Commit Graph

707086 Commits

Author SHA1 Message Date
Vineet Gupta bd6d3588c8 ARC: [plat-eznps] Update platform maintainer as Noam left
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-10-03 20:36:49 -07:00
Eugeniy Paltsev ef833eab1d ARC: [plat-hsdk] use actual clk driver to manage cpu clk
With corresponding clk driver now merged upstream, switch to it.

 - core_clk now represent the PLL (vs. fixed clk before)
 - input_clk represent the clk signal src for PLL (basically xtal)

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-10-03 20:36:49 -07:00
Alexey Brodkin 9583833e9e ARC: [*defconfig] Reenable soft lock-up detector
Commit 92e5aae457 "kernel/watchdog: split up config options"
introduced SOFTLOCKUP_DETECTOR which selects LOCKUP_DETECTOR
instead of the latter to be selected itself.

We need to adjust our defconfigs accordingly.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-10-03 20:36:49 -07:00
Eugeniy Paltsev 976e78a522 ARC: [plat-axs10x] sdio: Temporary fix of sdio ciu frequency
DW sdio controller has external ciu clock divider controlled
via register in SDIO IP. It divides sdio_ref_clk
(which comes from CGU) by 16 for default. So default mmcclk
clock (which comes to sdk_in) is 25000000 Hz.

So fix wrong current value (50000000 Hz) to actual 25000000 Hz.

Note this is a preventive fix, in line with similar change for HSDK
where this was actually needed. see:
http://lists.infradead.org/pipermail/linux-snps-arc/2017-September/002924.html

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-10-03 20:36:49 -07:00
Eugeniy Paltsev 6afa3bcf1f ARC: [plat-hsdk] sdio: Temporary fix of sdio ciu frequency
DW sdio controller has external ciu clock divider controlled via
register in SDIO IP. Due to its unexpected default value
(it should divide by 1 but it divides by 8)
SDIO IP uses wrong ciu clock and works unstable

So add temporary fix and change clock frequency from 100000000
to 12500000 Hz until we fix dw sdio driver itself.

Fixes SNPS STAR 9001204800

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-10-03 20:36:49 -07:00
Eugeniy Paltsev 043d1e729b ARC: [plat-axs103] Add temporary quirk to reset ethernet IP
DW ethernet controller on AXS10x hangs sometimes after SW reset, so
add temporary quirk to reset DW ethernet controller IP core.
This quirk can be removed after axs10x reset driver
(see http://patchwork.ozlabs.org/patch/800273/)
or simple reset driver
(see https://patchwork.kernel.org/patch/9903375/)
will be available in upstream.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-10-03 20:36:49 -07:00
Olof Johansson 7ea696af44 Fixes for omaps for v4.14-rc cycle
Few minor fixes for omaps, mostly just boot time warning fixes:
 
 - Drop undocumented camera binding that got merged during the merge window by
   accident as I applied before Sakari's comments
 
 - Fix soft reset warning for dra7 kexec boot for gpio1 as the optional clocks
   need to be enabled for reset
 
 - Fix dra7 kexec boot clock rate for McASP as the rate is no longer the default
   rate after kexec
 
 - Fix omap3 pandora MMC warning during boot
 
 - Add am33xx SPI alias like we have on other SoCs
 
 - Remove node for non-existing CPSW EMAC Ethernet on am43xx-epos-evm
 -----BEGIN PGP SIGNATURE-----
 
 iQJFBAABCAAvFiEEkgNvrZJU/QSQYIcQG9Q+yVyrpXMFAlnSn1IRHHRvbnlAYXRv
 bWlkZS5jb20ACgkQG9Q+yVyrpXOANA//bLGKjAtCv0VRBGP8fTyGRRuLZAdPSaeK
 UNOgjUZxtQqmPVQ60GGWOisKVmnfIzoZzYN1s7/Y5XqwW5qrVDD2ME1F0aoGWOrG
 FAPQOw4WCzdcT5d8iDZVU0R+nFomWE8pZUiX5ZHXXrB0m0G/hKI63KqXtzXYJ4vR
 GH/V7UlgqAH3EFJZYgNP55wyC645zvfCFH5jZrIMaEAHNUbBpzz8IonwpSA9QqjI
 p+GWi/ULK2+HKbFTZog2W3fA0fk8ISfYvX82Y7krwKPbPwP0UktQ1m5q+o9LjWk2
 +tdCOlspewmCei0PciwR7/hkArQlqh8PBGRT3Tti95iXfOXNuowhymRfcNUMEVTi
 v5Iuv7r4TZnuVM03L+Ui4stnUPNLHFl1h5jSY2uKLhpyAgYFdCa6jBaXVJ26iqA/
 t/05EaaNKZXvKgxmxENfAibQu1i9hyRGpfhS0Hqi3zM6SkS84IY4kpBQXNrAYTHN
 djDertSxcHhfzw+7KB5+moJ26/j4p3E04tn8XB+nqHJz6MP5xxxL22Oxv3FafiL4
 hT317lztpCrpwzn/5i6D4UH2wJlTnJT75zI/ra7gu3LFRxTiTyeZ9n1uCKn+HHqG
 cRP8ZBJg0K5JtODpvSxZSRHxlB4aS3GxNOgS82cwnuMrgVbWqyQhA+NX1dJVaPSy
 pFbGn95uo9k=
 =abMX
 -----END PGP SIGNATURE-----

Merge tag 'omap-for-v4.14/fixes-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into fixes

Fixes for omaps for v4.14-rc cycle

Few minor fixes for omaps, mostly just boot time warning fixes:

- Drop undocumented camera binding that got merged during the merge window by
  accident as I applied before Sakari's comments

- Fix soft reset warning for dra7 kexec boot for gpio1 as the optional clocks
  need to be enabled for reset

- Fix dra7 kexec boot clock rate for McASP as the rate is no longer the default
  rate after kexec

- Fix omap3 pandora MMC warning during boot

- Add am33xx SPI alias like we have on other SoCs

- Remove node for non-existing CPSW EMAC Ethernet on am43xx-epos-evm

* tag 'omap-for-v4.14/fixes-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
  ARM: dts: am43xx-epos-evm: Remove extra CPSW EMAC entry
  ARM: dts: am33xx: Add spi alias to match SOC schematics
  ARM: OMAP2+: hsmmc: fix logic to call either omap_hsmmc_init or omap_hsmmc_late_init but not both
  ARM: dts: dra7: Set a default parent to mcasp3_ahclkx_mux
  ARM: OMAP2+: dra7xx: Set OPT_CLKS_IN_RESET flag for gpio1
  ARM: dts: nokia n900: drop unneeded/undocumented parts of the dts

Signed-off-by: Olof Johansson <olof@lixom.net>
2017-10-03 18:15:58 -07:00
Olof Johansson 081069efb6 Adding the operating points on rk3368 like they were did not end up well
for the boards as all of them are missing their cpu supplies, the OPPs
 actually need to follow the <target min max> format as the regulator is
 shared between both clusters and the one rk3368 board I have, somehow also
 doesn't like the higher opps at all - all of which I only realized after
 I brought my rk3368 board online again, after its bootloader broke.
 So we revert that OPP addition for now.
 
