UBIFS handles extended attributes just like files, as consequence of
that, they also have inodes.
Therefore UBIFS does all the inode machinery also for xattrs. Since new
inodes have i_nlink of 1, a file or xattr inode will be evicted
if i_nlink goes down to 0 after an unlink. UBIFS assumes this model also
for xattrs, which is not correct.
One can create a file "foo" with xattr "user.test". By reading
"user.test" an inode will be created, and by deleting "user.test" it
will get evicted later. The assumption breaks if the file "foo", which
hosts the xattrs, will be removed. VFS nor UBIFS does not remove each
xattr via ubifs_xattr_remove(), it just removes the host inode from
the TNC and all underlying xattr nodes too and the inode will remain
in the cache and wastes memory.
To solve this problem, remove xattr inodes from the VFS inode cache in
ubifs_xattr_remove() to make sure that they get evicted.
Fixes: 1e51764a3c2ac05a ("UBIFS: add new flash file system") Cc: <stable@vger.kernel.org> Signed-off-by: Richard Weinberger <richard@nod.at>
Eric Biggers [Tue, 23 May 2017 00:39:44 +0000 (17:39 -0700)]
ubifs: don't bother checking for encryption key in ->mmap()
Since only an open file can be mmap'ed, and we only allow open()ing an
encrypted file when its key is available, there is no need to check for
the key again before permitting each mmap().
Signed-off-by: Eric Biggers <ebiggers@google.com> Acked-by: Richard Weinberger <richard@nod.at> Signed-off-by: Richard Weinberger <richard@nod.at>
Eric Biggers [Tue, 13 Jun 2017 23:47:55 +0000 (16:47 -0700)]
ubifs: require key for truncate(2) of encrypted file
Currently, filesystems allow truncate(2) on an encrypted file without
the encryption key. However, it's impossible to correctly handle the
case where the size being truncated to is not a multiple of the
filesystem block size, because that would require decrypting the final
block, zeroing the part beyond i_size, then encrypting the block.
As other modifications to encrypted file contents are prohibited without
the key, just prohibit truncate(2) as well, making it fail with ENOKEY.
Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Richard Weinberger <richard@nod.at>
Linus Torvalds [Sun, 11 Jun 2017 23:17:29 +0000 (16:17 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull key subsystem fixes from James Morris:
"Here are a bunch of fixes for Linux keyrings, including:
- Fix up the refcount handling now that key structs use the
refcount_t type and the refcount_t ops don't allow a 0->1
transition.
- Fix a potential NULL deref after error in x509_cert_parse().
- Don't put data for the crypto algorithms to use on the stack.
- Fix the handling of a null payload being passed to add_key().
- Fix incorrect cleanup an uninitialised key_preparsed_payload in
key_update().
- Explicit sanitisation of potentially secure data before freeing.
- Fixes for the Diffie-Helman code"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (23 commits)
KEYS: fix refcount_inc() on zero
KEYS: Convert KEYCTL_DH_COMPUTE to use the crypto KPP API
crypto : asymmetric_keys : verify_pefile:zero memory content before freeing
KEYS: DH: add __user annotations to keyctl_kdf_params
KEYS: DH: ensure the KDF counter is properly aligned
KEYS: DH: don't feed uninitialized "otherinfo" into KDF
KEYS: DH: forbid using digest_null as the KDF hash
KEYS: sanitize key structs before freeing
KEYS: trusted: sanitize all key material
KEYS: encrypted: sanitize all key material
KEYS: user_defined: sanitize key payloads
KEYS: sanitize add_key() and keyctl() key payloads
KEYS: fix freeing uninitialized memory in key_update()
KEYS: fix dereferencing NULL payload with nonzero length
KEYS: encrypted: use constant-time HMAC comparison
KEYS: encrypted: fix race causing incorrect HMAC calculations
KEYS: encrypted: fix buffer overread in valid_master_desc()
KEYS: encrypted: avoid encrypting/decrypting stack buffers
KEYS: put keyring if install_session_keyring_to_cred() fails
KEYS: Delete an error message for a failed memory allocation in get_derived_key()
...
Linus Torvalds [Sun, 11 Jun 2017 22:51:56 +0000 (15:51 -0700)]
compiler, clang: properly override 'inline' for clang
Commit abb2ea7dfd82 ("compiler, clang: suppress warning for unused
static inline functions") just caused more warnings due to re-defining
the 'inline' macro.
So undef it before re-defining it, and also add the 'notrace' attribute
like the gcc version that this is overriding does.
Linus Torvalds [Sun, 11 Jun 2017 19:02:01 +0000 (12:02 -0700)]
Merge tag 'random_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random
Pull randomness fixes from Ted Ts'o:
"Improve performance by using a lockless update mechanism suggested by
Linus, and make sure we refresh per-CPU entropy returned get_random_*
as soon as the CRNG is initialized"
* tag 'random_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
random: invalidate batched entropy after crng init
random: use lockless method of accessing and updating f->reg_idx
Linus Torvalds [Sun, 11 Jun 2017 18:57:47 +0000 (11:57 -0700)]
Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 fixes from Ted Ts'o:
"Fix various bug fixes in ext4 caused by races and memory allocation
failures"
* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: fix fdatasync(2) after extent manipulation operations
ext4: fix data corruption for mmap writes
ext4: fix data corruption with EXT4_GET_BLOCKS_ZERO
ext4: fix quota charging for shared xattr blocks
ext4: remove redundant check for encrypted file on dio write path
ext4: remove unused d_name argument from ext4_search_dir() et al.
ext4: fix off-by-one error when writing back pages before dio read
ext4: fix off-by-one on max nr_pages in ext4_find_unwritten_pgoff()
ext4: keep existing extra fields when inode expands
ext4: handle the rest of ext4_mb_load_buddy() ENOMEM errors
ext4: fix off-by-in in loop termination in ext4_find_unwritten_pgoff()
ext4: fix SEEK_HOLE
jbd2: preserve original nofs flag during journal restart
ext4: clear lockdep subtype for quota files on quota off
Linus Torvalds [Sun, 11 Jun 2017 18:34:27 +0000 (11:34 -0700)]
Merge tag 'gpio-v4.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull GPIO fixes from Linus Walleij:
"A few overdue GPIO patches for the v4.12 kernel.
- Fix debounce logic on the Aspeed platform.
- Fix the "virtual gpio" things on the Intel Crystal Cove.
- Fix the blink counter selection on the MVEBU platform"
* tag 'gpio-v4.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
gpio: mvebu: fix gpio bank registration when pwm is used
gpio: mvebu: fix blink counter register selection
MAINTAINERS: remove self from GPIO maintainers
gpio: crystalcove: Do not write regular gpio registers for virtual GPIOs
gpio: aspeed: Don't attempt to debounce if disabled
Linus Torvalds [Sun, 11 Jun 2017 18:29:15 +0000 (11:29 -0700)]
Merge tag 'char-misc-4.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver fixes from Greg KH:
"Here are some small driver fixes for 4.12-rc5. Nothing major here,
just some small bugfixes found by people testing, and a MAINTAINERS
file update for the genwqe driver.
All have been in linux-next with no reported issues"
[ The cxl driver fix came in through the powerpc tree earlier ]
* tag 'char-misc-4.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
cxl: Avoid double free_irq() for psl,slice interrupts
mei: make sysfs modalias format similar as uevent modalias
drivers: char: mem: Fix wraparound check to allow mappings up to the end
MAINTAINERS: Change maintainer of genwqe driver
goldfish_pipe: use GFP_ATOMIC under spin lock
firmware: vpd: do not leak kobjects
firmware: vpd: avoid potential use-after-free when destroying section
firmware: vpd: do not leave freed section attributes to the list
Linus Torvalds [Sun, 11 Jun 2017 18:25:51 +0000 (11:25 -0700)]
Merge tag 'staging-4.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging/IIO fixes from Greg KH:
"These are mostly all IIO driver fixes, resolving a number of tiny
issues. There's also a ccree and lustre fix in here as well, both fix
problems found in those codebases.
