From: Edward Cree <ecree@solarflare.com>
Date: Tue, 26 Sep 2017 16:35:13 +0100
Subject: bpf/verifier: improve disassembly of BPF_END instructions
Patch-mainline: v4.15-rc1
Git-commit: 2b7c6ba945fd3c10ca3e030be402098aff2f89d3
References: bsc#1073928
print_bpf_insn() was treating all BPF_ALU[64] the same, but BPF_END has a
different structure: it has a size in insn->imm (even if it's BPF_X) and
uses the BPF_SRC (X or K) to indicate which endianness to use. So it
needs different code to print it.
Signed-off-by: Edward Cree <ecree@solarflare.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Michal Kubecek <mkubecek@suse.cz>
---
kernel/bpf/verifier.c | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 844bb834e72e..8fb853980feb 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -325,26 +325,40 @@ static const char *const bpf_jmp_string[16] = {
[BPF_EXIT >> 4] = "exit",
};
+static void print_bpf_end_insn(const struct bpf_verifier_env *env,
+ const struct bpf_insn *insn)
+{
+ verbose("(%02x) r%d = %s%d r%d\n", insn->code, insn->dst_reg,
+ BPF_SRC(insn->code) == BPF_TO_BE ? "be" : "le",
+ insn->imm, insn->dst_reg);
+}
+
static void print_bpf_insn(const struct bpf_verifier_env *env,
const struct bpf_insn *insn)
{
u8 class = BPF_CLASS(insn->code);
if (class == BPF_ALU || class == BPF_ALU64) {
- if (BPF_SRC(insn->code) == BPF_X)
+ if (BPF_OP(insn->code) == BPF_END) {
+ if (class == BPF_ALU64)
+ verbose("BUG_alu64_%02x\n", insn->code);
+ else
+ print_bpf_end_insn(env, insn);
+ } else if (BPF_SRC(insn->code) == BPF_X) {
verbose("(%02x) %sr%d %s %sr%d\n",
insn->code, class == BPF_ALU ? "(u32) " : "",
insn->dst_reg,
bpf_alu_string[BPF_OP(insn->code) >> 4],
class == BPF_ALU ? "(u32) " : "",
insn->src_reg);
- else
+ } else {
verbose("(%02x) %sr%d %s %s%d\n",
insn->code, class == BPF_ALU ? "(u32) " : "",
insn->dst_reg,
bpf_alu_string[BPF_OP(insn->code) >> 4],
class == BPF_ALU ? "(u32) " : "",
insn->imm);
+ }
} else if (class == BPF_STX) {
if (BPF_MODE(insn->code) == BPF_MEM)
verbose("(%02x) *(%s *)(r%d %+d) = r%d\n",
--
2.15.1