Commit Graph

560985 Commits

Author SHA1 Message Date
Rusty Russell
7523e4dc50 module: use a structure to encapsulate layout.
Makes it easier to handle init vs core cleanly, though the change is
fairly invasive across random architectures.

It simplifies the rbtree code immediately, however, while keeping the
core data together in the same cachline (now iff the rbtree code is
enabled).

Acked-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-12-04 22:46:25 +01:00
Rusty Russell
c65abf358f gcov: use within_module() helper.
An exact mapping would be within_module_core(), but at this stage
(MODULE_STATE_GOING) the init section is empty, and this is clearer.

Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-12-04 22:46:25 +01:00
Josh Poimboeuf
20ef10c1b3 module: Use the same logic for setting and unsetting RO/NX
When setting a module's RO and NX permissions, set_section_ro_nx() is
used, but when clearing them, unset_module_{init,core}_ro_nx() are used.
The unset functions don't have the same checks the set function has for
partial page protections.  It's probably harmless, but it's still
confusingly asymmetrical.

Instead, use the same logic to do both.  Also add some new
set_module_{init,core}_ro_nx() helper functions for more symmetry with
the unset functions.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-12-04 22:46:24 +01:00
Linus Torvalds
78c4a49a69 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro:
 "A couple of fixes for sendfile lockups caught by Dmitry + a fix for
  ancient sysvfs symlink breakage"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  vfs: Avoid softlockups with sendfile(2)
  vfs: Make sendfile(2) killable even better
  fix sysvfs symlinks
2015-11-25 15:11:08 -08:00
Linus Torvalds
9b81d512a4 Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull more block layer fixes from Jens Axboe:
 "I wasn't going to send off a new pull before next week, but the blk
  flush fix from Jan from the other day introduced a regression.  It's
  rare enough not to have hit during testing, since it requires both a
  device that rejects the first flush, and bad timing while it does
  that.  But since someone did hit it, let's get the revert into 4.4-rc3
  so we don't have a released rc with that known issue.

  Apart from that revert, three other fixes:

   - From Christoph, a fix for a missing unmap in NVMe request
     preparation.

   - An NVMe fix from Nishanth that fixes data corruption on powerpc.

   - Also from Christoph, fix a list_del() attempt on blk-mq that didn't
     have a matching list_add() at timer start"

* 'for-linus' of git://git.kernel.dk/linux-block:
  Revert "blk-flush: Queue through IO scheduler when flush not required"
  block: fix blk_abort_request for blk-mq drivers
  nvme: add missing unmaps in nvme_queue_rq
  NVMe: default to 4k device page size
2015-11-25 11:08:35 -08:00
Jens Axboe
dcd8376c36 Revert "blk-flush: Queue through IO scheduler when flush not required"
This reverts commit 1b2ff19e6a.

Jan writes:

--

Thanks for report! After some investigation I found out we allocate
elevator specific data in __get_request() only for non-flush requests. And
this is actually required since the flush machinery uses the space in
struct request for something else. Doh. So my patch is just wrong and not
easy to fix since at the time __get_request() is called we are not sure
whether the flush machinery will be used in the end. Jens, please revert
1b2ff19e6a. Thanks!

I'm somewhat surprised that you can reliably hit the race where flushing
gets disabled for the device just while the request is in flight. But I
guess during boot it makes some sense.

--

So let's just revert it, we can fix the queue run manually after the
fact. This race is rare enough that it didn't trigger in testing, it
requires the specific disable-while-in-flight scenario to trigger.
2015-11-25 10:12:54 -07:00
Linus Torvalds
4cf193b4b2 Bug fixes for all architectures. Nothing really stands out.
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQEcBAABAgAGBQJWVcuuAAoJEL/70l94x66DmUEIAKnU6SCojoFOxWY0/EH/PBue
 m53mjiRiHp+YH/74dW0XF843+IKLfbLiADRaWHTqc9VW0ifnXmRjOv/bYpC7I/+R
 8XKHaJZQfpb6yvICEqWvMItBpddoakbhv8DJOf4bUfipNY0zx5F2STFfx0KICtbc
 mHTB4y5bFgIz8mJBLX+Dmh/UyXL0kbjSnksu0WA80Szr0pq2Sr4Csrx8PqGAEfIJ
 e5DUW0h3UXY77J5fQbpgJs93hzp1YwkuRKEeYpB8POx4fmvssHoybmOk46sP0Ipb
 IYxrJ+CUQ4o6Vpp3LTMjzMfJ4Y/NaOHCvYxL0okhxtUuq+UbUZjM5ziclfQ/32M=
 =cbxQ
 -----END PGP SIGNATURE-----

