A later commit will need to lookup a subset of these opcodes. To
avoid duplicating code, pull out a table.
The shift opcodes won't be needed by that later commit, but they're
already duplicated, so fold them into the table anyway.
Change-Id: Ia6888f9fa65da6225c33b530ea16911bf2f70750
Signed-off-by: Brendan Jackman <[email protected]>
---
arch/x86/net/bpf_jit_comp.c | 33 +++++++++++++++------------------
1 file changed, 15 insertions(+), 18 deletions(-)
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 171ce539f6b9..ee7905051ee9 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -205,6 +205,18 @@ static u8 add_2reg(u8 byte, u32 dst_reg, u32 src_reg)
return byte + reg2hex[dst_reg] + (reg2hex[src_reg] << 3);
}
+/* Some 1-byte opcodes for binary ALU operations */
+static u8 simple_alu_opcodes[] = {
+ [BPF_ADD] = 0x01,
+ [BPF_SUB] = 0x29,
+ [BPF_AND] = 0x21,
+ [BPF_OR] = 0x09,
+ [BPF_XOR] = 0x31,
+ [BPF_LSH] = 0xE0,
+ [BPF_RSH] = 0xE8,
+ [BPF_ARSH] = 0xF8,
+};
+
static void jit_fill_hole(void *area, unsigned int size)
{
/* Fill whole space with INT3 instructions */
@@ -878,15 +890,9 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
case BPF_ALU64 | BPF_AND | BPF_X:
case BPF_ALU64 | BPF_OR | BPF_X:
case BPF_ALU64 | BPF_XOR | BPF_X:
- switch (BPF_OP(insn->code)) {
- case BPF_ADD: b2 = 0x01; break;
- case BPF_SUB: b2 = 0x29; break;
- case BPF_AND: b2 = 0x21; break;
- case BPF_OR: b2 = 0x09; break;
- case BPF_XOR: b2 = 0x31; break;
- }
maybe_emit_mod(&prog, dst_reg, src_reg,
BPF_CLASS(insn->code) == BPF_ALU64);
+ b2 = simple_alu_opcodes[BPF_OP(insn->code)];
EMIT2(b2, add_2reg(0xC0, dst_reg, src_reg));
break;
@@ -1063,12 +1069,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
else if (is_ereg(dst_reg))
EMIT1(add_1mod(0x40, dst_reg));
- switch (BPF_OP(insn->code)) {
- case BPF_LSH: b3 = 0xE0; break;
- case BPF_RSH: b3 = 0xE8; break;
- case BPF_ARSH: b3 = 0xF8; break;
- }
-
+ b3 = simple_alu_opcodes[BPF_OP(insn->code)];
if (imm32 == 1)
EMIT2(0xD1, add_1reg(b3, dst_reg));
else
@@ -1102,11 +1103,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
else if (is_ereg(dst_reg))
EMIT1(add_1mod(0x40, dst_reg));
- switch (BPF_OP(insn->code)) {
- case BPF_LSH: b3 = 0xE0; break;
- case BPF_RSH: b3 = 0xE8; break;
- case BPF_ARSH: b3 = 0xF8; break;
- }
+ b3 = simple_alu_opcodes[BPF_OP(insn->code)];
EMIT2(0xD3, add_1reg(b3, dst_reg));
if (src_reg != BPF_REG_4)
--
2.29.2.454.gaff20da3a2-goog