linux.git/arch/x86/Kconfig.debug, branch v5.9

locking/lockdep: Fix TRACE_IRQFLAGS vs. NMIs

2020-07-27T13:13:29+00:00

Prior to commit:

  859d069ee1dd ("lockdep: Prepare for NMI IRQ state tracking")

IRQ state tracking was disabled in NMIs due to nmi_enter()
doing lockdep_off() -- with the obvious requirement that NMI entry
call nmi_enter() before trace_hardirqs_off().

[ AFAICT, PowerPC and SH violate this order on their NMI entry ]

However, that commit explicitly changed lockdep_hardirqs_*() to ignore
lockdep_off() and breaks every architecture that has irq-tracing in
it's NMI entry that hasn't been fixed up (x86 being the only fixed one
at this point).

The reason for this change is that by ignoring lockdep_off() we can:

  - get rid of 'current->lockdep_recursion' in lockdep_assert_irqs*()
    which was going to to give header-recursion issues with the
    seqlock rework.

  - allow these lockdep_assert_*() macros to function in NMI context.

Restore the previous state of things and allow an architecture to
opt-in to the NMI IRQ tracking support, however instead of relying on
lockdep_off(), rely on in_nmi(), both are part of nmi_enter() and so
over-all entry ordering doesn't need to change.

Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Ingo Molnar 
Link: https://lore.kernel.org/r/20200727124852.GK119549@hirez.programming.kicks-ass.net

treewide: replace '---help---' in Kconfig files with 'help'

2020-06-13T16:57:21+00:00

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

  a) 4 spaces + '---help---'
  b) 7 spaces + '---help---'
  c) 8 spaces + '---help---'
  d) 1 space + 1 tab + '---help---'
  e) 1 tab + '---help---'    (correct indentation)
  f) 1 tab + 1 space + '---help---'
  g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

  $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada

x86: mm: use ARCH_HAS_DEBUG_WX instead of arch defined

2020-06-04T03:09:50+00:00

Extract DEBUG_WX to mm/Kconfig.debug for shared use.  Change to use
ARCH_HAS_DEBUG_WX instead of DEBUG_WX defined by arch port.

Signed-off-by: Zong Li 
Signed-off-by: Andrew Morton 
Cc: Borislav Petkov 
Cc: Catalin Marinas 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Palmer Dabbelt 
Cc: Paul Walmsley 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Link: http://lkml.kernel.org/r/430736828d149df3f5b462d291e845ec690e0141.1587455584.git.zong.li@sifive.com
Signed-off-by: Linus Torvalds

x86/32: Remove CONFIG_DOUBLEFAULT

2020-04-14T12:24:05+00:00

Make the doublefault exception handler unconditional on 32-bit. Yes,
it is important to be able to catch #DF exceptions instead of silent
reboots. Yes, the code size increase is worth every byte. And one less
CONFIG symbol is just the cherry on top.

No functional changes.

Signed-off-by: Borislav Petkov 
Acked-by: Andy Lutomirski 
Link: https://lkml.kernel.org/r/20200404083646.8897-1-bp@alien8.de

x86: mm: convert dump_pagetables to use walk_page_range

2020-02-04T03:05:25+00:00

Make use of the new functionality in walk_page_range to remove the arch
page walking code and use the generic code to walk the page tables.

The effective permissions are passed down the chain using new fields in
struct pg_state.

The KASAN optimisation is implemented by setting action=CONTINUE in the
callbacks to skip an entire tree of entries.

Link: http://lkml.kernel.org/r/20191218162402.45610-21-steven.price@arm.com
Signed-off-by: Steven Price 
Cc: Albert Ou 
Cc: Alexandre Ghiti 
Cc: Andy Lutomirski 
Cc: Ard Biesheuvel 
Cc: Arnd Bergmann 
Cc: Benjamin Herrenschmidt 
Cc: Borislav Petkov 
Cc: Catalin Marinas 
Cc: Christian Borntraeger 
Cc: Dave Hansen 
Cc: David S. Miller 
Cc: Heiko Carstens 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: James Hogan 
Cc: James Morse 
Cc: Jerome Glisse 
Cc: "Liang, Kan" 
Cc: Mark Rutland 
Cc: Michael Ellerman 
Cc: Paul Burton 
Cc: Paul Mackerras 
Cc: Paul Walmsley 
Cc: Peter Zijlstra 
Cc: Ralf Baechle 
Cc: Russell King 
Cc: Thomas Gleixner 
Cc: Vasily Gorbik 
Cc: Vineet Gupta 
Cc: Will Deacon 
Cc: Zong Li 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

x86/traps: Disentangle the 32-bit and 64-bit doublefault code

2019-11-26T20:53:34+00:00

The 64-bit doublefault handler is much nicer than the 32-bit one.
As a first step toward unifying them, make the 64-bit handler
self-contained.  This should have no effect no functional effect
except in the odd case of x86_64 with CONFIG_DOUBLEFAULT=n in which
case it will change the logging a bit.

