From: Thomas Gleixner <tglx@linutronix.de>
To: Andy Lutomirski <luto@kernel.org>
Cc: Sasha Levin <sashal@kernel.org>,
Andrew Lutomirski <luto@kernel.org>,
Andi Kleen <ak@linux.intel.com>, Jonathan Corbet <corbet@lwn.net>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
X86 ML <x86@kernel.org>, Shuah Khan <shuah@kernel.org>,
Greg KH <gregkh@linuxfoundation.org>,
Tony Luck <tony.luck@intel.com>, "Bae\,
Chang Seok" <chang.seok.bae@intel.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>,
"open list\:DOCUMENTATION" <linux-doc@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Subject: Re: [PATCH v13 00/16] Enable FSGSBASE instructions
Date: Thu, 18 Jun 2020 20:25:30 +0200 [thread overview]
Message-ID: <87wo44b59h.fsf@nanos.tec.linutronix.de> (raw)
In-Reply-To: <CALCETrUeRPVq2n0UVuZZ9WTugH8Aetdw5rY+cccCT_=YgnJ_og@mail.gmail.com>
Andy Lutomirski <luto@kernel.org> writes:
> Is there a plan to deal with:
>
> /*
> * This function has some ABI oddities.
> *
> * A 32-bit ptracer probably expects that writing FS or GS will change
> * FSBASE or GSBASE respectively. In the absence of FSGSBASE support,
> * this code indeed has that effect. When FSGSBASE is added, this
> * will require a special case.
> *
> * For existing 64-bit ptracers, writing FS or GS *also* currently
> * changes the base if the selector is nonzero the next time the task
> * is run. This behavior may? not be needed, and trying to preserve it
> * when FSGSBASE is added would be complicated at best.
> */
>
> in arch/x86/kernel/ptrace.c?
Not that I'm aware of.
prev parent reply other threads:[~2020-06-18 18:25 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-28 20:13 [PATCH v13 00/16] Enable FSGSBASE instructions Sasha Levin
2020-05-28 20:13 ` [PATCH v13 01/16] x86/ptrace: Prevent ptrace from clearing the FS/GS selector Sasha Levin
2020-05-28 20:13 ` [PATCH v13 02/16] x86/cpu: Add 'unsafe_fsgsbase' to enable CR4.FSGSBASE Sasha Levin
2020-05-28 20:13 ` [PATCH v13 03/16] x86/fsgsbase/64: Add intrinsics for FSGSBASE instructions Sasha Levin
2020-05-28 20:13 ` [PATCH v13 04/16] x86/fsgsbase/64: Enable FSGSBASE instructions in helper functions Sasha Levin
2020-05-28 20:13 ` [PATCH v13 05/16] x86/process/64: Use FSBSBASE in switch_to() if available Sasha Levin
2020-05-28 20:13 ` [PATCH v13 06/16] x86/process/64: Make save_fsgs() public available Sasha Levin
2020-06-18 13:50 ` [tip: x86/fsgsbase] x86/process/64: Make save_fsgs_for_kvm() ready for FSGSBASE tip-bot2 for Thomas Gleixner
2020-05-28 20:13 ` [PATCH v13 07/16] x86/process/64: Use FSGSBASE instructions on thread copy and ptrace Sasha Levin
2020-05-28 20:13 ` [PATCH v13 08/16] x86/speculation/swapgs: Check FSGSBASE in enabling SWAPGS mitigation Sasha Levin
2020-06-18 13:50 ` [tip: x86/fsgsbase] " tip-bot2 for Tony Luck
2020-05-28 20:13 ` [PATCH v13 09/16] x86/entry/64: Switch CR3 before SWAPGS in paranoid entry Sasha Levin
2020-05-28 20:13 ` [PATCH v13 10/16] x86/entry/64: Introduce the FIND_PERCPU_BASE macro Sasha Levin
2020-05-28 20:13 ` [PATCH v13 11/16] x86/entry/64: Handle FSGSBASE enabled paranoid entry/exit Sasha Levin
2020-05-28 20:13 ` [PATCH v13 12/16] x86/cpu: Enable FSGSBASE on 64bit by default and add a chicken bit Sasha Levin
2020-05-28 20:13 ` [PATCH v13 13/16] x86/elf: Enumerate kernel FSGSBASE capability in AT_HWCAP2 Sasha Levin
2020-10-26 17:18 ` [PATCH] x86/elf: Fix use of internal macro BIT in uapi header Thiago Macieira
2020-05-28 20:14 ` [PATCH v13 14/16] Documentation/x86/64: Add documentation for GS/FS addressing mode Sasha Levin
2020-06-18 13:50 ` [tip: x86/fsgsbase] " tip-bot2 for Thomas Gleixner
2020-05-28 20:14 ` [PATCH v13 15/16] selftests/x86/fsgsbase: Test GS selector on ptracer-induced GS base write Sasha Levin
2020-05-29 14:40 ` Shuah Khan
2020-06-18 13:50 ` [tip: x86/fsgsbase] " tip-bot2 for Chang S. Bae
2020-05-28 20:14 ` [PATCH v13 16/16] selftests/x86/fsgsbase: Test ptracer-induced GS base write with FSGSBASE Sasha Levin
2020-05-29 14:42 ` Shuah Khan
2020-06-18 13:50 ` [tip: x86/fsgsbase] " tip-bot2 for Chang S. Bae
2020-06-18 14:18 ` [PATCH v13 00/16] Enable FSGSBASE instructions Thomas Gleixner
2020-06-18 18:08 ` Andy Lutomirski
2020-06-18 18:25 ` Thomas Gleixner [this message]
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