Now that also the last in-tree user of the xdp_adjust_head bit has
been removed, we can remove the flag from struct bpf_prog altogether.
This, at the same time, also makes sure that any future driver for
XDP comes with bpf_xdp_adjust_head() support right away.
A rejection based on this flag would also mean that tail calls
couldn't be used with such driver as per c2002f983767 ("bpf: fix
checking xdp_adjust_head on tail calls") fix, thus lets not allow
for it in the first place.
Signed-off-by: Daniel Borkmann <dan...@iogearbox.net>
Acked-by: Alexei Starovoitov <a...@kernel.org>
---
include/linux/filter.h | 3 +--
kernel/bpf/verifier.c | 3 ---
2 files changed, 1 insertion(+), 5 deletions(-)
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 511fe91..9a7786d 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -413,8 +413,7 @@ struct bpf_prog {
locked:1, /* Program image locked? */
gpl_compatible:1, /* Is filter GPL compatible?
*/
cb_access:1, /* Is control block accessed? */
- dst_needed:1, /* Do we need dst entry? */
- xdp_adjust_head:1; /* Adjusting pkt head? */
+ dst_needed:1; /* Do we need dst entry? */
kmemcheck_bitfield_end(meta);
enum bpf_prog_type type; /* Type of BPF program */
u32 len; /* Number of filter blocks */
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index ca15cf2..6f8b6ed 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3346,8 +3346,6 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env)
prog->dst_needed = 1;
if (insn->imm == BPF_FUNC_get_prandom_u32)
bpf_user_rnd_init_once();
- if (insn->imm == BPF_FUNC_xdp_adjust_head)
- prog->xdp_adjust_head = 1;
if (insn->imm == BPF_FUNC_tail_call) {
/* If we tail call into other programs, we
* cannot make any assumptions since they can
@@ -3355,7 +3353,6 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env)
* the program array.
*/
prog->cb_access = 1;
- prog->xdp_adjust_head = 1;
/* mark bpf_tail_call as different opcode to avoid
* conditional branch in the interpeter for every normal
--
1.9.3
