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kernel-ark/arch/arm
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Jinbum Park b26d07a0f5 ARM: 8742/1: Always use REFCOUNT_FULL 
refcount_t overflow detection is implemented as two way.

1. REFCOUNT_FULL

- It means the full refcount_t implementation
  which has validation but is slightly slower.
- (fd25d19f6b ("locking/refcount:
  Create unchecked atomic_t implementation"))

2. ARCH_HAS_REFCOUNT

- refcount_t overflow detection can be optimized
  via an arch-dependent way.
- It is based on atomic_t infrastructure
  with some instruction added for detection.
- It is faster than REFCOUNT_FULL,
  as fast as unprotected atomic_t infrastructure.
- (7a46ec0e2f ("locking/refcounts, x86/asm:
  Implement fast refcount overflow protection"))

ARCH_HAS_REFCOUNT has implemented for x86,
not implemented for others.

In the case of arm64,
Will Deacon said he didn't want the specialized
"fast but technically incomplete" refcounting as seen with x86's.

But rather to set REFCOUNT_FULL by default
because no one could point to real-world performance impacts with
REFCOUNT_FULL vs unprotected atomic_t infrastructure.

This is the reason arm64 ended up enabling REFCOUNT_FULL.
(4adcec1164 ("arm64: Always use REFCOUNT_FULL"))

As with the decision of arm64,
arm can set REFCOUNT_FULL by default.

Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jinbum Park <jinb.park7@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-01-21 15:32:26 +00:00
..
boot ARM: verify size of zImage 2017-12-17 22:14:05 +00:00
common Merge branch 'pm-sleep' 2017-11-13 01:41:20 +01:00
configs ARM: SoC platform updates for 4.15 2017-11-16 14:05:12 -08:00
crypto License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
firmware
include ARM: 8739/1: NOMMU: Setup VBAR/Hivecs for secondaries cores 2018-01-21 15:32:23 +00:00
kernel ARM: 8739/1: NOMMU: Setup VBAR/Hivecs for secondaries cores 2018-01-21 15:32:23 +00:00
kvm GICv4 Support for KVM/ARM for v4.15 2017-11-17 13:20:01 +01:00
lib License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-actions ARM: SoC platform updates for 4.15 2017-11-16 14:05:12 -08:00
mach-alpine License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-artpec
mach-asm9260
mach-aspeed
mach-at91 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-axxia License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-bcm ARM: SoC platform updates for 4.15 2017-11-16 14:05:12 -08:00
mach-berlin
mach-clps711x License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-cns3xxx License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-davinci ARM: Device-tree updates for 4.15 2017-11-16 15:48:26 -08:00
mach-digicolor License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-dove License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-ebsa110 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-efm32 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-ep93xx ARM: SoC platform updates for 4.15 2017-11-16 14:05:12 -08:00
mach-exynos
mach-footbridge Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-13 17:56:58 -08:00
mach-gemini License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-highbank License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-hisi License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-imx ARM: SoC platform updates for 4.15 2017-11-16 14:05:12 -08:00
mach-integrator ARM: SoC platform updates for 4.15 2017-11-16 14:05:12 -08:00
mach-iop13xx License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-iop32x treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
mach-iop33x License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-ixp4xx treewide: Switch DEFINE_TIMER callbacks to struct timer_list * 2017-11-21 15:57:05 -08:00
mach-keystone License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-ks8695 Merge branch 'i2c/for-4.15' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2017-11-14 17:52:21 -08:00
mach-lpc18xx
mach-lpc32xx
mach-mediatek
mach-meson ARM: meson: enable MESON_IRQ_GPIO in Kconfig for meson8b 2017-10-29 08:40:08 -07:00
mach-mmp License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-moxart
mach-mv78xx0 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-mvebu License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-mxs
mach-netx
mach-nomadik
mach-nspire
mach-omap1 ARM: SoC platform updates for 4.15 2017-11-16 14:05:12 -08:00
mach-omap2 ARM: SoC platform updates for 4.15 2017-11-16 14:05:12 -08:00
mach-orion5x treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
mach-oxnas
mach-picoxcell
mach-prima2 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-pxa This pull request contains the following core changes: 2017-11-22 20:46:06 -10:00
mach-qcom
mach-realview
mach-rockchip
mach-rpc License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-s3c24xx ARM: SoC platform updates for 4.15 2017-11-16 14:05:12 -08:00
mach-s3c64xx ARM: SoC platform updates for 4.15 2017-11-16 14:05:12 -08:00
mach-s5pv210
mach-sa1100 Merge branch 'i2c/for-4.15' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2017-11-14 17:52:21 -08:00
mach-shmobile ARM: SoC platform updates for 4.15 2017-11-16 14:05:12 -08:00
mach-socfpga License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-spear License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-sti
mach-stm32
mach-sunxi
mach-tango License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-tegra Merge branch 'linus' into locking/core, to resolve conflicts 2017-11-07 10:32:44 +01:00
mach-u300 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-uniphier kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
mach-ux500 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-versatile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-vexpress ARM: SoC platform updates for 4.15 2017-11-16 14:05:12 -08:00
mach-vt8500 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-w90x900 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-zx License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mach-zynq License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mm ARM: 8741/1: B15: fix unused label warnings 2018-01-21 15:32:25 +00:00
net
nwfpe License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
oprofile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
plat-iop License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
plat-omap ARM: SoC platform updates for 4.15 2017-11-16 14:05:12 -08:00
plat-orion
plat-pxa
plat-samsung ARM: SoC platform updates for 4.15 2017-11-16 14:05:12 -08:00
plat-versatile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
probes ARM: probes: avoid adding kprobes to sensitive kernel-entry/exit code 2017-12-17 22:14:21 +00:00
tools License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
vdso Merge branch 'linus' into locking/core, to resolve conflicts 2017-11-07 10:32:44 +01:00
vfp
xen xen: re-introduce support for grant v2 interface 2017-11-06 15:50:17 -05:00
Kconfig ARM: 8742/1: Always use REFCOUNT_FULL 2018-01-21 15:32:26 +00:00
Kconfig-nommu Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm 2017-11-16 12:50:35 -08:00
Kconfig.debug ARM: 8737/1: mm: dump: add checking for writable and executable 2018-01-21 15:32:20 +00:00
Makefile ARM: 8723/2: always assume the "unified" syntax for assembly code 2017-12-17 22:14:21 +00:00