 And also two fixes for the mipi dsi controller on rk3399, which was
 referencing a clock to high up in the clock-tree so that an intermediate
 gate could be disabled inadvertently and also needs a clock for its area
 in the general register files of the rk3399 soc.
 -----BEGIN PGP SIGNATURE-----
 
 iQFEBAABCAAuFiEE7v+35S2Q1vLNA3Lx86Z5yZzRHYEFAlnL6QsQHGhlaWtvQHNu
 dGVjaC5kZQAKCRDzpnnJnNEdgUx1B/4pbbWGvxKA/1Osih4Fs/q8rLzNq9N8tsV1
 VEQ06VU0TuuyECiNhCv1sD8QoccdAfAu/QlFM2IVg3Js2HB+CtnYw0LVhMEpdf0m
 c4Vh/GgpCIgPTaZTDtcHdHh9VbbYDsgsVgLPiuBnbK98GeDVZCIke10J0cUBrwSY
 ncJKFfJQh1wor9p54mQfBWtKWfUfDQYxBpENkwq1SD0TJgE/osyKevWXConjMN1f
 vyH+BmEJq96Wz76QqEXtiEU47HoHaIMwA7/2LbRJhe5W3ifBFBQD664RH6L/a28o
 IhRTq3pvy4v7lip4OTRMby4+C6Yku7Xb3UF3/HAKPntE5eKlpIjV
 =DwOn
 -----END PGP SIGNATURE-----

Merge tag 'v4.14-rockchip-dts64fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mmind/linux-rockchip into fixes

Adding the operating points on rk3368 like they were did not end up well
for the boards as all of them are missing their cpu supplies, the OPPs
actually need to follow the <target min max> format as the regulator is
shared between both clusters and the one rk3368 board I have, somehow also
doesn't like the higher opps at all - all of which I only realized after
I brought my rk3368 board online again, after its bootloader broke.
So we revert that OPP addition for now.

And also two fixes for the mipi dsi controller on rk3399, which was
referencing a clock to high up in the clock-tree so that an intermediate
gate could be disabled inadvertently and also needs a clock for its area
in the general register files of the rk3399 soc.

* tag 'v4.14-rockchip-dts64fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mmind/linux-rockchip:
  arm64: dts: rockchip: add the grf clk for dw-mipi-dsi on rk3399
  arm64: dts: rockchip: Correct MIPI DPHY PLL clock on rk3399
  Revert "arm64: dts: rockchip: Add basic cpu frequencies for RK3368"

Signed-off-by: Olof Johansson <olof@lixom.net>
2017-10-03 18:13:35 -07:00
Olof Johansson aab4b4177e mvebu fixes for 4.14 (part 1)
Update MAINTAINERS for the Macchiatobin board (Armada 8K based)
 Fix AP806 system controller size on Armada 7K/8K
 -----BEGIN PGP SIGNATURE-----
 
 iIEEABECAEEWIQQYqXDMF3cvSLY+g9cLBhiOFHI71QUCWcTR4CMcZ3JlZ29yeS5j
 bGVtZW50QGZyZWUtZWxlY3Ryb25zLmNvbQAKCRALBhiOFHI71ZOIAJ0Wh05lcRfe
 0wugR0R319wn9gD5HwCfURWc08Qvo97ZdGp38wQaAuNnJfw=
 =5jLY
 -----END PGP SIGNATURE-----

Merge tag 'mvebu-fixes-4.14-1' of git://git.infradead.org/linux-mvebu into fixes

mvebu fixes for 4.14 (part 1)

Update MAINTAINERS for the Macchiatobin board (Armada 8K based)
Fix AP806 system controller size on Armada 7K/8K

* tag 'mvebu-fixes-4.14-1' of git://git.infradead.org/linux-mvebu:
  arm64: dt marvell: Fix AP806 system controller size
  MAINTAINERS: add Macchiatobin maintainers entry

Signed-off-by: Olof Johansson <olof@lixom.net>
2017-10-03 18:10:40 -07:00
Olof Johansson 180eb4f17e Reset controller fixes for v4.14
- Remove misleading HSDK v1 suffix, as there is no v2 planned
 - Add missing DT binding documentation for HSDK reset driver
 - Fix HSDK reset driver dependencies
 -----BEGIN PGP SIGNATURE-----
 
 iQJMBAABCAA2FiEEBsBxhV1FaKwXuCOBUMKIHHCeYOsFAlnD45UYHHBoaWxpcHAu
 emFiZWxAZ21haWwuY29tAAoJEFDCiBxwnmDr4nEP/jDhdvcNVEDn6+AVoEUDIXPF
 vray929miIdCrSGD0TIqo4lARuyOIe9+jT6Nw0oSnheRDcb/QpqsCKm+177lHIEd
 OiJiCoI3NFCwzLwPiKFHzh5JPUWnCVo5uf9lqtc9uyW3vvtnmHHPnD4xT74xQZnE
 wZToOnJGjxvDzRtDj1BJTwN6zCf6dyUbN9Eg07QIucu/pig6Ingai0dINzt2aFK0
 H1IiEdawX+J/BphHffopstyN7u1Da72N38gtV05L8kvSFmNBwU8VOkWtkSL5ef8v
 FSWepDjqepODV8jtYw04yf5CP+O7fElzS26hC7tFzCgJM26yFUXmxhpNhRIZ+S8h
 YxwCYTnbr7+gx8oPpV+SdxT/8vEpDxK8rH1yEpW1CltTIr2U0VNC5b86MYc4hKkj
 oJl/vMFoHNJEw283dlPZG2yliAtDrWD+Y+YqgSYuiXVsVMj9umfkMm92lg4sBI9Y
 CbgBiyuPgXQh2UHmb6scWLrhur3quiEDvIMHxTR0uB5eDw7uSL+x1bf9EjeOqClY
 Bt96w/wSQ0trIvPIh/Wz6sBbXuwJsw2u+U8OMtiAq2T7pwWqHbCk+jMZRV57PMFT
 b+TcI74dRLHMfRYs/DDPSk3f4awLX8UWViqJdSP/lMVAyiGpsqWOojy4jDde+t3P
 S4ACP6FwidTvNyrMYJZu
 =Jx/i
 -----END PGP SIGNATURE-----

Merge tag 'reset-fixes-for-4.14' of git://git.pengutronix.de/git/pza/linux into fixes

Reset controller fixes for v4.14

- Remove misleading HSDK v1 suffix, as there is no v2 planned
- Add missing DT binding documentation for HSDK reset driver
- Fix HSDK reset driver dependencies

* tag 'reset-fixes-for-4.14' of git://git.pengutronix.de/git/pza/linux:
  reset: Restrict RESET_HSDK to ARC_SOC_HSDK or COMPILE_TEST
  ARC: reset: remove the misleading v1 suffix all over
  ARC: reset: add missing DT binding documentation for HSDKv1 reset driver
  ARC: reset: Only build on archs that have IOMEM

