From: Borislav Petkov <bp@alien8.de>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>,
Denys Vlasenko <dvlasenk@redhat.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
X86 ML <x86@kernel.org>, Ingo Molnar <mingo@kernel.org>
Subject: Re: ia32_sysenter_target does not preserve EFLAGS
Date: Sat, 28 Mar 2015 10:42:27 +0100 [thread overview]
Message-ID: <20150328094226.GC17284@pd.tnic> (raw)
In-Reply-To: <CA+55aFyJ6SnjhFwk7vgm-FfpXO+L_cgsfFqW1UK1NUgYBtRXYA@mail.gmail.com>
On Fri, Mar 27, 2015 at 01:09:34PM -0700, Linus Torvalds wrote:
> I think AMD documented that the sti "interrupt shadow" shadows even
> NMI.
Hmm, official docs says this:
"15.21.5 Interrupt Shadows
The x86 architecture defines the notion of an interrupt shadow—a
single-instruction window during which interrupts are not recognized.
For example, the instruction after an STI instruction that sets
EFLAGS.IF (from zero to one) does not recognize interrupts or certain
debug traps."
And I think with "interrupts" this means maskable interrupts, i.e. not
NMI.
STI description itself:
"Sets the interrupt flag (IF) in the rFLAGS register to 1, thereby
allowing external interrupts received on the INTR input. Interrupts
received on the non-maskable interrupt (NMI) input are not affected by
this instruction."
but there might be some other documentation which I cannot find right
now.
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
--
next prev parent reply other threads:[~2015-03-28 9:44 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-27 14:25 ia32_sysenter_target does not preserve EFLAGS Denys Vlasenko
2015-03-27 17:12 ` Borislav Petkov
2015-03-27 18:37 ` Andy Lutomirski
2015-03-27 20:09 ` Linus Torvalds
2015-03-27 20:16 ` Andy Lutomirski
2015-03-27 20:31 ` Linus Torvalds
2015-03-27 21:11 ` Andy Lutomirski
2015-03-28 9:42 ` Borislav Petkov [this message]
2015-03-27 20:53 ` Brian Gerst
2015-03-27 21:02 ` Linus Torvalds
2015-03-28 9:30 ` Ingo Molnar
2015-03-28 9:39 ` Ingo Molnar
2015-03-27 20:00 ` Linus Torvalds
2015-03-28 0:34 ` Denys Vlasenko
2015-03-28 9:28 ` Olivier Galibert
2015-03-28 9:46 ` Ingo Molnar
2015-03-28 11:17 ` Denys Vlasenko
2015-03-29 17:12 ` Andy Lutomirski
[not found] ` <CA+55aFxwNq6g+Oi-UhGBgEZuDQyNkeg6qZnkDY11PNhTN=fmzg@mail.gmail.com>
2015-03-28 11:01 ` Denys Vlasenko
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20150328094226.GC17284@pd.tnic \
--to=bp@alien8.de \
--cc=dvlasenk@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@amacapital.net \
--cc=mingo@kernel.org \
--cc=torvalds@linux-foundation.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.