Groups > linux.kernel > #1193973

Re: [PATCH v2 2/3] x86/entry/64: Teach idtentry to use the IRQ stack

From	Borislav Petkov <bp@alien8.de>
Newsgroups	linux.kernel
Subject	Re: [PATCH v2 2/3] x86/entry/64: Teach idtentry to use the IRQ stack
Date	2015-07-28 12:00 +0200
Message-ID	<pR9PY-5AL-35@gated-at.bofh.it> (permalink)
References	<pQ0F3-42m-1@gated-at.bofh.it> <pQ0F4-42m-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Fri, Jul 24, 2015 at 10:57:05PM -0700, Andy Lutomirski wrote:
> We don't specifically need IST for things like kprobes, but we do
> want to avoid rare, surprising extra stack usage if a kprobe hits
> with a deep stack.
> 
> Teach idtentry to use the IRQ stack for selected entries.
> 
> This implementation uses the IRQ stack even if we entered from user
> mode.  This disallows tricks like ist_begin_non_atomic.  If we ever
> need such a trick in one of these entries, we can rework this.  For
> now, let's keep it simple.
> 
> Signed-off-by: Andy Lutomirski <luto@kernel.org>
> ---
>  arch/x86/entry/entry_64.S | 14 +++++++++++++-
>  1 file changed, 13 insertions(+), 1 deletion(-)

Reviewed-by: Borislav Petkov <bp@suse.de>

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
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Re: [PATCH v2 2/3] x86/entry/64: Teach idtentry to use the IRQ stack Borislav Petkov <bp@alien8.de> - 2015-07-28 12:00 +0200

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