Signed-off-by: Olof Johansson <olof@lixom.net>
2017-10-03 18:10:12 -07:00
Olof Johansson 5f3daa2393 A fix for random ethernet mac address problem
on DA850 EVM.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJZwiEgAAoJEGFBu2jqvgRNhKUQAIL/zJzg1+qnnNhrzaDW2pnn
 F5+kit+8f5VoD0IzBdSIm6VyiFkY/HJMR8w++UNXXgdyF9DPz59hQxu/MXf3oJwo
 8OzGDANRHIXHpYQ3rRZEB3zSP/i8XLdyjsj7eLw5t9ao37KQIv/yBKA/JHCHvZ4v
 dUoPXFpovv5iC5mJtM1XEKHQosx4qr2bSJ+oHiTwobMdfXMdrLg8ySFo2O3xwRr3
 t6UkwLzQG7CdwxX+IdxPoW+bGkXlrcQ0hCIhgqqOsm7+BWSl75fMKsGMuma6jlqz
 EmGUpJfGbSqMzt/G+kAiVBYJoOWpmUxPIxAbIococMRdw3PZ5KPF2WXd3X9eXgmK
 yowdTCR7C8cGXvVHcc1jRbrugqp2cNKS3i5sZUxl1Mb+zoY6y2ivAPVK5AG7UQsl
 TaesDkmsqn0KvUKP2rtRXlHS52Qp+8V+nCiaDL5il4IgHXurt5qFWrZXeSOlxp0a
 DmvaEZ4K6aXxH/fR4wZXBy3JPS2EUpqI8Ht4AG/sq2mB6Tj2yWYNeprFU4E9eU8T
 HeHM5Pu+PCHDYPcDrrzE64ubsQNGrE0vieWDMrefg4cHSok9vbdJQ4F+xtXaH7pT
 lw/yrsHaeeWy3c2bvcUL4GE5ZaEKLuTMKnmqDxFGMKvVY5Vv1KURpAwqN0GTzPaL
 zZ4LUloQKx1zVWrY+e8u
 =fiWW
 -----END PGP SIGNATURE-----

Merge tag 'davinci-fixes-for-v4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/nsekhar/linux-davinci into fixes

A fix for random ethernet mac address problem
on DA850 EVM.

* tag 'davinci-fixes-for-v4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/nsekhar/linux-davinci:
  ARM: dts: da850-evm: add serial and ethernet aliases

Signed-off-by: Olof Johansson <olof@lixom.net>
2017-10-03 18:09:08 -07:00
Olof Johansson 24f5a731e5 Fixes for 4.14:
- three DT fixes for the newly introduced sama5d27_som1_ek board
 - one treewide modification that didn't touch this new PM code: we
   synchronize now to be coherent with the other ARM platforms
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJZv+9LAAoJEAf03oE53VmQ8pwH/i8kzx5nHFyzAAmgye9WlvSQ
 WSIliLLrITv3lM5YWpWuIq2y4ou8pvRmWxkb02Ih58E/A3TGsTzuvide0DgNAzOf
 blrFWF0cjcMEw1RwwdbhJZlxi/5PpKAPhR8TKLeB5RBtUhdcDenp3SMIDGeK/XZK
 ejJXm6OuT8NLGo69+7DbJ6/6zRlbFRe+TwehOz5afmTsRemvqf+U1k65nEwuVhLK
 F9ic2ADGT7noqc6+NPtyrW5pXIEis4+hnkSTGOo0k6GWmp64fWU4Vdt+qgwqDqhl
 ts81yk/sOA+nVS417AHYw5rA2VlzxpibJ/7U84QJyBNf+5gWijAhIrpORAS3FuA=
 =4X2n
 -----END PGP SIGNATURE-----

Merge tag 'at91-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nferre/linux-at91 into fixes

Fixes for 4.14:
- three DT fixes for the newly introduced sama5d27_som1_ek board
- one treewide modification that didn't touch this new PM code: we
  synchronize now to be coherent with the other ARM platforms

* tag 'at91-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nferre/linux-at91:
  ARM: at91: Replace uses of virt_to_phys with __pa_symbol
  ARM: dts: at91: sama5d27_som1_ek: fix USB host vbus
  ARM: dts: at91: sama5d27_som1_ek: fix typos
  ARM: dts: at91: sama5d27_som1_ek: update pinmux/pinconf for LEDs and USB

Signed-off-by: Olof Johansson <olof@lixom.net>
2017-10-03 18:08:27 -07:00
Linus Walleij 0694b2ee87 ARM: defconfig: update Gemini defconfig
This updates the Gemini defconfig with drivers merged
for v4.13 or v4.14:
- ATA driver is merged
- DMA driver is merged
- RTC driver gets selected from default Kconfig

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>
2017-10-03 18:08:05 -07:00
Arnd Bergmann e4c77f8b9b ARM: defconfig: FRAMEBUFFER_CONSOLE can no longer be =m
It is no longer possible to load this at runtime, so let's
change the few remaining users to have it built-in all
the time.

arch/arm/configs/zeus_defconfig:115:warning: symbol value 'm' invalid for FRAMEBUFFER_CONSOLE
arch/arm/configs/viper_defconfig:116:warning: symbol value 'm' invalid for FRAMEBUFFER_CONSOLE
arch/arm/configs/pxa_defconfig:474:warning: symbol value 'm' invalid for FRAMEBUFFER_CONSOLE

Reported-by: kernelci.org bot <bot@kernelci.org>
Fixes: 6104c37094 ("fbcon: Make fbcon a built-time depency for fbdev")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Olof Johansson <olof@lixom.net>
2017-10-03 18:06:27 -07:00
Mike Rapoport 32e57c29e3 include/linux/fs.h: fix comment about struct address_space
Before commit 9c5d760b8d ("mm: split gfp_mask and mapping flags into
separate fields") the private_* fields of struct adrress_space were
grouped together and using "ditto" in comments describing the last
fields was correct.

With introduction of gpf_mask between private_lock and private_list
"ditto" references the wrong description.

Fix it by using the elaborate description.

Link: http://lkml.kernel.org/r/1507009987-8746-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:26 -07:00
Stafford Horne a08ffbef4a checkpatch: fix ignoring cover-letter logic
Currently running checkpatch on a directory with a cover-letter.patch
file reports the following error:

  -----------------------------------------
  patches/smp-v2/v2-0000-cover-letter.patch
  -----------------------------------------

  ERROR: Does not appear to be a unified-diff format patch

The logic to suppress the unified-diff check for cover letters is there
but is checking $file instead of $filename.  Fix the variable to use the
correct one.

Link: http://lkml.kernel.org/r/20170909090406.31523-1-shorne@gmail.com
Signed-off-by: Stafford Horne <shorne@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:26 -07:00
Sudip Mukherjee d22e3d69ee m32r: fix build failure
The allmodconfig build of m32r is failing with the error:

  lib/mpi/mpih-div.o: In function 'mpihelp_divrem':
  mpih-div.c:(.text+0x40): undefined reference to 'abort'
  mpih-div.c:(.text+0x40): relocation truncated to fit:
	R_M32R_26_PCREL_RELA against undefined symbol 'abort'

The function 'abort' was never defined for the m32r architecture.

Create 'abort' as is done in other arch like 'arm' and 'unicore32'.

Link: http://lkml.kernel.org/r/1506727220-6108-1-git-send-email-sudip.mukherjee@codethink.co.uk
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:26 -07:00
Sergey Senozhatsky 656d61ce96 lib/ratelimit.c: use deferred printk() version
printk_ratelimit() invokes ___ratelimit() which may invoke a normal
printk() (pr_warn() in this particular case) to warn about suppressed
output.  Given that printk_ratelimit() may be called from anywhere, that
pr_warn() is dangerous - it may end up deadlocking the system.  Fix
___ratelimit() by using deferred printk().

