Re: [PATCH v2 net-next] bpf: arm64: remove callee-save registers use for tmp registers

From: Yang Shi yang.shi@linaro.org Date: Mon, 16 May 2016 16:36:26 -0700

In the current implementation of ARM64 eBPF JIT, R23 and R24 are used for tmp registers, which are callee-saved registers. This leads to variable size of JIT prologue and epilogue. The latest blinding constant change prefers to constant size of prologue and epilogue. AAPCS reserves R9 ~ R15 for temp registers which not need to be saved/restored during function call. So, replace R23 and R24 to R10 and R11, and remove tmp_used flag to save 2 instructions for some jited BPF program.

CC: Daniel Borkmann daniel@iogearbox.net Acked-by: Zi Shen Lim zlim.lnx@gmail.com Signed-off-by: Yang Shi yang.shi@linaro.org

Applied.