aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorMarkos Chandras <markos.chandras@imgtec.com>2014-06-23 10:38:58 +0100
committerRalf Baechle <ralf@linux-mips.org>2014-06-26 10:48:22 +0100
commitb4fe0ec86dae91abfa9f932cd0e2e9d50e336c8b (patch)
treea40109b4861da4da8fff62c37bac63907c2e1600
parent95782bf434437b3292f5cb9ce21b53bdbc1beda1 (diff)
downloadlinux-stericsson-b4fe0ec86dae91abfa9f932cd0e2e9d50e336c8b.tar.gz
MIPS: bpf: Fix PKT_TYPE case for big-endian cores
The skb->pkt_type field is defined as follows: u8 pkt_type:3, fclone:2, ipvs_property:1, peeked:1, nf_trace:1 resulting to the following layout in big-endian systems [pkt_type][fclone][ipvs_propery][peeked][nf_trace] ^ ^ | | LSB MSB As a result, the existing code did not work because it was trying to match pkt_type == 7 whereas in reality it is 7<<5 on big-endian systems. This has been fixed in the interpreter in 0dcceabb0c1bf2d4c12a748df9933fad303072a7 "net: filter: fix SKF_AD_PKTTYPE extension on big-endian" The fix is to look for 7<<5 on big-endian systems for the pkt_type field, and shift by 5 so the packet type will be at the lower 3 bits of the A register. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: David S. Miller <davem@davemloft.net> Cc: Daniel Borkmann <dborkman@redhat.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: netdev@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7132/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
-rw-r--r--arch/mips/net/bpf_jit.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/arch/mips/net/bpf_jit.c b/arch/mips/net/bpf_jit.c
index 9476e7f061a1..4505e2e6ab53 100644
--- a/arch/mips/net/bpf_jit.c
+++ b/arch/mips/net/bpf_jit.c
@@ -751,13 +751,17 @@ static u64 jit_get_skb_w(struct sk_buff *skb, unsigned offset)
return (u64)err << 32 | ntohl(ret);
}
-#define PKT_TYPE_MAX 7
+#ifdef __BIG_ENDIAN_BITFIELD
+#define PKT_TYPE_MAX (7 << 5)
+#else
+#define PKT_TYPE_MAX 7
+#endif
static int pkt_type_offset(void)
{
struct sk_buff skb_probe = {
.pkt_type = ~0,
};
- char *ct = (char *)&skb_probe;
+ u8 *ct = (u8 *)&skb_probe;
unsigned int off;
for (off = 0; off < sizeof(struct sk_buff); off++) {
@@ -1320,6 +1324,10 @@ jmp_cmp:
emit_load_byte(r_tmp, r_skb, off, ctx);
/* Keep only the last 3 bits */
emit_andi(r_A, r_tmp, PKT_TYPE_MAX, ctx);
+#ifdef __BIG_ENDIAN_BITFIELD
+ /* Get the actual packet type to the lower 3 bits */
+ emit_srl(r_A, r_A, 5, ctx);
+#endif
break;
case BPF_ANC | SKF_AD_QUEUE:
ctx->flags |= SEEN_SKB | SEEN_A;