Sasha reported the following lockdep error:

 : Unregister pv shared memory for cpu 8
 : select_fallback_rq: 3 callbacks suppressed
 : process 8583 (trinity-c78) no longer affine to cpu8
 :
 : ======================================================
 : WARNING: possible circular locking dependency detected
 : 4.14.0-rc2-next-20170927+ #252 Not tainted
 : ------------------------------------------------------
 : migration/8/62 is trying to acquire lock:
 : (&port_lock_key){-.-.}, at: serial8250_console_write()
 :
 : but task is already holding lock:
 : (&rq->lock){-.-.}, at: sched_cpu_dying()
 :
 : which lock already depends on the new lock.
 :
 :
 : the existing dependency chain (in reverse order) is:
 :
 : -> #3 (&rq->lock){-.-.}:
 : __lock_acquire()
 : lock_acquire()
 : _raw_spin_lock()
 : task_fork_fair()
 : sched_fork()
 : copy_process.part.31()
 : _do_fork()
 : kernel_thread()
 : rest_init()
 : start_kernel()
 : x86_64_start_reservations()
 : x86_64_start_kernel()
 : verify_cpu()
 :
 : -> #2 (&p->pi_lock){-.-.}:
 : __lock_acquire()
 : lock_acquire()
 : _raw_spin_lock_irqsave()
 : try_to_wake_up()
 : default_wake_function()
 : woken_wake_function()
 : __wake_up_common()
 : __wake_up_common_lock()
 : __wake_up()
 : tty_wakeup()
 : tty_port_default_wakeup()
 : tty_port_tty_wakeup()
 : uart_write_wakeup()
 : serial8250_tx_chars()
 : serial8250_handle_irq.part.25()
 : serial8250_default_handle_irq()
 : serial8250_interrupt()
 : __handle_irq_event_percpu()
 : handle_irq_event_percpu()
 : handle_irq_event()
 : handle_level_irq()
 : handle_irq()
 : do_IRQ()
 : ret_from_intr()
 : native_safe_halt()
 : default_idle()
 : arch_cpu_idle()
 : default_idle_call()
 : do_idle()
 : cpu_startup_entry()
 : rest_init()
 : start_kernel()
 : x86_64_start_reservations()
 : x86_64_start_kernel()
 : verify_cpu()
 :
 : -> #1 (&tty->write_wait){-.-.}:
 : __lock_acquire()
 : lock_acquire()
 : _raw_spin_lock_irqsave()
 : __wake_up_common_lock()
 : __wake_up()
 : tty_wakeup()
 : tty_port_default_wakeup()
 : tty_port_tty_wakeup()
 : uart_write_wakeup()
 : serial8250_tx_chars()
 : serial8250_handle_irq.part.25()
 : serial8250_default_handle_irq()
 : serial8250_interrupt()
 : __handle_irq_event_percpu()
 : handle_irq_event_percpu()
 : handle_irq_event()
 : handle_level_irq()
 : handle_irq()
 : do_IRQ()
 : ret_from_intr()
 : native_safe_halt()
 : default_idle()
 : arch_cpu_idle()
 : default_idle_call()
 : do_idle()
 : cpu_startup_entry()
 : rest_init()
 : start_kernel()
 : x86_64_start_reservations()
 : x86_64_start_kernel()
 : verify_cpu()
 :
 : -> #0 (&port_lock_key){-.-.}:
 : check_prev_add()
 : __lock_acquire()
 : lock_acquire()
 : _raw_spin_lock_irqsave()
 : serial8250_console_write()
 : univ8250_console_write()
 : console_unlock()
 : vprintk_emit()
 : vprintk_default()
 : vprintk_func()
 : printk()
 : ___ratelimit()
 : __printk_ratelimit()
 : select_fallback_rq()
 : sched_cpu_dying()
 : cpuhp_invoke_callback()
 : take_cpu_down()
 : multi_cpu_stop()
 : cpu_stopper_thread()
 : smpboot_thread_fn()
 : kthread()
 : ret_from_fork()
 :
 : other info that might help us debug this:
 :
 : Chain exists of:
 :   &port_lock_key --> &p->pi_lock --> &rq->lock
 :
 :  Possible unsafe locking scenario:
 :
 :        CPU0                    CPU1
 :        ----                    ----
 :   lock(&rq->lock);
 :                                lock(&p->pi_lock);
 :                                lock(&rq->lock);
 :   lock(&port_lock_key);
 :
 :  *** DEADLOCK ***
 :
 : 4 locks held by migration/8/62:
 : #0: (&p->pi_lock){-.-.}, at: sched_cpu_dying()
 : #1: (&rq->lock){-.-.}, at: sched_cpu_dying()
 : #2: (printk_ratelimit_state.lock){....}, at: ___ratelimit()
 : #3: (console_lock){+.+.}, at: vprintk_emit()
 :
 : stack backtrace:
 : CPU: 8 PID: 62 Comm: migration/8 Not tainted 4.14.0-rc2-next-20170927+ #252
 : Call Trace:
 : dump_stack()
 : print_circular_bug()
 : check_prev_add()
 : ? add_lock_to_list.isra.26()
 : ? check_usage()
 : ? kvm_clock_read()
 : ? kvm_sched_clock_read()
 : ? sched_clock()
 : ? check_preemption_disabled()
 : __lock_acquire()
 : ? __lock_acquire()
 : ? add_lock_to_list.isra.26()
 : ? debug_check_no_locks_freed()
 : ? memcpy()
 : lock_acquire()
 : ? serial8250_console_write()
 : _raw_spin_lock_irqsave()
 : ? serial8250_console_write()
 : serial8250_console_write()
 : ? serial8250_start_tx()
 : ? lock_acquire()
 : ? memcpy()
 : univ8250_console_write()
 : console_unlock()
 : ? __down_trylock_console_sem()
 : vprintk_emit()
 : vprintk_default()
 : vprintk_func()
 : printk()
 : ? show_regs_print_info()
 : ? lock_acquire()
 : ___ratelimit()
 : __printk_ratelimit()
 : select_fallback_rq()
 : sched_cpu_dying()
 : ? sched_cpu_starting()
 : ? rcutree_dying_cpu()
 : ? sched_cpu_starting()
 : cpuhp_invoke_callback()
 : ? cpu_disable_common()
 : take_cpu_down()
 : ? trace_hardirqs_off_caller()
 : ? cpuhp_invoke_callback()
 : multi_cpu_stop()
 : ? __this_cpu_preempt_check()
 : ? cpu_stop_queue_work()
 : cpu_stopper_thread()
 : ? cpu_stop_create()
 : smpboot_thread_fn()
 : ? sort_range()
 : ? schedule()
 : ? __kthread_parkme()
 : kthread()
 : ? sort_range()
 : ? kthread_create_on_node()
 : ret_from_fork()
 : process 9121 (trinity-c78) no longer affine to cpu8
 : smpboot: CPU 8 is now offline

Link: http://lkml.kernel.org/r/20170928120405.18273-1-sergey.senozhatsky@gmail.com
Fixes: 6b1d174b0c ("ratelimit: extend to print suppressed messages on release")
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reported-by: Sasha Levin <levinsasha928@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Borislav Petkov <bp@suse.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:26 -07:00
Jean Delvare e0596c80f4 kernel/params.c: improve STANDARD_PARAM_DEF readability
Align the parameters passed to STANDARD_PARAM_DEF for clarity.

Link: http://lkml.kernel.org/r/20170928162728.756143cc@endymion
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Suggested-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:26 -07:00
Jean Delvare 96802e6b1d kernel/params.c: fix an overflow in param_attr_show
Function param_attr_show could overflow the buffer it is operating on.

