| Message ID | 6e25ef44c5de02d1feb8b4cc8a2cf60adb4a596e.1493064530.git.daniel@iogearbox.net |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Daniel Borkmann <daniel@iogearbox.net> Date: Mon, 24 Apr 2017 22:14:35 +0200 > 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 <daniel@iogearbox.net> > Acked-by: Alexei Starovoitov <ast@kernel.org> Applied, thanks Daniel.
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
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 <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> --- include/linux/filter.h | 3 +-- kernel/bpf/verifier.c | 3 --- 2 files changed, 1 insertion(+), 5 deletions(-)