linux.git/arch/arm/kernel/entry-armv.S, branch v5.5

docs: arm: convert docs to ReST and rename to *.rst

2019-07-15T12:20:24+00:00

Converts ARM the text files to ReST, preparing them to be an
architecture book.

The conversion is actually:
  - add blank lines and identation in order to identify paragraphs;
  - fix tables markups;
  - add some lists markups;
  - mark literal blocks;
  - adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab 
Reviewed-by Corentin Labbe  # For sun4i-ss

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

2019-06-19T15:09:55+00:00

Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Enrico Weigelt 
Reviewed-by: Kate Stewart 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman

ARM: 8844/1: use unified assembler in assembly files

2019-02-26T11:26:07+00:00

Use unified assembler syntax (UAL) in assembly files. Divided
syntax is considered deprecated. This will also allow to build
the kernel using LLVM's integrated assembler.

Signed-off-by: Stefan Agner 
Acked-by: Nicolas Pitre 
Signed-off-by: Russell King

ARM: Convert to GENERIC_IRQ_MULTI_HANDLER

2018-08-03T10:14:08+00:00

Converts the ARM interrupt code to use the recently added
GENERIC_IRQ_MULTI_HANDLER, which is essentially just a copy of ARM's
existhing MULTI_IRQ_HANDLER.  The only changes are:

* handle_arch_irq is now defined in a generic C file instead of an
  arm-specific assembly file.
 
* handle_arch_irq is now marked as __ro_after_init.

Signed-off-by: Palmer Dabbelt 
Signed-off-by: Thomas Gleixner 
Cc: linux@armlinux.org.uk
Cc: catalin.marinas@arm.com
Cc: Will Deacon 
Cc: jonas@southpole.se
Cc: stefan.kristiansson@saunalahti.fi
Cc: shorne@gmail.com
Cc: jason@lakedaemon.net
Cc: marc.zyngier@arm.com
Cc: Arnd Bergmann 
Cc: nicolas.pitre@linaro.org
Cc: vladimir.murzin@arm.com
Cc: keescook@chromium.org
Cc: jinb.park7@gmail.com
Cc: yamada.masahiro@socionext.com
Cc: alexandre.belloni@bootlin.com
Cc: pombredanne@nexb.com
Cc: Greg KH 
Cc: kstewart@linuxfoundation.org
Cc: jhogan@kernel.org
Cc: mark.rutland@arm.com
Cc: ard.biesheuvel@linaro.org
Cc: james.morse@arm.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: openrisc@lists.librecores.org
Link: https://lkml.kernel.org/r/20180622170126.6308-3-palmer@sifive.com

Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables

2018-06-14T03:21:18+00:00

The changes to automatically test for working stack protector compiler
support in the Kconfig files removed the special STACKPROTECTOR_AUTO
option that picked the strongest stack protector that the compiler
supported.

That was all a nice cleanup - it makes no sense to have the AUTO case
now that the Kconfig phase can just determine the compiler support
directly.

HOWEVER.

It also meant that doing "make oldconfig" would now _disable_ the strong
stackprotector if you had AUTO enabled, because in a legacy config file,
the sane stack protector configuration would look like

  CONFIG_HAVE_CC_STACKPROTECTOR=y
  # CONFIG_CC_STACKPROTECTOR_NONE is not set
  # CONFIG_CC_STACKPROTECTOR_REGULAR is not set
  # CONFIG_CC_STACKPROTECTOR_STRONG is not set
  CONFIG_CC_STACKPROTECTOR_AUTO=y

and when you ran this through "make oldconfig" with the Kbuild changes,
it would ask you about the regular CONFIG_CC_STACKPROTECTOR (that had
been renamed from CONFIG_CC_STACKPROTECTOR_REGULAR to just
CONFIG_CC_STACKPROTECTOR), but it would think that the STRONG version
used to be disabled (because it was really enabled by AUTO), and would
disable it in the new config, resulting in:

  CONFIG_HAVE_CC_STACKPROTECTOR=y
  CONFIG_CC_HAS_STACKPROTECTOR_NONE=y
  CONFIG_CC_STACKPROTECTOR=y
  # CONFIG_CC_STACKPROTECTOR_STRONG is not set
  CONFIG_CC_HAS_SANE_STACKPROTECTOR=y

That's dangerously subtle - people could suddenly find themselves with
the weaker stack protector setup without even realizing.