The buffer size is PAGE_SIZE, and the string returned by
attribute->param->ops->get is generated by scnprintf(buffer, PAGE_SIZE,
...) so it could be PAGE_SIZE - 1 long, with the terminating '\0' at the
very end of the buffer.  Calling strcat(..., "\n") on this isn't safe, as
the '\0' will be replaced by '\n' (OK) and then another '\0' will be added
past the end of the buffer (not OK.)

Simply add the trailing '\n' when writing the attribute contents to the
buffer originally.  This is safe, and also faster.

Credits to Teradata for discovering this issue.

Link: http://lkml.kernel.org/r/20170928162602.60c379c7@endymion
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:26 -07:00
Jean Delvare 90ceb2a3ad kernel/params.c: fix the maximum length in param_get_string
The length parameter of strlcpy() is supposed to reflect the size of the
target buffer, not of the source string.  Harmless in this case as the
buffer is PAGE_SIZE long and the source string is always much shorter than
this, but conceptually wrong, so let's fix it.

Link: http://lkml.kernel.org/r/20170928162515.24846b4f@endymion
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:26 -07:00
YASUAKI ISHIMATSU d09b0137d2 mm/memory_hotplug: define find_{smallest|biggest}_section_pfn as unsigned long
find_{smallest|biggest}_section_pfn()s find the smallest/biggest section
and return the pfn of the section.  But the functions are defined as int.
So the functions always return 0x00000000 - 0xffffffff.  It means if
memory address is over 16TB, the functions does not work correctly.

To handle 64 bit value, the patch defines
find_{smallest|biggest}_section_pfn() as unsigned long.

Fixes: 815121d2b5 ("memory_hotplug: clear zone when removing the memory")
Link: http://lkml.kernel.org/r/d9d5593a-d0a4-c4be-ab08-493df59a85c6@gmail.com
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:26 -07:00
YASUAKI ISHIMATSU 1dd2bfc868 mm/memory_hotplug: change pfn_to_section_nr/section_nr_to_pfn macro to inline function
pfn_to_section_nr() and section_nr_to_pfn() are defined as macro.
pfn_to_section_nr() has no issue even if it is defined as macro.  But
section_nr_to_pfn() has overflow issue if sec is defined as int.

section_nr_to_pfn() just shifts sec by PFN_SECTION_SHIFT.  If sec is
defined as unsigned long, section_nr_to_pfn() returns pfn as 64 bit value.
But if sec is defined as int, section_nr_to_pfn() returns pfn as 32 bit
value.

__remove_section() calculates start_pfn using section_nr_to_pfn() and
scn_nr defined as int.  So if hot-removed memory address is over 16TB,
overflow issue occurs and section_nr_to_pfn() does not calculate correct
pfn.

To make callers use proper arg, the patch changes the macros to inline
functions.

Fixes: 815121d2b5 ("memory_hotplug: clear zone when removing the memory")
Link: http://lkml.kernel.org/r/e643a387-e573-6bbf-d418-c60c8ee3d15e@gmail.com
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:25 -07:00
Cyrill Gorcunov c9653850c9 kernel/kcmp.c: drop branch leftover typo
The else branch been left over and escaped the source code refresh.  Not
a problem but better clean it up.

Fixes: 0791e3644e ("kcmp: add KCMP_EPOLL_TFD mode to compare epoll target files")
Link: http://lkml.kernel.org/r/20170917165838.GA1887@uranus.lan
Reported-by: Eugene Syromiatnikov <esyr@redhat.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrei Vagin <avagin@virtuozzo.com>
Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:25 -07:00
Michal Hocko 1fdcce6e16 memremap: add scheduling point to devm_memremap_pages
devm_memremap_pages is initializing struct pages in for_each_device_pfn
and that can take quite some time.  We have even seen a soft lockup
triggering on a non preemptive kernel

  NMI watchdog: BUG: soft lockup - CPU#61 stuck for 22s! [kworker/u641:11:1808]
  [...]
  RIP: 0010:[<ffffffff8118b6b7>]  [<ffffffff8118b6b7>] devm_memremap_pages+0x327/0x430
  [...]
  Call Trace:
    pmem_attach_disk+0x2fd/0x3f0 [nd_pmem]
    nvdimm_bus_probe+0x64/0x110 [libnvdimm]
    driver_probe_device+0x1f7/0x420
    bus_for_each_drv+0x52/0x80
    __device_attach+0xb0/0x130
    bus_probe_device+0x87/0xa0
    device_add+0x3fc/0x5f0
    nd_async_device_register+0xe/0x40 [libnvdimm]
    async_run_entry_fn+0x43/0x150
    process_one_work+0x14e/0x410
    worker_thread+0x116/0x490
    kthread+0xc7/0xe0
    ret_from_fork+0x3f/0x70

fix this by adding cond_resched every 1024 pages.

Link: http://lkml.kernel.org/r/20170918121410.24466-4-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Johannes Thumshirn <jthumshirn@suse.de>
Tested-by: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Dan Williams <dan.j.williams@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:25 -07:00
Michal Hocko 9b6e63cbf8 mm, page_alloc: add scheduling point to memmap_init_zone
memmap_init_zone gets a pfn range to initialize and it can be really
large resulting in a soft lockup on non-preemptible kernels

  NMI watchdog: BUG: soft lockup - CPU#31 stuck for 23s! [kworker/u642:5:1720]
  [...]
  task: ffff88ecd7e902c0 ti: ffff88eca4e50000 task.ti: ffff88eca4e50000
  RIP: move_pfn_range_to_zone+0x185/0x1d0
  [...]
  Call Trace:
    devm_memremap_pages+0x2c7/0x430
    pmem_attach_disk+0x2fd/0x3f0 [nd_pmem]
    nvdimm_bus_probe+0x64/0x110 [libnvdimm]
    driver_probe_device+0x1f7/0x420
    bus_for_each_drv+0x52/0x80
    __device_attach+0xb0/0x130
    bus_probe_device+0x87/0xa0
    device_add+0x3fc/0x5f0
    nd_async_device_register+0xe/0x40 [libnvdimm]
    async_run_entry_fn+0x43/0x150
    process_one_work+0x14e/0x410
    worker_thread+0x116/0x490
    kthread+0xc7/0xe0
    ret_from_fork+0x3f/0x70

Fix this by adding a scheduling point once per page block.

Link: http://lkml.kernel.org/r/20170918121410.24466-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Johannes Thumshirn <jthumshirn@suse.de>
Tested-by: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Dan Williams <dan.j.williams@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:25 -07:00
Michal Hocko f64ac5e6e3 mm, memory_hotplug: add scheduling point to __add_pages
Patch series "mm, memory_hotplug: fix few soft lockups in memory
hotadd".

Johannes has noticed few soft lockups when adding a large nvdimm device.
All of them were caused by a long loop without any explicit cond_resched
which is a problem for !PREEMPT kernels.

The fix is quite straightforward.  Just make sure that cond_resched gets
called from time to time.

This patch (of 3):

__add_pages gets a pfn range to add and there is no upper bound for a
single call.  This is usually a memory block aligned size for the
regular memory hotplug - smaller sizes are usual for memory balloning
drivers, or the whole NUMA node for physical memory online.  There is no
explicit scheduling point in that code path though.

