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authorKP Singh <kpsingh@google.com>2020-11-13 00:59:30 +0000
committerDaniel Borkmann <daniel@iogearbox.net>2020-11-13 15:47:21 +0100
commit6f100640ca5b2a2ff67b001c9fd3de21f7b12cf2 (patch)
treea4042f33ba0e08936832c64d6d0d53b476732c3b
parent423f16108c9d832bd96059d5c882c8ef6d76eb96 (diff)
downloadlinux-6f100640ca5b2a2ff67b001c9fd3de21f7b12cf2.tar.bz2
bpf: Expose bpf_d_path helper to sleepable LSM hooks
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 sleepable hooks as the initial subset of LSM hooks where it can be used. Signed-off-by: KP Singh <kpsingh@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20201113005930.541956-3-kpsingh@chromium.org
-rw-r--r--kernel/trace/bpf_trace.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index cfce60ad1cb5..02986c7b90eb 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -16,6 +16,8 @@
#include <linux/syscalls.h>
#include <linux/error-injection.h>
#include <linux/btf_ids.h>
+#include <linux/bpf_lsm.h>
+
#include <net/bpf_sk_storage.h>
#include <uapi/linux/bpf.h>
@@ -1179,7 +1181,11 @@ 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)