Commit Graph

37 Commits

Author SHA1 Message Date
Masahiro Yamada c9c5c23b77 ARM: 9051/1: vdso: remove unneded extra-y addition
The vdso linker script is prepocessed on demand. Adding it to 'targets'
is enough, and line 13 of this Makefile does that. This extra-y addition
is unneeded.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2021-02-01 19:48:06 +00:00
Linus Walleij d5d44e7e35 ARM: 9013/2: Disable KASan instrumentation for some code
Disable instrumentation for arch/arm/boot/compressed/*
since that code is executed before the kernel has even
set up its mappings and definately out of scope for
KASan.

Disable instrumentation of arch/arm/vdso/* because that code
is not linked with the kernel image, so the KASan management
code would fail to link.

Disable instrumentation of arch/arm/mm/physaddr.c. See commit
ec6d06efb0 ("arm64: Add support for CONFIG_DEBUG_VIRTUAL")
for more details.

Disable kasan check in the function unwind_pop_register because
it does not matter that kasan checks failed when unwind_pop_register()
reads the stack memory of a task.

Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: kasan-dev@googlegroups.com
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Ard Biesheuvel <ardb@kernel.org> # QEMU/KVM/mach-virt/LPAE/8G
Tested-by: Florian Fainelli <f.fainelli@gmail.com> # Brahma SoCs
Tested-by: Ahmad Fatoum <a.fatoum@pengutronix.de> # i.MX6Q
Reported-by: Florian Fainelli <f.fainelli@gmail.com>
Reported-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Abbott Liu <liuwenliang@huawei.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2020-10-27 12:11:04 +00:00
Bill Wendling a968433723 kbuild: explicitly specify the build id style
ld's --build-id defaults to "sha1" style, while lld defaults to "fast".
The build IDs are very different between the two, which may confuse
programs that reference them.

Signed-off-by: Bill Wendling <morbo@google.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-10-09 23:57:30 +09:00
Alexander Popov ddfaf0e43e ARM: vdso: Don't use gcc plugins for building vgettimeofday.c
Don't use gcc plugins for building arch/arm/vdso/vgettimeofday.c to
avoid unneeded instrumentation. As previously discussed[1]:

arm_ssp_per_task_plugin.c
	32-bit ARM only (but likely needs disabling for 32-bit ARM vDSO?)

cyc_complexity_plugin.c
	compile-time reporting only

latent_entropy_plugin.c
	this shouldn't get triggered for the vDSO (no __latent_entropy
	nor __init attributes in vDSO), but perhaps explicitly disabling
	it would be a sensible thing to do, just for robustness?

randomize_layout_plugin.c
	this shouldn't get triggered (again, lacking attributes), but
	should likely be disabled too.

sancov_plugin.c
	This should be tracking the KCOV directly (see
	scripts/Makefile.kcov), which is already disabled here.

structleak_plugin.c
	This should be fine in the vDSO, but there's no security
	boundary here, so it wouldn't be important to KEEP it enabled.

[1] https://lore.kernel.org/lkml/20200610073046.GA15939@willie-the-truck/

Signed-off-by: Alexander Popov <alex.popov@linux.com>
Link: https://lore.kernel.org/r/20200624123330.83226-3-alex.popov@linux.com
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-06-24 07:48:27 -07:00
Masahiro Yamada d198b34f38 .gitignore: add SPDX License Identifier
Add SPDX License Identifier to all .gitignore files.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-25 11:50:48 +01:00
Masahiro Yamada 5f2fb52fac kbuild: rename hostprogs-y/always to hostprogs/always-y
In old days, the "host-progs" syntax was used for specifying host
programs. It was renamed to the current "hostprogs-y" in 2004.

It is typically useful in scripts/Makefile because it allows Kbuild to
selectively compile host programs based on the kernel configuration.

This commit renames like follows:

  always       ->  always-y
  hostprogs-y  ->  hostprogs

So, scripts/Makefile will look like this:

  always-$(CONFIG_BUILD_BIN2C) += ...
  always-$(CONFIG_KALLSYMS)    += ...
      ...
  hostprogs := $(always-y) $(always-m)

I think this makes more sense because a host program is always a host
program, irrespective of the kernel configuration. We want to specify
which ones to compile by CONFIG options, so always-y will be handier.

