Joel Fernandes (Google) ab3948f58f mm/memfd: add an F_SEAL_FUTURE_WRITE seal to memfd ... Android uses ashmem for sharing memory regions. We are looking forward to migrating all usecases of ashmem to memfd so that we can possibly remove the ashmem driver in the future from staging while also benefiting from using memfd and contributing to it. Note staging drivers are also not ABI and generally can be removed at anytime. One of the main usecases Android has is the ability to create a region and mmap it as writeable, then add protection against making any "future" writes while keeping the existing already mmap'ed writeable-region active. This allows us to implement a usecase where receivers of the shared memory buffer can get a read-only view, while the sender continues to write to the buffer. See CursorWindow documentation in Android for more details: https://developer.android.com/reference/android/database/CursorWindow This usecase cannot be implemented with the existing F_SEAL_WRITE seal. To support the usecase, this patch adds a new F_SEAL_FUTURE_WRITE seal which prevents any future mmap and write syscalls from succeeding while keeping the existing mmap active. A better way to do F_SEAL_FUTURE_WRITE seal was discussed [1] last week where we don't need to modify core VFS structures to get the same behavior of the seal. This solves several side-effects pointed by Andy. self-tests are provided in later patch to verify the expected semantics. [1] https://lore.kernel.org/lkml/20181111173650.GA256781@google.com/ Thanks a lot to Andy for suggestions to improve code. Link: http://lkml.kernel.org/r/20190112203816.85534-2-joel@joelfernandes.org Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Acked-by: John Stultz <john.stultz@linaro.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Jann Horn <jannh@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: J. Bruce Fields <bfields@fieldses.org> Cc: Jeff Layton <jlayton@kernel.org> Cc: Marc-Andr Lureau <marcandre.lureau@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2019-03-05 21:07:19 -08:00
..
android	binderfs: use __u32 for device numbers	2019-01-22 12:13:17 +01:00
byteorder
caif
can
cifs
dvb	media: dvb/audio.h: get rid of unused APIs	2018-07-30 16:21:49 -04:00
genwqe
hdlc
hsi
iio
isdn
mmc	mmc: document 'Reliable Write' bit in uapi header	2018-12-17 08:26:24 +01:00
netfilter	netfilter: nft_tunnel: Add NFTA_TUNNEL_MODE options	2019-02-04 14:39:58 +01:00
netfilter_arp
netfilter_bridge
netfilter_ipv4
netfilter_ipv6
nfsd
raid
sched
spi
sunrpc
tc_act	net: Move all TC actions identifiers to one place	2019-02-10 09:28:43 -08:00
tc_ematch
usb	USB for v4.20	2018-10-05 08:32:01 -07:00
wimax
a.out.h
acct.h
adb.h
adfs_fs.h
affs_hardblocks.h
agpgart.h
