Andrea Arcangeli a9b85f9415 userfaultfd: change the read API to return a uffd_msg ... I had requests to return the full address (not the page aligned one) to userland. It's not entirely clear how the page offset could be relevant because userfaults aren't like SIGBUS that can sigjump to a different place and it actually skip resolving the fault depending on a page offset. There's currently no real way to skip the fault especially because after a UFFDIO_COPY|ZEROPAGE, the fault is optimized to be retried within the kernel without having to return to userland first (not even self modifying code replacing the .text that touched the faulting address would prevent the fault to be repeated). Userland cannot skip repeating the fault even more so if the fault was triggered by a KVM secondary page fault or any get_user_pages or any copy-user inside some syscall which will return to kernel code. The second time FAULT_FLAG_RETRY_NOWAIT won't be set leading to a SIGBUS being raised because the userfault can't wait if it cannot release the mmap_map first (and FAULT_FLAG_RETRY_NOWAIT is required for that). Still returning userland a proper structure during the read() on the uffd, can allow to use the current UFFD_API for the future non-cooperative extensions too and it looks cleaner as well. Once we get additional fields there's no point to return the fault address page aligned anymore to reuse the bits below PAGE_SHIFT. The only downside is that the read() syscall will read 32bytes instead of 8bytes but that's not going to be measurable overhead. The total number of new events that can be extended or of new future bits for already shipped events, is limited to 64 by the features field of the uffdio_api structure. If more will be needed a bump of UFFD_API will be required. [akpm@linux-foundation.org: use __packed] Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com> Cc: zhang.zhanghailiang@huawei.com Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Andres Lagar-Cavilla <andreslc@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Feiner <pfeiner@google.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2015-09-04 16:54:41 -07:00
..
ABI	This is the bulk of GPIO changes for the v4.3 kernel cycle:	2015-09-04 10:07:45 -07:00
DocBook	Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs	2015-09-03 12:28:30 -07:00
EDID	…
PCI	The documentation tree update for 4.1. Numerous fixes, the overdue removal	2015-04-18 11:10:49 -04:00
RCU	Merge branches 'doc.2015.07.15a' and 'torture.2015.07.15a' into HEAD	2015-08-04 08:42:02 -07:00
accounting	…
acpi	ACPI / Documentation: Update method tracing documentation.	2015-08-07 02:42:22 +02:00
aoe	…
arm	ARM: SoC platform updates for v4.3	2015-09-01 12:18:40 -07:00
arm64	arm64/Documentation: clarify wording regarding memory below the Image	2015-07-29 18:32:10 +01:00
auxdisplay	…
backlight	…
blackfin	Docs: blackfin: Use new switch macro SAMPLE_IRQ_TIMER instead of IRQ_TIMER5	2015-05-07 09:35:14 -06:00
block	Documentation: update notes in biovecs about arbitrarily sized bios	2015-08-13 12:32:07 -06:00
blockdev	zram: add dynamic device add/remove functionality	2015-06-25 17:00:36 -07:00
bus-devices	…
cdrom	…
cgroups	Merge branch 'for-4.3-unified-base' into for-4.3	2015-08-25 14:19:29 -04:00
cma	cma: debug: document new debugfs interface	2015-04-14 16:49:00 -07:00
connector	…
console	…
cpu-freq	cpufreq: remove redundant CPUFREQ_INCOMPATIBLE notifier event	2015-09-01 15:50:38 +02:00
cpuidle	…
cris	…
crypto	crypto: doc - AEAD / RNG AF_ALG interface	2015-03-09 21:06:18 +11:00
development-process	…
device-mapper	dm raid: document RAID 4/5/6 discard support	2015-08-31 15:05:31 -04:00
devicetree	This is the bulk of pin control changes for the v4.3 development	2015-09-04 10:22:09 -07:00
