arm64: bpf: optimize LD_ABS, LD_IND

Remove superfluous stack frame, saving us 3 instructions for every
LD_ABS or LD_IND.

Signed-off-by: Zi Shen Lim <zlim.lnx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: zlim

arch/arm64/net/bpf_jit_comp.c

@@ -731,11 +731,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
 		emit_a64_mov_i64(r3, size, ctx);
 		emit(A64_SUB_I(1, r4, fp, STACK_SIZE), ctx);
 		emit_a64_mov_i64(r5, (unsigned long)bpf_load_pointer, ctx);
-		emit(A64_PUSH(A64_FP, A64_LR, A64_SP), ctx);
-		emit(A64_MOV(1, A64_FP, A64_SP), ctx);
 		emit(A64_BLR(r5), ctx);
 		emit(A64_MOV(1, r0, A64_R(0)), ctx);
-		emit(A64_POP(A64_FP, A64_LR, A64_SP), ctx);
 
 		jmp_offset = epilogue_offset(ctx);
 		check_imm19(jmp_offset);