The "always", "hostprogs-y", "hostprogs-m" will be kept for backward
compatibility for a while.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-02-04 01:53:07 +09:00
Thomas Gleixner 715f23b610 ARM: vdso: Set BUILD_VDSO32 and provide 32bit fallbacks
Setting BUILD_VDSO32 is required to expose the legacy 32bit interfaces in
the generic VDSO code which are going to be hidden behind an #ifdef
BUILD_VDSO32.

The 32bit fallbacks are necessary to remove the existing
VDSO_HAS_32BIT_FALLBACK hackery.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/87tv4zq9dc.fsf@nanos.tec.linutronix.de
2020-01-14 12:20:43 +01:00
Vincenzo Frascino 74d06efb9c ARM: 8932/1: Add clock_gettime64 entry point
With the release of Linux 5.1 has been added a new syscall,
clock_gettime64, that provided a 64 bit time value for a specified
clock_ID to make the kernel Y2038 safe on 32 bit architectures.

Update the arm specific vDSO library accordingly with what it has
been done for the kernel syscall exposing the clock_gettime64 entry
point.

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-11-15 22:21:15 +00:00
Vincenzo Frascino 052e76a31b ARM: 8931/1: Add clock_getres entry point
The generic vDSO library provides an implementation of clock_getres() that
can be leveraged by each architecture.

Add clock_getres() entry point on arm to be on pair with arm64.

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-11-15 22:21:14 +00:00
Vincenzo Frascino 20e2fc4231 ARM: 8930/1: Add support for generic vDSO
The arm vDSO library requires some adaptations to take advantage of
the newly introduced generic vDSO library.

Introduce the following changes:
 - Modification vdso.c to be compliant with the common vdso datapage
 - Use of lib/vdso for gettimeofday
 - Implementation of elf note

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-11-15 22:21:12 +00:00
Masahiro Yamada 89ff7131f7 kbuild: add --hash-style= and --build-id unconditionally
As commit 1e0221374e ("mips: vdso: drop unnecessary cc-ldoption")
explained, these flags are supported by the minimal required version
of binutils. They are supported by ld.lld too.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
2019-07-17 22:37:51 +09:00
Linus Torvalds 2b49350b16 ARM updates:
- Add a "cut here" to make it clearer where oops dumps should be cut
   from - we already have a marker for the end of the dumps.
 - Add logging severity to show_pte()
 - Drop unnecessary common-page-size linker flag
 - Errata workarounds for Cortex A12 857271, Cortex A17 857272 and
   Cortex A7 814220.
 - Remove some unused variables that had started to provoke a compiler
   warning.
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Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm

Pull ARM updates from Russell King:

 - Add a "cut here" to make it clearer where oops dumps should be cut
   from - we already have a marker for the end of the dumps.

 - Add logging severity to show_pte()

 - Drop unnecessary common-page-size linker flag

 - Errata workarounds for Cortex A12 857271, Cortex A17 857272 and
   Cortex A7 814220.

 - Remove some unused variables that had started to provoke a compiler
   warning.

* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: 8863/1: stm32: select ARM errata 814220
  ARM: 8862/1: errata: 814220-B-Cache maintenance by set/way operations can execute out of order
  ARM: 8865/1: mm: remove unused variables
  ARM: 8864/1: Add workaround for I-Cache line size mismatch between CPU cores
  ARM: 8861/1: errata: Workaround errata A12 857271 / A17 857272
  ARM: 8860/1: VDSO: Drop implicit common-page-size linker flag
  ARM: arrange show_pte() to issue severity-based messages
  ARM: add "8<--- cut here ---" to kernel dumps
2019-07-08 21:08:34 -07:00
Russell King 5ccd3bd992 Merge branches 'fixes' and 'misc'
Fix up the conflict between "VDSO: Drop implicit common-page-size
linker flag" and "vdso: pass --be8 to linker if necessary"

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-07-08 11:32:21 +01:00
Linus Torvalds a4c33bbb66 Just one ARM fix this time around for Jason Donenfeld, fixing a
problem with the VDSO generation on big endian.
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Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm

Pull ARM fix from Russell King:
 "Just one ARM fix this time around for Jason Donenfeld, fixing a
  problem with the VDSO generation on big endian"

* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: 8867/1: vdso: pass --be8 to linker if necessary
2019-06-21 11:11:30 -07:00
Nick Desaulniers b777a981d5 ARM: 8860/1: VDSO: Drop implicit common-page-size linker flag
GNU linker's -z common-page-size's default value is based on the target
architecture. arch/arm/vdso/Makefile sets it to the architecture
default, which is implicit and redundant. Drop it.

