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Date:   Fri, 29 Apr 2022 13:13:40 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Chen Zhongjin <chenzhongjin@huawei.com>
Cc:     linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-arch@vger.kernel.org, jthierry@redhat.com,
        catalin.marinas@arm.com, will@kernel.org, masahiroy@kernel.org,
        jpoimboe@redhat.com, ycote@redhat.com, herbert@gondor.apana.org.au,
        mark.rutland@arm.com, davem@davemloft.net, ardb@kernel.org,
        maz@kernel.org, tglx@linutronix.de, luc.vanoostenryck@gmail.com
Subject: Re: [RFC PATCH v4 25/37] arm64: bpf: Skip validation of
 ___bpf_prog_run
Message-ID: <YmvIZG5Ke6vElb/e@hirez.programming.kicks-ass.net>
References: <20220429094355.122389-1-chenzhongjin@huawei.com>
 <20220429094355.122389-26-chenzhongjin@huawei.com>
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On Fri, Apr 29, 2022 at 05:43:43PM +0800, Chen Zhongjin wrote:
> There is a jump table encoded in ___bpf_prog_run and objtool-arm64
> can't deal with it now. Skip validate it for arm64.

But, but, but, an earlier patch did -fno-jump-tables!

> 
> Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
> ---
>  kernel/bpf/core.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
> index 13e9dbeeedf3..d702f1d83176 100644
> --- a/kernel/bpf/core.c
> +++ b/kernel/bpf/core.c
> @@ -2022,6 +2022,9 @@ static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn)
>  		BUG_ON(1);
>  		return 0;
>  }
> +#ifdef CONFIG_ARM64
> +STACK_FRAME_NON_STANDARD(___bpf_prog_run);
> +#endif
>  
>  #define PROG_NAME(stack_size) __bpf_prog_run##stack_size
>  #define DEFINE_BPF_PROG_RUN(stack_size) \
> -- 
> 2.17.1
>