All have been in linux-next with no reported issues"
* tag 'staging-4.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
staging: ccree: fix buffer copy
staging/lustre/lov: remove set_fs() call from lov_getstripe()
staging: ccree: add CRYPTO dependency
iio: adc: sun4i-gpadc-iio: fix parent device being used in devm function
iio: light: ltr501 Fix interchanged als/ps register field
iio: adc: bcm_iproc_adc: swap primary and secondary isr handler's
iio: trigger: fix NULL pointer dereference in iio_trigger_write_current()
iio: adc: max9611: Fix attribute measure unit
iio: adc: ti_am335x_adc: allocating too much in probe
iio: adc: sun4i-gpadc-iio: Fix module autoload when OF devices are registered
iio: adc: sun4i-gpadc-iio: Fix module autoload when PLATFORM devices are registered
iio: proximity: as3935: fix iio_trigger_poll issue
iio: proximity: as3935: fix AS3935_INT mask
iio: adc: Max9611: checking for ERR_PTR instead of NULL in probe
iio: proximity: as3935: recalibrate RCO after resume
Linus Torvalds [Sun, 11 Jun 2017 18:21:08 +0000 (11:21 -0700)]
Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley:
"This is a set of user visible fixes (excepting one format string
change).
Four of the qla2xxx fixes only affect the firmware dump path, but it's
still important to the enterprise. The rest are various NULL pointer
crash conditions or outright driver hangs"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: cxgb4i: libcxgbi: in error case RST tcp conn
scsi: scsi_debug: Avoid PI being disabled when TPGS is enabled
scsi: qla2xxx: Fix extraneous ref on sp's after adapter break
scsi: lpfc: prevent potential null pointer dereference
scsi: lpfc: Avoid NULL pointer dereference in lpfc_els_abort()
scsi: lpfc: nvmet_fc: fix format string
scsi: qla2xxx: Fix crash due to NULL pointer dereference of ctx
scsi: qla2xxx: Fix mailbox pointer error in fwdump capture
scsi: qla2xxx: Set bit 15 for DIAG_ECHO_TEST MBC
scsi: qla2xxx: Modify T262 FW dump template to specify same start/end to debug customer issues
scsi: qla2xxx: Fix crash due to mismatch mumber of Q-pair creation for Multi queue
scsi: qla2xxx: Fix NULL pointer access due to redundant fc_host_port_name call
scsi: qla2xxx: Fix recursive loop during target mode configuration for ISP25XX leaving system unresponsive
scsi: bnx2fc: fix race condition in bnx2fc_get_host_stats()
scsi: qla2xxx: don't disable a not previously enabled PCI device
Linus Torvalds [Sun, 11 Jun 2017 18:15:09 +0000 (11:15 -0700)]
Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm fix from Dan Williams:
"We expanded the device-dax fs type in 4.12 to be a generic provider of
a struct dax_device with an embedded inode. However, Sasha found some
basic negative testing was not run to verify that this fs cleanly
handles being mounted directly.
Note that the fresh rebase was done to remove an unnecessary Cc:
<stable> tag, but this commit otherwise had a build success
notification from the 0day robot."
Wanpeng Li [Fri, 9 Jun 2017 03:13:40 +0000 (20:13 -0700)]
KVM: async_pf: avoid async pf injection when in guest mode
INFO: task gnome-terminal-:1734 blocked for more than 120 seconds.
Not tainted 4.12.0-rc4+ #8
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
gnome-terminal- D 0 1734 1015 0x00000000
Call Trace:
__schedule+0x3cd/0xb30
schedule+0x40/0x90
kvm_async_pf_task_wait+0x1cc/0x270
? __vfs_read+0x37/0x150
? prepare_to_swait+0x22/0x70
do_async_page_fault+0x77/0xb0
? do_async_page_fault+0x77/0xb0
async_page_fault+0x28/0x30
This is triggered by running both win7 and win2016 on L1 KVM simultaneously,
and then gives stress to memory on L1, I can observed this hang on L1 when
at least ~70% swap area is occupied on L0.
This is due to async pf was injected to L2 which should be injected to L1,
L2 guest starts receiving pagefault w/ bogus %cr2(apf token from the host
actually), and L1 guest starts accumulating tasks stuck in D state in
kvm_async_pf_task_wait() since missing PAGE_READY async_pfs.
This patch fixes the hang by doing async pf when executing L1 guest.
Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Guenter Roeck [Wed, 3 May 2017 03:44:16 +0000 (20:44 -0700)]
hexagon: Use raw_copy_to_user
Commit ac4691fac8ad ("hexagon: switch to RAW_COPY_USER") replaced
__copy_to_user_hexagon() with raw_copy_to_user(), but did not catch
all callers, resulting in the following build error.
arch/hexagon/mm/uaccess.c: In function '__clear_user_hexagon':
arch/hexagon/mm/uaccess.c:40:3: error:
implicit declaration of function '__copy_to_user_hexagon'
Fixes: ac4691fac8ad ("hexagon: switch to RAW_COPY_USER") Cc: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Richard Kuo <rkuo@codeaurora.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Linus Torvalds [Sat, 10 Jun 2017 18:09:23 +0000 (11:09 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull UFS fixes from Al Viro:
"This is just the obvious backport fodder; I'm pretty sure that there
will be more - definitely so wrt performance and quite possibly
correctness as well"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
ufs: we need to sync inode before freeing it
excessive checks in ufs_write_failed() and ufs_evict_inode()
ufs_getfrag_block(): we only grab ->truncate_mutex on block creation path
ufs_extend_tail(): fix the braino in calling conventions of ufs_new_fragments()
ufs: set correct ->s_maxsize
ufs: restore maintaining ->i_blocks
fix ufs_isblockset()
ufs: restore proper tail allocation
Linus Torvalds [Sat, 10 Jun 2017 18:06:05 +0000 (11:06 -0700)]
Merge branch 'for-linus-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
"Some fixes that Dave Sterba collected.
We've been hitting an early enospc problem on production machines that
Omar tracked down to an old int->u64 mistake. I waited a bit on this
pull to make sure it was really the problem from production, but it's
on ~2100 hosts now and I think we're good.
Omar also noticed a commit in the queue would make new early ENOSPC
problems. I pulled that out for now, which is why the top three
commits are younger than the rest.
Otherwise these are all fixes, some explaining very old bugs that
we've been poking at for a while"
* 'for-linus-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: fix delalloc accounting leak caused by u32 overflow
Btrfs: clear EXTENT_DEFRAG bits in finish_ordered_io
btrfs: tree-log.c: Wrong printk information about namelen
btrfs: fix race with relocation recovery and fs_root setup
btrfs: fix memory leak in update_space_info failure path
btrfs: use correct types for page indices in btrfs_page_exists_in_range
btrfs: fix incorrect error return ret being passed to mapping_set_error
btrfs: Make flush bios explicitely sync
btrfs: fiemap: Cache and merge fiemap extent before submit it to user
Linus Torvalds [Sat, 10 Jun 2017 17:51:25 +0000 (10:51 -0700)]
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
"Misc fixes: a Geode fix plus a microcode loader fix"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/microcode/intel: Clear patch pointer before jettisoning the initrd
x86/cpu/cyrix: Add alternative Device ID of Geode GX1 SoC
Linus Torvalds [Sat, 10 Jun 2017 17:22:35 +0000 (10:22 -0700)]
Merge branch 'rcu-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU fixes from Ingo Molnar:
"Fix an SRCU bug affecting KVM IRQ injection"
* 'rcu-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
srcu: Allow use of Classic SRCU from both process and interrupt context
srcu: Allow use of Tiny/Tree SRCU from both process and interrupt context
Linus Torvalds [Sat, 10 Jun 2017 05:30:55 +0000 (22:30 -0700)]
Merge tag 'iommu-fixes-v4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
Pull IOMMU fixes from Joerg Roedel:
- another compile-fix for my header cleanup
- a couple of fixes for the recently merged IOMMU probe deferal code
- fixes for ACPI/IORT code necessary with IOMMU probe deferal
* tag 'iommu-fixes-v4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
arm: dma-mapping: Reset the device's dma_ops
ACPI/IORT: Move the check to get iommu_ops from translated fwspec
ARM: dma-mapping: Don't tear down third-party mappings
ACPI/IORT: Ignore all errors except EPROBE_DEFER
iommu/of: Ignore all errors except EPROBE_DEFER
iommu/of: Fix check for returning EPROBE_DEFER
iommu/dma: Fix function declaration
Linus Torvalds [Sat, 10 Jun 2017 05:28:33 +0000 (22:28 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
Pull input fixes from Dmitry Torokhov:
- mark "guest" RMI device as pass-through port to avoid "phantom" ALPS
toouchpad on newer Lenovo Carbons
- add two more laptops to the Elantech's lists of devices using CRC
mode
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: synaptics-rmi4 - register F03 port as pass-through serio
Input: elantech - add Fujitsu Lifebook E546/E557 to force crc_enabled
Linus Torvalds [Sat, 10 Jun 2017 05:18:41 +0000 (22:18 -0700)]
Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
"A set of fixes in the area of block IO, that should go into the next
-rc release. This contains:
- An OOPS fix from Dmitry, fixing a regression with the bio integrity
code in this series.
