From mboxrd@z Thu Jan 1 00:00:00 1970 From: Edward Cree Subject: [PATCH v2 net-next 1/2] bpf/verifier: improve disassembly of BPF_END instructions Date: Tue, 26 Sep 2017 16:35:13 +0100 Message-ID: References: <52270348-67f1-4e7a-cd2f-9d611ae94064@solarflare.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: , , , To: Return-path: Received: from dispatch1-us1.ppe-hosted.com ([67.231.154.164]:33410 "EHLO dispatch1-us1.ppe-hosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031415AbdIZPf0 (ORCPT ); Tue, 26 Sep 2017 11:35:26 -0400 In-Reply-To: <52270348-67f1-4e7a-cd2f-9d611ae94064@solarflare.com> Sender: netdev-owner@vger.kernel.org List-ID: 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 --- 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 799b245..3aaa3262 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",