dmaengine	Merge branch 'topic/pxa' into for-linus	2015-06-25 09:21:58 +05:30
driver-model	Char/Misc driver patches for 4.1-rc1	2015-04-21 09:42:58 -07:00
dvb	…
early-userspace	…
extcon	…
fault-injection	futex: Fault/error injection capabilities	2015-07-20 11:45:45 +02:00
fb	Documentation/fb: add documentation for sm712fb	2015-08-07 15:05:01 -07:00
features	Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile	2015-09-04 08:59:53 -07:00
filesystems	Merge tag 'for-f2fs-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs	2015-09-03 13:10:22 -07:00
firmware_class	…
fmc	…
frv	…
gpio	Documentation: gpio: consumer: describe active low property	2015-08-17 10:38:52 +02:00
hid	HID: sensor: Update document for custom sensor	2015-04-10 22:22:56 +02:00
hwmon	hwmon: (fam15h_power) Add documentation for new processors support	2015-08-27 07:51:15 -07:00
i2c	Merge branch 'i2c/for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux	2015-06-25 18:42:39 -07:00
ia64	virtual: Documentation: simplify and generalize paravirt_ops.txt	2015-02-13 17:15:44 +10:30
ide	…
infiniband	…
input	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input	2015-08-09 09:38:42 +02:00
ioctl	userfaultfd: uAPI	2015-09-04 16:54:41 -07:00
isdn	…
ja_JP	Doc: ja_JP: Fix typo in HOWTO	2015-06-08 16:43:09 -06:00
kbuild	kbuild: Allow arch Makefiles to override {cpp,ld,c}flags	2015-07-06 11:09:00 +05:30
kdump	kernel: add panic_on_warn	2014-12-10 17:41:10 -08:00
ko_KR	…
laptops	Move freefall program from Documentation/ to tools/	2015-06-08 16:42:07 -06:00
leds	Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds	2015-07-01 19:09:11 -07:00
locking	Documentation changes for 3.20	2015-02-11 13:03:11 -08:00
m68k	…
memory-devices	…
metag	…
mic	Char/Misc driver patches for 4.2-rc1	2015-06-26 14:51:15 -07:00
mips	…
misc-devices	mei: add async event notification ioctls	2015-08-03 17:30:00 -07:00
mmc	…
mn10300	…
mtd	…
namespaces	…
netlabel	…
networking	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2015-09-03 08:08:17 -07:00
nfc	NFC: Fix typo in nfc-hci.txt	2015-06-08 23:15:45 +02:00
nios2	Documentation: Add documentation for Nios2 architecture	2014-12-08 12:56:06 +08:00
nvdimm	libnvdimm: Non-Volatile Devices	2015-06-26 11:23:38 -04:00
nvmem	Documentation: nvmem: add nvmem api level and how-to doc	2015-08-05 13:43:45 -07:00
parisc	…
pcmcia	pcmcia: Fix typo in locking documentation	2015-08-07 14:34:58 +02:00
phy	…
platform	…
power	Power management and ACPI material for v4.3-rc1	2015-09-01 19:45:46 -07:00
powerpc	SCSI misc on 20150901	2015-09-02 12:22:54 -07:00
pps	Doc: pps: Fix file name in pps.txt	2015-07-14 12:35:42 -06:00
prctl	Documentation/prctl: don't build tsc tests when cross compiling	2015-06-22 16:05:04 -06:00
pti	…
ptp	…
rapidio	…
s390	KVM: s390: remove outdated documentation	2015-07-29 11:02:35 +02:00
scheduler	sched/dl/Documentation: Split Section 3	2015-05-19 08:39:21 +02:00
scsi	Merge branch 'for-4.2/sg' of git://git.kernel.dk/linux-block	2015-06-25 15:22:36 -07:00
security	Smack: allow multiple labels in onlycap	2015-06-02 11:53:42 -07:00
serial	Doc: serial-rs485.txt: update RS485 driver interface	2015-06-12 17:39:51 -07:00
sh	…
sound	Doc: sound:oss: Fix typo in sound/oss	2015-06-09 17:23:00 +02:00
spi	Documentation/spi/spidev_test.c: fix warning	2015-04-17 09:04:12 -04:00
sysctl	Documentation: mm: fix location of extfrag_index	2015-07-24 15:05:56 +02:00
target	Documentation/target: Fix tcm_mod_builder.py build breakage	2015-07-24 17:48:55 -07:00
thermal	thermal: support slope and offset coefficients	2015-05-11 19:46:52 -07:00
timers	documentation: Update NO_HZ_FULL interaction with POSIX timers	2015-02-26 11:57:29 -08:00
tpm	…
trace	powerpc updates for 4.3	2015-09-03 16:41:38 -07:00
usb	Revert "usb: interface authorization: Documentation part"	2015-08-18 09:57:15 -07:00