- Fix truncation of elevator io context cache name, from Eric
Biggers.
- NVMe pull from Christoph includes FC fixes from James, APST
fixes/tweaks from Kai-Heng, removal fix from Rakesh, and an RDMA
fix from Sagi.
- Two tweaks for the block throttling code. One from Joseph Qi,
fixing an oops from the timer code, and one from Shaohua, improving
the behavior on rotatonal storage.
- Two blk-mq fixes from Ming, fixing corner cases with the direct
issue code.
- Locking fix for bfq cgroups from Paolo"
* 'for-linus' of git://git.kernel.dk/linux-block:
block, bfq: access and cache blkg data only when safe
Fix loop device flush before configure v3
blk-throttle: set default latency baseline for harddisk
blk-throttle: fix NULL pointer dereference in throtl_schedule_pending_timer
nvme: relax APST default max latency to 100ms
nvme: only consider exit latency when choosing useful non-op power states
nvme-fc: fix missing put reference on controller create failure
nvme-fc: on lldd/transport io error, terminate association
nvme-rdma: fast fail incoming requests while we reconnect
nvme-pci: fix multiple ctrl removal scheduling
nvme: fix hang in remove path
elevator: fix truncation of icq_cache_name
blk-mq: fix direct issue
blk-mq: pass correct hctx to blk_mq_try_issue_directly
bio-integrity: Do not allocate integrity context for bio w/o data
Linus Torvalds [Sat, 10 Jun 2017 05:15:08 +0000 (22:15 -0700)]
Merge tag 'sound-4.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
"This update contains a slightly hight amount of changes due to the
pending ASoC fixes:
- ALSA timer core got a couple of fixes for races between read and
ioctl, leading to potential read of uninitialized kmalloced memory
- ASoC core fixed the de-registration pattern for use-after-free bug
- The rewrite of probe code in ASoC Intel Skylake for i915 component
- ASoC R-snd got a series of fixes for SSI
- ASoC simple-card, atmel, da7213, and rt286 trivial fixes
- HD-audio ALC269 quirk and rearrangement of quirk table"
* tag 'sound-4.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: timer: Fix missing queue indices reset at SNDRV_TIMER_IOCTL_SELECT
ALSA: timer: Fix race between read and ioctl
ALSA: hda/realtek - Reorder ALC269 ASUS quirk entries
ALSA: hda/realtek: Fix mic and headset jack sense on Asus X705UD
ASoC: rsnd: fixup parent_clk_name of AUDIO_CLKOUTx
ASoC: Intel: Skylake: Fix to parse consecutive string tkns in manifest
ASoC: Intel: Skylake: Fix IPC rx_list corruption
ASoC: rsnd: SSI PIO adjust to 24bit mode
MAINTAINERS: Update email address for patches to Wolfson parts
ASoC: Fix use-after-free at card unregistration
ASoC: simple-card: fix mic jack initialization
ASoC: rsnd: don't call free_irq() on Parent SSI
ASoC: atmel-classd: sync regcache when resuming
ASoC: rsnd: don't use PDTA bit for 24bit on SSI
ASoC: da7213: Fix incorrect usage of bitwise '&' operator for SRM check
rt286: add Thinkpad Helix 2 to force_combo_jack_table
ASoC: Intel: Skylake: Move i915 registration to worker thread
Linus Torvalds [Sat, 10 Jun 2017 05:12:06 +0000 (22:12 -0700)]
Merge tag 'drm-fixes-for-v4.12-rc5' of git://people.freedesktop.org/~airlied/linux
Pull drm fixes from Dave Airlie:
"Intel, nouveau, rockchip, vmwgfx, imx, meson, mediatek and core fixes.
Bit more spread out fixes this time, fixes for 7 drivers + a couple of
core fixes.
i915 and vmwgfx are the main ones. The vmwgfx ones fix a bunch of
regressions in their atomic rework, and a few fixes destined for
stable. i915 has some 4.12 regressions and older things that need to
be fixed in stable as well.
nouveau also has some runtime pm fixes and a timer list handling fix,
otherwise a couple of core and small driver regression fixes"
* tag 'drm-fixes-for-v4.12-rc5' of git://people.freedesktop.org/~airlied/linux: (37 commits)
drm/i915: fix warning for unused variable
drm/meson: Fix driver bind when only CVBS is available
drm/i915: Fix 90/270 rotated coordinates for FBC
drm/i915: Restore has_fbc=1 for ILK-M
drm/i915: Workaround VLV/CHV DSI scanline counter hardware fail
drm/i915: Fix logical inversion for gen4 quirking
drm/i915: Guard against i915_ggtt_disable_guc() being invoked unconditionally
drm/i915: Always recompute watermarks when distrust_bios_wm is set, v2.
drm/i915: Prevent the system suspend complete optimization
drm/i915/psr: disable psr2 for resolution greater than 32X20
drm/i915: Hold a wakeref for probing the ring registers
drm/i915: Short-circuit i915_gem_wait_for_idle() if already idle
drm/i915: Disable decoupled MMIO
drm/i915/guc: Remove stale comment for q_fail
drm/vmwgfx: Bump driver minor and date
drm/vmwgfx: Remove unused legacy cursor functions
drm/vmwgfx: fix spelling mistake "exeeds" -> "exceeds"
drm/vmwgfx: Fix large topology crash
drm/vmwgfx: Make sure to update STDU when FB is updated
drm/vmwgfx: Make sure backup_handle is always valid
...
Al Viro [Fri, 9 Jun 2017 20:20:34 +0000 (16:20 -0400)]
excessive checks in ufs_write_failed() and ufs_evict_inode()
As it is, short copy in write() to append-only file will fail
to truncate the excessive allocated blocks. As the matter of
fact, all checks in ufs_truncate_blocks() are either redundant
or wrong for that caller. As for the only other caller
(ufs_evict_inode()), we only need the file type checks there.
Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Omar Sandoval [Fri, 2 Jun 2017 08:20:01 +0000 (01:20 -0700)]
Btrfs: fix delalloc accounting leak caused by u32 overflow
btrfs_calc_trans_metadata_size() does an unsigned 32-bit multiplication,
which can overflow if num_items >= 4 GB / (nodesize * BTRFS_MAX_LEVEL * 2).
For a nodesize of 16kB, this overflow happens at 16k items. Usually,
num_items is a small constant passed to btrfs_start_transaction(), but
we also use btrfs_calc_trans_metadata_size() for metadata reservations
for extent items in btrfs_delalloc_{reserve,release}_metadata().