This also gets rid of CONFIG_DOUBLEFAULT configurability on 64-bit
kernels.  It didn't do anything useful -- CONFIG_DOUBLEFAULT=n
didn't actually disable doublefault handling on x86_64.

Signed-off-by: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Linus Torvalds 
Signed-off-by: Ingo Molnar

x86/stacktrace: update kconfig help text for reliable unwinders

2019-11-07T14:48:18+00:00

commit 6415b38bae26 ("x86/stacktrace: Enable HAVE_RELIABLE_STACKTRACE
for the ORC unwinder") added the ORC unwinder as a "reliable" unwinder.
Update the help text to reflect that change: the frame pointer unwinder
is no longer the only one that can provide HAVE_RELIABLE_STACKTRACE.

Link: http://lkml.kernel.org/r/20191107032958.14034-1-joe.lawrence@redhat.com
To: linux-kernel@vger.kernel.org
To: live-patching@vger.kernel.org
Signed-off-by: Joe Lawrence 
Acked-by: Josh Poimboeuf 
Acked-by: Miroslav Benes 
Reviewed-by: Kamalesh Babulal 
Signed-off-by: Petr Mladek

x86, perf: Fix the dependency of the x86 insn decoder selftest

2019-09-02T18:05:58+00:00

Since x86 instruction decoder is not only for kprobes,
it should be tested when the insn.c is compiled.
(e.g. perf is enabled but kprobes is disabled)

Signed-off-by: Masami Hiramatsu 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Fixes: cbe5c34c8c1f ("x86: Compile insn.c and inat.c only for KPROBES")
Signed-off-by: Ingo Molnar

Merge tag 'docs-5.3' of git://git.lwn.net/linux

2019-07-09T19:34:26+00:00

Pull Documentation updates from Jonathan Corbet:
 "It's been a relatively busy cycle for docs:

   - A fair pile of RST conversions, many from Mauro. These create more
     than the usual number of simple but annoying merge conflicts with
     other trees, unfortunately. He has a lot more of these waiting on
     the wings that, I think, will go to you directly later on.

   - A new document on how to use merges and rebases in kernel repos,
     and one on Spectre vulnerabilities.

   - Various improvements to the build system, including automatic
     markup of function() references because some people, for reasons I
     will never understand, were of the opinion that
     :c:func:``function()`` is unattractive and not fun to type.

   - We now recommend using sphinx 1.7, but still support back to 1.4.

   - Lots of smaller improvements, warning fixes, typo fixes, etc"

* tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits)
  docs: automarkup.py: ignore exceptions when seeking for xrefs
  docs: Move binderfs to admin-guide
  Disable Sphinx SmartyPants in HTML output
  doc: RCU callback locks need only _bh, not necessarily _irq
  docs: format kernel-parameters -- as code
  Doc : doc-guide : Fix a typo
  platform: x86: get rid of a non-existent document
  Add the RCU docs to the core-api manual
  Documentation: RCU: Add TOC tree hooks
  Documentation: RCU: Rename txt files to rst
  Documentation: RCU: Convert RCU UP systems to reST
  Documentation: RCU: Convert RCU linked list to reST
  Documentation: RCU: Convert RCU basic concepts to reST
  docs: filesystems: Remove uneeded .rst extension on toctables
  scripts/sphinx-pre-install: fix out-of-tree build
  docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/
  Documentation: PGP: update for newer HW devices
  Documentation: Add section about CPU vulnerabilities for Spectre
  Documentation: platform: Delete x86-laptop-drivers.txt
  docs: Note that :c:func: should no longer be used
  ...

docs: fix broken documentation links

2019-06-08T19:42:13+00:00

Mostly due to x86 and acpi conversion, several documentation
links are still pointing to the old file. Fix them.

Signed-off-by: Mauro Carvalho Chehab 
Reviewed-by: Wolfram Sang 
Reviewed-by: Sven Van Asbroeck 
Reviewed-by: Bhupesh Sharma 
Acked-by: Mark Brown 
Signed-off-by: Jonathan Corbet