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Paolo Bonzini:
 "Bug fixes for all architectures.  Nothing really stands out"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (21 commits)
  KVM: nVMX: remove incorrect vpid check in nested invvpid emulation
  arm64: kvm: report original PAR_EL1 upon panic
  arm64: kvm: avoid %p in __kvm_hyp_panic
  KVM: arm/arm64: vgic: Trust the LR state for HW IRQs
  KVM: arm/arm64: arch_timer: Preserve physical dist. active state on LR.active
  KVM: arm/arm64: Fix preemptible timer active state crazyness
  arm64: KVM: Add workaround for Cortex-A57 erratum 834220
  arm64: KVM: Fix AArch32 to AArch64 register mapping
  ARM/arm64: KVM: test properly for a PTE's uncachedness
  KVM: s390: fix wrong lookup of VCPUs by array index
  KVM: s390: avoid memory overwrites on emergency signal injection
  KVM: Provide function for VCPU lookup by id
  KVM: s390: fix pfmf intercept handler
  KVM: s390: enable SIMD only when no VCPUs were created
  KVM: x86: request interrupt window when IRQ chip is split
  KVM: x86: set KVM_REQ_EVENT on local interrupt request from user space
  KVM: x86: split kvm_vcpu_ready_for_interrupt_injection out of dm_request_for_irq_injection
  KVM: x86: fix interrupt window handling in split IRQ chip case
  MIPS: KVM: Uninit VCPU in vcpu_create error path
  MIPS: KVM: Fix CACHE immediate offset sign extension
  ...
2015-11-25 09:01:49 -08:00
Haozhong Zhang
b2467e744f KVM: nVMX: remove incorrect vpid check in nested invvpid emulation
This patch removes the vpid check when emulating nested invvpid
instruction of type all-contexts invalidation. The existing code is
incorrect because:
 (1) According to Intel SDM Vol 3, Section "INVVPID - Invalidate
     Translations Based on VPID", invvpid instruction does not check
     vpid in the invvpid descriptor when its type is all-contexts
     invalidation.
 (2) According to the same document, invvpid of type all-contexts
     invalidation does not require there is an active VMCS, so/and
     get_vmcs12() in the existing code may result in a NULL-pointer
     dereference. In practice, it can crash both KVM itself and L1
     hypervisors that use invvpid (e.g. Xen).

Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-25 15:52:55 +01:00
Christoph Hellwig
55ce0da1da block: fix blk_abort_request for blk-mq drivers
We only added the request to the request list for the !blk-mq case,
so we should only delete it in that case as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-24 15:24:10 -07:00
Christoph Hellwig
bf508e910b nvme: add missing unmaps in nvme_queue_rq
When we fail various metadata related operations in nvme_queue_rq we
need to unmap the data SGL.

Cc: stable@vger.kernel.org
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-24 15:24:05 -07:00
Nishanth Aravamudan
c5c9f25b98 NVMe: default to 4k device page size
We received a bug report recently when DDW (64-bit direct DMA on Power)
is not enabled for NVMe devices. In that case, we fall back to 32-bit
DMA via the IOMMU, which is always done via 4K TCEs (Translation Control
Entries).

The NVMe device driver, though, assumes that the DMA alignment for the
PRP entries will match the device's page size, and that the DMA aligment
matches the kernel's page aligment. On Power, the the IOMMU page size,
as mentioned above, can be 4K, while the device can have a page size of
8K, while the kernel has a page size of 64K. This eventually trips the
BUG_ON in nvme_setup_prps(), as we have a 'dma_len' that is a multiple
of 4K but not 8K (e.g., 0xF000).