In drop_outstanding_extents(), num_items is calculated as
inode->reserved_extents - inode->outstanding_extents. The difference
between these two counters is usually small, but if many delalloc
extents are reserved and then the outstanding extents are merged in
btrfs_merge_extent_hook(), the difference can become large enough to
overflow in btrfs_calc_trans_metadata_size().
The overflow manifests itself as a leak of a multiple of 4 GB in
delalloc_block_rsv and the metadata bytes_may_use counter. This in turn
can cause early ENOSPC errors. Additionally, these WARN_ONs in
extent-tree.c will be hit when unmounting:
Fix it by casting nodesize to a u64 so that
btrfs_calc_trans_metadata_size() does a full 64-bit multiplication.
While we're here, do the same in btrfs_calc_trunc_metadata_size(); this
can't overflow with any existing uses, but it's better to be safe here
than have another hard-to-debug problem later on.
Cc: stable@vger.kernel.org Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
Liu Bo [Fri, 26 May 2017 23:44:23 +0000 (17:44 -0600)]
Btrfs: clear EXTENT_DEFRAG bits in finish_ordered_io
Before this, we use 'filled' mode here, ie. if all range has been
filled with EXTENT_DEFRAG bits, get to clear it, but if the defrag
range joins the adjacent delalloc range, then we'll have EXTENT_DEFRAG
bits in extent_state until releasing this inode's pages, and that
prevents extent_data from being freed.
This clears the bit if any was found within the ordered extent.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
Su Yue [Wed, 24 May 2017 01:31:32 +0000 (09:31 +0800)]
btrfs: tree-log.c: Wrong printk information about namelen
In verify_dir_item, it wants to printk name_len of dir_item but
printk data_len acutally.
Fix it by calling btrfs_dir_name_len instead of btrfs_dir_data_len.
Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
Linus Torvalds [Fri, 9 Jun 2017 16:59:51 +0000 (09:59 -0700)]
Merge tag 'for-linus-4.12b-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fix from Juergen Gross:
"A fix for Xen on ARM when dealing with 64kB page size of a guest"
* tag 'for-linus-4.12b-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/privcmd: Support correctly 64KB page granularity when mapping memory
Dmitry Torokhov [Tue, 6 Jun 2017 20:05:03 +0000 (13:05 -0700)]
Input: synaptics-rmi4 - register F03 port as pass-through serio
The 5th generation Thinkpad X1 Carbons use Synaptics touchpads accessible
over SMBus/RMI, combined with ALPS or Elantech trackpoint devices instead
of classic IBM/Lenovo trackpoints. Unfortunately there is no way for ALPS
driver to detect whether it is dealing with touchpad + trackpoint
combination or just a trackpoint, so we end up with a "phantom" dualpoint
ALPS device in addition to real touchpad and trackpoint.
Given that we do not have any special advanced handling for ALPS or
Elantech trackpoints (unlike IBM trackpoints that have separate driver and
a host of options) we are better off keeping the trackpoints in PS/2
emulation mode. We achieve that by setting serio type to SERIO_PS_PSTHRU,
which will limit number of protocols psmouse driver will try. In addition
to getting rid of the "phantom" touchpads, this will also speed up probing
of F03 pass-through port.
Reported-by: Damjan Georgievski <gdamjan@gmail.com> Suggested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Linus Torvalds [Fri, 9 Jun 2017 16:44:46 +0000 (09:44 -0700)]
Merge tag 'powerpc-4.12-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"Mostly fairly minor, of note are:
- Fix percpu allocations to be NUMA aware
- Limit 4k page size config to 64TB virtual address space
- Avoid needlessly restoring FP and vector registers
Thanks to Aneesh Kumar K.V, Breno Leitao, Christophe Leroy, Frederic
Barrat, Madhavan Srinivasan, Michael Bringmann, Nicholas Piggin,
Vaibhav Jain"
* tag 'powerpc-4.12-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/book3s64: Move PPC_DT_CPU_FTRs and enable it by default
powerpc/mm/4k: Limit 4k page size config to 64TB virtual address space
cxl: Fix error path on bad ioctl
powerpc/perf: Fix Power9 test_adder fields
powerpc/numa: Fix percpu allocations to be NUMA aware
cxl: Avoid double free_irq() for psl,slice interrupts
powerpc/kernel: Initialize load_tm on task creation
powerpc/kernel: Fix FP and vector register restoration
powerpc/64: Reclaim CPU_FTR_SUBCORE
powerpc/hotplug-mem: Fix missing endian conversion of aa_index
powerpc/sysdev/simple_gpio: Fix oops in gpio save_regs function
powerpc/spufs: Fix coredump of SPU contexts
powerpc/64s: Add dt_cpu_ftrs boot time setup option
Linus Torvalds [Fri, 9 Jun 2017 16:40:08 +0000 (09:40 -0700)]
Merge tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC fixes from Olof Johansson:
"Been sitting on these for a couple of weeks waiting on some larger
batches to come in but it's been pretty quiet.
Just your garden variety fixes here:
- A few maintainers updates (ep93xx, Exynos, TI, Marvell)
- Some PM fixes for Atmel/at91 and Marvell
- A few DT fixes for Marvell, Versatile, TI Keystone, bcm283x
- A reset driver patch to set module license for symbol access"
* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
MAINTAINERS: EP93XX: Update maintainership
MAINTAINERS: remove kernel@stlinux.com obsolete mailing list
ARM: dts: versatile: use #include "..." to include local DT
MAINTAINERS: add device-tree files to TI DaVinci entry
ARM: at91: select CONFIG_ARM_CPU_SUSPEND
ARM: dts: keystone-k2l: fix broken Ethernet due to disabled OSR
arm64: defconfig: enable some core options for 64bit Rockchip socs
arm64: marvell: dts: fix interrupts in 7k/8k crypto nodes
reset: hi6220: Set module license so that it can be loaded
MAINTAINERS: add irqchip related drivers to Marvell EBU maintainers
MAINTAINERS: sort F entries for Marvell EBU maintainers
ARM: davinci: PM: Do not free useful resources in normal path in 'davinci_pm_init'
ARM: davinci: PM: Free resources in error handling path in 'davinci_pm_init'
ARM: dts: bcm283x: Reserve first page for firmware
memory: atmel-ebi: mark PM ops as __maybe_unused
MAINTAINERS: Remove Javier Martinez Canillas as reviewer for Exynos
The inode destruction path for the 'dax' device filesystem incorrectly
assumes that the inode was initialized through 'alloc_dax()'. However,
if someone attempts to directly mount the dax filesystem with 'mount -t
dax dax mnt' that will bypass 'alloc_dax()' and the following failure
signatures may occur as a result:
kill_dax() must be called before final iput()
WARNING: CPU: 2 PID: 1188 at drivers/dax/super.c:243 dax_destroy_inode+0x48/0x50
RIP: 0010:dax_destroy_inode+0x48/0x50
Call Trace:
destroy_inode+0x3b/0x60
evict+0x139/0x1c0
iput+0x1f9/0x2d0
dentry_unlink_inode+0xc3/0x160
__dentry_kill+0xcf/0x180
? dput+0x37/0x3b0
dput+0x3a3/0x3b0
do_one_tree+0x36/0x40
shrink_dcache_for_umount+0x2d/0x90
generic_shutdown_super+0x1f/0x120
kill_anon_super+0x12/0x20
deactivate_locked_super+0x43/0x70
deactivate_super+0x4e/0x60
ida_remove called for id=0 which is not allocated.
WARNING: CPU: 0 PID: 0 at lib/idr.c:383 ida_remove+0x110/0x120
[..]
Call Trace:
<IRQ>
ida_simple_remove+0x2b/0x50
? dax_destroy_inode+0x50/0x50
dax_i_callback+0x3c/0x60
rcu_process_callbacks+0x298/0x740
Add missing initialization of the 'struct dax_device' and inode so that
the destruction path does not kfree() or ida_simple_remove()
uninitialized data.