The solution here is to just rename not just the old RECULAR stack
protector option, but also the strong one.  This does that by just
removing the CC_ prefix entirely for the user choices, because it really
is not about the compiler support (the compiler support now instead
automatially impacts _visibility_ of the options to users).

This results in "make oldconfig" actually asking the user for their
choice, so that we don't have any silent subtle security model changes.
The end result would generally look like this:

  CONFIG_HAVE_CC_STACKPROTECTOR=y
  CONFIG_CC_HAS_STACKPROTECTOR_NONE=y
  CONFIG_STACKPROTECTOR=y
  CONFIG_STACKPROTECTOR_STRONG=y
  CONFIG_CC_HAS_SANE_STACKPROTECTOR=y

where the "CC_" versions really are about internal compiler
infrastructure, not the user selections.

Acked-by: Masahiro Yamada 
Signed-off-by: Linus Torvalds

ARM: probes: avoid adding kprobes to sensitive kernel-entry/exit code

2017-12-17T22:14:21+00:00

Avoid adding kprobes to any of the kernel entry/exit or startup
assembly code, or code in the identity-mapped region.  This code does
not conform to the standard C conventions, which means that the
expectations of the kprobes code is not forfilled.

Placing kprobes at some of these locations results in the kernel trying
to return to userspace addresses while retaining the CPU in kernel mode.

Tested-by: Naresh Kamboju 
Signed-off-by: Russell King

Merge branches 'fixes' and 'misc' into for-linus

2017-09-09T15:34:41+00:00

ARM: align .data section

2017-08-14T15:22:55+00:00

Robert Jarzmik reports that his PXA25x system fails to boot with 4.12,
failing at __flush_whole_cache in arch/arm/mm/proc-xscale.S:215:

   0xc0019e20 <+0>:     ldr     r1, [pc, #788]
   0xc0019e24 <+4>:     ldr     r0, [r1]	<== here

with r1 containing 0xc06f82cd, which is the address of "clean_addr".
Examination of the System.map shows:

c06f22c8 D user_pmd_table
c06f22cc d __warned.19178
c06f22cd d clean_addr

indicating that a .data.unlikely section has appeared just before the
.data section from proc-xscale.S.  According to objdump -h, it appears
that our assembly files default their .data alignment to 2**0, which
is bad news if the preceding .data section size is not power-of-2
aligned at link time.

Add the appropriate .align directives to all assembly files in arch/arm
that are missing them where we require an appropriate alignment.

Reported-by: Robert Jarzmik 
Tested-by: Robert Jarzmik 
Signed-off-by: Russell King

ARM: Prepare for randomized task_struct

2017-06-30T19:00:50+00:00

With the new task struct randomization, we can run into a build
failure for certain random seeds, which will place fields beyond
the allow immediate size in the assembly:

arch/arm/kernel/entry-armv.S: Assembler messages:
arch/arm/kernel/entry-armv.S:803: Error: bad immediate value for offset (4096)

Only two constants in asm-offset.h are affected, and I'm changing
both of them here to work correctly in all configurations.

One more macro has the problem, but is currently unused, so this
removes it instead of adding complexity.

Suggested-by: Ard Biesheuvel 
Signed-off-by: Arnd Bergmann 
[kees: Adjust commit log slightly]
Signed-off-by: Kees Cook

ARM: fix address limit restoration for undefined instructions

2016-08-09T21:57:59+00:00

During boot, sometimes the kernel will test to see if an instruction
causes an undefined instruction exception.  Unfortunately, the exit
path for these exceptions did not restore the address limit, which
causes the rootfs mount code to fail.  Fix the missing address limit
restoration.

Tested-by: Guenter Roeck 
Signed-off-by: Russell King