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| author | Tycho Andersen <tycho.andersen@canonical.com> | 2015-09-10 18:25:07 -0600 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-09-11 14:52:41 -0700 |
| commit | 19539ce783dd27768d4f7f3b753152bf983db65b (patch) | |
| tree | 9b60e9e3326ed629ada5b85bbfbdb018550eb223 /net/core | |
| parent | 1853c949646005b5959c483becde86608f548f24 (diff) | |
| download | linux-19539ce783dd27768d4f7f3b753152bf983db65b.tar.gz linux-19539ce783dd27768d4f7f3b753152bf983db65b.tar.bz2 linux-19539ce783dd27768d4f7f3b753152bf983db65b.zip | |
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/core')
| -rw-r--r-- | net/core/filter.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index 13079f03902e..05a04ea87172 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. */ |