Similar to commit b4b29f9485 ("locking/osq: Fix ordering of node
initialisation in osq_lock") the use of xchg_acquire() is
fundamentally broken with MCS like constructs.
Furthermore, it turns out we rely on the global transitivity of this
operation because the unlock path observes the pointer with a
READ_ONCE(), not an smp_load_acquire().
This is non-critical because the MCS code isn't actually used and
mostly serves as documentation, a stepping stone to the more complex
things we've build on top of the idea.
Reported-by: Andrea Parri <parri.andrea@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Fixes: 3552a07a9c ("locking/mcs: Use acquire/release semantics")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull perf fixes from Thomas Gleixner:
"A rather largish series of 12 patches addressing a maze of race
conditions in the perf core code from Peter Zijlstra"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Robustify task_function_call()
perf: Fix scaling vs. perf_install_in_context()
perf: Fix scaling vs. perf_event_enable()
perf: Fix scaling vs. perf_event_enable_on_exec()
perf: Fix ctx time tracking by introducing EVENT_TIME
perf: Cure event->pending_disable race
perf: Fix race between event install and jump_labels
perf: Fix cloning
perf: Only update context time when active
perf: Allow perf_release() with !event->ctx
perf: Do not double free
perf: Close install vs. exit race
Pull x86 fixes from Thomas Gleixner:
"This update contains:
- Hopefully the last ASM CLAC fixups
- A fix for the Quark family related to the IMR lock which makes
kexec work again
- A off-by-one fix in the MPX code. Ironic, isn't it?
- A fix for X86_PAE which addresses once more an unsigned long vs
phys_addr_t hickup"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mpx: Fix off-by-one comparison with nr_registers
x86/mm: Fix slow_virt_to_phys() for X86_PAE again
x86/entry/compat: Add missing CLAC to entry_INT80_32
x86/entry/32: Add an ASM_CLAC to entry_SYSENTER_32
x86/platform/intel/quark: Change the kernel's IMR lock bit to false
Pull scheduler fixlet from Thomas Gleixner:
"A trivial printk typo fix"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/deadline: Fix trivial typo in printk() message
Pull irq fixes from Thomas Gleixner:
"Four small fixes for irqchip drivers:
- Add missing low level irq handler initialization on mxs, so
interrupts can acutally be delivered
- Add a missing barrier to the GIC driver
- Two fixes for the GIC-V3-ITS driver, addressing a double EOI write
and a cache flush beyond the actual region"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/gic-v3: Add missing barrier to 32bit version of gic_read_iar()
irqchip/mxs: Add missing set_handle_irq()
irqchip/gicv3-its: Avoid cache flush beyond ITS_BASERn memory size
irqchip/gic-v3-its: Fix double ICC_EOIR write for LPI in EOImode==1
Pull staging/android fix from Greg KH:
"Here is one patch, for the android binder driver, to resolve a
reported problem. Turns out it has been around for a while (since
3.15), so it is good to finally get it resolved.
It has been in linux-next for a while with no reported issues"
* tag 'staging-4.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
drivers: android: correct the size of struct binder_uintptr_t for BC_DEAD_BINDER_DONE
Pull USB fixes from Greg KH:
"Here are a few USB fixes for 4.5-rc6
They fix a reported bug for some USB 3 devices by reverting the recent
patch, a MAINTAINERS change for some drivers, some new device ids, and
of course, the usual bunch of USB gadget driver fixes.
All have been in linux-next for a while with no reported issues"
* tag 'usb-4.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
MAINTAINERS: drop OMAP USB and MUSB maintainership
usb: musb: fix DMA for host mode
usb: phy: msm: Trigger USB state detection work in DRD mode
usb: gadget: net2280: fix endpoint max packet for super speed connections
usb: gadget: gadgetfs: unregister gadget only if it got successfully registered
usb: gadget: remove driver from pending list on probe error
Revert "usb: hub: do not clear BOS field during reset device"
usb: chipidea: fix return value check in ci_hdrc_pci_probe()
usb: chipidea: error on overflow for port_test_write
USB: option: add "4G LTE usb-modem U901"
USB: cp210x: add IDs for GE B650V3 and B850V3 boards
USB: option: add support for SIM7100E
usb: musb: Fix DMA desired mode for Mentor DMA engine
usb: gadget: fsl_qe_udc: fix IS_ERR_VALUE usage
usb: dwc2: USB_DWC2 should depend on HAS_DMA
usb: dwc2: host: fix the data toggle error in full speed descriptor dma
usb: dwc2: host: fix logical omissions in dwc2_process_non_isoc_desc
usb: dwc3: Fix assignment of EP transfer resources
usb: dwc2: Add extra delay when forcing dr_mode
Pull vfs fixes from Al Viro.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
do_last(): ELOOP failure exit should be done after leaving RCU mode
should_follow_link(): validate ->d_seq after having decided to follow
namei: ->d_inode of a pinned dentry is stable only for positives
do_last(): don't let a bogus return value from ->open() et.al. to confuse us
fs: return -EOPNOTSUPP if clone is not supported
hpfs: don't truncate the file when delete fails
Pull ARM SoC fixes from Olof Johansson:
"We didn't have a batch last week, so this one is slightly larger.