vDSO	Documentation/vDSO: don't build tests when cross compiling	2015-06-22 16:04:57 -06:00
video4linux	[media] Documentation: update cardlists	2015-06-09 18:43:47 -03:00
virtual	kvm/x86: add sending hyper-v crash notification to user space	2015-07-23 08:27:06 +02:00
vm	userfaultfd: change the read API to return a uffd_msg	2015-09-04 16:54:41 -07:00
w1	w1: Add support for DS28EA00 sequence to w1-therm	2015-05-24 12:08:59 -07:00
watchdog	watchdog: omap_wdt: early_enable module parameter	2015-07-01 16:43:17 +02:00
wimax	…
x86	Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-09-01 10:07:40 -07:00
xtensa	…
zh_CN	Documentation updates for 4.2	2015-06-24 20:01:36 -07:00
00-INDEX	Update of Documentation/dmaengine/00-INDEX	2014-12-29 15:28:24 -07:00
BUG-HUNTING	…
Changes	Documentation: GNU is frequently spelled Gnu	2014-12-29 15:33:17 -07:00
CodeOfConflict	Code of Conflict	2015-02-27 11:44:24 -08:00
CodingStyle	Documentation: CodingStyle: remove broken links in the References section	2015-07-10 13:54:34 -06:00
DMA-API-HOWTO.txt	Documentation updates for 4.2	2015-06-24 20:01:36 -07:00
DMA-API.txt	PCI: Add pci_bus_addr_t	2015-05-29 17:21:45 -05:00
DMA-ISA-LPC.txt	…
DMA-attributes.txt	…
HOWTO	docs: update HOWTO for 3.x -> 4.x versioning	2015-08-24 11:28:17 -06:00
IPMI.txt	ipmi:ssif: Ignore spaces when comparing I2C adapter names	2015-05-05 14:24:45 -05:00
IRQ-affinity.txt	…
IRQ-domain.txt	IRQCHIP: Update docs regarding irq_domain_add_tree()	2015-04-01 17:21:35 +02:00
IRQ.txt	…
Intel-IOMMU.txt	Documentation/Intel-IOMMU.txt: Modify definition of DRHD	2015-08-24 11:39:45 -06:00
Makefile	Documentation: Remove ZBOOT MMC/SDHI utility and docs	2015-02-24 06:45:25 +09:00
ManagementStyle	…
SAK.txt	…
SM501.txt	…
SecurityBugs	…
SubmitChecklist	…
SubmittingDrivers	…
SubmittingPatches	Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2015-09-01 18:46:42 -07:00
VGA-softcursor.txt	…
adding-syscalls.txt	Documentation: describe how to add a system call	2015-08-13 17:54:06 -06:00
applying-patches.txt	…
assoc_array.txt	…
atomic_ops.txt	locking/Documentation: Clarify failed cmpxchg() memory ordering semantics	2015-08-03 10:57:09 +02:00
bad_memory.txt	…
basic_profiling.txt	…
bcache.txt	…
binfmt_misc.txt	…
braille-console.txt	…
bt8xxgpio.txt	…
btmrvl.txt	…
bus-virt-phys-mapping.txt	…
cachetlb.txt	rmap: drop support of non-linear mappings	2015-02-10 14:30:31 -08:00
circular-buffers.txt	…
clk.txt	clk: change clk_ops' ->determine_rate() prototype	2015-07-27 18:12:01 -07:00
coccinelle.txt	…
cpu-hotplug.txt	cpumask: fix cpu-hotplug documentation	2015-03-05 13:37:01 +10:30
cpu-load.txt	…
cputopology.txt	Documentation: Update cputopology.txt	2015-05-27 15:22:15 +02:00
crc32.txt	…
dcdbas.txt	…
debugging-modules.txt	…
debugging-via-ohci1394.txt	Doc: Change wikipedia's URL from http to https	2015-06-22 10:14:05 -06:00
dell_rbu.txt	…
devices.txt	…
digsig.txt	…
dma-buf-sharing.txt	dma-buf: cleanup dma_buf_export() to make it easily extensible	2015-04-21 14:47:16 +05:30
dontdiff	…
dynamic-debug-howto.txt	…
edac.txt	EDAC: Update Documentation/edac.txt	2015-06-24 18:17:40 +02:00
efi-stub.txt	…
eisa.txt	…
email-clients.txt	fix Evolution submenu name in email-clients.txt	2015-07-24 15:05:57 +02:00
flexible-arrays.txt	…
futex-requeue-pi.txt	doc: Fix misnamed FUTEX_CMP_REQUEUE_PI op constants	2015-01-19 12:05:32 +01:00
gcov.txt	…
gdb-kernel-debugging.txt	scripts/gdb: add basic documentation	2015-02-17 14:34:54 -08:00
highuid.txt	…
hsi.txt	…
hw_random.txt	…
hwspinlock.txt	hwspinlock/core: add device tree support	2015-05-02 09:54:30 +03:00
init.txt	…
initrd.txt	…
intel_txt.txt	…
io-mapping.txt	…
io_ordering.txt	…
iostats.txt	…
irqflags-tracing.txt	…
isapnp.txt	…
java.txt	…
kasan.txt	Merge branch 'doc/4.2' into docs-next	2015-06-08 17:04:11 -06:00
