summaryrefslogtreecommitdiffstats
path: root/net
diff options
context:
space:
mode:
authorTycho Andersen <tycho.andersen@canonical.com>2015-09-10 18:25:07 -0600
committerDavid S. Miller <davem@davemloft.net>2015-09-11 14:52:41 -0700
commit19539ce783dd27768d4f7f3b753152bf983db65b (patch)
tree9b60e9e3326ed629ada5b85bbfbdb018550eb223 /net
parent1853c949646005b5959c483becde86608f548f24 (diff)
downloadop-kernel-dev-19539ce783dd27768d4f7f3b753152bf983db65b.zip
op-kernel-dev-19539ce783dd27768d4f7f3b753152bf983db65b.tar.gz
ebpf: emit correct src_reg for conditional jumps
Instead of always emitting BPF_REG_X, let's emit BPF_REG_X only when the source actually is BPF_X. This causes programs generated by the classic converter to not be importable via bpf(), as the eBPF verifier checks that the src_reg is correct or 0. While not a problem yet, this will be a problem when BPF_PROG_DUMP lands, and we can potentially dump and re-import programs generated by the converter. Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com> CC: Alexei Starovoitov <ast@kernel.org> CC: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/filter.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/core/filter.c b/net/core/filter.c
index 13079f0..05a04ea 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -478,9 +478,9 @@ do_pass:
bpf_src = BPF_X;
} else {
insn->dst_reg = BPF_REG_A;
- insn->src_reg = BPF_REG_X;
insn->imm = fp->k;
bpf_src = BPF_SRC(fp->code);
+ insn->src_reg = bpf_src == BPF_X ? BPF_REG_X : 0;
}
/* Common case where 'jump_false' is next insn. */
OpenPOWER on IntegriCloud