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From: Daniel Borkmann <daniel@iogearbox.net>
To: David Miller <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org, netdev@vger.kernel.org, ast@kernel.org
Subject: Re: [PATCH RFC] sparc64: eBPF JIT
Date: Mon, 17 Apr 2017 22:55:01 +0200	[thread overview]
Message-ID: <58F52BA5.1090808@iogearbox.net> (raw)
In-Reply-To: <20170417.150326.345314944044934203.davem@davemloft.net>

On 04/17/2017 09:03 PM, David Miller wrote:
> From: Daniel Borkmann <daniel@iogearbox.net>
> Date: Mon, 17 Apr 2017 20:44:35 +0200
>
>> On 04/17/2017 05:38 AM, David Miller wrote:
>>> +/* Map BPF registers to SPARC registers */
>>> +static const int bpf2sparc[] = {
>>> + /* return value from in-kernel function, and exit value from eBPF */
>>> +	[BPF_REG_0] = I5,
>>> +
>>> +	/* arguments from eBPF program to in-kernel function */
>>> +	[BPF_REG_1] = I0,
>>> +	[BPF_REG_2] = I1,
>>> +	[BPF_REG_3] = I2,
>>> +	[BPF_REG_4] = I3,
>>> +	[BPF_REG_5] = I4,
>>> +
>>> + /* callee saved registers that in-kernel function will preserve */
>>> +	[BPF_REG_6] = L0,
>>> +	[BPF_REG_7] = L1,
>>> +	[BPF_REG_8] = L2,
>>> +	[BPF_REG_9] = L3,
>>> +
>>> +	/* read-only frame pointer to access stack */
>>> +	[BPF_REG_FP] = FP,
>>
>> On a quick initial glance, you also need to map BPF_REG_AX. If
>> I understand the convention correctly, you could use L7 for that.
>>
>> You can test for it through tools/testing/selftests/bpf/test_kmod.sh
>> which exercises the test_bpf.ko under various sysctl combinations as
>> part of the BPF selftest suite.
>
> Oh I see, it's used for constant blinding.  I can use a global register
> for that since it's only used as a temporary right?

Yeah, correct.

WARNING: multiple messages have this Message-ID (diff)
From: Daniel Borkmann <daniel@iogearbox.net>
To: David Miller <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org, netdev@vger.kernel.org, ast@kernel.org
Subject: Re: [PATCH RFC] sparc64: eBPF JIT
Date: Mon, 17 Apr 2017 20:55:01 +0000	[thread overview]
Message-ID: <58F52BA5.1090808@iogearbox.net> (raw)
In-Reply-To: <20170417.150326.345314944044934203.davem@davemloft.net>

On 04/17/2017 09:03 PM, David Miller wrote:
> From: Daniel Borkmann <daniel@iogearbox.net>
> Date: Mon, 17 Apr 2017 20:44:35 +0200
>
>> On 04/17/2017 05:38 AM, David Miller wrote:
>>> +/* Map BPF registers to SPARC registers */
>>> +static const int bpf2sparc[] = {
>>> + /* return value from in-kernel function, and exit value from eBPF */
>>> +	[BPF_REG_0] = I5,
>>> +
>>> +	/* arguments from eBPF program to in-kernel function */
>>> +	[BPF_REG_1] = I0,
>>> +	[BPF_REG_2] = I1,
>>> +	[BPF_REG_3] = I2,
>>> +	[BPF_REG_4] = I3,
>>> +	[BPF_REG_5] = I4,
>>> +
>>> + /* callee saved registers that in-kernel function will preserve */
>>> +	[BPF_REG_6] = L0,
>>> +	[BPF_REG_7] = L1,
>>> +	[BPF_REG_8] = L2,
>>> +	[BPF_REG_9] = L3,
>>> +
>>> +	/* read-only frame pointer to access stack */
>>> +	[BPF_REG_FP] = FP,
>>
>> On a quick initial glance, you also need to map BPF_REG_AX. If
>> I understand the convention correctly, you could use L7 for that.
>>
>> You can test for it through tools/testing/selftests/bpf/test_kmod.sh
>> which exercises the test_bpf.ko under various sysctl combinations as
>> part of the BPF selftest suite.
>
> Oh I see, it's used for constant blinding.  I can use a global register
> for that since it's only used as a temporary right?

Yeah, correct.

  reply	other threads:[~2017-04-17 20:55 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-17  3:38 [PATCH RFC] sparc64: eBPF JIT David Miller
2017-04-17  3:38 ` David Miller
2017-04-17 18:44 ` Daniel Borkmann
2017-04-17 18:44   ` Daniel Borkmann
2017-04-17 19:03   ` David Miller
2017-04-17 19:03     ` David Miller
2017-04-17 20:55     ` Daniel Borkmann [this message]
2017-04-17 20:55       ` Daniel Borkmann
2017-04-17 20:12   ` David Miller
2017-04-17 20:12     ` David Miller
2017-04-21 16:46   ` David Miller
2017-04-21 16:46     ` David Miller
2017-04-21 16:50     ` Daniel Borkmann
2017-04-21 16:50       ` Daniel Borkmann
2017-04-21 18:49     ` Alexei Starovoitov
2017-04-21 18:49       ` Alexei Starovoitov
2017-04-21 19:02       ` David Miller
2017-04-21 19:02         ` David Miller
2017-04-21 19:26         ` Alexei Starovoitov
2017-04-21 19:26           ` Alexei Starovoitov
2017-04-21 19:41           ` David Miller
2017-04-21 19:41             ` David Miller
2017-04-17 23:27 ` Alexei Starovoitov
2017-04-17 23:27   ` Alexei Starovoitov
2017-04-18  1:12   ` David Miller
2017-04-18  1:12     ` David Miller
2017-04-18  5:44     ` Alexei Starovoitov
2017-04-18  5:44       ` Alexei Starovoitov
2017-04-18 18:37       ` David Miller
2017-04-18 18:37         ` David Miller
2017-04-18 22:57         ` Alexei Starovoitov
2017-04-18 22:57           ` Alexei Starovoitov
2017-04-19  2:27           ` David Miller
2017-04-19  2:27             ` David Miller
2017-04-22  1:19           ` David Miller
2017-04-22  1:19             ` David Miller

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