Re: [PATCH RFC net-next 08/14] bpf: add eBPF verifier
From: Daniel Borkmann <hidden>
Date: 2014-07-01 08:05:55
Also in:
linux-api, lkml
On 06/28/2014 02:06 AM, Alexei Starovoitov wrote:
Safety of eBPF programs is statically determined by the verifier, which detects: - loops - out of range jumps - unreachable instructions - invalid instructions - uninitialized register access - uninitialized stack access - misaligned stack access - out of range stack access - invalid calling convention
...
More details in Documentation/networking/filter.txt Signed-off-by: Alexei Starovoitov <ast-uqk4Ao+rVK5Wk0Htik3J/w@public.gmane.org> ---
...
kernel/bpf/verifier.c | 1431 +++++++++++++++++++++++++++++++++++
Looking at classic BPF verifier which checks safety of BPF user space programs, it's roughly 200 loc. :-/
quoted hunk ↗ jump to hunk
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c new file mode 100644
...
+#define _(OP) ({ int ret = OP; if (ret < 0) return ret; })...
+ _(get_map_info(env, map_id, &map));
...
+ _(size = bpf_size_to_bytes(bpf_size));
Nit: such macros should be removed, please.