This can lead to long latencies while __add_pages is executed and we
have even seen a soft lockup report during nvdimm initialization with
!PREEMPT kernel

  NMI watchdog: BUG: soft lockup - CPU#11 stuck for 23s! [kworker/u641:3:832]
  [...]
  Workqueue: events_unbound async_run_entry_fn
  task: ffff881809270f40 ti: ffff881809274000 task.ti: ffff881809274000
  RIP: _raw_spin_unlock_irqrestore+0x11/0x20
  RSP: 0018:ffff881809277b10  EFLAGS: 00000286
  [...]
  Call Trace:
    sparse_add_one_section+0x13d/0x18e
    __add_pages+0x10a/0x1d0
    arch_add_memory+0x4a/0xc0
    devm_memremap_pages+0x29d/0x430
    pmem_attach_disk+0x2fd/0x3f0 [nd_pmem]
    nvdimm_bus_probe+0x64/0x110 [libnvdimm]
    driver_probe_device+0x1f7/0x420
    bus_for_each_drv+0x52/0x80
    __device_attach+0xb0/0x130
    bus_probe_device+0x87/0xa0
    device_add+0x3fc/0x5f0
    nd_async_device_register+0xe/0x40 [libnvdimm]
    async_run_entry_fn+0x43/0x150
    process_one_work+0x14e/0x410
    worker_thread+0x116/0x490
    kthread+0xc7/0xe0
    ret_from_fork+0x3f/0x70
  DWARF2 unwinder stuck at ret_from_fork+0x3f/0x70

Fix this by adding cond_resched once per each memory section in the
given pfn range.  Each section is constant amount of work which itself
is not too expensive but many of them will just add up.

Link: http://lkml.kernel.org/r/20170918121410.24466-2-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Johannes Thumshirn <jthumshirn@suse.de>
Tested-by: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Dan Williams <dan.j.williams@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:25 -07:00
Eric Biggers a70e43a59d lib/idr.c: fix comment for idr_replace()
idr_replace() returns the old value on success, not 0.

Link: http://lkml.kernel.org/r/20170918162642.37511-1-ebiggers3@gmail.com
Signed-off-by: Eric Biggers <ebiggers@google.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:25 -07:00
Johannes Weiner f80c7dab95 mm: memcontrol: use vmalloc fallback for large kmem memcg arrays
For quick per-memcg indexing, slab caches and list_lru structures
maintain linear arrays of descriptors.  As the number of concurrent
memory cgroups in the system goes up, this requires large contiguous
allocations (8k cgroups = order-5, 16k cgroups = order-6 etc.) for every
existing slab cache and list_lru, which can easily fail on loaded
systems.  E.g.:

  mkdir: page allocation failure: order:5, mode:0x14040c0(GFP_KERNEL|__GFP_COMP), nodemask=(null)
  CPU: 1 PID: 6399 Comm: mkdir Not tainted 4.13.0-mm1-00065-g720bbe532b7c-dirty #481
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-20170228_101828-anatol 04/01/2014
  Call Trace:
   ? __alloc_pages_direct_compact+0x4c/0x110
   __alloc_pages_nodemask+0xf50/0x1430
   alloc_pages_current+0x60/0xc0
   kmalloc_order_trace+0x29/0x1b0
   __kmalloc+0x1f4/0x320
   memcg_update_all_list_lrus+0xca/0x2e0
   mem_cgroup_css_alloc+0x612/0x670
   cgroup_apply_control_enable+0x19e/0x360
   cgroup_mkdir+0x322/0x490
   kernfs_iop_mkdir+0x55/0x80
   vfs_mkdir+0xd0/0x120
   SyS_mkdirat+0x6c/0xe0
   SyS_mkdir+0x14/0x20
   entry_SYSCALL_64_fastpath+0x18/0xad
  Mem-Info:
  active_anon:2965 inactive_anon:19 isolated_anon:0
   active_file:100270 inactive_file:98846 isolated_file:0
   unevictable:0 dirty:0 writeback:0 unstable:0
   slab_reclaimable:7328 slab_unreclaimable:16402
   mapped:771 shmem:52 pagetables:278 bounce:0
   free:13718 free_pcp:0 free_cma:0

This output is from an artificial reproducer, but we have repeatedly
observed order-7 failures in production in the Facebook fleet.  These
systems become useless as they cannot run more jobs, even though there
is plenty of memory to allocate 128 individual pages.

Use kvmalloc and kvzalloc to fall back to vmalloc space if these arrays
prove too large for allocating them physically contiguous.

Link: http://lkml.kernel.org/r/20170918184919.20644-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:25 -07:00
Luis R. Rodriguez 3181c38e4d kernel/sysctl.c: remove duplicate UINT_MAX check on do_proc_douintvec_conv()
do_proc_douintvec_conv() has two UINT_MAX checks, we can remove one.
This has no functional changes other than fixing a compiler warning:

  kernel/sysctl.c:2190]: (warning) Identical condition '*lvalp>UINT_MAX', second condition is always false

Fixes: 4f2fec00af ("sysctl: simplify unsigned int support")
Link: http://lkml.kernel.org/r/20170919072918.12066-1-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Reported-by: David Binderman <dcb314@hotmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:25 -07:00
Masahiro Yamada 7240767450 include/linux/bitfield.h: remove 32bit from FIELD_GET comment block
I do not see anything that restricts this macro to 32 bit width.

Link: http://lkml.kernel.org/r/1505921975-23379-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:25 -07:00
Colin Ian King 8cb5d74828 lib/lz4: make arrays static const, reduces object code size
Don't populate the read-only arrays dec32table and dec64table on the
stack, instead make them both static const.  Makes the object code
smaller by over 10K bytes:

  Before:
     text	   data	    bss	    dec	    hex	filename
    31500	      0	      0	  31500	   7b0c	lib/lz4/lz4_decompress.o

  After:
     text	   data	    bss	    dec	    hex	filename
    20237	    176	      0	  20413	   4fbd	lib/lz4/lz4_decompress.o

(gcc version 7.2.0 x86_64)

Link: http://lkml.kernel.org/r/20170921221939.20820-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:25 -07:00
Oleg Nesterov 50097f7493 exec: binfmt_misc: kill the onstack iname[BINPRM_BUF_SIZE] array
After the previous change "fmt" can't go away, we can kill
iname/iname_addr and use fmt->interpreter.

Link: http://lkml.kernel.org/r/20170922143653.GA17232@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ben Woodard <woodard@redhat.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jim Foraker <foraker1@llnl.gov>
Cc: <tdhooge@llnl.gov>
Cc: Travis Gummels <tgummels@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:25 -07:00
Oleg Nesterov 43a4f26190 exec: binfmt_misc: fix race between load_misc_binary() and kill_node()
load_misc_binary() makes a local copy of fmt->interpreter under
entries_lock to avoid the race with kill_node() but this is not enough;
the whole Node can be freed after we drop entries_lock, not only the
->interpreter string.

Add dget/dput(fmt->dentry) to ensure bm_evict_inode() can't destroy/free
this Node.

Link: http://lkml.kernel.org/r/20170922143650.GA17227@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ben Woodard <woodard@redhat.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jim Foraker <foraker1@llnl.gov>
Cc: Travis Gummels <tgummels@redhat.com>
Cc: <tdhooge@llnl.gov>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:25 -07:00
Oleg Nesterov eb23aa0317 exec: binfmt_misc: remove the confusing e->interp_file != NULL checks
If MISC_FMT_OPEN_FILE flag is set e->interp_file must be valid or we
have a bug which should not be silently ignored.

