From: "Andy Lutomirski" <luto@kernel.org>
To: "Sohil Mehta" <sohil.mehta@intel.com>,
"H. Peter Anvin" <hpa@zytor.com>,
"the arch/x86 maintainers" <x86@kernel.org>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
"Borislav Petkov" <bp@alien8.de>
Cc: "Jonathan Corbet" <corbet@lwn.net>,
"Josh Poimboeuf" <jpoimboe@kernel.org>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
"Ard Biesheuvel" <ardb@kernel.org>,
"Kirill A . Shutemov" <kas@kernel.org>, "Xin Li" <xin@zytor.com>,
"David Woodhouse" <dwmw@amazon.co.uk>,
"Sean Christopherson" <seanjc@google.com>,
"Rick P Edgecombe" <rick.p.edgecombe@intel.com>,
"Vegard Nossum" <vegard.nossum@oracle.com>,
"Andrew Cooper" <andrew.cooper3@citrix.com>,
"Randy Dunlap" <rdunlap@infradead.org>,
"Geert Uytterhoeven" <geert@linux-m68k.org>,
"Kees Cook" <kees@kernel.org>, "Tony Luck" <tony.luck@intel.com>,
"Alexander Shishkin" <alexander.shishkin@linux.intel.com>,
linux-doc@vger.kernel.org,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
linux-efi@vger.kernel.org
Subject: Re: [PATCH v11 9/9] x86/cpu: Enable LASS by default during CPU initialization
Date: Thu, 30 Oct 2025 10:31:56 -0700 [thread overview]
Message-ID: <202682ea-304d-43b2-8a69-c8bc9d8e3e2c@app.fastmail.com> (raw)
In-Reply-To: <e3215a62-335f-463b-98d1-de95e5859b9d@intel.com>
On Thu, Oct 30, 2025, at 10:24 AM, Sohil Mehta wrote:
> On 10/30/2025 9:53 AM, Andy Lutomirski wrote:
>
>>> On the other hand, supporting EMULATE mode during a #GP is a bit tricky,
>>> which isn't worth the effort.
>>
>> I would say it's definitely worth the effort, but it probably does make sense to get the rest of the series in a mergeable condition such that it only works with vsyscall=none.
>
> I meant the full emulation mode where the Vsyscall page is readable. It
> is only available via vsyscall=emulate. No one should be using that one,
> right?
>
> I thought you and Linus agreed on removing EMULATE mode completely:
> https://lore.kernel.org/all/CALCETrXHJ7837+cmahg-wjR3iRHbDJ6JtVGaoDFC4dx-L8r8OA@mail.gmail.com/
>
> I agree that it would be worthwhile (and relatively easy) to support the
> execute (XONLY) mode (that only does instruction fetches). That is what
> the separate vsyscall series would do once the LASS base is in.
Ah, I misunderstood you. I agree.
next prev parent reply other threads:[~2025-10-30 17:32 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-29 21:03 [PATCH v11 0/9] x86: Enable Linear Address Space Separation support Sohil Mehta
2025-10-29 21:03 ` [PATCH v11 1/9] x86/cpufeatures: Enumerate the LASS feature bits Sohil Mehta
2025-10-31 17:03 ` Dave Hansen
2025-10-29 21:03 ` [PATCH v11 2/9] x86/cpu: Add an LASS dependency on SMAP Sohil Mehta
2025-10-31 17:04 ` Dave Hansen
2025-10-29 21:03 ` [PATCH v11 3/9] x86/asm: Introduce inline memcpy and memset Sohil Mehta
2025-10-31 17:06 ` Dave Hansen
2025-10-29 21:03 ` [PATCH v11 4/9] x86/alternatives: Disable LASS when patching kernel code Sohil Mehta
2025-10-31 17:10 ` Dave Hansen
2025-11-10 18:15 ` Sohil Mehta
2025-11-10 19:09 ` H. Peter Anvin
2025-11-10 19:24 ` Borislav Petkov
2025-11-12 13:56 ` Ard Biesheuvel
2025-11-12 14:51 ` Dave Hansen
2025-11-12 14:57 ` H. Peter Anvin
2025-11-12 15:18 ` Ard Biesheuvel
2025-11-12 15:23 ` H. Peter Anvin
2025-11-12 15:28 ` Ard Biesheuvel
2025-11-12 15:47 ` H. Peter Anvin
2025-11-12 16:18 ` Sohil Mehta
2025-11-12 16:26 ` H. Peter Anvin
2025-11-12 16:29 ` H. Peter Anvin
2025-10-29 21:03 ` [PATCH v11 5/9] x86/efi: Disable LASS while mapping the EFI runtime services Sohil Mehta
2025-10-31 17:11 ` Dave Hansen
2025-10-31 17:38 ` Andy Lutomirski
2025-10-31 17:41 ` Dave Hansen
2025-10-31 18:03 ` Sohil Mehta
2025-10-31 18:12 ` Dave Hansen
2025-11-07 9:04 ` Peter Zijlstra
2025-11-07 9:22 ` Ard Biesheuvel
2025-11-07 9:27 ` H. Peter Anvin
2025-11-07 9:35 ` Ard Biesheuvel
2025-11-07 9:40 ` Peter Zijlstra
2025-11-07 10:09 ` Ard Biesheuvel
2025-11-07 10:27 ` Peter Zijlstra
2025-11-08 0:48 ` Andy Lutomirski
2025-11-08 16:18 ` H. Peter Anvin
2025-11-08 22:50 ` H. Peter Anvin
2025-11-07 10:10 ` Peter Zijlstra
2025-11-07 10:17 ` Ard Biesheuvel
2025-10-31 19:04 ` Sohil Mehta
2025-11-07 7:36 ` Sohil Mehta
2025-10-31 18:32 ` Sohil Mehta
2025-10-29 21:03 ` [PATCH v11 6/9] x86/kexec: Disable LASS during relocate kernel Sohil Mehta
2025-10-31 17:14 ` Dave Hansen
2025-10-29 21:03 ` [PATCH v11 7/9] x86/traps: Communicate a LASS violation in #GP message Sohil Mehta
2025-10-31 17:16 ` Dave Hansen
2025-10-31 19:59 ` Sohil Mehta
2025-10-31 20:03 ` Andy Lutomirski
2025-10-31 20:56 ` Dave Hansen
2025-10-29 21:03 ` [PATCH v11 8/9] selftests/x86: Update the negative vsyscall tests to expect a #GP Sohil Mehta
2025-10-31 17:20 ` Dave Hansen
2025-10-29 21:03 ` [PATCH v11 9/9] x86/cpu: Enable LASS by default during CPU initialization Sohil Mehta
2025-10-30 8:40 ` H. Peter Anvin
2025-10-30 15:45 ` Andy Lutomirski
2025-10-30 16:44 ` Sohil Mehta
2025-10-30 16:53 ` Andy Lutomirski
2025-10-30 17:24 ` Sohil Mehta
2025-10-30 17:31 ` Andy Lutomirski [this message]
2025-10-30 21:13 ` David Laight
2025-10-31 6:41 ` H. Peter Anvin
2025-10-31 16:55 ` Dave Hansen
2025-10-30 16:27 ` Dave Hansen
2025-11-07 8:01 ` H. Peter Anvin
2025-11-07 20:08 ` Sohil Mehta
2025-10-31 17:21 ` Dave Hansen
2025-10-31 20:04 ` Sohil Mehta
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