From: Sohil Mehta <sohil.mehta@intel.com>
To: Andy Lutomirski <luto@kernel.org>,
"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 10:24:24 -0700 [thread overview]
Message-ID: <e3215a62-335f-463b-98d1-de95e5859b9d@intel.com> (raw)
In-Reply-To: <ed1a6e12-68cb-4103-946a-761260d18eab@app.fastmail.com>
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.
next prev parent reply other threads:[~2025-10-30 17:24 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 [this message]
2025-10-30 17:31 ` Andy Lutomirski
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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