Fixes: 7b6be8444e0f ("dax: refactor dax-fs into a generic provider of 'struct dax_device' instances") Reported-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
7b0a911478c7 efi/x86: Move the EFI BGRT init code to early init code
The root cause is the firmware on those machines provides invalid BGRT
image addresses.
In a kernel before above commit BGRT initializes late and uses ioremap()
to map the image address. Ioremap validates the address, if it is not a
valid physical address ioremap() just fails and returns. However in current
kernel EFI BGRT initializes early and uses early_memremap() which does not
validate the image address, and kernel panic happens.
According to ACPI spec the BGRT image address should fall into
EFI_BOOT_SERVICES_DATA, see the section 5.2.22.4 of below document:
Fix this issue by validating the image address in efi_bgrt_init(). If the
image address does not fall into any EFI_BOOT_SERVICES_DATA areas we just
bail out with a warning message.
Reported-by: Maniaxx <tripleshiftone@gmail.com> Signed-off-by: Dave Young <dyoung@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Fixes: 7b0a911478c7 ("efi/x86: Move the EFI BGRT init code to early init code") Link: http://lkml.kernel.org/r/20170609084558.26766-2-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Vaibhav Jain [Fri, 2 Jun 2017 16:56:48 +0000 (22:26 +0530)]
cxl: Avoid double free_irq() for psl,slice interrupts
During an eeh call to cxl_remove can result in double free_irq of
psl,slice interrupts. This can happen if perst_reloads_same_image == 1
and call to cxl_configure_adapter() fails during slot_reset
callback. In such a case we see a kernel oops with following back-trace:
This patch fixes the issue of double free_irq by checking that
variables that hold the virqs (err_hwirq, serr_hwirq, psl_virq) are
not '0' before un-mapping and resetting these variables to '0' when
they are un-mapped.
Richard Genoud [Thu, 1 Jun 2017 12:18:26 +0000 (14:18 +0200)]
gpio: mvebu: fix gpio bank registration when pwm is used
If more than one gpio bank has the "pwm" property, only one will be
registered successfully, all the others will fail with:
mvebu-gpio: probe of f1018140.gpio failed with error -17
That's because in alloc_pwms(), the chip->base (aka "int pwm"), was not
set (thus, ==0) ; and 0 is a meaningful start value in alloc_pwm().
What was intended is mvpwm->chip->base = -1.
Like that, the numbering will be done auto-magically
Moreover, as the region might be already occupied by another pwm, we
shouldn't force:
mvpwm->chip->base = 0
nor
mvpwm->chip->base = id * MVEBU_MAX_GPIO_PER_BANK;
Richard Genoud [Thu, 1 Jun 2017 12:18:25 +0000 (14:18 +0200)]
gpio: mvebu: fix blink counter register selection
The blink counter A was always selected because 0 was forced in the
blink select counter register.
The variable 'set' was obviously there to be used as the register value,
selecting the B counter when id==1 and A counter when id==0.
Ingo Molnar [Fri, 9 Jun 2017 06:17:10 +0000 (08:17 +0200)]
Merge branch 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into rcu/urgent
Pull RCU fix from Paul E. McKenney:
" This series enables srcu_read_lock() and srcu_read_unlock() to be used from
interrupt handlers, which fixes a bug in KVM's use of SRCU in delivery
of interrupts to guest OSes. "
Mark Rutland [Thu, 8 Jun 2017 13:47:41 +0000 (14:47 +0100)]
KEYS: fix refcount_inc() on zero
If a key's refcount is dropped to zero between key_lookup() peeking at
the refcount and subsequently attempting to increment it, refcount_inc()
will see a zero refcount. Here, refcount_inc() will WARN_ONCE(), and
will *not* increment the refcount, which will remain zero.
Once key_lookup() drops key_serial_lock, it is possible for the key to
be freed behind our back.
This patch uses refcount_inc_not_zero() to perform the peek and increment
atomically.
Fixes: fff292914d3a2f1e ("security, keys: convert key.usage from atomic_t to refcount_t") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: David Howells <dhowells@redhat.com> Cc: David Windsor <dwindsor@gmail.com> Cc: Elena Reshetova <elena.reshetova@intel.com> Cc: Hans Liljestrand <ishkamiel@gmail.com> Cc: James Morris <james.l.morris@oracle.com> Cc: Kees Cook <keescook@chromium.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: James Morris <james.l.morris@oracle.com>
Mat Martineau [Thu, 8 Jun 2017 13:50:11 +0000 (14:50 +0100)]
KEYS: Convert KEYCTL_DH_COMPUTE to use the crypto KPP API
The initial Diffie-Hellman computation made direct use of the MPI
library because the crypto module did not support DH at the time. Now
that KPP is implemented, KEYCTL_DH_COMPUTE should use it to get rid of
duplicate code and leverage possible hardware acceleration.
This fixes an issue whereby the input to the KDF computation would
include additional uninitialized memory when the result of the
Diffie-Hellman computation was shorter than the input prime number.
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
Eric Biggers [Thu, 8 Jun 2017 13:49:57 +0000 (14:49 +0100)]
KEYS: DH: add __user annotations to keyctl_kdf_params
Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: James Morris <james.l.morris@oracle.com>
Eric Biggers [Thu, 8 Jun 2017 13:49:49 +0000 (14:49 +0100)]
KEYS: DH: ensure the KDF counter is properly aligned
Accessing a 'u8[4]' through a '__be32 *' violates alignment rules. Just
make the counter a __be32 instead.
Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: James Morris <james.l.morris@oracle.com>
Eric Biggers [Thu, 8 Jun 2017 13:49:42 +0000 (14:49 +0100)]
KEYS: DH: don't feed uninitialized "otherinfo" into KDF
If userspace called KEYCTL_DH_COMPUTE with kdf_params containing NULL
otherinfo but nonzero otherinfolen, the kernel would allocate a buffer
for the otherinfo, then feed it into the KDF without initializing it.
Fix this by always doing the copy from userspace (which will fail with
EFAULT in this scenario).
Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: James Morris <james.l.morris@oracle.com>
Eric Biggers [Thu, 8 Jun 2017 13:49:34 +0000 (14:49 +0100)]
KEYS: DH: forbid using digest_null as the KDF hash
Requesting "digest_null" in the keyctl_kdf_params caused an infinite
loop in kdf_ctr() because the "null" hash has a digest size of 0. Fix
it by rejecting hash algorithms with a digest size of 0.
Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: James Morris <james.l.morris@oracle.com>
Eric Biggers [Thu, 8 Jun 2017 13:49:26 +0000 (14:49 +0100)]
KEYS: sanitize key structs before freeing
While a 'struct key' itself normally does not contain sensitive
information, Documentation/security/keys.txt actually encourages this:
"Having a payload is not required; and the payload can, in fact,
just be a value stored in the struct key itself."
In case someone has taken this advice, or will take this advice in the
future, zero the key structure before freeing it. We might as well, and
as a bonus this could make it a bit more difficult for an adversary to
determine which keys have recently been in use.
This is safe because the key_jar cache does not use a constructor.
Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
Eric Biggers [Thu, 8 Jun 2017 13:49:18 +0000 (14:49 +0100)]
KEYS: trusted: sanitize all key material
As the previous patch did for encrypted-keys, zero sensitive any
potentially sensitive data related to the "trusted" key type before it
is freed. Notably, we were not zeroing the tpm_buf structures in which
the actual key is stored for TPM seal and unseal, nor were we zeroing
the trusted_key_payload in certain error paths.
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: David Safford <safford@us.ibm.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
Eric Biggers [Thu, 8 Jun 2017 13:49:11 +0000 (14:49 +0100)]
KEYS: encrypted: sanitize all key material
For keys of type "encrypted", consistently zero sensitive key material
before freeing it. This was already being done for the decrypted
payloads of encrypted keys, but not for the master key and the keys
derived from the master key.