In this particular case of page sizes, we clearly want to use the
IOMMU's page size in the driver. And generally, the NVMe driver in this
function should be using the IOMMU's page size for the default device
page size, rather than the kernel's page size. There is not currently an
API to obtain the IOMMU's page size across all architectures and in the
interest of a stop-gap fix to this functional issue, default the NVMe
device page size to 4K, with the intent of adding such an API and
implementation across all architectures in the next merge window.

With the functionally equivalent v3 of this patch, our hardware test
exerciser survives when using 32-bit DMA; without the patch, the kernel
will BUG within a few minutes.

Signed-off-by: Nishanth Aravamudan <nacc at linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-24 15:05:51 -07:00
Linus Torvalds
6ffeba9607 Two fixes for 4.4-rc1's DM ioctl changes that introduced the potential
for infinite recursion on ioctl (with DM multipath).
 
 And four stable fixes:
 
 - A DM thin-provisioning fix to restore 'error_if_no_space' setting when
   a thin-pool is made writable again (after having been out of space).
 
 - A DM thin-provisioning fix to properly advertise discard support for
   thin volumes that are stacked on a thin-pool whose underlying data
   device doesn't support discards.
 
 - A DM ioctl fix to allow ctrl-c to break out of an ioctl retry loop
   when DM multipath is configured to 'queue_if_no_path'.
 
 - A DM crypt fix for a possible hang on dm-crypt device removal.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJWVMgcAAoJEMUj8QotnQNawbMIAK9SqJoLWNVmxMFbUMr8LkWM
 8TPfdt/TiwXE2FmiBs3Yhj0GuQsdcihGvfjrS7sIbP8XNpsjtiKVHIWwjAk0UFKm
 dS3R6yYZWySeaG1tLmQcuvmGf5JUQJ7hufyqAgkVdQ9bqeORJ4dJFx24Rjciz73s
 UbyhxOeu1bJC3ECtiiUcPpUrlwhsOir4i1HWUQcQjo2r4y0vYUY3lndDdI6w9tis
 K7M/V3YNkw5WMupg+VPE9hJdp97zHKHNNMQgb8Q5Z0Y/PnrZ7uVEr9yyrgpKBE+P
 u3GUUIqH+N7CZxJDld0LTJ+GcK+gIgnzJqAtB3EWSeONHkBAuAR+Pvqh/qqYhsI=
 =8WtB
 -----END PGP SIGNATURE-----

Merge tag 'dm-4.4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:
 "Two fixes for 4.4-rc1's DM ioctl changes that introduced the potential
  for infinite recursion on ioctl (with DM multipath).

  And four stable fixes:

   - A DM thin-provisioning fix to restore 'error_if_no_space' setting
     when a thin-pool is made writable again (after having been out of
     space).

   - A DM thin-provisioning fix to properly advertise discard support
     for thin volumes that are stacked on a thin-pool whose underlying
     data device doesn't support discards.

   - A DM ioctl fix to allow ctrl-c to break out of an ioctl retry loop
     when DM multipath is configured to 'queue_if_no_path'.

   - A DM crypt fix for a possible hang on dm-crypt device removal"

* tag 'dm-4.4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm thin: fix regression in advertised discard limits
  dm crypt: fix a possible hang due to race condition on exit
  dm mpath: fix infinite recursion in ioctl when no paths and !queue_if_no_path
  dm: do not reuse dm_blk_ioctl block_device input as local variable
  dm: fix ioctl retry termination with signal
  dm thin: restore requested 'error_if_no_space' setting on OODS to WRITE transition
2015-11-24 12:53:11 -08:00
Eric Dumazet
81b1a832d7 pidns: fix NULL dereference in __task_pid_nr_ns()
I got a crash during a "perf top" session that was caused by a race in
__task_pid_nr_ns() :

pid_nr_ns() was inlined, but apparently compiler chose to read
task->pids[type].pid twice, and the pid->level dereference crashed
because we got a NULL pointer at the second read :

    if (pid && ns->level <= pid->level) { // CRASH

Just use RCU API properly to solve this race, and not worry about "perf
top" crashing hosts :(

