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Date:   Wed, 2 Mar 2022 11:01:38 -0500
From:   Steven Rostedt <rostedt@goodmis.org>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        alexei.starovoitov@gmail.com, alyssa.milburn@intel.com,
        andrew.cooper3@citrix.com, hjl.tools@gmail.com,
        joao@overdrivepizza.com, jpoimboe@redhat.com,
        keescook@chromium.org, linux-kernel@vger.kernel.org,
        mark.rutland@arm.com, mbenes@suse.cz, ndesaulniers@google.com,
        samitolvanen@google.com, x86@kernel.org
Subject: Re: [PATCH v2 12/39] x86/ibt,ftrace: Search for __fentry__ location
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On Wed, 2 Mar 2022 14:20:23 +0100
Peter Zijlstra <peterz@infradead.org> wrote:

> Like so, or is something else needed?
> 
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index 68ecd3e35342..d1b30b5c5c23 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -4980,7 +4980,8 @@ ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
>  {
>  	struct ftrace_func_entry *entry;
>  
> -	if (!ftrace_location(ip))
> +	ip = ftrace_location(ip);
> +	if (!ip)
>  		return -EINVAL;

This could possibly work. I'd have to test all this though.

I probably could just take this patch and try it out. You can remove the
"x86/ibt" from the subject, as this patch may be a requirement for that
(include that in the commit log), but it is has no changes to x86/ibt
specifically.

-- Steve


>  
>  	if (remove) {