From: Peter Zijlstra <peterz@infradead.org>
To: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Miroslav Benes <mbenes@suse.cz>,
joao@overdrivepizza.com, nstange@suse.de, pmladek@suse.cz,
jpoimboe@redhat.com, live-patching@vger.kernel.org
Subject: Re: CET/IBT support and live-patches
Date: Tue, 23 Nov 2021 22:16:36 +0100 [thread overview]
Message-ID: <20211123211636.GE721624@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <08d4a24d-02c2-6760-96bf-b72f51025808@redhat.com>
On Tue, Nov 23, 2021 at 03:58:51PM -0500, Joe Lawrence wrote:
> Yep, kpatch-build uses its own klp-relocation conversion and not kallsyms.
>
> I'm not familiar with CET/IBT, but it sounds like if a function pointer
> is not taken at build time (or maybe some other annotation), the
> compiler won't generate the needed endbr landing spot in said function?
Currently it does, but then I'm having objtool scribble it on purpose.
> And that would be a problem for modules using kallsyms lookup to get to
> said function.
Which is ofcourse the whole purpose of the exercise. If it's not
exported you don't get to call it via a back-door :-) This should kill a
whole heap of dodgy modules quite dead I hope.
next prev parent reply other threads:[~2021-11-23 21:16 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <70828ca9f840960c7a3f66cd8dc141f5@overdrivepizza.com>
2021-11-23 9:58 ` CET/IBT support and live-patches Miroslav Benes
2021-11-23 10:48 ` Peter Zijlstra
2021-11-23 11:39 ` Miroslav Benes
2021-11-23 14:10 ` Peter Zijlstra
2021-11-23 16:03 ` Steven Rostedt
2021-11-23 20:40 ` Peter Zijlstra
2021-11-24 10:02 ` Miroslav Benes
2021-11-23 20:58 ` Joe Lawrence
2021-11-23 21:16 ` Peter Zijlstra [this message]
2021-12-01 18:57 ` Joe Lawrence
2021-12-06 6:12 ` Josh Poimboeuf
2021-11-24 10:16 ` Miroslav Benes
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