Out of an abundance of caution and because it is trivial to do so, also
zero buffers containing the key payload in encrypted form, although
depending on how the encrypted-keys feature is used such information
does not necessarily need to be kept secret.
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: David Safford <safford@us.ibm.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
Eric Biggers [Thu, 8 Jun 2017 13:49:04 +0000 (14:49 +0100)]
KEYS: user_defined: sanitize key payloads
Zero the payloads of user and logon keys before freeing them. This
prevents sensitive key material from being kept around in the slab
caches after a key is released.
Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
Eric Biggers [Thu, 8 Jun 2017 13:48:57 +0000 (14:48 +0100)]
KEYS: sanitize add_key() and keyctl() key payloads
Before returning from add_key() or one of the keyctl() commands that
takes in a key payload, zero the temporary buffer that was allocated to
hold the key payload copied from userspace. This may contain sensitive
key material that should not be kept around in the slab caches.
Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
Eric Biggers [Thu, 8 Jun 2017 13:48:47 +0000 (14:48 +0100)]
KEYS: fix freeing uninitialized memory in key_update()
key_update() freed the key_preparsed_payload even if it was not
initialized first. This would cause a crash if userspace called
keyctl_update() on a key with type like "asymmetric" that has a
->preparse() method but not an ->update() method. Possibly it could
even be triggered for other key types by racing with keyctl_setperm() to
make the KEY_NEED_WRITE check fail (the permission was already checked,
so normally it wouldn't fail there).
Reproducer with key type "asymmetric", given a valid cert.der:
Fixes: 4d8c0250b841 ("KEYS: Call ->free_preparse() even after ->preparse() returns an error") Cc: stable@vger.kernel.org # 3.17+ Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
Eric Biggers [Thu, 8 Jun 2017 13:48:40 +0000 (14:48 +0100)]
KEYS: fix dereferencing NULL payload with nonzero length
sys_add_key() and the KEYCTL_UPDATE operation of sys_keyctl() allowed a
NULL payload with nonzero length to be passed to the key type's
->preparse(), ->instantiate(), and/or ->update() methods. Various key
types including asymmetric, cifs.idmap, cifs.spnego, and pkcs7_test did
not handle this case, allowing an unprivileged user to trivially cause a
NULL pointer dereference (kernel oops) if one of these key types was
present. Fix it by doing the copy_from_user() when 'plen' is nonzero
rather than when '_payload' is non-NULL, causing the syscall to fail
with EFAULT as expected when an invalid buffer is specified.
Cc: stable@vger.kernel.org # 2.6.10+ Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
Eric Biggers [Thu, 8 Jun 2017 13:48:32 +0000 (14:48 +0100)]
KEYS: encrypted: use constant-time HMAC comparison
MACs should, in general, be compared using crypto_memneq() to prevent
timing attacks.
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
The encrypted-keys module was using a single global HMAC transform,
which could be rekeyed by multiple threads concurrently operating on
different keys, causing incorrect HMAC values to be calculated. Fix
this by allocating a new HMAC transform whenever we need to calculate a
HMAC. Also simplify things a bit by allocating the shash_desc's using
SHASH_DESC_ON_STACK() for both the HMAC and unkeyed hashes.
The following script reproduces the bug:
keyctl new_session
keyctl add user master "abcdefghijklmnop" @s
for i in $(seq 2); do
(
set -e
for j in $(seq 1000); do
keyid=$(keyctl add encrypted desc$i "new user:master 25" @s)
datablob="$(keyctl pipe $keyid)"
keyctl unlink $keyid > /dev/null
keyid=$(keyctl add encrypted desc$i "load $datablob" @s)
keyctl unlink $keyid > /dev/null
done
) &
done
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
Eric Biggers [Thu, 8 Jun 2017 13:48:18 +0000 (14:48 +0100)]
KEYS: encrypted: fix buffer overread in valid_master_desc()
With the 'encrypted' key type it was possible for userspace to provide a
data blob ending with a master key description shorter than expected,
e.g. 'keyctl add encrypted desc "new x" @s'. When validating such a
master key description, validate_master_desc() could read beyond the end
of the buffer. Fix this by using strncmp() instead of memcmp(). [Also
clean up the code to deduplicate some logic.]
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
Since v4.9, the crypto API cannot (normally) be used to encrypt/decrypt
stack buffers because the stack may be virtually mapped. Fix this for
the padding buffers in encrypted-keys by using ZERO_PAGE for the
encryption padding and by allocating a temporary heap buffer for the
decryption padding.
Eric Biggers [Thu, 8 Jun 2017 13:48:03 +0000 (14:48 +0100)]
KEYS: put keyring if install_session_keyring_to_cred() fails
In join_session_keyring(), if install_session_keyring_to_cred() were to
fail, we would leak the keyring reference, just like in the bug fixed by
commit 23567fd052a9 ("KEYS: Fix keyring ref leak in
join_session_keyring()"). Fortunately this cannot happen currently, but
we really should be more careful. Do this by adding and using a new
error label at which the keyring reference is dropped.
Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
Dan Carpenter [Thu, 8 Jun 2017 13:47:49 +0000 (14:47 +0100)]
X.509: Fix error code in x509_cert_parse()
We forgot to set the error code on this path so it could result in
returning NULL which leads to a NULL dereference.
Fixes: db6c43bd2132 ("crypto: KEYS: convert public key and digsig asym to the akcipher api") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
Davidlohr Bueso [Thu, 8 Jun 2017 13:47:34 +0000 (14:47 +0100)]
security: use READ_ONCE instead of deprecated ACCESS_ONCE
With the new standardized functions, we can replace all ACCESS_ONCE()
calls across relevant security/keyrings/.
ACCESS_ONCE() does not work reliably on non-scalar types. For example
gcc 4.6 and 4.7 might remove the volatile tag for such accesses during
the SRA (scalar replacement of aggregates) step:
Bilal Amarni [Thu, 8 Jun 2017 13:47:26 +0000 (14:47 +0100)]
security/keys: add CONFIG_KEYS_COMPAT to Kconfig
CONFIG_KEYS_COMPAT is defined in arch-specific Kconfigs and is missing for
several 64-bit architectures : mips, parisc, tile.
At the moment and for those architectures, calling in 32-bit userspace the
keyctl syscall would return an ENOSYS error.
This patch moves the CONFIG_KEYS_COMPAT option to security/keys/Kconfig, to
make sure the compatibility wrapper is registered by default for any 64-bit
architecture as long as it is configured with CONFIG_COMPAT.
[DH: Modified to remove arm64 compat enablement also as requested by Eric
Biggers]
Signed-off-by: Bilal Amarni <bilal.amarni@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
cc: Eric Biggers <ebiggers3@gmail.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
Dave Airlie [Fri, 9 Jun 2017 03:12:02 +0000 (13:12 +1000)]
Merge branch 'vmwgfx-fixes-4.12' of git://people.freedesktop.org/~thomash/linux into drm-fixes
A bunch of fixes for vmwgfx 4.12 regressions and older stuff. In the latter
case either trivial, cc'd stable or requiring backports for stable.
