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Subject: Re: [PATCH] MIPS/bpf: Enable bpf_probe_read{, str}() on MIPS again
To:     Tiezhu Yang <yangtiezhu@loongson.cn>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc:     linux-mips@vger.kernel.org, bpf@vger.kernel.org,
        linux-kernel@vger.kernel.org, Xuefeng Li <lixuefeng@loongson.cn>
References: <1615965307-6926-1-git-send-email-yangtiezhu@loongson.cn>
From:   Daniel Borkmann <daniel@iogearbox.net>
Message-ID: <6b239565-8fbb-d183-6a4d-13fc90af3e27@iogearbox.net>
Date:   Wed, 17 Mar 2021 23:18:48 +0100
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On 3/17/21 8:15 AM, Tiezhu Yang wrote:
> After commit 0ebeea8ca8a4 ("bpf: Restrict bpf_probe_read{, str}() only to
> archs where they work"), bpf_probe_read{, str}() functions were not longer
> available on MIPS, so there exists some errors when running bpf program:
> 
> root@linux:/home/loongson/bcc# python examples/tracing/task_switch.py
> bpf: Failed to load program: Invalid argument
> [...]
> 11: (85) call bpf_probe_read#4
> unknown func bpf_probe_read#4
> [...]
> Exception: Failed to load BPF program count_sched: Invalid argument
> 
> So select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE in arch/mips/Kconfig,
> otherwise the bpf old helper bpf_probe_read() will not be available.
> 
> This is similar with the commit d195b1d1d1196 ("powerpc/bpf: Enable
> bpf_probe_read{, str}() on powerpc again").
> 
> Fixes: 0ebeea8ca8a4 ("bpf: Restrict bpf_probe_read{, str}() only to archs where they work")
> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>

Thomas, I presume you pick this up via mips tree (with typos fixed)? Or do you
want us to route the fix via bpf with your ACK? (I'm fine either way.)

Thanks,
Daniel