s390/bpf: fix lcgr instruction encoding
authorIlya Leoshkevich <iii@linux.ibm.com>
Mon, 12 Aug 2019 15:03:32 +0000 (17:03 +0200)
committerDaniel Borkmann <daniel@iogearbox.net>
Mon, 12 Aug 2019 16:03:35 +0000 (18:03 +0200)
commitbb2d267c448f4bc3a3389d97c56391cb779178ae
treeaaa921c0da8814d38672b391a2dbd63d3747329c
parent125b7e0949d4e72b15c2b1a1590f8cece985a918
s390/bpf: fix lcgr instruction encoding

"masking, test in bounds 3" fails on s390, because
BPF_ALU64_IMM(BPF_NEG, BPF_REG_2, 0) ignores the top 32 bits of
BPF_REG_2. The reason is that JIT emits lcgfr instead of lcgr.
The associated comment indicates that the code was intended to
emit lcgr in the first place, it's just that the wrong opcode
was used.

Fix by using the correct opcode.

Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
arch/s390/net/bpf_jit_comp.c