfuncs are only available for LSM program type, but fs
kfuncs are general and useful for scenarios other than LSM.

This patch makes fs kfuncs available for SYSCALL program type.

Signed-off-by: Juntong Deng <juntong.deng@outlook.com>
---
 fs/bpf_fs_kfuncs.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)
diff mbox series

Patch

diff --git a/fs/bpf_fs_kfuncs.c b/fs/bpf_fs_kfuncs.c
index 4a810046dcf3..8a7e9ed371de 100644
--- a/fs/bpf_fs_kfuncs.c
+++ b/fs/bpf_fs_kfuncs.c
@@ -26,8 +26,6 @@  __bpf_kfunc_start_defs();
  * acquired by this BPF kfunc will result in the BPF program being rejected by
  * the BPF verifier.
  *
- * This BPF kfunc may only be called from BPF LSM programs.
- *
  * Internally, this BPF kfunc leans on get_task_exe_file(), such that calling
  * bpf_get_task_exe_file() would be analogous to calling get_task_exe_file()
  * directly in kernel context.
@@ -49,8 +47,6 @@  __bpf_kfunc struct file *bpf_get_task_exe_file(struct task_struct *task)
  * passed to this BPF kfunc. Attempting to pass an unreferenced file pointer, or
  * any other arbitrary pointer for that matter, will result in the BPF program
  * being rejected by the BPF verifier.
- *
- * This BPF kfunc may only be called from BPF LSM programs.
  */
 __bpf_kfunc void bpf_put_file(struct file *file)
 {
@@ -70,8 +66,6 @@  __bpf_kfunc void bpf_put_file(struct file *file)
  * reference, or else the BPF program will be outright rejected by the BPF
  * verifier.
  *
- * This BPF kfunc may only be called from BPF LSM programs.
- *
  * Return: A positive integer corresponding to the length of the resolved
  * pathname in *buf*, including the NUL termination character. On error, a
  * negative integer is returned.
@@ -184,7 +178,8 @@  BTF_KFUNCS_END(bpf_fs_kfunc_set_ids)
 static int bpf_fs_kfuncs_filter(const struct bpf_prog *prog, u32 kfunc_id)
 {
 	if (!btf_id_set8_contains(&bpf_fs_kfunc_set_ids, kfunc_id) ||
-	    prog->type == BPF_PROG_TYPE_LSM)
+	    prog->type == BPF_PROG_TYPE_LSM ||
+	    prog->type == BPF_PROG_TYPE_SYSCALL)
 		return 0;
 	return -EACCES;
 }
@@ -197,7 +192,10 @@  static const struct btf_kfunc_id_set bpf_fs_kfunc_set = {
 
 static int __init bpf_fs_kfuncs_init(void)
 {
-	return register_btf_kfunc_id_set(BPF_PROG_TYPE_LSM, &bpf_fs_kfunc_set);
+	int ret;
+
+	ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_LSM, &bpf_fs_kfunc_set);
+	return ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SYSCALL, &bpf_fs_kfunc_set);
 }
 
 late_initcall(bpf_fs_kfuncs_init);