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authorDaniel Borkmann <daniel@iogearbox.net>2017-04-24 22:14:35 +0200
committerDavid S. Miller <davem@davemloft.net>2017-04-24 16:18:10 -0400
commite390b55d5aefe2b51569068b2a505d19d72afbf1 (patch)
treea3f9dcb6e95ede17e39fa54bcc37f23044d95f72
parent91ec701a553cb3de470fd471c6fefe3ad1125455 (diff)
downloadlinux-e390b55d5aefe2b51569068b2a505d19d72afbf1.tar.bz2
bpf: make bpf_xdp_adjust_head support mandatory
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> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/linux/filter.h3
-rw-r--r--kernel/bpf/verifier.c3
2 files changed, 1 insertions, 5 deletions
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 511fe910bf1d..9a7786db14fa 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 ca15cf2b85bb..6f8b6ed690be 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