aio_abi.h	aio: Comment use of IOCB_FLAG_IOPRIO aio flag	2018-11-19 19:03:43 -07:00
am437x-vpfe.h
apm_bios.h
arcfb.h
arm_sdei.h
aspeed-lpc-ctrl.h
atalk.h
atm_eni.h
atm_he.h
atm_idt77105.h
atm_nicstar.h
atm_tcp.h
atm_zatm.h
atm.h
atmapi.h
atmarp.h
atmbr2684.h
atmclip.h
atmdev.h
atmioc.h
atmlec.h
atmmpc.h
atmppp.h
atmsap.h
atmsvc.h
audit.h	Fix a handful of audit-related issue	2019-01-07 08:45:47 -08:00
auto_dev-ioctl.h
auto_fs4.h
auto_fs.h	autofs: add strictexpire mount option	2019-01-04 13:13:47 -08:00
auxvec.h
ax25.h
b1lli.h
batadv_packet.h	batman-adv: Fix typo "reseved" -> "reserved"	2019-02-09 14:27:47 +01:00
batman_adv.h	batman-adv: Add throughput_override hardif genl configuration	2019-02-09 14:28:15 +01:00
baycom.h
bcache.h	bcache: style fix to add a blank line after declarations	2018-08-11 15:46:41 -06:00
bcm933xx_hcs.h
bfs_fs.h	bfs: extra sanity checking and static inode bitmap	2019-01-04 13:13:47 -08:00
binfmts.h
blkpg.h
blktrace_api.h
blkzoned.h	uapi: fix ioctl documentation	2019-01-24 11:11:42 -07:00
bpf_common.h
bpf_perf_event.h
bpf.h	bpf: add bpf helper bpf_skb_ecn_set_ce	2019-03-02 10:48:27 -08:00
bpfilter.h
bpqether.h
bsg.h
bt-bmc.h
btf.h	bpf: btf: fix struct/union/fwd types with kind_flag	2018-12-18 01:11:59 +01:00
btrfs_tree.h	btrfs: Introduce support for FSID change without metadata rewrite	2018-12-17 14:51:37 +01:00
btrfs.h	btrfs: Introduce support for FSID change without metadata rewrite	2018-12-17 14:51:37 +01:00
can.h
capability.h
capi.h
cciss_defs.h
cciss_ioctl.h
cdrom.h
cec-funcs.h
cec.h	media: cec: add new tx/rx status bits to detect aborts/timeouts	2018-10-05 11:22:39 -04:00
cgroupstats.h
chio.h
cm4000_cs.h
cn_proc.h
coda_psdev.h
coda.h
coff.h
connector.h
const.h
coresight-stm.h
cramfs_fs.h
cryptouser.h	crypto: user - rename err_cnt parameter	2018-12-07 14:15:00 +08:00
cuda.h
cyclades.h
cycx_cfm.h
dcbnl.h	net: dcb: add DSCP to comment about priority selector types	2018-07-29 12:53:54 -07:00
dccp.h
devlink.h	devlink: Rename devlink health attributes	2019-02-21 10:38:51 -08:00
dlm_device.h
dlm_netlink.h
dlm_plock.h
dlm.h
dlmconstants.h
dm-ioctl.h
dm-log-userspace.h
dma-buf.h
dn.h
dns_resolver.h	dns: Allow the dns resolver to retrieve a server set	2018-10-04 09:40:52 -07:00
dqblk_xfs.h
edd.h
efs_fs_sb.h
elf-em.h	arch/csky patches for 4.21-rc1	2019-01-05 09:50:07 -08:00
elf-fdpic.h
elf.h	Here's the main MIPS pull for Linux 4.21. Core architecture changes	2018-12-26 10:45:33 -08:00
elfcore.h
errno.h
errqueue.h	errqueue.h: Include time_types.h	2019-02-14 11:51:51 -05:00
erspan.h
ethtool.h	net: phy: improve definition of __ETHTOOL_LINK_MODE_MASK_NBITS	2019-02-24 17:33:59 -08:00
eventpoll.h
fadvise.h
falloc.h
fanotify.h	fanotify: introduce new event mask FAN_OPEN_EXEC_PERM	2018-11-13 18:41:05 +01:00
fb.h	fbdev: make FB_BACKLIGHT a tristate	2018-12-20 19:13:07 +01:00