Link: https://lkml.kernel.org/r/20181206191231.192355-1-ndesaulniers@google.com

Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nathan Lynch <nathanl@linux.ibm.com>
Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-06-20 22:29:54 +01:00
Jason A. Donenfeld c5d0e49e8d ARM: 8867/1: vdso: pass --be8 to linker if necessary
The commit fe00e50b2d ("ARM: 8858/1: vdso: use $(LD) instead of $(CC)
to link VDSO") removed the passing of CFLAGS, since ld doesn't take
those directly. However, prior, big-endian ARM was relying on gcc to
translate its -mbe8 option into ld's --be8 option. Lacking this, ld
generated be32 code, making the VDSO generate SIGILL when called by
userspace.

This commit passes --be8 if CONFIG_CPU_ENDIAN_BE8 is enabled.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-06-20 22:28:52 +01:00
Thomas Gleixner caab277b1d treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234
Based on 1 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
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not see http www gnu org
  licenses

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 503 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Enrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:07 +02:00
Thomas Gleixner 2b72c9e36c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 340
Based on 1 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 as published by
  the free software foundation version 2 of the license this program
  is distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not see http www gnu org
  licenses

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 15 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000437.052642892@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:37:07 +02:00
Linus Torvalds 8c05f3b965 ARM development updates:
- more unified assembly conversions for clang
 - drop obsolete -mauto-it assembler option
 - remove arm_memory_present in preference to the generic version
 - remove unused asm/limits.h header
 - vdso linker update
 
 We tried to make the assembler warn if unified syntax was not used,
 but unfortunately older versions of GCC warn, so the commit had to
 be reverted.
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Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm

Pull ARM updates from Russell King:
 "ARM development updates:

   - more unified assembly conversions for clang

   - drop obsolete -mauto-it assembler option

   - remove arm_memory_present in preference to the generic version

   - remove unused asm/limits.h header

   - vdso linker update

  We tried to make the assembler warn if unified syntax was not used,
  but unfortunately older versions of GCC warn, so the commit had to be
  reverted"

* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
  Revert "ARM: 8846/1: warn if divided syntax assembler is used"
  ARM: 8858/1: vdso: use $(LD) instead of $(CC) to link VDSO
  ARM: 8855/1: remove unused <asm/limits.h>
  ARM: 8850/1: use memblocks_present
  ARM: 8854/1: drop -mauto-it
  ARM: 8846/1: warn if divided syntax assembler is used
  ARM: 8853/1: drop WASM to work around LLVM issue
  ARM: 8852/1: uaccess: use unified assembler language syntax
  ARM: 8851/1: add TUSERCOND() macro for conditional postfix
2019-05-16 09:41:54 -07:00
Marc Zyngier 1f5b62f09f ARM: vdso: Remove dependency with the arch_timer driver internals
The VDSO code uses the kernel helper that was originally designed
to abstract the access between 32 and 64bit systems. It worked so
far because this function is declared as 'inline'.

As we're about to revamp that part of the code, the VDSO would
break. Let's fix it by doing what should have been done from
the start, a proper system register access.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-30 16:09:07 +01:00
Masahiro Yamada fe00e50b2d ARM: 8858/1: vdso: use $(LD) instead of $(CC) to link VDSO
We use $(LD) to link vmlinux, modules, decompressors, etc.

VDSO is the only exceptional case where $(CC) is used as the linker
driver, but I do not know why we need to do so. VDSO uses a special
linker script, and does not link standard libraries at all.

I changed the Makefile to use $(LD) rather than $(CC). I confirmed
the same vdso.so.raw was still produced.

Users will be able to use their favorite linker (e.g. lld instead of
of bfd) by passing LD= from the command line.

My plan is to rewrite all VDSO Makefiles to use $(LD), then delete

cc-ldoption.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-04-23 17:22:10 +01:00
Dmitry Vyukov 758517202b arm: port KCOV to arm
KCOV is code coverage collection facility used, in particular, by
syzkaller system call fuzzer.  There is some interest in using syzkaller
on arm devices.  So port KCOV to arm.

