From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jakub Kicinski Subject: [RFCv2 05/16] bpf: recognize 64bit immediate loads as consts Date: Fri, 26 Aug 2016 19:06:04 +0100 Message-ID: <1472234775-29453-6-git-send-email-jakub.kicinski@netronome.com> References: <1472234775-29453-1-git-send-email-jakub.kicinski@netronome.com> Cc: ast@kernel.org, daniel@iogearbox.net, dinan.gunawardena@netronome.com, jiri@resnulli.us, john.fastabend@gmail.com, kubakici@wp.pl, Jakub Kicinski To: netdev@vger.kernel.org Return-path: Received: from mail-wm0-f50.google.com ([74.125.82.50]:38435 "EHLO mail-wm0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753308AbcHZSQF (ORCPT ); Fri, 26 Aug 2016 14:16:05 -0400 Received: by mail-wm0-f50.google.com with SMTP id o80so3561651wme.1 for ; Fri, 26 Aug 2016 11:16:05 -0700 (PDT) In-Reply-To: <1472234775-29453-1-git-send-email-jakub.kicinski@netronome.com> Sender: netdev-owner@vger.kernel.org List-ID: When verifier sees a generic BPF_LD | BPF_IMM | BPF_DW it should mark the dst register as CONST_IMM with the loaded value stored in imm. Signed-off-by: Jakub Kicinski --- kernel/bpf/verifier.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index abb61f3f6900..db68a0e5db1e 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1787,9 +1787,14 @@ static int check_ld_imm(struct verifier_env *env, struct bpf_insn *insn) if (err) return err; - if (insn->src_reg == 0) + if (insn->src_reg == 0) { /* generic move 64-bit immediate into a register */ + u64 imm = ((u64)(insn + 1)->imm << 32) | (u32)insn->imm; + + regs[insn->dst_reg].type = CONST_IMM; + regs[insn->dst_reg].imm = imm; return 0; + } /* replace_map_fd_with_map_ptr() should have caught bad ld_imm64 */ BUG_ON(insn->src_reg != BPF_PSEUDO_MAP_FD); -- 1.9.1