From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH net-next 2/3] arm64: bpf: optimize JMP_CALL
Date: Mon, 6 Jun 2016 18:05:15 +0100 [thread overview]
Message-ID: <20160606170515.GK669@arm.com> (raw)
In-Reply-To: <1465077630-633-2-git-send-email-zlim.lnx@gmail.com>
On Sat, Jun 04, 2016 at 03:00:29PM -0700, Zi Shen Lim wrote:
> Remove superfluous stack frame, saving us 3 instructions for
> every JMP_CALL.
>
> Signed-off-by: Zi Shen Lim <zlim.lnx@gmail.com>
> ---
> arch/arm64/net/bpf_jit_comp.c | 3 ---
> 1 file changed, 3 deletions(-)
>
> diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
> index 51abc97..7ae304e 100644
> --- a/arch/arm64/net/bpf_jit_comp.c
> +++ b/arch/arm64/net/bpf_jit_comp.c
> @@ -578,11 +578,8 @@ emit_cond_jmp:
> const u64 func = (u64)__bpf_call_base + imm;
>
> emit_a64_mov_i64(tmp, func, ctx);
> - emit(A64_PUSH(A64_FP, A64_LR, A64_SP), ctx);
> - emit(A64_MOV(1, A64_FP, A64_SP), ctx);
> emit(A64_BLR(tmp), ctx);
> emit(A64_MOV(1, r0, A64_R(0)), ctx);
> - emit(A64_POP(A64_FP, A64_LR, A64_SP), ctx);
> break;
> }
Is the jitted code intended to be unwindable by standard tools?
Will
WARNING: multiple messages have this Message-ID (diff)
From: Will Deacon <will.deacon@arm.com>
To: Zi Shen Lim <zlim.lnx@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>,
Catalin Marinas <catalin.marinas@arm.com>,
Yang Shi <yang.shi@linaro.org>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next 2/3] arm64: bpf: optimize JMP_CALL
Date: Mon, 6 Jun 2016 18:05:15 +0100 [thread overview]
Message-ID: <20160606170515.GK669@arm.com> (raw)
In-Reply-To: <1465077630-633-2-git-send-email-zlim.lnx@gmail.com>
On Sat, Jun 04, 2016 at 03:00:29PM -0700, Zi Shen Lim wrote:
> Remove superfluous stack frame, saving us 3 instructions for
> every JMP_CALL.
>
> Signed-off-by: Zi Shen Lim <zlim.lnx@gmail.com>
> ---
> arch/arm64/net/bpf_jit_comp.c | 3 ---
> 1 file changed, 3 deletions(-)
>
> diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
> index 51abc97..7ae304e 100644
> --- a/arch/arm64/net/bpf_jit_comp.c
> +++ b/arch/arm64/net/bpf_jit_comp.c
> @@ -578,11 +578,8 @@ emit_cond_jmp:
> const u64 func = (u64)__bpf_call_base + imm;
>
> emit_a64_mov_i64(tmp, func, ctx);
> - emit(A64_PUSH(A64_FP, A64_LR, A64_SP), ctx);
> - emit(A64_MOV(1, A64_FP, A64_SP), ctx);
> emit(A64_BLR(tmp), ctx);
> emit(A64_MOV(1, r0, A64_R(0)), ctx);
> - emit(A64_POP(A64_FP, A64_LR, A64_SP), ctx);
> break;
> }
Is the jitted code intended to be unwindable by standard tools?
Will
next prev parent reply other threads:[~2016-06-06 17:05 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-04 22:00 [PATCH net-next 1/3] arm64: bpf: implement bpf_tail_call() helper Zi Shen Lim
2016-06-04 22:00 ` Zi Shen Lim
2016-06-04 22:00 ` [PATCH net-next 2/3] arm64: bpf: optimize JMP_CALL Zi Shen Lim
2016-06-04 22:00 ` Zi Shen Lim
2016-06-06 17:05 ` Will Deacon [this message]
2016-06-06 17:05 ` Will Deacon
2016-06-07 4:36 ` Z Lim
2016-06-07 4:36 ` Z Lim
2016-06-07 8:10 ` Will Deacon
2016-06-07 8:10 ` Will Deacon
2016-06-04 22:00 ` [PATCH net-next 3/3] arm64: bpf: optimize LD_ABS, LD_IND Zi Shen Lim
2016-06-04 22:00 ` Zi Shen Lim
2016-06-04 23:46 ` [PATCH net-next 1/3] arm64: bpf: implement bpf_tail_call() helper kbuild test robot
2016-06-04 23:46 ` kbuild test robot
2016-06-05 7:53 ` Daniel Borkmann
2016-06-05 7:53 ` Daniel Borkmann
2016-06-06 4:56 ` Z Lim
2016-06-06 4:56 ` Z Lim
2016-06-06 8:11 ` Daniel Borkmann
2016-06-06 8:11 ` Daniel Borkmann
2016-06-07 2:33 ` Zi Shen Lim
2016-06-07 2:33 ` Zi Shen Lim
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