* 'vmwgfx-fixes-4.12' of git://people.freedesktop.org/~thomash/linux:
drm/vmwgfx: Bump driver minor and date
drm/vmwgfx: Remove unused legacy cursor functions
drm/vmwgfx: fix spelling mistake "exeeds" -> "exceeds"
drm/vmwgfx: Fix large topology crash
drm/vmwgfx: Make sure to update STDU when FB is updated
drm/vmwgfx: Make sure backup_handle is always valid
drm/vmwgfx: Handle vmalloc() failure in vmw_local_fifo_reserve()
drm/vmwgfx: Don't create proxy surface for cursor
drm/vmwgfx: limit the number of mip levels in vmw_gb_surface_define_ioctl()
Dave Airlie [Fri, 9 Jun 2017 02:18:07 +0000 (12:18 +1000)]
Merge tag 'drm-intel-fixes-2017-06-08' of git://anongit.freedesktop.org/git/drm-intel into drm-fixes
drm/i915 fixes for v4.12-rc5
* tag 'drm-intel-fixes-2017-06-08' of git://anongit.freedesktop.org/git/drm-intel:
drm/i915: fix warning for unused variable
drm/i915: Fix 90/270 rotated coordinates for FBC
drm/i915: Restore has_fbc=1 for ILK-M
drm/i915: Workaround VLV/CHV DSI scanline counter hardware fail
drm/i915: Fix logical inversion for gen4 quirking
drm/i915: Guard against i915_ggtt_disable_guc() being invoked unconditionally
drm/i915: Always recompute watermarks when distrust_bios_wm is set, v2.
drm/i915: Prevent the system suspend complete optimization
drm/i915/psr: disable psr2 for resolution greater than 32X20
drm/i915: Hold a wakeref for probing the ring registers
drm/i915: Short-circuit i915_gem_wait_for_idle() if already idle
drm/i915: Disable decoupled MMIO
drm/i915/guc: Remove stale comment for q_fail
drm/i915: Serialize GTT/Aperture accesses on BXT
Dave Airlie [Fri, 9 Jun 2017 02:17:27 +0000 (12:17 +1000)]
Merge tag 'drm-misc-fixes-2017-06-07' of git://anongit.freedesktop.org/git/drm-misc into drm-fixes
Driver Changes:
- kirin: Use correct dt port for the bridge (John)
- meson: Fix regression caused by adding HDMI support to allow board
configurations without HDMI (Neil)
Cc: John Stultz <john.stultz@linaro.org> Cc: Neil Armstrong <narmstrong@baylibre.com>
* tag 'drm-misc-fixes-2017-06-07' of git://anongit.freedesktop.org/git/drm-misc:
drm/meson: Fix driver bind when only CVBS is available
drm: kirin: Fix drm_of_find_panel_or_bridge conversion
Dave Airlie [Fri, 9 Jun 2017 02:16:25 +0000 (12:16 +1000)]
Merge tag 'imx-drm-fixes-2017-06-08' of git://git.pengutronix.de/git/pza/linux into drm-fixes
imx-drm: PRE clock gating, panelless LDB, and VDIC CSI selection fixes
- Keep the external clock input to the PRE ungated and only use the internal
soft reset to keep the module in low power state, to avoid sporadic startup
failures.
- Ignore -ENODEV return values from drm_of_find_panel_or_bridge in the LDB
driver to fix probing for devices that still do not specify a panel in the
device tree.
- Fix the CSI input selection to the VDIC. According to experiments, the real
behaviour differs a bit from the documentation.
* tag 'imx-drm-fixes-2017-06-08' of git://git.pengutronix.de/git/pza/linux:
gpu: ipu-v3: Fix CSI selection for VDIC
drm/imx: imx-ldb: Accept drm_of_find_panel_or_bridge failure
gpu: ipu-v3: pre: only use internal clock gating
Linus Torvalds [Fri, 9 Jun 2017 00:40:32 +0000 (17:40 -0700)]
Merge tag 'pm-4.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fixes from Rafael Wysocki:
"These revert one problematic commit related to system sleep and fix
one recent intel_pstate regression.
Specifics:
- Revert a recent commit that attempted to avoid spurious wakeups
from suspend-to-idle via ACPI SCI, but introduced regressions on
some systems (Rafael Wysocki).
We will get back to the problem it tried to address in the next
cycle.
- Fix a possible division by 0 during intel_pstate initialization
due to a missing check (Rafael Wysocki)"
* tag 'pm-4.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
Revert "ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle"
cpufreq: intel_pstate: Avoid division by 0 in min_perf_pct_min()
Namhyung Kim [Thu, 8 Jun 2017 07:31:09 +0000 (16:31 +0900)]
perf symbols: Kill dso__build_id_is_kmod()
The commit e7ee40475760 ("perf symbols: Fix symbols searching for module
in buildid-cache") added the function to check kernel modules reside in
the build-id cache. This was because there's no way to identify a DSO
which is actually a kernel module. So it searched linkname of the file
and find ".ko" suffix.
But this does not work for compressed kernel modules and now such DSOs
hCcave correct symtab_type now. So no need to check it anymore. This
patch essentially reverts the commit.
Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170608073109.30699-10-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Namhyung Kim [Thu, 8 Jun 2017 07:31:08 +0000 (16:31 +0900)]
perf symbols: Keep DSO->symtab_type after decompress
The symsrc__init() overwrites dso->symtab_type as symsrc->type in
dso__load_sym(). But for compressed kernel modules in the build-id
cache, it should have original symtab type to be decompressed as needed.
This fixes perf annotate to show disassembly of the function properly.
Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170608073109.30699-9-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Namhyung Kim [Thu, 8 Jun 2017 07:31:07 +0000 (16:31 +0900)]
perf tests: Decompress kernel module before objdump
If a kernel modules is compressed, it should be decompressed before
running objdump to parse binary data correctly. This fixes a failure of
object code reading test for me.
Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: David Ahern <dsahern@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170608073109.30699-8-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Namhyung Kim [Thu, 8 Jun 2017 07:31:06 +0000 (16:31 +0900)]
perf tools: Consolidate error path in __open_dso()
On failure, it should free the 'name', so clean up the error path using
goto.
Signed-off-by: Namhyung Kim <namhyung@kernel.org> Suggested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170608073109.30699-7-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Namhyung Kim [Thu, 8 Jun 2017 07:31:05 +0000 (16:31 +0900)]
perf tools: Decompress kernel module when reading DSO data
Currently perf decompresses kernel modules when loading the symbol table
but it missed to do it when reading raw data.
Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170608073109.30699-6-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Namhyung Kim [Thu, 8 Jun 2017 07:31:04 +0000 (16:31 +0900)]
perf annotate: Use dso__decompress_kmodule_path()
Convert open-coded decompress routine to use the function.
Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170608073109.30699-5-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Move decompress_kmodule() to util/dso.c and split it into two functions
returning fd and (decompressed) file path. The existing user only wants
the fd version but the path version will be used soon.
Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170608073109.30699-4-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Namhyung Kim [Thu, 8 Jun 2017 07:31:02 +0000 (16:31 +0900)]
perf tools: Fix a memory leak in __open_dso()
The 'name' variable should be freed on the error path.
Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170608073109.30699-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Namhyung Kim [Thu, 8 Jun 2017 07:31:01 +0000 (16:31 +0900)]
perf annotate: Fix symbolic link of build-id cache
The commit 6ebd2547dd24 ("perf annotate: Fix a bug following symbolic
link of a build-id file") changed to use dirname to follow the symlink.
But it only considers new-style build-id cache names so old names fail
on readlink() and force to use system path which might not available.
Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Taeung Song <treeze.taeung@gmail.com> Cc: Wang Nan <wangnan0@huawei.com> Cc: kernel-team@lge.com Fixes: 6ebd2547dd24 ("perf annotate: Fix a bug following symbolic link of a build-id file") Link: http://lkml.kernel.org/r/20170608073109.30699-2-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Linus Torvalds [Thu, 8 Jun 2017 17:50:04 +0000 (10:50 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk
Pull printk fix from Petr Mladek:
"This reverts a fix added into 4.12-rc1. It caused the kernel log to be
printed on another console when two consoles of the same type were
defined, e.g. console=ttyS0 console=ttyS1.
This configuration was never supported by kernel itself, but it
started to make sense with systemd. In other words, the commit broke
userspace"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
Revert "printk: fix double printing with earlycon"
Linus Torvalds [Thu, 8 Jun 2017 17:02:58 +0000 (10:02 -0700)]
Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto fixes from Herbert Xu:
"This fixes a couple of places in the crypto code that were doing
interruptible sleeps dangerously. They have been converted to use
non-interruptible sleeps.
