From: daniel@iogearbox.net (Daniel Borkmann)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 net-next] bpf: arm64: remove callee-save registers use for tmp registers
Date: Tue, 17 May 2016 13:52:19 +0200 [thread overview]
Message-ID: <573B05F3.7000009@iogearbox.net> (raw)
In-Reply-To: <1463441786-32224-1-git-send-email-yang.shi@linaro.org>
On 05/17/2016 01:36 AM, Yang Shi wrote:
> 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>
LGTM, thanks!
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
WARNING: multiple messages have this Message-ID (diff)
From: Daniel Borkmann <daniel@iogearbox.net>
To: Yang Shi <yang.shi@linaro.org>, ast@kernel.org, davem@davemloft.net
Cc: will.deacon@arm.com, catalin.marinas@arm.com, zlim.lnx@gmail.com,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linaro-kernel@lists.linaro.org
Subject: Re: [PATCH v2 net-next] bpf: arm64: remove callee-save registers use for tmp registers
Date: Tue, 17 May 2016 13:52:19 +0200 [thread overview]
Message-ID: <573B05F3.7000009@iogearbox.net> (raw)
In-Reply-To: <1463441786-32224-1-git-send-email-yang.shi@linaro.org>
On 05/17/2016 01:36 AM, Yang Shi wrote:
> 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>
LGTM, thanks!
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
next prev parent reply other threads:[~2016-05-17 11:52 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-16 23:36 [PATCH v2 net-next] bpf: arm64: remove callee-save registers use for tmp registers Yang Shi
2016-05-16 23:36 ` Yang Shi
2016-05-17 11:13 ` Catalin Marinas
2016-05-17 11:13 ` Catalin Marinas
2016-05-17 11:52 ` Daniel Borkmann [this message]
2016-05-17 11:52 ` Daniel Borkmann
2016-05-17 18:03 ` David Miller
2016-05-17 18:03 ` David Miller
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