netdev - [PATH bpf-next 04/13] x86_64: bpf: implement jitting of JMP32

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Message-Id: <1545259460-13376-5-git-send-email-jiong.wang@netronome.com>
Date:   Wed, 19 Dec 2018 17:44:11 -0500
From:   Jiong Wang <jiong.wang@...ronome.com>
To:     ast@...nel.org, daniel@...earbox.net
Cc:     netdev@...r.kernel.org, oss-drivers@...ronome.com,
        Jiong Wang <jiong.wang@...ronome.com>
Subject: [PATH bpf-next 04/13] x86_64: bpf: implement jitting of JMP32

This patch implements code-gen for new JMP32 instructions on x86_64.

Cc: Alexei Starovoitov <ast@...nel.org>
Cc: Daniel Borkmann <daniel@...earbox.net>
Signed-off-by: Jiong Wang <jiong.wang@...ronome.com>
---
 arch/x86/net/bpf_jit_comp.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 5542303..499f1c1 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -882,8 +882,12 @@ xadd:			if (is_imm8(insn->off))
 		case BPF_JMP | BPF_JSGE | BPF_X:
 		case BPF_JMP | BPF_JSLE | BPF_X:
 			/* cmp dst_reg, src_reg */
-			EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x39,
-			      add_2reg(0xC0, dst_reg, src_reg));
+			if (!imm32) /* JMP32 */
+				EMIT1(add_2mod(0x48, dst_reg, src_reg));
+			else if (is_ereg(dst_reg) || is_ereg(src_reg))
+				EMIT1(add_2mod(0x40, dst_reg, src_reg));
+
+			EMIT2(0x39, add_2reg(0xC0, dst_reg, src_reg));
 			goto emit_cond_jmp;
 
 		case BPF_JMP | BPF_JSET | BPF_X:
@@ -909,7 +913,10 @@ xadd:			if (is_imm8(insn->off))
 		case BPF_JMP | BPF_JSGE | BPF_K:
 		case BPF_JMP | BPF_JSLE | BPF_K:
 			/* cmp dst_reg, imm8/32 */
-			EMIT1(add_1mod(0x48, dst_reg));
+			if (!src_reg) /* JMP32 */
+				EMIT1(add_1mod(0x48, dst_reg));
+			else if (is_ereg(dst_reg))
+				EMIT1(add_1mod(0x40, dst_reg));
 
 			if (is_imm8(imm32))
 				EMIT3(0x83, add_1reg(0xF8, dst_reg), imm32);
-- 
2.7.4