get_task_pid() can benefit from same fix.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-24 12:03:55 -08:00
Paolo Bonzini
8bd142c016 KVM/ARM Fixes for v4.4-rc3.
Includes some timer fixes, properly unmapping PTEs, an errata fix, and two
 tweaks to the EL2 panic code.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJWVJ7gAAoJEEtpOizt6ddyD5MH/3M/nhtZTnT6v0RPDvHWJo7s
 5BQmITJYPHFkTO14OHWTVLXiGgLws8gPZnWHxC4jjHjpuJnL+/MM551FpCOqDDd7
 vweYgVlSqD8ANH5nKbv1PPnzjrqhTVN+yi3ZItXy2pxsfvu63FC6Z43B2axelLvw
 XYmHoMZaeWBBw2gHi3djGfju3Yj/2SOe+ozuvAXpxA5+NhSiPHHnMefGy5k3wKnJ
 sETwshPdjiMeK4ItfMhveFTDRjl4uh9uQyORfaa5gqG0uePt3EalYynw+gEjZ6RX
 Bpc3nLwboIfRIa/WwyoHm+nmLIUYjU8dAgLwUOIbdeG0igpdALdvsB0aBHCgngk=
 =+7ED
 -----END PGP SIGNATURE-----

Merge tag 'kvm-arm-for-v4.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master

KVM/ARM Fixes for v4.4-rc3.

Includes some timer fixes, properly unmapping PTEs, an errata fix, and two
tweaks to the EL2 panic code.
2015-11-24 19:34:40 +01:00
Linus Torvalds
4ce01c518e Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block layer fixes from Jens Axboe:
 "A round of fixes/updates for the current series.

  This looks a little bigger than it is, but that's mainly because we
  pushed the lightnvm enabled null_blk change out of the merge window so
  it could be updated a bit.  The rest of the volume is also mostly
  lightnvm.  In particular:

   - Lightnvm.  Various fixes, additions, updates from Matias and
     Javier, as well as from Wenwei Tao.

   - NVMe:
        - Fix for potential arithmetic overflow from Keith.
        - Also from Keith, ensure that we reap pending completions from
          a completion queue before deleting it.  Fixes kernel crashes
          when resetting a device with IO pending.
        - Various little lightnvm related tweaks from Matias.

   - Fixup flushes to go through the IO scheduler, for the cases where a
     flush is not required.  Fixes a case in CFQ where we would be
     idling and not see this request, hence not break the idling.  From
     Jan Kara.

   - Use list_{first,prev,next} in elevator.c for cleaner code.  From
     Gelian Tang.

   - Fix for a warning trigger on btrfs and raid on single queue blk-mq
     devices, where we would flush plug callbacks with preemption
     disabled.  From me.

   - A mac partition validation fix from Kees Cook.

   - Two merge fixes from Ming, marked stable.  A third part is adding a
     new warning so we'll notice this quicker in the future, if we screw
     up the accounting.

   - Cleanup of thread name/creation in mtip32xx from Rasmus Villemoes"

* 'for-linus' of git://git.kernel.dk/linux-block: (32 commits)
  blk-merge: warn if figured out segment number is bigger than nr_phys_segments
  blk-merge: fix blk_bio_segment_split
  block: fix segment split
  blk-mq: fix calling unplug callbacks with preempt disabled
  mac: validate mac_partition is within sector
  mtip32xx: use formatting capability of kthread_create_on_node
  NVMe: reap completion entries when deleting queue
  lightnvm: add free and bad lun info to show luns
  lightnvm: keep track of block counts
  nvme: lightnvm: use admin queues for admin cmds
  lightnvm: missing free on init error
  lightnvm: wrong return value and redundant free
  null_blk: do not del gendisk with lightnvm
  null_blk: use device addressing mode
  null_blk: use ppa_cache pool
  NVMe: Fix possible arithmetic overflow for max segments
  blk-flush: Queue through IO scheduler when flush not required
  null_blk: register as a LightNVM device
  elevator: use list_{first,prev,next}_entry
  lightnvm: cleanup queue before target removal
  ...
2015-11-24 10:26:30 -08:00
Mark Rutland
fbb4574ce9 arm64: kvm: report original PAR_EL1 upon panic
If we call __kvm_hyp_panic while a guest context is active, we call
__restore_sysregs before acquiring the system register values for the
panic, in the process throwing away the PAR_EL1 value at the point of
the panic.

