diff options
| author | Michael Holzheu <holzheu@linux.vnet.ibm.com> | 2015-07-29 21:15:18 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-07-29 14:59:58 -0700 |
| commit | 9db7f2b818809ef2c40fbd64cfcf5ccb0107d7e8 (patch) | |
| tree | e4d0b2ed3dc2e6900106edff81e834f063007e1c /arch/s390/net/bpf_jit.h | |
| parent | cde66c2d88da1d73d755109c80ce4c34b917596b (diff) | |
| download | linux-9db7f2b818809ef2c40fbd64cfcf5ccb0107d7e8.tar.bz2 | |
s390/bpf: recache skb->data/hlen for skb_vlan_push/pop
Allow eBPF programs attached to TC qdiscs call skb_vlan_push/pop
via helper functions. These functions may change skb->data/hlen.
This data is cached by s390 JIT to improve performance of ld_abs/ld_ind
instructions. Therefore after a change we have to reload the data.
In case of usage of skb_vlan_push/pop, in the prologue we store
the SKB pointer on the stack and restore it after BPF_JMP_CALL
to skb_vlan_push/pop.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/s390/net/bpf_jit.h')
| -rw-r--r-- | arch/s390/net/bpf_jit.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/s390/net/bpf_jit.h b/arch/s390/net/bpf_jit.h index f6498eec9ee1..f010c93a88b1 100644 --- a/arch/s390/net/bpf_jit.h +++ b/arch/s390/net/bpf_jit.h @@ -36,6 +36,8 @@ extern u8 sk_load_word[], sk_load_half[], sk_load_byte[]; * | BPF stack | | * | | | * +---------------+ | + * | 8 byte skbp | | + * R15+170 -> +---------------+ | * | 8 byte hlen | | * R15+168 -> +---------------+ | * | 4 byte align | | @@ -51,11 +53,12 @@ extern u8 sk_load_word[], sk_load_half[], sk_load_byte[]; * We get 160 bytes stack space from calling function, but only use * 12 * 8 byte for old backchain, r15..r6, and tail_call_cnt. */ -#define STK_SPACE (MAX_BPF_STACK + 8 + 4 + 4 + 160) +#define STK_SPACE (MAX_BPF_STACK + 8 + 8 + 4 + 4 + 160) #define STK_160_UNUSED (160 - 12 * 8) #define STK_OFF (STK_SPACE - STK_160_UNUSED) #define STK_OFF_TMP 160 /* Offset of tmp buffer on stack */ #define STK_OFF_HLEN 168 /* Offset of SKB header length on stack */ +#define STK_OFF_SKBP 170 /* Offset of SKB pointer on stack */ #define STK_OFF_R6 (160 - 11 * 8) /* Offset of r6 on stack */ #define STK_OFF_TCCNT (160 - 12 * 8) /* Offset of tail_call_cnt on stack */ |