Minimal supplement to upstream Kernel Self Protection Project changes. Features already provided by SELinux + Yama and archs other than multiarch arm64 / x86_64 aren't in scope. Only tags have stable history. Shared IRC channel with KSPP: irc.libera.chat #linux-hardening
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Hans de Goede b6a3780dad efi/reboot: Fall back to original power-off method if EFI_RESET_SHUTDOWN returns
Commit:

  44be28e9dd ("x86/reboot: Add EFI reboot quirk for ACPI Hardware Reduced flag")

sets pm_power_off to efi_power_off() when the acpi_gbl_reduced_hardware
flag is set.

According to its commit message this is necessary because: "BayTrail-T
class of hardware requires EFI in order to powerdown and reboot and no
other reliable method exists".

But I have a Bay Trail CR tablet where the EFI_RESET_SHUTDOWN call does
not work, it simply returns without doing anything (AFAICT).

So it seems that some Bay Trail devices must use EFI for power-off, while
for others only ACPI works.

Note that efi_power_off() only gets used if the platform code defines
efi_poweroff_required() and that returns true, this currently only ever
happens on x86.

Since on the devices which need ACPI for power-off the EFI_RESET_SHUTDOWN
call simply returns, this patch makes the efi-reboot code remember the
old pm_power_off handler and if EFI_RESET_SHUTDOWN returns it falls back
to calling that.

This seems preferable to dmi-quirking our way out of this, since there
are likely quite a few devices suffering from this.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20170818194947.19347-7-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-21 09:43:50 +02:00
arch efi/libstub/arm64: Use hidden attribute for struct screen_info reference 2017-08-21 09:43:49 +02:00
block blk-mq-pci: add a fallback when pci_irq_get_affinity returns NULL 2017-08-18 08:08:14 -06:00
certs modsign: add markers to endif-statements in certs/Makefile 2017-07-14 11:01:37 +10:00
crypto crypto: authencesn - Fix digest_null crash 2017-07-18 17:01:11 +08:00
Documentation printk-formats.txt: Better describe the difference between %pS and %pF 2017-08-16 21:09:45 +02:00
drivers efi/reboot: Fall back to original power-off method if EFI_RESET_SHUTDOWN returns 2017-08-21 09:43:50 +02:00
firmware firmware/Makefile: force recompilation if makefile changes 2017-05-08 17:15:10 -07:00
fs Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-08-20 09:36:52 -07:00
include Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-08-20 09:20:57 -07:00
init random: do not ignore early device randomness 2017-07-12 16:26:00 -07:00
ipc ipc: add missing container_of()s for randstruct 2017-08-02 17:16:12 -07:00
kernel Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-08-20 09:20:57 -07:00
lib kernel/watchdog: Prevent false positives with turbo modes 2017-08-18 12:35:02 +02:00
mm Sanitize 'move_pages()' permission checks 2017-08-20 13:26:27 -07:00
net net_sched: remove warning from qdisc_hash_add 2017-08-15 17:16:39 -07:00
samples samples/bpf: fix bpf tunnel cleanup 2017-07-31 22:02:47 -07:00
scripts parse-maintainers: Move matching sections from MAINTAINERS 2017-08-08 11:16:14 -07:00
security Now that IPC and other changes have landed, enable manual markings for 2017-07-19 08:55:18 -07:00
sound ALSA: emu10k1: Fix forgotten user-copy conversion in init code 2017-08-18 10:59:02 +02:00
tools test_kmod: fix description for -s -and -c parameters 2017-08-18 15:32:01 -07:00
usr ramfs: clarify help text that compression applies to ramfs as well as legacy ramdisk. 2017-07-06 16:24:30 -07:00
virt KVM/ARM Fixes for v4.13-rc4 2017-08-03 17:59:58 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Add hch to .get_maintainer.ignore 2015-08-21 14:30:10 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: Add support to generate LLVM assembly files 2017-04-25 08:13:52 +09:00
.mailmap power supply and reset changes for the v4.12 series (part 2) 2017-05-12 12:02:21 -07:00
COPYING
CREDITS avr32: remove support for AVR32 architecture 2017-05-01 09:27:15 +02:00
Kbuild kbuild: Consolidate header generation from ASM offset information 2017-04-13 05:43:37 +09:00
Kconfig
MAINTAINERS Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-08-20 09:07:56 -07:00
Makefile Linux 4.13-rc6 2017-08-20 14:13:52 -07:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.