linux-stable/arch/s390/net
Daniel Borkmann d93a47f735 bpf, s390: add support for constant blinding
This patch adds recently added constant blinding helpers into the
s390 eBPF JIT. In the bpf_int_jit_compile() path, requirements are
to utilize bpf_jit_blind_constants()/bpf_jit_prog_release_other()
pair for rewriting the program into a blinded one, and to map the
BPF_REG_AX register to a CPU register. The mapping of BPF_REG_AX
is at r12 and similarly like in x86 case performs reloading when
ld_abs/ind is used. When blinding is not used, there's no additional
overhead in the generated image.

When BPF_REG_AX is used, we don't need to emit skb->data reload when
helper function changed skb->data, as this will be reloaded later
on anyway from stack on ld_abs/ind, where skb->data is needed. s390
allows for this w/o much additional complexity unlike f.e. x86.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-16 13:49:33 -04:00
..
bpf_jit.h s390/bpf: recache skb->data/hlen for skb_vlan_push/pop 2015-07-29 14:59:58 -07:00
bpf_jit.S s390/bpf: Add s390x eBPF JIT compiler backend 2015-04-15 12:23:49 +02:00
bpf_jit_comp.c bpf, s390: add support for constant blinding 2016-05-16 13:49:33 -04:00
Makefile