Link: http://lkml.kernel.org/r/20170922143647.GA17222@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ben Woodard <woodard@redhat.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jim Foraker <foraker1@llnl.gov>
Cc: <tdhooge@llnl.gov>
Cc: Travis Gummels <tgummels@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:25 -07:00
Oleg Nesterov 83f918274e exec: binfmt_misc: shift filp_close(interp_file) from kill_node() to bm_evict_inode()
To ensure that load_misc_binary() can't use the partially destroyed
Node, see also the next patch.

The current logic looks wrong in any case, once we close interp_file it
doesn't make any sense to delay kfree(inode->i_private), this Node is no
longer valid.  Even if the MISC_FMT_OPEN_FILE/interp_file checks were
not racy (they are), load_misc_binary() should not try to reopen
->interpreter if MISC_FMT_OPEN_FILE is set but ->interp_file is NULL.

And I can't understand why do we use filp_close(), not fput().

Link: http://lkml.kernel.org/r/20170922143644.GA17216@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ben Woodard <woodard@redhat.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jim Foraker <foraker1@llnl.gov>
Cc: <tdhooge@llnl.gov>
Cc: Travis Gummels <tgummels@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:25 -07:00
Oleg Nesterov baba1b2973 exec: binfmt_misc: don't nullify Node->dentry in kill_node()
kill_node() nullifies/checks Node->dentry to avoid double free.  This
complicates the next changes and this is very confusing:

 - we do not need to check dentry != NULL under entries_lock,
   kill_node() is always called under inode_lock(d_inode(root)) and we
   rely on this inode_lock() anyway, without this lock the
   MISC_FMT_OPEN_FILE cleanup could race with itself.

 - if kill_inode() was already called and ->dentry == NULL we should not
   even try to close e->interp_file.

We can change bm_entry_write() to simply check !list_empty(list) before
kill_node.  Again, we rely on inode_lock(), in particular it saves us
from the race with bm_status_write(), another caller of kill_node().

Link: http://lkml.kernel.org/r/20170922143641.GA17210@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ben Woodard <woodard@redhat.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jim Foraker <foraker1@llnl.gov>
Cc: <tdhooge@llnl.gov>
Cc: Travis Gummels <tgummels@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:25 -07:00
Oleg Nesterov c2315c187f exec: load_script: kill the onstack interp[BINPRM_BUF_SIZE] array
Patch series "exec: binfmt_misc: fix use-after-free, kill
iname[BINPRM_BUF_SIZE]".

It looks like this code was always wrong, then commit 948b701a60
("binfmt_misc: add persistent opened binary handler for containers")
added more problems.

This patch (of 6):

load_script() can simply use i_name instead, it points into bprm->buf[]
and nobody can change this memory until we call prepare_binprm().

The only complication is that we need to also change the signature of
bprm_change_interp() but this change looks good too.

While at it, do whitespace/style cleanups.

NOTE: the real motivation for this change is that people want to
increase BINPRM_BUF_SIZE, we need to change load_misc_binary() too but
this looks more complicated because afaics it is very buggy.

Link: http://lkml.kernel.org/r/20170918163446.GA26793@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Travis Gummels <tgummels@redhat.com>
Cc: Ben Woodard <woodard@redhat.com>
Cc: Jim Foraker <foraker1@llnl.gov>
Cc: <tdhooge@llnl.gov>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:25 -07:00
Andrea Arcangeli 384632e67e userfaultfd: non-cooperative: fix fork use after free
When reading the event from the uffd, we put it on a temporary
fork_event list to detect if we can still access it after releasing and
retaking the event_wqh.lock.

If fork aborts and removes the event from the fork_event all is fine as
long as we're still in the userfault read context and fork_event head is
still alive.

We've to put the event allocated in the fork kernel stack, back from
fork_event list-head to the event_wqh head, before returning from
userfaultfd_ctx_read, because the fork_event head lifetime is limited to
the userfaultfd_ctx_read stack lifetime.

Forgetting to move the event back to its event_wqh place then results in
__remove_wait_queue(&ctx->event_wqh, &ewq->wq); in
userfaultfd_event_wait_completion to remove it from a head that has been
already freed from the reader stack.

This could only happen if resolve_userfault_fork failed (for example if
there are no file descriptors available to allocate the fork uffd).  If
it succeeded it was put back correctly.

Furthermore, after find_userfault_evt receives a fork event, the forked
userfault context in fork_nctx and uwq->msg.arg.reserved.reserved1 can
be released by the fork thread as soon as the event_wqh.lock is
released.  Taking a reference on the fork_nctx before dropping the lock
prevents an use after free in resolve_userfault_fork().

If the fork side aborted and it already released everything, we still
try to succeed resolve_userfault_fork(), if possible.

Fixes: 893e26e61d ("userfaultfd: non-cooperative: Add fork() event")
Link: http://lkml.kernel.org/r/20170920180413.26713-1-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:25 -07:00
Reza Arbab 7d790d2da3 mm/device-public-memory: fix edge case in _vm_normal_page()
With device public pages at the end of my memory space, I'm getting
output from _vm_normal_page():

  BUG: Bad page map in process migrate_pages  pte:c0800001ffff0d06 pmd:f95d3000
  addr:00007fff89330000 vm_flags:00100073 anon_vma:c0000000fa899320 mapping:          (null) index:7fff8933
  file:          (null) fault:          (null) mmap:          (null) readpage:          (null)
  CPU: 0 PID: 13963 Comm: migrate_pages Tainted: P    B      OE 4.14.0-rc1-wip #155
  Call Trace:
     dump_stack+0xb0/0xf4 (unreliable)
     print_bad_pte+0x28c/0x340
     _vm_normal_page+0xc0/0x140
     zap_pte_range+0x664/0xc10
     unmap_page_range+0x318/0x670
     unmap_vmas+0x74/0xe0
     exit_mmap+0xe8/0x1f0
     mmput+0xac/0x1f0
     do_exit+0x348/0xcd0
     do_group_exit+0x5c/0xf0
     SyS_exit_group+0x1c/0x20
     system_call+0x58/0x6c

The pfn causing this is the very last one.  Correct the bounds check
accordingly.

Fixes: df6ad69838 ("mm/device-public-memory: device memory cache coherent with CPU")
Link: http://lkml.kernel.org/r/1506092178-20351-1-git-send-email-arbab@linux.vnet.ibm.com
Signed-off-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Reviewed-by: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:25 -07:00
Shaohua Li 9625456cc7 mm: fix data corruption caused by lazyfree page
MADV_FREE clears pte dirty bit and then marks the page lazyfree (clear
SwapBacked).  There is no lock to prevent the page is added to swap
cache between these two steps by page reclaim.  If page reclaim finds
such page, it will simply add the page to swap cache without pageout the
page to swap because the page is marked as clean.  Next time, page fault
will read data from the swap slot which doesn't have the original data,
so we have a data corruption.  To fix issue, we mark the page dirty and
pageout the page.

However, we shouldn't dirty all pages which is clean and in swap cache.
swapin page is swap cache and clean too.  So we only dirty page which is
added into swap cache in page reclaim, which shouldn't be swapin page.
As Minchan suggested, simply dirty the page in add_to_swap can do the
job.