fcntl.h	mm/memfd: add an F_SEAL_FUTURE_WRITE seal to memfd	2019-03-05 21:07:19 -08:00
fd.h
fdreg.h
fib_rules.h
fiemap.h
filter.h
firewire-cdev.h	FireWire: clean up firewire-cdev.h kernel-doc	2018-09-06 09:40:59 -06:00
firewire-constants.h
flat.h
fou.h
fpga-dfl.h
fs.h	Add Adiantum support for fscrypt	2019-01-06 12:21:11 -08:00
fsi.h
fsl_hypervisor.h
fsmap.h
fuse.h	fuse: enable caching of symlinks	2018-10-15 15:43:07 +02:00
futex.h
gameport.h
gen_stats.h	net/core: Add new basic hardware counter	2018-09-24 12:18:42 -07:00
genetlink.h
gfs2_ondisk.h
gigaset_dev.h
gpio.h	gpio: uapi: Grammar s/array/array of/	2018-09-13 10:46:24 +02:00
gsmmux.h
gtp.h
hash_info.h	crypto: streebog - register Streebog in hash info for IMA	2018-11-16 14:09:40 +08:00
hdlc.h
hdlcdrv.h
hdreg.h
hid.h
hiddev.h
hidraw.h
hpet.h
hsr_netlink.h
hw_breakpoint.h
hyperv.h
hysdn_if.h
i2c-dev.h
i2c.h
i2o-dev.h
i8k.h
icmp.h
icmpv6.h	bridge: Snoop Multicast Router Advertisements	2019-01-22 17:18:09 -08:00
if_addr.h	if_addr: add IFA_TARGET_NETNSID	2018-09-05 22:27:11 -07:00
if_addrlabel.h
if_alg.h
if_arcnet.h
if_arp.h	net: if_arp: use define instead of hard-coded value	2018-09-21 19:22:32 -07:00
if_bonding.h	bonding: add support for xstats and export 3ad stats	2019-01-22 12:04:14 -08:00
if_bridge.h	net: bridge: add no_linklocal_learn bool option	2018-11-27 15:04:15 -08:00
if_cablemodem.h
if_eql.h
if_ether.h
if_fc.h
if_fddi.h	FDDI: defza: Add support for DEC FDDIcontroller 700 TURBOchannel adapter	2018-10-15 21:46:06 -07:00
if_frad.h
if_hippi.h
if_infiniband.h
if_link.h	bonding: add support for xstats and export 3ad stats	2019-01-22 12:04:14 -08:00
if_ltalk.h
if_macsec.h
if_packet.h	packet: add sockopt to ignore outgoing packets	2018-09-05 22:09:37 -07:00
if_phonet.h
if_plip.h
if_ppp.h
if_pppol2tp.h
if_pppox.h
if_slip.h
if_team.h
if_tun.h	tun: implement carrier change	2018-11-30 17:16:38 -08:00
if_tunnel.h	iptunnel: make TUNNEL_FLAGS available in uapi	2018-12-19 15:58:01 -08:00
if_vlan.h
if_x25.h
if_xdp.h
if.h
ife.h
igmp.h	bridge: Snoop Multicast Router Advertisements	2019-01-22 17:18:09 -08:00
ila.h
in6.h	net: ipv6: add socket option IPV6_ROUTER_ALERT_ISOLATE	2019-03-03 21:05:10 -08:00
in_route.h
in.h	bridge: join all-snoopers multicast address	2019-01-22 17:18:08 -08:00
inet_diag.h	inet_diag: fix reporting cgroup classid and fallback to priority	2019-02-12 13:35:57 -05:00
inotify.h
input-event-codes.h	Merge branches 'for-4.20/upstream-fixes', 'for-4.21/core', 'for-4.21/hid-asus', 'for-4.21/hid-core', 'for-4.21/hid-cougar', 'for-4.21/hidraw', 'for-4.21/highres-wheel' and 'for-4.21/ish' into for-linus	2019-01-03 12:50:28 +01:00
input.h	Input: input_event - fix the CONFIG_SPARC64 mixup	2019-01-24 00:38:39 -08:00
ioctl.h
ip6_tunnel.h
ip_vs.h