This patch modifies __kvm_hyp_panic to stash the PAR_EL1 value prior to
restoring host register values, enabling us to report the original
values at the point of the panic.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-24 18:20:58 +01:00
Mark Rutland
1d7a4e313a arm64: kvm: avoid %p in __kvm_hyp_panic
Currently __kvm_hyp_panic uses %p for values which are not pointers,
such as the ESR value. This can confusingly lead to "(null)" being
printed for the value.

Use %x instead, and only use %p for host pointers.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-24 18:18:13 +01:00
Christoffer Dall
9f958c11b7 KVM: arm/arm64: vgic: Trust the LR state for HW IRQs
We were probing the physial distributor state for the active state of a
HW virtual IRQ, because we had seen evidence that the LR state was not
cleared when the guest deactivated a virtual interrupted.

However, this issue turned out to be a software bug in the GIC, which
was solved by: 84aab5e68c2a5e1e18d81ae8308c3ce25d501b29
(KVM: arm/arm64: arch_timer: Preserve physical dist. active
state on LR.active, 2015-11-24)

Therefore, get rid of the complexities and just look at the LR.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-24 18:08:37 +01:00
Christoffer Dall
0e3dfda91d KVM: arm/arm64: arch_timer: Preserve physical dist. active state on LR.active
We were incorrectly removing the active state from the physical
distributor on the timer interrupt when the timer output level was
deasserted.  We shouldn't be doing this without considering the virtual
interrupt's active state, because the architecture requires that when an
LR has the HW bit set and the pending or active bits set, then the
physical interrupt must also have the corresponding bits set.

This addresses an issue where we have been observing an inconsistency
between the LR state and the physical distributor state where the LR
state was active and the physical distributor was not active, which
shouldn't happen.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-24 18:07:40 +01:00
Christoffer Dall
7e16aa81f9 KVM: arm/arm64: Fix preemptible timer active state crazyness
We were setting the physical active state on the GIC distributor in a
preemptible section, which could cause us to set the active state on
different physical CPU from the one we were actually going to run on,
hacoc ensues.

Since we are no longer descheduling/scheduling soft timers in the
flush/sync timer functions, simply moving the timer flush into a
non-preemptible section.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-24 18:04:00 +01:00
Marc Zyngier
498cd5c32b arm64: KVM: Add workaround for Cortex-A57 erratum 834220
Cortex-A57 parts up to r1p2 can misreport Stage 2 translation faults
when a Stage 1 permission fault or device alignment fault should
have been reported.

This patch implements the workaround (which is to validate that the
Stage-1 translation actually succeeds) by using code patching.

Cc: stable@vger.kernel.org
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-24 17:58:14 +01:00
Marc Zyngier
c0f0963464 arm64: KVM: Fix AArch32 to AArch64 register mapping
When running a 32bit guest under a 64bit hypervisor, the ARMv8
architecture defines a mapping of the 32bit registers in the 64bit
space. This includes banked registers that are being demultiplexed
over the 64bit ones.

On exceptions caused by an operation involving a 32bit register, the
HW exposes the register number in the ESR_EL2 register. It was so
far understood that SW had to distinguish between AArch32 and AArch64
accesses (based on the current AArch32 mode and register number).

It turns out that I misinterpreted the ARM ARM, and the clue is in
D1.20.1: "For some exceptions, the exception syndrome given in the
ESR_ELx identifies one or more register numbers from the issued
instruction that generated the exception. Where the exception is
taken from an Exception level using AArch32 these register numbers
give the AArch64 view of the register."

Which means that the HW is already giving us the translated version,
and that we shouldn't try to interpret it at all (for example, doing
an MMIO operation from the IRQ mode using the LR register leads to
very unexpected behaviours).

The fix is thus not to perform a call to vcpu_reg32() at all from
vcpu_reg(), and use whatever register number is supplied directly.
The only case we need to find out about the mapping is when we
actively generate a register access, which only occurs when injecting
a fault in a guest.