On implementation level this merely declares that KCOV is supported and
disables instrumentation of 3 special cases.  Reasons for disabling are
commented in code.

Tested with qemu-system-arm/vexpress-a15.

Link: http://lkml.kernel.org/r/20180511143248.112484-1-dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Abbott Liu <liuwenliang@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Koguchi Takuo <takuo.koguchi.sw@hitachi.com>
Cc: <syzkaller@googlegroups.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-15 07:55:24 +09:00
Ingo Molnar 8c5db92a70 Merge branch 'linus' into locking/core, to resolve conflicts
Conflicts:
	include/linux/compiler-clang.h
	include/linux/compiler-gcc.h
	include/linux/compiler-intel.h
	include/uapi/linux/stddef.h

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-07 10:32:44 +01:00
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Mark Rutland 6aa7de0591 locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE()
Please do not apply this to mainline directly, instead please re-run the
coccinelle script shown below and apply its output.

For several reasons, it is desirable to use {READ,WRITE}_ONCE() in
preference to ACCESS_ONCE(), and new code is expected to use one of the
former. So far, there's been no reason to change most existing uses of
ACCESS_ONCE(), as these aren't harmful, and changing them results in
churn.

However, for some features, the read/write distinction is critical to
correct operation. To distinguish these cases, separate read/write
accessors must be used. This patch migrates (most) remaining
ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following
coccinelle script:

----
// Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and
// WRITE_ONCE()

// $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch

virtual patch

@ depends on patch @
expression E1, E2;
@@

- ACCESS_ONCE(E1) = E2
+ WRITE_ONCE(E1, E2)

@ depends on patch @
expression E;
@@

- ACCESS_ONCE(E)
+ READ_ONCE(E)
----

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: davem@davemloft.net
Cc: linux-arch@vger.kernel.org
Cc: mpe@ellerman.id.au
Cc: shuah@kernel.org
Cc: snitzer@redhat.com
Cc: thor.thayer@linux.intel.com
Cc: tj@kernel.org
Cc: viro@zeniv.linux.org.uk
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-25 11:01:08 +02:00
Masahiro Yamada 2e8d696b79 kbuild: drop FORCE from PHONY targets
These targets are marked as PHONY.  No need to add FORCE to their
dependency.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-04-20 10:27:20 +02:00
David Brown 11bf9b8658 ARM/vdso: Mark the vDSO code read-only after init
Although the ARM vDSO is cleanly separated by code/data with the code
being read-only in userspace mappings, the code page is still writable
from the kernel.

There have been exploits (such as http://itszn.com/blog/?p=21) that
take advantage of this on x86 to go from a bad kernel write to full
root.

Prevent this specific exploit class on ARM as well by putting the vDSO
code page in post-init read-only memory as well.

Before:
	vdso: 1 text pages at base 80927000
	root@Vexpress:/ cat /sys/kernel/debug/kernel_page_tables
	---[ Modules ]---
	---[ Kernel Mapping ]---
	0x80000000-0x80100000           1M     RW NX SHD
	0x80100000-0x80600000           5M     ro x  SHD
	0x80600000-0x80800000           2M     ro NX SHD
	0x80800000-0xbe000000         984M     RW NX SHD

After:
	vdso: 1 text pages at base 8072b000
	root@Vexpress:/ cat /sys/kernel/debug/kernel_page_tables
	---[ Modules ]---
	---[ Kernel Mapping ]---
	0x80000000-0x80100000           1M     RW NX SHD
	0x80100000-0x80600000           5M     ro x  SHD
	0x80600000-0x80800000           2M     ro NX SHD
	0x80800000-0xbe000000         984M     RW NX SHD

Inspired by https://lkml.org/lkml/2016/1/19/494 based on work by the
PaX Team, Brad Spengler, and Kees Cook.

Signed-off-by: David Brown <david.brown@linaro.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brad Spengler <spender@grsecurity.net>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Emese Revfy <re.emese@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathias Krause <minipli@googlemail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nathan Lynch <nathan_lynch@mentor.com>
Cc: PaX Team <pageexec@freemail.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-hardening@lists.openwall.com
Cc: linux-arch <linux-arch@vger.kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1455748879-21872-8-git-send-email-keescook@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-22 08:51:39 +01:00
H. Nikolaus Schaller 38850d786a ARM: 8449/1: fix bug in vdsomunge swab32 macro
Commit 8a603f91cc ("ARM: 8445/1: fix vdsomunge not to depend on
glibc specific byteswap.h") unfortunately introduced a bug created but
not found during discussion and patch simplification.

