From: Andi Kleen <ak@linux.intel.com>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Andi Kleen <andi@firstfloor.org>, X86 ML <x86@kernel.org>,
Andrew Lutomirski <luto@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Borislav Petkov <bp@alien8.de>
Subject: Re: [PATCH 4/8] x86: Add support for rd/wr fs/gs base
Date: Fri, 10 Apr 2015 13:57:02 -0700 [thread overview]
Message-ID: <20150410205702.GV15335@tassilo.jf.intel.com> (raw)
In-Reply-To: <CALCETrVWzEwKXKPs5=Ay=9-g+=YHAC4BVhvvYoQLp3AR96q1MQ@mail.gmail.com>
> I think all of this stems from unfortunate naming. DEBUG_STACK isn't
> one stack -- it's a debug stack *array*. The IST shift mechanism
> means that we can use different entries in that array as our stacks
> depending on how deeply nested we are.
I still think it's a terrible idea.
> > Just handling it in the code is simple enough.
>
> It seems to account for over half the asm diff. I'm talking about the
> addition of approximately two lines of C and the removal of a huge
> chunk of the asm diff.
It's just adding offsets to the stack code. Nothing complicated.
It's also straight forward code. Far more preferable than your magic
overlapping stacks.
-Andi
--
ak@linux.intel.com -- Speaking for myself only
next prev parent reply other threads:[~2015-04-10 20:57 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-10 15:50 Updated RD/WRFS/GSBASE patchkit Andi Kleen
2015-04-10 15:50 ` [PATCH 1/8] percpu: Add a DEFINE_PER_CPU_2PAGE_ALIGNED Andi Kleen
2015-04-10 15:50 ` [PATCH 2/8] x86: Naturally align the debug IST stack Andi Kleen
2015-04-10 18:50 ` Andy Lutomirski
2015-04-10 15:50 ` [PATCH 3/8] x86: Add intrinsics/macros for new rd/wr fs/gs base instructions Andi Kleen
2015-04-10 19:06 ` Andy Lutomirski
2015-04-10 19:07 ` Andy Lutomirski
2015-04-10 15:50 ` [PATCH 4/8] x86: Add support for rd/wr fs/gs base Andi Kleen
2015-04-10 19:12 ` Andy Lutomirski
2015-04-10 20:21 ` Andi Kleen
2015-04-10 20:25 ` Borislav Petkov
2015-04-10 20:52 ` Andi Kleen
2015-04-10 20:53 ` Borislav Petkov
2015-04-10 20:34 ` Andy Lutomirski
2015-04-10 20:41 ` Andi Kleen
2015-04-10 20:47 ` Andy Lutomirski
2015-04-10 20:57 ` Andi Kleen [this message]
2015-04-10 21:07 ` Andy Lutomirski
2015-04-10 22:52 ` Andi Kleen
2015-04-10 23:00 ` Andy Lutomirski
2015-04-10 23:05 ` Andi Kleen
2015-04-10 23:15 ` Andy Lutomirski
2015-04-10 23:18 ` Andi Kleen
2015-04-10 23:21 ` Andy Lutomirski
2015-04-10 23:16 ` Andi Kleen
2015-04-13 7:07 ` Jan Beulich
2015-04-10 15:50 ` [PATCH 5/8] x86: Make old K8 swapgs workaround conditional Andi Kleen
2015-04-10 21:46 ` Andy Lutomirski
2015-04-10 22:01 ` Borislav Petkov
2015-04-10 23:10 ` Andi Kleen
2015-04-11 7:18 ` Borislav Petkov
2015-04-10 15:50 ` [PATCH 6/8] x86: Enumerate kernel FSGS capability in AT_HWCAP2 Andi Kleen
2015-04-10 19:15 ` Andy Lutomirski
2015-04-10 22:14 ` Borislav Petkov
2015-04-10 23:07 ` Andi Kleen
2015-04-10 23:08 ` Andi Kleen
2015-04-11 7:16 ` Borislav Petkov
2015-04-11 8:35 ` Intel FSGSBASE support (was: Re: [PATCH 6/8] x86: Enumerate kernel FSGS capability in AT_HWCAP2) Ingo Molnar
2015-04-10 15:50 ` [PATCH 7/8] x86: Add documentation for rd/wr fs/gs base Andi Kleen
2015-04-10 19:17 ` Andy Lutomirski
2015-04-10 20:22 ` Andi Kleen
2015-04-10 20:38 ` Andy Lutomirski
2015-04-10 20:46 ` Andi Kleen
2015-04-10 20:52 ` Andy Lutomirski
2015-04-10 15:50 ` [PATCH 8/8] x86: Use rd/wr fs/gs base in arch_prctl Andi Kleen
2015-04-10 19:19 ` Andy Lutomirski
2015-04-10 19:58 ` Andi Kleen
-- strict thread matches above, loose matches on Subject: below --
2014-11-10 23:55 [PATCH 1/8] percpu: Add a DEFINE_PER_CPU_2PAGE_ALIGNED Andi Kleen
2014-11-10 23:55 ` [PATCH 4/8] x86: Add support for rd/wr fs/gs base Andi Kleen
2014-11-11 20:05 ` Andy Lutomirski
2014-11-11 20:49 ` Andy Lutomirski
2014-10-15 5:11 [PATCH 1/8] percpu: Add a DEFINE_PER_CPU_2PAGE_ALIGNED Andi Kleen
2014-10-15 5:11 ` [PATCH 4/8] x86: Add support for rd/wr fs/gs base Andi Kleen
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