kernel-doc-nano-HOWTO.txt	Documenation: Update location of docproc.c	2015-07-14 12:36:39 -06:00
kernel-docs.txt	…
kernel-parameters.txt	Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-08-31 18:12:07 -07:00
kernel-per-CPU-kthreads.txt	documentation: Update per-CPU kthreads documentation	2015-02-26 11:57:30 -08:00
kmemcheck.txt	Documentation: update the CONFIG_DEBUG_PAGEALLOC description	2015-03-20 07:41:55 -06:00
kmemleak.txt	Doc: Change wikipedia's URL from http to https	2015-06-22 10:14:05 -06:00
kobject.txt	kobject: grammar fix	2014-12-08 09:07:11 -05:00
kprobes.txt	kprobes: Update Documentation/kprobes.txt	2015-03-20 07:41:55 -06:00
kref.txt	…
kselftest.txt	kselftest: Move the docs to the Documentation dir	2014-11-24 10:49:54 -07:00
ldm.txt	…
local_ops.txt	percpu: update local_ops.txt to reflect this_cpu operations	2014-12-13 12:42:53 -08:00
lockup-watchdogs.txt	watchdog: add watchdog_cpumask sysctl to assist nohz	2015-06-24 17:49:40 -07:00
logo.gif	…
logo.txt	…
lzo.txt	…
magic-number.txt	Documentation/magic-number: Remove SCC_MAGIC	2015-05-13 15:39:04 -04:00
mailbox.txt	Documentation: minor typo fix in mailbox.txt	2015-08-13 18:03:18 -06:00
md-cluster.txt	md-cluster: Design Documentation	2015-02-23 07:16:46 -06:00
md.txt	doc:md: fix typo in md.txt.	2015-06-23 06:49:44 -06:00
media-framework.txt	…
memory-barriers.txt	Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-09-03 15:46:07 -07:00
memory-hotplug.txt	mem-hotplug: fix typo in Documentation/memory-hotplug.txt	2015-03-20 07:41:55 -06:00
men-chameleon-bus.txt	Documentation: Minor changes to men-chameleon-bus.txt	2015-07-24 15:15:17 +02:00
module-signing.txt	modsign: change default key details	2015-04-30 09:35:41 -07:00
mono.txt	…
nommu-mmap.txt	fs: introduce f_op->mmap_capabilities for nommu mmap support	2015-01-20 14:02:58 -07:00
ntb.txt	NTB: Rename Intel code names to platform names	2015-07-04 14:09:25 -04:00
numastat.txt	…
oops-tracing.txt	livepatch: kernel: add TAINT_LIVEPATCH	2014-12-22 15:40:48 +01:00
padata.txt	…
parport-lowlevel.txt	…
parport.txt	…
percpu-rw-semaphore.txt	…
phy.txt	phy: core: Add devm_of_phy_get_by_index to phy-core	2015-05-11 21:42:23 +05:30
pi-futex.txt	…
pinctrl.txt	pinctrl: move strict option to pinmux_ops	2015-05-06 14:45:19 +02:00
pnp.txt	…
preempt-locking.txt	x86/fpu: Rename math_state_restore() to fpu__restore()	2015-05-19 15:47:18 +02:00
printk-formats.txt	The documentation tree update for 4.1. Numerous fixes, the overdue removal	2015-04-18 11:10:49 -04:00
pwm.txt	…
ramoops.txt	pstore-ram: Allow optional mapping with pgprot_noncached	2014-12-11 13:38:31 -08:00
rbtree.txt	…
remoteproc.txt	remoteproc: introduce rproc_get_by_phandle API	2015-06-16 21:12:52 +03:00
rfkill.txt	rfkill: document rfkill module parameters	2015-01-09 23:22:12 +01:00
robust-futex-ABI.txt	…
robust-futexes.txt	…
rpmsg.txt	…
rtc.txt	Documentation, split up rtc.txt into documentation and test file	2015-03-24 22:01:58 -06:00
serial-console.txt	…
sgi-ioc4.txt	…
smsc_ece1099.txt	…
sparse.txt	…
stable_api_nonsense.txt	…
stable_kernel_rules.txt	stable: Update documentation to clarify preferred procedure	2015-05-22 09:38:56 -06:00
static-keys.txt	jump label, locking/static_keys: Update docs	2015-08-03 11:51:14 +02:00
svga.txt	…
sysfs-rules.txt	…
sysrq.txt	Documentation/sysrq.txt: Mention MIPS TLB dump (x)	2015-09-03 12:07:43 +02:00
this_cpu_ops.txt	…
unaligned-memory-access.txt	…
unicode.txt	…
unshare.txt	…
vfio.txt	vfio: powerpc/spapr: Support Dynamic DMA windows	2015-06-11 15:16:55 +10:00
vgaarbiter.txt	…
video-output.txt	…
vme_api.txt	Documentation: mention vme_master_mmap() in VME API	2015-06-12 17:26:56 -07:00
volatile-considered-harmful.txt	…
workqueue.txt	workqueue: fix trivial typo in Documentation/workqueue.txt	2015-05-05 09:50:38 -04:00
xillybus.txt	…
xz.txt	…
zorro.txt	…