Reported-by: Efraim Yawitz <efraim.yawitz@gmail.com>
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Fixes: 8a603f91cc ("ARM: 8445/1: fix vdsomunge not to depend on glibc specific byteswap.h")
Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-10-29 15:20:15 +00:00
H. Nikolaus Schaller 8a603f91cc ARM: 8445/1: fix vdsomunge not to depend on glibc specific byteswap.h
If the host toolchain is not glibc based then the arm kernel build
fails with

  HOSTCC  arch/arm/vdso/vdsomunge
  arch/arm/vdso/vdsomunge.c:48:22: fatal error: byteswap.h: No such file or directory

Observed: with omap2plus_defconfig and compile on Mac OS X with arm ELF
cross-compiler.

Reason: byteswap.h is a glibc only header.

Solution: replace by private byte-swapping macros (taken from
arch/mips/boot/elf2ecoff.c and kindly improved by Russell King)

Tested to compile on Mac OS X 10.9.5 host.

Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-10-19 17:07:32 +01:00
Nathan Lynch 3473f26592 ARM: 8405/1: VDSO: fix regression with toolchains lacking ld.bfd executable
The Sourcery CodeBench Lite 2014.05 toolchain (gcc 4.8.3, binutils
2.24.51) has a GCC which implements -fuse-ld, and it doesn't include
the gold linker, but it lacks an ld.bfd executable in its
installation.  This means that passing -fuse-ld=bfd fails with:

      VDSO    arch/arm/vdso/vdso.so.raw
    collect2: fatal error: cannot find 'ld'

Arguably this is a deficiency in the toolchain, but I suspect it's
commonly used enough that it's worth accommodating: just use

cc-ldoption (to cause a link attempt) instead of cc-option to test
whether we can use -fuse-ld.  So -fuse-ld=bfd won't be used with this
toolchain, but the build will rightly succeed, just as it does for
toolchains which don't implement -fuse-ld (and don't use gold as the
default linker).

Note: this will change the failure mode for a corner case I was trying
to handle in d2b30cd4b7, where the toolchain defaults to the gold
linker and the BFD linker is not found in PATH, from:

      VDSO    arch/arm/vdso/vdso.so.raw
    collect2: fatal error: cannot find 'ld'

i.e. the BFD linker is not found, to:

      OBJCOPY arch/arm/vdso/vdso.so
    BFD: arch/arm/vdso/vdso.so: Not enough room for program headers, try
    linking with -N

that is, we fail to prevent gold from being used as the linker, and it
produces an object that objcopy can't digest.

Reported-by: Baruch Siach <baruch@tkos.co.il>
Tested-by: Baruch Siach <baruch@tkos.co.il>
Tested-by: Raphaël Poggi <poggi.raph@gmail.com>
Fixes: d2b30cd4b7 ("ARM: 8384/1: VDSO: force use of BFD linker")
Cc: stable@vger.kernel.org
Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-07-31 18:54:45 +01:00
Russell King 06be5eefe1 Merge branches 'fixes' and 'ioremap' into for-linus 2015-07-07 12:35:33 +01:00
Szabolcs Nagy 13ee9fdba9 ARM: 8397/1: fix vdsomunge not to depend on glibc specific error.h
If the host toolchain is not glibc based then the arm kernel build
fails with

 arch/arm/vdso/vdsomunge.c:53:19: fatal error: error.h: No such file or directory

error.h is a glibc only header (ie not available in musl, newlib and
bsd libcs).  Changed the error reporting to standard conforming code
to avoid depending on specific C implementations.

Signed-off-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Fixes: 8512287a81 ("ARM: 8330/1: add VDSO user-space code")
Cc: stable@vger.kernel.org
Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-07-03 09:57:21 +01:00
Nathan Lynch d2b30cd4b7 ARM: 8384/1: VDSO: force use of BFD linker
When using a toolchain with gold as the default linker, the VDSO build
fails:

  VDSO    arch/arm/vdso/vdso.so.raw
  HOSTCC  arch/arm/vdso/vdsomunge
  MUNGE   arch/arm/vdso/vdso.so.dbg
  OBJCOPY arch/arm/vdso/vdso.so
BFD: arch/arm/vdso/vdso.so: Not enough room for program headers, try
linking with -N

For whatever reason, ld.gold is omitting an exidx program header that
ld.bfd emits, and even when I work around that, I don't get a working
VDSO.

