Messages in this thread | | | From | Andrii Nakryiko <> | Date | Thu, 12 Nov 2020 10:50:46 -0800 | Subject | Re: [PATCH bpf-next 2/2] bpf: Expose bpf_d_path helper to sleepable LSM hooks |
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On Thu, Nov 12, 2020 at 9:20 AM KP Singh <kpsingh@chromium.org> wrote: > > From: KP Singh <kpsingh@google.com> > > Sleepable hooks are never called from an NMI/interrupt context, so it is > safe to use the bpf_d_path helper in LSM programs attaching to these > hooks. > > The helper is not restricted to sleepable programs and merely uses the > list of sleeable hooks as the initial subset of LSM hooks where it can > be used. > > Signed-off-by: KP Singh <kpsingh@google.com> > ---
LGTM.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
> kernel/trace/bpf_trace.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c > index e4515b0f62a8..eab1af02c90d 100644 > --- a/kernel/trace/bpf_trace.c > +++ b/kernel/trace/bpf_trace.c > @@ -16,6 +16,7 @@ > #include <linux/syscalls.h> > #include <linux/error-injection.h> > #include <linux/btf_ids.h> > +#include <linux/bpf_lsm.h> > > #include <uapi/linux/bpf.h> > #include <uapi/linux/btf.h> > @@ -1178,7 +1179,11 @@ BTF_SET_END(btf_allowlist_d_path) > > static bool bpf_d_path_allowed(const struct bpf_prog *prog) > { > - return btf_id_set_contains(&btf_allowlist_d_path, prog->aux->attach_btf_id); > + if (prog->type == BPF_PROG_TYPE_LSM) > + return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id); > + > + return btf_id_set_contains(&btf_allowlist_d_path, > + prog->aux->attach_btf_id); > } > > BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path) > -- > 2.29.2.222.g5d2a92d10f8-goog >
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