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From:   Alexei Starovoitov <alexei.starovoitov@gmail.com>
Date:   Wed, 4 Sep 2019 08:26:52 -0700
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Subject: Re: [PATCH 2/2] sched/debug: add sched_update_nr_running tracepoint
To:     Joel Fernandes <joel@joelfernandes.org>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Valentin Schneider <valentin.schneider@arm.com>,
        =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= <rkrcmar@redhat.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Ingo Molnar <mingo@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Andy Lutomirski <luto@kernel.org>,
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        X86 ML <x86@kernel.org>, Qais Yousef <qais.yousef@arm.com>
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On Wed, Sep 4, 2019 at 6:14 AM Joel Fernandes <joel@joelfernandes.org> wrote:
>
> True. However, for kprobes-based BPF program - it does check for kernel
> version to ensure that the BPF program is built against the right kernel
> version (in order to ensure the program is built against the right set of
> kernel headers). If it is not, then BPF refuses to load the program.

This is not true anymore. Users found few ways to workaround that check
in practice. It became useless and it was deleted some time ago.