On Fri, Jan 22, 2021 at 11:33 PM KP Singh <kpsingh@xxxxxxxxxx> wrote:
>
> On Fri, Jan 22, 2021 at 1:32 PM Mikko Ylinen
> <mikko.ylinen@xxxxxxxxxxxxxxx> wrote:
> >
> > Networking LSM hooks are conditionally enabled and when building the new
> > sleepable BPF LSM hooks with the networking LSM hooks disabled, the
> > following build error occurs:
> >
> > BTFIDS vmlinux
> > FAILED unresolved symbol bpf_lsm_socket_socketpair
> >
> > To fix the error, conditionally add the networking LSM hooks to the
> > sleepable set.
> >
> > Fixes: 423f16108c9d8 ("bpf: Augment the set of sleepable LSM hooks")
> > Signed-off-by: Mikko Ylinen <mikko.ylinen@xxxxxxxxxxxxxxx>
>
> Thanks!
>
> Acked-by: KP Singh <kpsingh@xxxxxxxxxx>
Btw, I was noticing that there's another hook that is surrounded by ifdefs:
diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c
index 70e5e0b6d69d..f7f7754e938d 100644
--- a/kernel/bpf/bpf_lsm.c
+++ b/kernel/bpf/bpf_lsm.c
@@ -166,7 +166,11 @@ BTF_ID(func, bpf_lsm_inode_symlink)
BTF_ID(func, bpf_lsm_inode_unlink)
BTF_ID(func, bpf_lsm_kernel_module_request)
BTF_ID(func, bpf_lsm_kernfs_init_security)
+
+#ifdef CONFIG_KEYS
BTF_ID(func, bpf_lsm_key_free)
+#endif
+
BTF_ID(func, bpf_lsm_mmap_file)
BTF_ID(func, bpf_lsm_netlink_send)
BTF_ID(func, bpf_lsm_path_notify)
It would be great if you can also add this to your patch :)
I guess the cleanest solution to never let this happen would be to
incorporate this in
lsm_hook_defs.h and mark hooks as SLEEPABLE and NON_SLEEPABLE with an
extra parameter to the LSM_HOOK macro and then only generate the BTF IDs
based on this macro parameter.
