diff options
| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2013-07-17 14:26:50 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2013-07-18 12:44:38 +0200 |
| commit | c9a7afa380ecaeb0fbeec2e82f86ec5548ad2963 (patch) | |
| tree | bc9339eef58875e52265babad5caeb5e5f2b78fd /arch/s390 | |
| parent | aa2d2c73c21f22ce4c643128b671aa7e7bbff54f (diff) | |
s390/bpf,jit: add pkt_type support
s390 version of 3b58908a "x86: bpf_jit_comp: add pkt_type support".
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/net/bpf_jit_comp.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index 788e22395acd..d5f10a43a58f 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -10,6 +10,7 @@ #include <linux/if_vlan.h> #include <linux/filter.h> #include <linux/random.h> +#include <linux/init.h> #include <asm/cacheflush.h> #include <asm/processor.h> #include <asm/facility.h> @@ -222,6 +223,37 @@ static void bpf_jit_epilogue(struct bpf_jit *jit) EMIT2(0x07fe); } +/* Helper to find the offset of pkt_type in sk_buff + * Make sure its still a 3bit field starting at the MSBs within a byte. + */ +#define PKT_TYPE_MAX 0xe0 +static int pkt_type_offset; + +static int __init bpf_pkt_type_offset_init(void) +{ + struct sk_buff skb_probe = { + .pkt_type = ~0, + }; + char *ct = (char *)&skb_probe; + int off; + + pkt_type_offset = -1; + for (off = 0; off < sizeof(struct sk_buff); off++) { + if (!ct[off]) + continue; + if (ct[off] == PKT_TYPE_MAX) + pkt_type_offset = off; + else { + /* Found non matching bit pattern, fix needed. */ + WARN_ON_ONCE(1); + pkt_type_offset = -1; + return -1; + } + } + return 0; +} +device_initcall(bpf_pkt_type_offset_init); + /* * make sure we dont leak kernel information to user */ @@ -721,6 +753,16 @@ call_fn: /* lg %r1,<d(function)>(%r13) */ EMIT4_DISP(0x88500000, 12); } break; + case BPF_S_ANC_PKTTYPE: + if (pkt_type_offset < 0) + goto out; + /* lhi %r5,0 */ + EMIT4(0xa7580000); + /* ic %r5,<d(pkt_type_offset)>(%r2) */ + EMIT4_DISP(0x43502000, pkt_type_offset); + /* srl %r5,5 */ + EMIT4_DISP(0x88500000, 5); + break; case BPF_S_ANC_CPU: /* A = smp_processor_id() */ #ifdef CONFIG_SMP /* l %r5,<d(cpu_nr)> */ |