ip.h	route: add support for directed broadcast forwarding	2018-07-29 12:37:06 -07:00
ipc.h
ipmi_bmc.h
ipmi_msgdefs.h
ipmi.h
ipsec.h
ipv6_route.h
ipv6.h
ipx.h
irqnr.h
isdn_divertif.h
isdn_ppp.h
isdn.h
isdnif.h
iso_fs.h
ivtv.h
ivtvfb.h
jffs2.h
joystick.h
Kbuild	arch: remove stale comments "UAPI Header export list"	2019-01-06 09:46:51 +09:00
kcm.h
kcmp.h
kcov.h
kd.h
kdev_t.h
kernel-page-flags.h	mm: convert PG_balloon to PG_offline	2019-03-05 21:07:14 -08:00
kernel.h
kernelcapi.h
kexec.h
keyboard.h
keyctl.h	KEYS: Provide keyctls to drive the new key type ops for asymmetric keys [ver #2]	2018-10-26 09:30:46 +01:00
kfd_ioctl.h	drm/amdkfd: Add DMABuf import functionality	2018-12-07 18:13:54 -05:00
kvm_para.h	KVM: X86: Implement PV IPIs in linux guest	2018-08-06 17:59:22 +02:00
kvm.h	x86/kvm/hyper-v: Introduce KVM_GET_SUPPORTED_HV_CPUID	2018-12-14 17:59:54 +01:00
l2tp.h	l2tp: ignore L2TP_ATTR_MTU	2018-08-03 10:03:57 -07:00
libc-compat.h
lightnvm.h
limits.h
lirc.h
llc.h
loop.h
lp.h
lwtunnel.h
magic.h	binder: implement binderfs	2018-12-19 09:40:13 +01:00
major.h
map_to_7segment.h
matroxfb.h
max2175.h
mdio.h	net: phy: Add generic support for 2.5GBaseT and 5GBaseT	2019-02-13 19:17:53 -05:00
media-bus-format.h	media: v4l: Add new 2X8 10-bit grayscale media bus code	2018-08-02 06:04:57 -04:00
media.h	media: uapi/linux/media.h: add request API	2018-08-31 11:04:23 -04:00
mei.h
membarrier.h
memfd.h	mm/hugetlb: add mmap() encodings for 32MB and 512MB page sizes	2018-10-05 16:32:04 -07:00
mempolicy.h
meye.h
mic_common.h
mic_ioctl.h
mii.h
minix_fs.h
mman.h	mm/hugetlb: add mmap() encodings for 32MB and 512MB page sizes	2018-10-05 16:32:04 -07:00
mmtimer.h
module.h
mount.h	vfs: Suppress MS_* flag defs within the kernel unless explicitly enabled	2018-12-20 16:32:56 +00:00
mpls_iptunnel.h
mpls.h
mqueue.h
mroute6.h	ipmr: ip6mr: Create new sockopt to clear mfc cache or vifs	2019-02-21 13:05:05 -08:00
mroute.h	ipmr: ip6mr: Create new sockopt to clear mfc cache or vifs	2019-02-21 13:05:05 -08:00
msdos_fs.h	fat: move MAX_FAT to fat.h and change it to inline function	2019-01-04 13:13:47 -08:00
msg.h
mtio.h
n_r3964.h
nbd-netlink.h
nbd.h
ncsi.h	net/ncsi: Configure multi-package, multi-channel modes with failover	2018-11-17 21:09:49 -08:00
ndctl.h	UAPI: ndctl: Remove use of PAGE_SIZE	2018-10-17 13:56:58 -07:00
neighbour.h	neighbor: Add protocol attribute	2018-12-16 12:15:25 -08:00
net_dropmon.h
net_namespace.h	netns: enable to dump full nsid translation table	2018-11-27 16:20:20 -08:00
net_tstamp.h	net: Use __kernel_clockid_t in uapi net_stamp.h	2018-12-18 15:59:29 -08:00
net.h
netconf.h	route: add support for directed broadcast forwarding	2018-07-29 12:37:06 -07:00
netdevice.h
netfilter_arp.h
netfilter_bridge.h	netfilter: bridge: define INT_MIN & INT_MAX in userspace	2018-10-25 10:25:22 +02:00
