Subject: Re: [PATCH v10 3/5] bpf: add a bpf_override_function helper
To: Josef Bacik <josef@toxicpanda.com>, <rostedt@goodmis.org>,
        <mingo@redhat.com>, <davem@davemloft.net>, <netdev@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <ast@kernel.org>, <kernel-team@fb.com>,
        <daniel@iogearbox.net>, <linux-btrfs@vger.kernel.org>,
        <darrick.wong@oracle.com>, <mhiramat@kernel.org>
References: <1513365176-6744-1-git-send-email-josef@toxicpanda.com>
 <1513365176-6744-4-git-send-email-josef@toxicpanda.com>
CC: Josef Bacik <jbacik@fb.com>
From: Alexei Starovoitov <ast@fb.com>
Message-ID: <5c212496-f898-988c-ea40-4ac6b7168d87@fb.com>
Date: Fri, 15 Dec 2017 12:34:18 -0800
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On 12/15/17 11:12 AM, Josef Bacik wrote:
> +#ifdef CONFIG_BPF_KPROBE_OVERRIDE
> +BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
> +{
> +	__this_cpu_write(bpf_kprobe_override, 1);
> +	regs_set_return_value(regs, rc);
> +	arch_ftrace_kprobe_override_function(regs);
> +	return 0;
> +}

since you're doing a respin can you adopt the change I did to make
this helper fail at load time if that #config is not set
instead of runtime?

Also how big is the v9-v10 change ?
May be do it as separate patch, since previous set already sitting
in bpf-next and there are patches on top?