linux-kernel - Re: [PATCH] Revert "x86: optimize page faults like all other achitectures and kill notifier cruft"

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <200801092007.13414.ak@suse.de>
Date:	Wed, 9 Jan 2008 20:07:13 +0100
From:	Andi Kleen <ak@...e.de>
To:	Mathieu Desnoyers <mathieu.desnoyers@...ymtl.ca>
Cc:	Ingo Molnar <mingo@...e.hu>, David Miller <davem@...emloft.net>,
	hch@....de, airlied@...ux.ie, akpm@...ux-foundation.org,
	torvalds@...ux-foundation.org, pq@....fi, jbeulich@...ell.com,
	linux-kernel@...r.kernel.org,
	Ananth N Mavinakayanahalli <ananth@...ibm.com>,
	Masami Hiramatsu <mhiramat@...hat.com>
Subject: Re: [PATCH] Revert "x86: optimize page faults like all other achitectures and kill notifier cruft"


> Probing vmalloc faults is _really_ tricky : it also implies that the
> handler (let's call it probe) connected to the probe point (marker or
> kprobe) should _never_ cause a vmalloc page fault, 

That is why vmalloc_sync_all() was invented. It might make sense
to just call that on kprobe registration.

But I agree the other problems makes it a bad idea.

I think the better solution is to keep the notifier, but make 
it cheaper (e.g. by using constant patching ...)

-Andi
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/