From: Sasha Levin <sashal@kernel.org>
To: Andi Kleen <ak@linux.intel.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>,
linux-kernel@vger.kernel.org, tglx@linutronix.de,
luto@kernel.org, tony.luck@intel.com, chang.seok.bae@intel.com
Subject: Re: [PATCH v10 00/18] Enable FSGSBASE instructions
Date: Mon, 11 May 2020 01:03:21 -0400 [thread overview]
Message-ID: <20200511050321.GO13035@sasha-vm> (raw)
In-Reply-To: <20200511005028.GA226400@tassilo.jf.intel.com>
On Sun, May 10, 2020 at 05:50:28PM -0700, Andi Kleen wrote:
>> So this is a check that checks if you're running in user mode if
>> you have a debug trap with single step, but somehow it triggered
>> for a user segment.
>>
>> Probably the regs got corrupted.
>>
>> Sasha, I suspect you're missing a mov %rsp,%rdi somewhere in the
>> debug entry path that sets up the regs argument for the C code.
>
>... Ah never mind. Thomas has a better explanation.
FWIW, this series was heavily tested for the past few months to the
point that we're comfortable in enabling it for 3rd party users on
Azure:
https://bugs.launchpad.net/ubuntu/+source/linux-azure/+bug/1877425.
--
Thanks,
Sasha
prev parent reply other threads:[~2020-05-11 5:03 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-23 23:21 [PATCH v10 00/18] Enable FSGSBASE instructions Sasha Levin
2020-04-23 23:21 ` [PATCH v10 01/18] x86/ptrace: Prevent ptrace from clearing the FS/GS selector Sasha Levin
2020-04-25 22:46 ` Andy Lutomirski
2020-04-23 23:21 ` [PATCH v10 02/18] selftests/x86/fsgsbase: Test GS selector on ptracer-induced GS base write Sasha Levin
2020-04-23 23:21 ` [PATCH v10 03/18] x86/cpu: Add 'unsafe_fsgsbase' to enable CR4.FSGSBASE Sasha Levin
2020-04-23 23:21 ` [PATCH v10 04/18] x86/entry/64: Clean up paranoid exit Sasha Levin
2020-04-23 23:21 ` [PATCH v10 05/18] x86/entry/64: Switch CR3 before SWAPGS in paranoid entry Sasha Levin
2020-04-23 23:21 ` [PATCH v10 06/18] x86/entry/64: Introduce the FIND_PERCPU_BASE macro Sasha Levin
2020-04-23 23:21 ` [PATCH v10 07/18] x86/entry/64: Handle FSGSBASE enabled paranoid entry/exit Sasha Levin
2020-04-23 23:21 ` [PATCH v10 08/18] x86/entry/64: Document GSBASE handling in the paranoid path Sasha Levin
2020-04-23 23:21 ` [PATCH v10 09/18] x86/fsgsbase/64: Add intrinsics for FSGSBASE instructions Sasha Levin
2020-04-23 23:21 ` [PATCH v10 10/18] x86/fsgsbase/64: Enable FSGSBASE instructions in helper functions Sasha Levin
2020-04-23 23:22 ` [PATCH v10 11/18] x86/fsgsbase/64: Use FSGSBASE in switch_to() if available Sasha Levin
2020-04-23 23:22 ` [PATCH v10 12/18] x86/fsgsbase/64: move save_fsgs to header file Sasha Levin
2020-04-23 23:22 ` [PATCH v10 13/18] x86/fsgsbase/64: Use FSGSBASE instructions on thread copy and ptrace Sasha Levin
2020-04-23 23:22 ` [PATCH v10 14/18] x86/speculation/swapgs: Check FSGSBASE in enabling SWAPGS mitigation Sasha Levin
2020-04-23 23:22 ` [PATCH v10 15/18] selftests/x86/fsgsbase: Test ptracer-induced GS base write with FSGSBASE Sasha Levin
2020-04-23 23:22 ` [PATCH v10 16/18] x86/fsgsbase/64: Enable FSGSBASE on 64bit by default and add a chicken bit Sasha Levin
2020-04-23 23:22 ` [PATCH v10 17/18] x86/elf: Enumerate kernel FSGSBASE capability in AT_HWCAP2 Sasha Levin
2020-04-23 23:22 ` [PATCH v10 18/18] Documentation/x86/64: Add documentation for GS/FS addressing mode Sasha Levin
2020-05-10 8:09 ` [PATCH v10 00/18] Enable FSGSBASE instructions Vegard Nossum
2020-05-10 8:29 ` Vegard Nossum
2020-05-10 10:15 ` Thomas Gleixner
2020-05-10 14:17 ` Sasha Levin
2020-05-11 0:48 ` Andi Kleen
2020-05-11 0:50 ` Andi Kleen
2020-05-11 5:03 ` Sasha Levin [this message]
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