Cc: stable@vger.kernel.org
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-24 17:58:08 +01:00
Ard Biesheuvel
e6fab54423 ARM/arm64: KVM: test properly for a PTE's uncachedness
The open coded tests for checking whether a PTE maps a page as
uncached use a flawed '(pte_val(xxx) & CONST) != CONST' pattern,
which is not guaranteed to work since the type of a mapping is
not a set of mutually exclusive bits

For HYP mappings, the type is an index into the MAIR table (i.e, the
index itself does not contain any information whatsoever about the
type of the mapping), and for stage-2 mappings it is a bit field where
normal memory and device types are defined as follows:

    #define MT_S2_NORMAL            0xf
    #define MT_S2_DEVICE_nGnRE      0x1

I.e., masking *and* comparing with the latter matches on the former,
and we have been getting lucky merely because the S2 device mappings
also have the PTE_UXN bit set, or we would misidentify memory mappings
as device mappings.

Since the unmap_range() code path (which contains one instance of the
flawed test) is used both for HYP mappings and stage-2 mappings, and
considering the difference between the two, it is non-trivial to fix
this by rewriting the tests in place, as it would involve passing
down the type of mapping through all the functions.

However, since HYP mappings and stage-2 mappings both deal with host
physical addresses, we can simply check whether the mapping is backed
by memory that is managed by the host kernel, and only perform the
D-cache maintenance if this is the case.

Cc: stable@vger.kernel.org
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Pavel Fedin <p.fedin@samsung.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-24 17:58:00 +01:00
Ming Lei
12e57f59ca blk-merge: warn if figured out segment number is bigger than nr_phys_segments
We had seen lots of reports of this kind issue, so add one
warnning in blk-merge, then it can be triggered easily and
avoid to depend on warning/bug from drivers.

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-23 20:16:55 -07:00
Ming Lei
02e707424c blk-merge: fix blk_bio_segment_split
Commit bdced438acd83a(block: setup bi_phys_segments after
splitting) introduces function of computing bio->bi_phys_segments
during bio splitting.

Unfortunately both bio->bi_seg_front_size and bio->bi_seg_back_size
arn't computed, so too many physical segments may be obtained
for one request since both the two are used to check if one segment
across two bios can be possible.

This patch fixes the issue by computing the two variables in
blk_bio_segment_split().

Fixes: bdced438acd83a(block: setup bi_phys_segments after splitting)
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Reported-by: Mark Salter <msalter@redhat.com>
Tested-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Tested-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-23 20:16:53 -07:00
Ming Lei
578270bfbd block: fix segment split
Inside blk_bio_segment_split(), previous bvec pointer(bvprvp)
always points to the iterator local variable, which is obviously
wrong, so fix it by pointing to the local variable of 'bvprv'.

Fixes: 5014c311baa2b(block: fix bogus compiler warnings in blk-merge.c)
Cc: stable@kernel.org #4.3
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Reported-by: Mark Salter <msalter@redhat.com>
Tested-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Tested-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-23 20:16:51 -07:00
Jan Kara
c2489e07c0 vfs: Avoid softlockups with sendfile(2)
The following test program from Dmitry can cause softlockups or RCU
stalls as it copies 1GB from tmpfs into eventfd and we don't have any
scheduling point at that path in sendfile(2) implementation:

        int r1 = eventfd(0, 0);
        int r2 = memfd_create("", 0);
        unsigned long n = 1<<30;
        fallocate(r2, 0, 0, n);
        sendfile(r1, r2, 0, n);

Add cond_resched() into __splice_from_pipe() to fix the problem.

CC: Dmitry Vyukov <dvyukov@google.com>
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-11-23 21:15:30 -05:00
Jan Kara
c725bfce79 vfs: Make sendfile(2) killable even better
Commit 296291cdd1 (mm: make sendfile(2) killable) fixed an issue where
sendfile(2) was doing a lot of tiny writes into a filesystem and thus
was unkillable for a long time. However sendfile(2) can be (mis)used to
issue lots of writes into arbitrary file descriptor such as evenfd or
similar special file descriptors which never hit the standard filesystem
write path and thus are still unkillable. E.g. the following example
from Dmitry burns CPU for ~16s on my test system without possibility to
be killed:

        int r1 = eventfd(0, 0);
        int r2 = memfd_create("", 0);
        unsigned long n = 1<<30;
        fallocate(r2, 0, 0, n);
        sendfile(r1, r2, 0, n);

There are actually quite a few tests for pending signals in sendfile
code however we data to write is always available none of them seems to
trigger. So fix the problem by adding a test for pending signal into
splice_from_pipe_next() also before the loop waiting for pipe buffers to
be available. This should fix all the lockup issues with sendfile of the
do-ton-of-tiny-writes nature.