None of them are scary though, a handful of fixes for small DT pieces,
replacing properties with newer conventions.
Highlights:
- N900 fix for setting system revision
- onenand init fix to avoid filesystem corruption
- Clock fix for audio on Beaglebone-x15
- Fixes on shmobile to deal with CONFIG_DEBUG_RODATA (default y in 4.6)
+ misc smaller stuff"
* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
MAINTAINERS: Extend info, add wiki and ml for meson arch
MAINTAINERS: alpine: add a new maintainer and update the entry
ARM: at91/dt: fix typo in sama5d2 pinmux descriptions
ARM: OMAP2+: Fix onenand initialization to avoid filesystem corruption
Revert "regulator: tps65217: remove tps65217.dtsi file"
ARM: shmobile: Remove shmobile_boot_arg
ARM: shmobile: Move shmobile_smp_{mpidr, fn, arg}[] from .text to .bss
ARM: shmobile: r8a7779: Remove remainings of removed SCU boot setup code
ARM: shmobile: Move shmobile_scu_base from .text to .bss
ARM: OMAP2+: Fix omap_device for module reload on PM runtime forbid
ARM: OMAP2+: Improve omap_device error for driver writers
ARM: DTS: am57xx-beagle-x15: Select SYS_CLK2 for audio clocks
ARM: dts: am335x/am57xx: replace gpio-key,wakeup with wakeup-source property
ARM: OMAP2+: Set system_rev from ATAGS for n900
ARM: dts: orion5x: fix the missing mtd flash on linkstation lswtgl
ARM: dts: kirkwood: use unique machine name for ds112
ARM: dts: imx6: remove bogus interrupt-parent from CAAM node
both do_last() and walk_component() risk picking a NULL inode out
of dentry about to become positive, *then* checking its flags and
seeing that it's not negative anymore and using (already stale by
then) value they'd fetched earlier. Usually ends up oopsing soon
after that...
Cc: stable@vger.kernel.org # v3.13+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... into returning a positive to path_openat(), which would interpret that
as "symlink had been encountered" and proceed to corrupt memory, etc.
It can only happen due to a bug in some ->open() instance or in some LSM
hook, etc., so we report any such event *and* make sure it doesn't trick
us into further unpleasantness.
Cc: stable@vger.kernel.org # v3.6+, at least
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-EBADF is a rather confusing error if an operations is not supported,
and nfsd gets rather upset about it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The delete opration can allocate additional space on the HPFS filesystem
due to btree split. The HPFS driver checks in advance if there is
available space, so that it won't corrupt the btree if we run out of space
during splitting.
If there is not enough available space, the HPFS driver attempted to
truncate the file, but this results in a deadlock since the commit
7dd29d8d86 ("HPFS: Introduce a global mutex
and lock it on every callback from VFS").
This patch removes the code that tries to truncate the file and -ENOSPC is
returned instead. If the user hits -ENOSPC on delete, he should try to
delete other files (that are stored in a leaf btree node), so that the
delete operation will make some space for deleting the file stored in
non-leaf btree node.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: stable@vger.kernel.org # 2.6.39+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Merge fixes from Andrew Morton:
"10 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
dax: move writeback calls into the filesystems
dax: give DAX clearing code correct bdev
ext4: online defrag not supported with DAX
ext2, ext4: only set S_DAX for regular inodes
block: disable block device DAX by default
ocfs2: unlock inode if deleting inode from orphan fails
mm: ASLR: use get_random_long()
drivers: char: random: add get_random_long()
mm: numa: quickly fail allocations for NUMA balancing on full nodes
mm: thp: fix SMP race condition between THP page fault and MADV_DONTNEED
Pull ext2/4 DAX fix from Ted Ts'o:
"This fixes a file system corruption bug with DAX"
* tag 'tags/ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext2, ext4: fix issue with missing journal entry in ext4_dax_mkwrite()
Ingo Molnar
Dan Streetman
Davidlohr Bueso
Waiman Long
Peter Zijlstra
Linus Torvalds
Al Viro
Christoph Hellwig
Mikulas Patocka