netfilter_decnet.h	netfilter: remove NFC_* cache bits	2018-12-01 12:38:32 +01:00
netfilter_ipv4.h	netfilter: remove NFC_* cache bits	2018-12-01 12:38:32 +01:00
netfilter_ipv6.h	netfilter: remove NFC_* cache bits	2018-12-01 12:38:32 +01:00
netfilter.h	netfilter: remove NFC_* cache bits	2018-12-01 12:38:32 +01:00
netlink_diag.h
netlink.h	net: netlink: rename NETLINK_DUMP_STRICT_CHK -> NETLINK_GET_STRICT_CHK	2018-12-14 11:44:31 -08:00
netrom.h
nfc.h
nfs2.h
nfs3.h
nfs4_mount.h
nfs4.h
nfs_fs.h
nfs_idmap.h
nfs_mount.h
nfs.h
nfsacl.h
nilfs2_api.h
nilfs2_ondisk.h
nl80211.h	nl80211: Allow set/del pmksa operations for AP	2019-01-25 21:09:21 +01:00
nsfs.h
nubus.h
nvme_ioctl.h
nvram.h
omap3isp.h
omapfb.h
oom.h
openvswitch.h
packet_diag.h
param.h
parport.h
patchkey.h
pci_regs.h	PCI: Add support for Immediate Readiness	2018-09-28 12:47:34 -05:00
pci.h
pcitest.h
perf_event.h	perf tools: Don't clone maps from parent when synthesizing forks	2018-10-31 10:18:01 -03:00
personality.h
pfkeyv2.h
pg.h
phantom.h
phonet.h
pkt_cls.h	net: Change TCA_ACT_* to TCA_ID_* to match that of TCA_ID_POLICE	2019-02-10 09:28:43 -08:00
pkt_sched.h	sch_cake: Permit use of connmarks as tin classifiers	2019-03-03 20:14:28 -08:00
pktcdvd.h
pmu.h	macintosh/via-pmu: Replace via-pmu68k driver with via-pmu driver	2018-07-31 19:56:42 +10:00
poll.h
posix_acl_xattr.h
posix_acl.h
posix_types.h
ppdev.h
ppp_defs.h
ppp-comp.h
ppp-ioctl.h	l2tp: remove pppol2tp_session_ioctl()	2018-08-11 12:13:49 -07:00
pps.h
pr.h
prctl.h	arm64 festive updates for 4.21	2018-12-25 17:41:56 -08:00
psample.h
psci.h
psp-sev.h
ptp_clock.h	ptp: uapi: change _IOW to IOWR in PTP_SYS_OFFSET_EXTENDED definition	2019-01-08 16:22:56 -05:00
ptrace.h
qemu_fw_cfg.h
qnx4_fs.h
qnxtypes.h
qrtr.h
quota.h
radeonfb.h
random.h
raw.h
rds.h	rds: add type of service(tos) infrastructure	2019-02-04 14:59:12 -08:00
reboot.h
reiserfs_fs.h
reiserfs_xattr.h
resource.h
rfkill.h
rio_cm_cdev.h
rio_mport_cdev.h
romfs_fs.h
rose.h
route.h
rpmsg.h
rseq.h
rtc.h
rtnetlink.h
rxrpc.h
scc.h
sched.h
scif_ioctl.h
screen_info.h
sctp.h	sctp: introduce SCTP_FUTURE/CURRENT/ALL_ASSOC	2019-01-30 00:44:06 -08:00
sdla.h
seccomp.h	seccomp: add a return code to trap to userspace	2018-12-11 16:28:41 -08:00
securebits.h
sed-opal.h
seg6_genl.h
seg6_hmac.h
seg6_iptunnel.h
seg6_local.h
seg6.h
selinux_netlink.h
sem.h
serial_core.h	tty: serial: Add RDA8810PL UART driver	2018-12-31 13:10:01 -08:00
serial_reg.h
serial.h	tty/serial_core: add ISO7816 infrastructure	2018-10-02 13:38:55 -07:00
serio.h
shm.h	mm/hugetlb: add mmap() encodings for 32MB and 512MB page sizes	2018-10-05 16:32:04 -07:00
signal.h
signalfd.h
smc_diag.h	net/smc: retain old name for diag_mode field	2018-10-07 21:06:28 -07:00
smc.h
smiapp.h
