linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Andi Kleen <ak@linux.intel.com>
To: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Sasha Levin <sashal@kernel.org>,
	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: Sun, 10 May 2020 17:48:42 -0700	[thread overview]
Message-ID: <20200511004842.GJ3538@tassilo.jf.intel.com> (raw)
In-Reply-To: <d7111932-6ba5-1484-4347-210d9e80316f@oracle.com>


> [ 6402.786418] ------------[ cut here ]------------
> [ 6402.787769] WARNING: CPU: 0 PID: 13802 at arch/x86/kernel/traps.c:811
> do_debug+0x16c/0x210
...

> [ 6402.848299]  ? trace_hardirqs_off_thunk+0x1a/0x33
> [ 6402.849593]  trace_hardirqs_off_caller+0xa6/0xd0
> [ 6402.850862]  ? debug+0x4e/0x70
> [ 6402.851727]  trace_hardirqs_off_thunk+0x1a/0x33
> [ 6402.852983]  debug+0x53/0x70
> [ 6402.853785] RIP: 0033:0x400060dd

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.

-Andi

  parent reply	other threads:[~2020-05-11  0:48 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-23 23:21 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 [this message]
2020-05-11  0:50       ` Andi Kleen
2020-05-11  5:03         ` Sasha Levin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200511004842.GJ3538@tassilo.jf.intel.com \
    --to=ak@linux.intel.com \
    --cc=chang.seok.bae@intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luto@kernel.org \
    --cc=sashal@kernel.org \
    --cc=tglx@linutronix.de \
    --cc=tony.luck@intel.com \
    --cc=vegard.nossum@oracle.com \
    --subject='Re: [PATCH v10 00/18] Enable FSGSBASE instructions' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
on how to clone and mirror all data and code used for this inbox