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authorDavid S. Miller <davem@davemloft.net>2019-10-14 12:17:21 -0700
committerDavid S. Miller <davem@davemloft.net>2019-10-14 12:17:21 -0700
commita98d62c3ee902851500ff35525f4936bffc51466 (patch)
tree19384ec33e826e3b9a46e580087eda5faae8df1d /arch
parent7e0d15ee0d8ba28a41ed02c8d2c1c17124b13234 (diff)
parentb8fc345d6b5d661e1125bd6a0e30b6fabf1a076e (diff)
downloadlinux-a98d62c3ee902851500ff35525f4936bffc51466.tar.gz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2019-10-14

The following pull-request contains BPF updates for your *net-next* tree.

12 days of development and
85 files changed, 1889 insertions(+), 1020 deletions(-)

The main changes are:

1) auto-generation of bpf_helper_defs.h, from Andrii.

2) split of bpf_helpers.h into bpf_{helpers, helper_defs, endian, tracing}.h
   and move into libbpf, from Andrii.

3) Track contents of read-only maps as scalars in the verifier, from Andrii.

4) small x86 JIT optimization, from Daniel.

5) cross compilation support, from Ivan.

6) bpf flow_dissector enhancements, from Jakub and Stanislav.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/net/bpf_jit_comp.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 991549a1c5f3..3ad2ba1ad855 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -909,6 +909,16 @@ xadd:			if (is_imm8(insn->off))
 		case BPF_JMP32 | BPF_JSLT | BPF_K:
 		case BPF_JMP32 | BPF_JSGE | BPF_K:
 		case BPF_JMP32 | BPF_JSLE | BPF_K:
+			/* test dst_reg, dst_reg to save one extra byte */
+			if (imm32 == 0) {
+				if (BPF_CLASS(insn->code) == BPF_JMP)
+					EMIT1(add_2mod(0x48, dst_reg, dst_reg));
+				else if (is_ereg(dst_reg))
+					EMIT1(add_2mod(0x40, dst_reg, dst_reg));
+				EMIT2(0x85, add_2reg(0xC0, dst_reg, dst_reg));
+				goto emit_cond_jmp;
+			}
+
 			/* cmp dst_reg, imm8/32 */
 			if (BPF_CLASS(insn->code) == BPF_JMP)
 				EMIT1(add_1mod(0x48, dst_reg));