snmp.h	tcp: implement coalescing on backlog queue	2018-11-30 13:26:54 -08:00
sock_diag.h
socket.h
sockios.h
sonet.h
sonypi.h
sound.h
soundcard.h
stat.h
stddef.h
stm.h
string.h
suspend_ioctls.h
swab.h
switchtec_ioctl.h
sync_file.h
synclink.h
sysctl.h	kernel/sysctl: add panic_print into sysctl	2019-01-04 13:13:47 -08:00
sysinfo.h
target_core_user.h
taskstats.h	delayacct: track delays from thrashing cache pages	2018-10-26 16:26:32 -07:00
tcp_metrics.h
tcp.h	tcp: add SRTT to SCM_TIMESTAMPING_OPT_STATS	2018-11-17 20:34:36 -08:00
tee.h
termios.h
thermal.h
time_types.h	time: Add time_types.h	2019-02-14 11:51:51 -05:00
time.h	time: Add time_types.h	2019-02-14 11:51:51 -05:00
timerfd.h
times.h
timex.h
tiocl.h
tipc_config.h
tipc_netlink.h
tipc_sockets_diag.h
tipc.h
tls.h	net: tls: Add tls 1.3 support	2019-02-01 15:00:55 -08:00
toshiba.h
tty_flags.h
tty.h
types.h
udf_fs_i.h
udmabuf.h	Add udmabuf misc device	2018-09-03 13:29:38 +02:00
udp.h	udp: implement GRO for plain UDP sockets.	2018-11-07 16:23:04 -08:00
uhid.h
uinput.h
uio.h
uleds.h
ultrasound.h
un.h
unistd.h
unix_diag.h
usbdevice_fs.h
usbip.h
userfaultfd.h
userio.h
utime.h
utsname.h
uuid.h
uvcvideo.h	media: uvcvideo: Send a control event when a Control Change interrupt arrives	2018-07-27 06:39:57 -04:00
v4l2-common.h	media: v4l2-common.h: put backwards compat defines under #ifndef __KERNEL__	2018-11-20 13:22:40 -05:00
v4l2-controls.h	media: mpeg2-ctrls.h: move MPEG2 state controls to non-public header	2018-12-05 13:06:31 -05:00
v4l2-dv-timings.h
v4l2-mediabus.h
v4l2-subdev.h
vbox_err.h
vbox_vmmdev_types.h
vboxguest.h
veth.h
vfio_ccw.h
vfio.h	vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriver	2018-12-21 16:20:47 +11:00
vhost_types.h	vhost: split structs into a separate header file	2018-12-19 18:23:49 -05:00
vhost.h	vhost: split structs into a separate header file	2018-12-19 18:23:49 -05:00
videodev2.h	media fixes for v4.20-rc8	2018-12-25 13:11:30 -08:00
virtio_9p.h
virtio_balloon.h	virtio-balloon: VIRTIO_BALLOON_F_PAGE_POISON	2018-10-24 20:57:55 -04:00
virtio_blk.h	virtio_blk: add discard and write zeroes support	2018-12-19 18:23:49 -05:00
virtio_config.h	virtio: support VIRTIO_F_ORDER_PLATFORM	2019-01-24 10:15:42 -05:00
virtio_console.h
virtio_crypto.h
virtio_gpu.h	virtio-gpu: add VIRTIO_GPU_F_EDID feature	2018-11-21 12:06:59 +01:00
virtio_ids.h
virtio_input.h
virtio_mmio.h
virtio_net.h
virtio_pci.h
virtio_ring.h	virtio: drop internal struct from UAPI	2019-02-05 15:29:48 -05:00
virtio_rng.h
virtio_scsi.h
virtio_types.h
virtio_vsock.h
vm_sockets_diag.h
vm_sockets.h
vmcore.h
vsockmon.h
vt.h
vtpm_proxy.h
wait.h
wanrouter.h
watchdog.h
wimax.h
wireless.h
wmi.h
x25.h
xattr.h
xdp_diag.h	xsk: add sock_diag interface for AF_XDP	2019-01-25 01:50:03 +01:00
xfrm.h
xilinx-v4l2-controls.h
zorro_ids.h
zorro.h