Thread (4 messages) flat view 4 messages, 4 authors, 2016-05-17

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

From: David Miller <davem@davemloft.net>
Date: 2016-05-17 18:03:50
Also in: linux-arm-kernel, lkml

From: Yang Shi <redacted>
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 <redacted>
Signed-off-by: Yang Shi <redacted>
Applied.
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