Fixes: 802a3a92ad ("mm: reclaim MADV_FREE pages")
Link: http://lkml.kernel.org/r/08c84256b007bf3f63c91d94383bd9eb6fee2daa.1506446061.git.shli@fb.com
Signed-off-by: Shaohua Li <shli@fb.com>
Reported-by: Artem Savkov <asavkov@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>	[4.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:25 -07:00
Shaohua Li 24c92eb7dc mm: avoid marking swap cached page as lazyfree
MADV_FREE clears pte dirty bit and then marks the page lazyfree (clear
SwapBacked).  There is no lock to prevent the page is added to swap
cache between these two steps by page reclaim.  Page reclaim could add
the page to swap cache and unmap the page.  After page reclaim, the page
is added back to lru.  At that time, we probably start draining per-cpu
pagevec and mark the page lazyfree.  So the page could be in a state
with SwapBacked cleared and PG_swapcache set.  Next time there is a
refault in the virtual address, do_swap_page can find the page from swap
cache but the page has PageSwapCache false because SwapBacked isn't set,
so do_swap_page will bail out and do nothing.  The task will keep
running into fault handler.

Fixes: 802a3a92ad ("mm: reclaim MADV_FREE pages")
Link: http://lkml.kernel.org/r/6537ef3814398c0073630b03f176263bc81f0902.1506446061.git.shli@fb.com
Signed-off-by: Shaohua Li <shli@fb.com>
Reported-by: Artem Savkov <asavkov@redhat.com>
Tested-by: Artem Savkov <asavkov@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>	[4.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:24 -07:00
Jeff Layton f4e222c56c mm: have filemap_check_and_advance_wb_err clear AS_EIO/AS_ENOSPC
Eryu noticed that he could sometimes get a leftover error reported when
it shouldn't be on fsync with ext2 and non-journalled ext4.

The problem is that writeback_single_inode still uses filemap_fdatawait.
That picks up a previously set AS_EIO flag, which would ordinarily have
been cleared before.

Since we're mostly using this function as a replacement for
filemap_check_errors, have filemap_check_and_advance_wb_err clear AS_EIO
and AS_ENOSPC when reporting an error.  That should allow the new
function to better emulate the behavior of the old with respect to these
flags.

Link: http://lkml.kernel.org/r/20170922133331.28812-1-jlayton@kernel.org
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reported-by: Eryu Guan <eguan@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:24 -07:00
Sudip Mukherjee 5bdfca6435 m32r: define CPU_BIG_ENDIAN
The build of m32r allmodconfig is giving lots of build warnings about:

  include/linux/byteorder/big_endian.h:7:2:
	warning: #warning inconsistent configuration,
		needs CONFIG_CPU_BIG_ENDIAN [-Wcpp]
	#warning inconsistent configuration, needs CONFIG_CPU_BIG_ENDIAN

Define CPU_BIG_ENDIAN like the way CPU_LITTLE_ENDIAN is defined.

Link: http://lkml.kernel.org/r/1505678083-10320-1-git-send-email-sudipm.mukherjee@gmail.com
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:24 -07:00
Minchan Kim ae94264ed4 zram: fix null dereference of handle
In testing I found handle passed to zs_map_object in __zram_bvec_read is
NULL so eh kernel goes oops in pin_object().

The reason is there is no routine to check the slot's freeing after
getting the slot's lock.  This patch fixes it.

[minchan@kernel.org: v2]
  Link: http://lkml.kernel.org/r/1505887347-10881-1-git-send-email-minchan@kernel.org
Link: http://lkml.kernel.org/r/1505788488-26723-1-git-send-email-minchan@kernel.org
Fixes: 1f7319c742 ("zram: partial IO refactoring")
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:24 -07:00
Christophe Leroy a872eb2131 mm: fix RODATA_TEST failure "rodata_test: test data was not read only"
On powerpc, RODATA_TEST fails with message the following messages:

  Freeing unused kernel memory: 528K
  rodata_test: test data was not read only

This is because GCC allocates it to .data section:

  c0695034 g     O .data	00000004 rodata_test_data

Since commit 056b9d8a76 ("mm: remove rodata_test_data export, add
pr_fmt"), rodata_test_data is used only inside rodata_test.c By
declaring it static, it gets properly allocated into .rodata section
instead of .data:

  c04df710 l     O .rodata	00000004 rodata_test_data

Fixes: 056b9d8a76 ("mm: remove rodata_test_data export, add pr_fmt")
Link: http://lkml.kernel.org/r/20170921093729.1080368AC1@po15668-vm-win7.idsi0.si.c-s.fr
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jinbum Park <jinb.park7@gmail.com>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:24 -07:00
Ioan Nicu 31d1e130f4 rapidio: remove global irq spinlocks from the subsystem
Locking of config and doorbell operations should be done only if the
underlying hardware requires it.

This patch removes the global spinlocks from the rapidio subsystem and
moves them to the mport drivers (fsl_rio and tsi721), only to the
necessary places.  For example, local config space read and write
operations (lcread/lcwrite) are atomic in all existing drivers, so there
should be no need for locking, while the cread/cwrite operations which
generate maintenance transactions need to be synchronized with a lock.

Later, each driver could chose to use a per-port lock instead of a
global one, or even more granular locking.

Link: http://lkml.kernel.org/r/20170824113023.GD50104@nokia.com
Signed-off-by: Ioan Nicu <ioan.nicu.ext@nokia.com>
Signed-off-by: Frank Kunz <frank.kunz@nokia.com>
Acked-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:24 -07:00
Arnd Bergmann 57148a64e8 mm: meminit: mark init_reserved_page as __meminit
The function is called from __meminit context and calls other __meminit
functions but isn't it self mark as such today:

  WARNING: vmlinux.o(.text.unlikely+0x4516): Section mismatch in reference from the function init_reserved_page() to the function .meminit.text:early_pfn_to_nid()
  The function init_reserved_page() references the function __meminit early_pfn_to_nid().
  This is often because init_reserved_page lacks a __meminit annotation or the annotation of early_pfn_to_nid is wrong.

On most compilers, we don't notice this because the function gets
inlined all the time.  Adding __meminit here fixes the harmless warning
for the old versions and is generally the correct annotation.

Link: http://lkml.kernel.org/r/20170915193149.901180-1-arnd@arndb.de
Fixes: 7e18adb4f8 ("mm: meminit: initialise remaining struct pages in parallel with kswapd")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:24 -07:00
Vitaly Wool 3552935742 z3fold: fix stale list handling
Fix the situation when clear_bit() is called for page->private before
the page pointer is actually assigned.  While at it, remove work_busy()
check because it is costly and does not give 100% guarantee anyway.

Signed-off-by: Vitaly Wool <vitalywool@gmail.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: <Oleksiy.Avramchenko@sony.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:24 -07:00
Davidlohr Bueso 6818600ff0 mm,compaction: serialize waitqueue_active() checks (for real)
Andrea brought to my attention that the L->{L,S} guarantees are
completely bogus for this case.  I was looking at the diagram, from the
offending commit, when that _is_ the race, we had the load reordered
already.

What we need is at least S->L semantics, thus simply use
wq_has_sleeper() to serialize the call for good.

Link: http://lkml.kernel.org/r/20170914175313.GB811@linux-80c1.suse
Fixes: 46acef048a (mm,compaction: serialize waitqueue_active() checks)
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reported-by: Andrea Parri <parri.andrea@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:24 -07:00