linux/Documentation
David Howells c8070b7875 mm: Don't pin ZERO_PAGE in pin_user_pages()
Make pin_user_pages*() leave a ZERO_PAGE unpinned if it extracts a pointer
to it from the page tables and make unpin_user_page*() correspondingly
ignore a ZERO_PAGE when unpinning.  We don't want to risk overrunning a
zero page's refcount as we're only allowed ~2 million pins on it -
something that userspace can conceivably trigger.

Add a pair of functions to test whether a page or a folio is a ZERO_PAGE.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Christoph Hellwig <hch@infradead.org>
cc: David Hildenbrand <david@redhat.com>
cc: Lorenzo Stoakes <lstoakes@gmail.com>
cc: Andrew Morton <akpm@linux-foundation.org>
cc: Jens Axboe <axboe@kernel.dk>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: Matthew Wilcox <willy@infradead.org>
cc: Jan Kara <jack@suse.cz>
cc: Jeff Layton <jlayton@kernel.org>
cc: Jason Gunthorpe <jgg@nvidia.com>
cc: Logan Gunthorpe <logang@deltatee.com>
cc: Hillf Danton <hdanton@sina.com>
cc: Christian Brauner <brauner@kernel.org>
cc: Linus Torvalds <torvalds@linux-foundation.org>
cc: linux-fsdevel@vger.kernel.org
cc: linux-block@vger.kernel.org
cc: linux-kernel@vger.kernel.org
cc: linux-mm@kvack.org
Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20230526214142.958751-2-dhowells@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-31 09:48:15 -06:00
..
ABI dmaengine updates for v6.4 2023-05-03 11:11:56 -07:00
accel
accounting Scheduler changes for v6.4: 2023-04-28 14:53:30 -07:00
admin-guide for-6.4/block-2023-05-06 2023-05-06 08:28:58 -07:00
arch A handful of late-arriving documentation fixes, plus one Spanish 2023-05-05 13:16:42 -07:00
arm ARM: SoC devicetree changes for 6.4 2023-04-25 12:11:54 -07:00
arm64
block Documentation/block: drop the request.rst file 2023-05-12 11:04:58 -06:00
bpf lsm/stable-6.4 PR 20230428 2023-04-29 10:17:05 -07:00
cdrom
core-api mm: Don't pin ZERO_PAGE in pin_user_pages() 2023-05-31 09:48:15 -06:00
cpu-freq
crypto
dev-tools Mainly singleton patches all over the place. Series of note are: 2023-04-27 19:57:00 -07:00
devicetree dt-bindings: PCI: fsl,imx6q: fix assigned-clocks warning 2023-05-09 08:01:49 +02:00
doc-guide
driver-api pwm: Changes for v6.4-rc1 2023-05-03 11:25:01 -07:00
fault-injection
fb
features
filesystems 9p patches for 6.4 merge window 2023-05-04 14:37:53 -07:00
firmware_class
firmware-guide
fpga
gpu
hid
hwmon hwmon: (aquacomputer_d5next) Add support for Aquacomputer Aquastream XT 2023-04-21 07:27:23 -07:00
i2c
iio
images
infiniband
input
isdn
kbuild parisc: update kbuild doc. aliases for parisc64 2023-05-03 17:43:10 +02:00
kernel-hacking
leds - New Drivers 2023-05-02 10:36:02 -07:00
litmus-tests LKMM scripting updates for v6.4 2023-04-24 12:02:25 -07:00
livepatch Objtool changes for v6.4: 2023-04-28 14:02:54 -07:00
locking
loongarch
maintainer
mhi
mips
misc-devices
mm - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
netlabel
netlink net/handshake: Add a kernel API for requesting a TLSv1.3 handshake 2023-04-19 18:48:48 -07:00
networking docs: networking: fix x25-iface.rst heading & index order 2023-05-10 10:31:46 +01:00
nvdimm
nvme
PCI
pcmcia
peci
power regulator: consumer.rst: fix 'regulator_enable' typo. 2023-04-27 21:55:38 +01:00
powerpc
process Mainly singleton patches all over the place. Series of note are: 2023-04-27 19:57:00 -07:00
RCU
riscv RISC-V Patches for the 6.4 Merge Window, Part 1 2023-04-28 16:55:39 -07:00
rust
s390
scheduler sh updates for v6.4 2023-04-27 17:41:23 -07:00
scsi
security lsm: move hook comments docs to security/security.c 2023-04-28 11:58:34 -04:00
sound ALSA: docs: Fix code block indentation in ALSA driver example 2023-05-03 08:08:25 +02:00
sphinx
sphinx-static
spi
staging
target
timers Documentation: timers: hrtimers: Make hybrid union historical 2023-05-02 10:49:58 -06:00
tools rtla/timerlat: Add auto-analysis only option 2023-04-25 19:26:17 -04:00
trace Minor tracing updates: 2023-05-05 13:11:02 -07:00
translations A handful of late-arriving documentation fixes, plus one Spanish 2023-05-05 13:16:42 -07:00
usb
userspace-api Char/Misc drivers for 6.4-rc1 2023-04-27 12:07:50 -07:00
virt VFIO updates for v6.4-rc1 2023-05-02 11:56:43 -07:00
w1
watchdog
.gitignore
atomic_bitops.txt
atomic_t.txt
Changes
CodingStyle
conf.py docs: turn off "smart quotes" in the HTML build 2023-04-20 17:53:18 -06:00
docutils.conf
dontdiff
index.rst
Kconfig
Makefile
memory-barriers.txt
SubmittingPatches
subsystem-apis.rst