This also fixes a bug in asymmetric_keys where it would trigger a
use-after-free if a request returned EBUSY due to a full device queue"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: gcm - wait for crypto op not signal safe
crypto: drbg - wait for crypto op not signal safe
crypto: asymmetric_keys - handle EBUSY due to backlog correctly
Paolo Valente [Mon, 5 Jun 2017 08:11:15 +0000 (10:11 +0200)]
block, bfq: access and cache blkg data only when safe
In blk-cgroup, operations on blkg objects are protected with the
request_queue lock. This is no more the lock that protects
I/O-scheduler operations in blk-mq. In fact, the latter are now
protected with a finer-grained per-scheduler-instance lock. As a
consequence, although blkg lookups are also rcu-protected, blk-mq I/O
schedulers may see inconsistent data when they access blkg and
blkg-related objects. BFQ does access these objects, and does incur
this problem, in the following case.
The blkg_lookup performed in bfq_get_queue, being protected (only)
through rcu, may happen to return the address of a copy of the
original blkg. If this is the case, then the blkg_get performed in
bfq_get_queue, to pin down the blkg, is useless: it does not prevent
blk-cgroup code from destroying both the original blkg and all objects
directly or indirectly referred by the copy of the blkg. BFQ accesses
these objects, which typically causes a crash for NULL-pointer
dereference of memory-protection violation.
Some additional protection mechanism should be added to blk-cgroup to
address this issue. In the meantime, this commit provides a quick
temporary fix for BFQ: cache (when safe) blkg data that might
disappear right after a blkg_lookup.
In particular, this commit exploits the following facts to achieve its
goal without introducing further locks. Destroy operations on a blkg
invoke, as a first step, hooks of the scheduler associated with the
blkg. And these hooks are executed with bfqd->lock held for BFQ. As a
consequence, for any blkg associated with the request queue an
instance of BFQ is attached to, we are guaranteed that such a blkg is
not destroyed, and that all the pointers it contains are consistent,
while that instance is holding its bfqd->lock. A blkg_lookup performed
with bfqd->lock held then returns a fully consistent blkg, which
remains consistent until this lock is held. In more detail, this holds
even if the returned blkg is a copy of the original one.
Finally, also the object describing a group inside BFQ needs to be
protected from destruction on the blkg_free of the original blkg
(which invokes bfq_pd_free). This commit adds private refcounting for
this object, to let it disappear only after no bfq_queue refers to it
any longer.
This commit also removes or updates some stale comments on locking
issues related to blk-cgroup operations.
Reported-by: Tomas Konir <tomas.konir@gmail.com> Reported-by: Lee Tibbert <lee.tibbert@gmail.com> Reported-by: Marco Piazza <mpiazza@gmail.com> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Tested-by: Tomas Konir <tomas.konir@gmail.com> Tested-by: Lee Tibbert <lee.tibbert@gmail.com> Tested-by: Marco Piazza <mpiazza@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Paolo Bonzini [Wed, 31 May 2017 12:03:11 +0000 (14:03 +0200)]
srcu: Allow use of Classic SRCU from both process and interrupt context
Linu Cherian reported a WARN in cleanup_srcu_struct() when shutting
down a guest running iperf on a VFIO assigned device. This happens
because irqfd_wakeup() calls srcu_read_lock(&kvm->irq_srcu) in interrupt
context, while a worker thread does the same inside kvm_set_irq(). If the
interrupt happens while the worker thread is executing __srcu_read_lock(),
updates to the Classic SRCU ->lock_count[] field or the Tree SRCU
->srcu_lock_count[] field can be lost.
The docs say you are not supposed to call srcu_read_lock() and
srcu_read_unlock() from irq context, but KVM interrupt injection happens
from (host) interrupt context and it would be nice if SRCU supported the
use case. KVM is using SRCU here not really for the "sleepable" part,
but rather due to its IPI-free fast detection of grace periods. It is
therefore not desirable to switch back to RCU, which would effectively
revert commit 719d93cd5f5c ("kvm/irqchip: Speed up KVM_SET_GSI_ROUTING",
2014-01-16).
However, the docs are overly conservative. You can have an SRCU instance
only has users in irq context, and you can mix process and irq context
as long as process context users disable interrupts. In addition,
__srcu_read_unlock() actually uses this_cpu_dec() on both Tree SRCU and
Classic SRCU. For those two implementations, only srcu_read_lock()
is unsafe.
When Classic SRCU's __srcu_read_unlock() was changed to use this_cpu_dec(),
in commit 5a41344a3d83 ("srcu: Simplify __srcu_read_unlock() via
this_cpu_dec()", 2012-11-29), __srcu_read_lock() did two increments.
Therefore it kept __this_cpu_inc(), with preempt_disable/enable in
the caller. Tree SRCU however only does one increment, so on most
architectures it is more efficient for __srcu_read_lock() to use
this_cpu_inc(), and any performance differences appear to be down in
the noise.
Cc: stable@vger.kernel.org Fixes: 719d93cd5f5c ("kvm/irqchip: Speed up KVM_SET_GSI_ROUTING") Reported-by: Linu Cherian <linuc.decode@gmail.com> Suggested-by: Linu Cherian <linuc.decode@gmail.com> Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paolo Bonzini [Wed, 31 May 2017 12:03:10 +0000 (14:03 +0200)]
srcu: Allow use of Tiny/Tree SRCU from both process and interrupt context
Linu Cherian reported a WARN in cleanup_srcu_struct() when shutting
down a guest running iperf on a VFIO assigned device. This happens
because irqfd_wakeup() calls srcu_read_lock(&kvm->irq_srcu) in interrupt
context, while a worker thread does the same inside kvm_set_irq(). If the
interrupt happens while the worker thread is executing __srcu_read_lock(),
updates to the Classic SRCU ->lock_count[] field or the Tree SRCU
->srcu_lock_count[] field can be lost.
The docs say you are not supposed to call srcu_read_lock() and
srcu_read_unlock() from irq context, but KVM interrupt injection happens
from (host) interrupt context and it would be nice if SRCU supported the
use case. KVM is using SRCU here not really for the "sleepable" part,
but rather due to its IPI-free fast detection of grace periods. It is
therefore not desirable to switch back to RCU, which would effectively
revert commit 719d93cd5f5c ("kvm/irqchip: Speed up KVM_SET_GSI_ROUTING",
2014-01-16).
However, the docs are overly conservative. You can have an SRCU instance
only has users in irq context, and you can mix process and irq context
as long as process context users disable interrupts. In addition,
__srcu_read_unlock() actually uses this_cpu_dec() on both Tree SRCU and
Classic SRCU. For those two implementations, only srcu_read_lock()
is unsafe.
When Classic SRCU's __srcu_read_unlock() was changed to use this_cpu_dec(),
in commit 5a41344a3d83 ("srcu: Simplify __srcu_read_unlock() via
this_cpu_dec()", 2012-11-29), __srcu_read_lock() did two increments.
Therefore it kept __this_cpu_inc(), with preempt_disable/enable in
the caller. Tree SRCU however only does one increment, so on most
architectures it is more efficient for __srcu_read_lock() to use
this_cpu_inc(), and any performance differences appear to be down in
the noise.
Unlike Classic and Tree SRCU, Tiny SRCU does increments and decrements on
a single variable. Therefore, as Peter Zijlstra pointed out, Tiny SRCU's
implementation already supports mixed-context use of srcu_read_lock()
and srcu_read_unlock(), at least as long as uses of srcu_read_lock()
and srcu_read_unlock() in each handler are nested and paired properly.
In other words, it is still illegal to (say) invoke srcu_read_lock()
in an interrupt handler and to invoke the matching srcu_read_unlock()
in a softirq handler. Therefore, the only change required for Tiny SRCU
is to its comments.
Fixes: 719d93cd5f5c ("kvm/irqchip: Speed up KVM_SET_GSI_ROUTING") Reported-by: Linu Cherian <linuc.decode@gmail.com> Suggested-by: Linu Cherian <linuc.decode@gmail.com> Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Paolo Bonzini <pbonzini@redhat.com>
projects / kernel.git / log