For now, instead of supporting gold (which will fail to link the
kernel anyway since it does not implement --pic-veneer), direct the
compiler to use the traditional bfd linker.  This is accomplished by
using -fuse-ld, which is implemented in GCC 4.8 and later.

Note: one limitation of this is that if the toolchain is configured
to use gold by default, and the bfd linker is not in $PATH, the VDSO
build will fail:

  VDSO    arch/arm/vdso/vdso.so.raw
collect2: fatal error: cannot find 'ld'

This will happen if CROSS_COMPILE begins with a path such as
/opt/bin/arm-linux-gnu- but /opt/bin is not in $PATH.  This is
considered an acceptable corner-case limitation and is easily worked
around.

Additonal note: we use cc-option instead of cc-ldoption so that
-fuse-ld=bfd is placed in the command line if the compiler recognizes
the option.  Using cc-ldoption results in an attempt to link, which
fails in the situation just described, causing -fuse-ld=bfd to be
omitted and gold to be used for the VDSO link, which is what we're
trying to prevent.

Reported-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-06-06 10:37:12 +01:00
Nathan Lynch d33ce23b21 ARM: 8385/1: VDSO: group link options
Currently the VDSO's link options are kind of a mess spread between

ccflags-y and cmd_vdsold.  Collect linker directives into one
variable, VDSO_LDFLAGS, and use that in cmd_vdsold.

Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-06-06 10:37:11 +01:00
Nathan Lynch f80f6531b4 ARM: 8344/1: VDSO: honor CONFIG_VDSO in Makefile
When CONFIG_VDSO=n, the build normally does not enter arch/arm/vdso/
because arch/arm/Makefile does not add it to core-y.

However, if the user runs 'make arch/arm/vdso/' the VDSO targets will
get visited.  This is because the VDSO Makefile itself does not
consider the value of CONFIG_VDSO.

It is arguably better and more consistent behavior to generate an
empty built-in.o when CONFIG_VDSO=n and the user attempts to build
arch/arm/vdso/.  It's nicer because it doesn't try to build things
that Kconfig dependencies are there to prevent (e.g. the dependency on
AEABI), and it's less confusing than building objects that won't be
used in the final image.

Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-04-21 15:28:02 +01:00
Nathan Lynch 2b507a2d9c ARM: 8343/1: VDSO: add build artifacts to .gitignore
vdsomunge and vdso.so.raw are outputs that don't get matched by the
normal ignore rules.

Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-04-21 15:27:53 +01:00
Nathan Lynch 8512287a81 ARM: 8330/1: add VDSO user-space code
Place VDSO-related user-space code in arch/arm/kernel/vdso/.

It is almost completely written in C with some assembly helpers to
load the data page address, sample the counter, and fall back to
system calls when necessary.

The VDSO can service gettimeofday and clock_gettime when
CONFIG_ARM_ARCH_TIMER is enabled and the architected timer is present
(and correctly configured).  It reads the CP15-based virtual counter
to compute high-resolution timestamps.

Of particular note is that a post-processing step ("vdsomunge") is
necessary to produce a shared object which is architecturally allowed
to be used by both soft- and hard-float EABI programs.

The 2012 edition of the ARM ABI defines Tag_ABI_VFP_args = 3 "Code is
compatible with both the base and VFP variants; the user did not
permit non-variadic functions to pass FP parameters/results."
Unfortunately current toolchains do not support this tag, which is
ideally what we would use.

The best available option is to ensure that both EF_ARM_ABI_FLOAT_SOFT
and EF_ARM_ABI_FLOAT_HARD are unset in the ELF header's e_flags,
indicating that the shared object is "old" and should be accepted for
backward compatibility's sake.  While binutils < 2.24 appear to
produce a vdso.so with both flags clear, 2.24 always sets
EF_ARM_ABI_FLOAT_SOFT, with no way to inhibit this behavior.  So we
have to fix things up with a custom post-processing step.

In fact, the VDSO code in glibc does much less validation (including
checking these flags) than the code for handling conventional
file-backed shared libraries, so this is a bit moot unless glibc's
VDSO code becomes more strict.

Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-03-27 22:20:45 +00:00