CC: stable@vger.kernel.org
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-11-23 21:15:30 -05:00
Al Viro
0ebf7f10d6 fix sysvfs symlinks
The thing got broken back in 2002 - sysvfs does *not* have inline
symlinks; even short ones have bodies stored in the first block
of file.  sysv_symlink() handles that correctly; unfortunately,
attempting to look an existing symlink up will end up confusing
them for inline symlinks, and interpret the block number containing
the body as the body itself.

Nobody has noticed until now, which says something about the level
of testing sysvfs gets ;-/

Cc: stable@vger.kernel.org # all of them, not that anyone cared
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-11-23 21:11:08 -05:00
Linus Torvalds
a2931547ee linux-kselftest-4.4-rc3
This update consists of one minor documentation fix and a fix
 to an existing test.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJWU1euAAoJEAsCRMQNDUMcC78P/3mIOPtVMRMHR0YwGA/MCavO
 +JhVbEJCsrVtg5aPRod1Psz3QU3ubqr37yAeDe7vCniJK1zDx0QBGXATv91dVGLz
 Fqjm6DZ1zJXrsSgoFhWZXtjicEI2khdMlzDsRD0vXNSDJATpWHRVa9eLMeeZnIVA
 DXMH/RRlo7b4lK8/Kf2YV190mqemMsJRF2PfUAiZ1ZqBd8hCnqsk0hYdkJNaIDfJ
 PydtUCDLbXuvjg3AfGaBndifudzRFzb/lYyQ9K3KPHj2cE5TMHCPn2jTZwJ5V3cZ
 IX+LtYtxEZu+gCz/3l9kN9QDzy0EVeozvPGgg8gY/YLmKinQVENBuVXV4+vR696y
 h/LtJm7NdVyy4fopI6YBTEvaq7TKeNQWKjnQ7p5clqMCchY1/9aSgbAVIMgw5OFb
 DPNnclcfWmVEMpzbmeyMTmfAbcqmttmQXAaklXH6WrcQ/C9KEWfMzexvY4ho/eur
 daIl7A3MyB83Z5bjUsryhVeNunPecklshE1wMwrmutnDIH8Wj+eJM6yHBJf/cgbO
 AnhKRcsqzkti0QXdlzEMRWfDWAfkzCXSbdjcORnRFV4Dw2X7RgizFXtfI6xccVxS
 AO4dtkNKbXUOt184XZlwrES+IXhtnlqBTO1HX/clQ2F7FVeT6Sq1eYuAlVugDH8H
 65mZzXyxAAfcjctk4U/r
 =8sYr
 -----END PGP SIGNATURE-----

Merge tag 'linux-kselftest-4.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest fixes from Shuah Khan:
 "This update consists of one minor documentation fix and a fix to an
  existing test"

* tag 'linux-kselftest-4.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests/seccomp: Get page size from sysconf
  tools:testing/selftests: fix typo in futex/README
2015-11-23 13:19:27 -08:00
Mike Snitzer
0fcb04d593 dm thin: fix regression in advertised discard limits
When establishing a thin device's discard limits we cannot rely on the
underlying thin-pool device's discard capabilities (which are inherited
from the thin-pool's underlying data device) given that DM thin devices
must provide discard support even when the thin-pool's underlying data
device doesn't support discards.

Users were exposed to this thin device discard limits regression if
their thin-pool's underlying data device does _not_ support discards.
This regression caused all upper-layers that called the
blkdev_issue_discard() interface to not be able to issue discards to
thin devices (because discard_granularity was 0).  This regression
wasn't caught earlier because the device-mapper-test-suite's extensive
'thin-provisioning' discard tests are only ever performed against
thin-pool's with data devices that support discards.

Fix is to have thin_io_hints() test the pool's 'discard_enabled' feature
rather than inferring whether or not a thin device's discard support
should be enabled by looking at the thin-pool's discard_granularity.

Fixes: 216076705 ("dm thin: disable discard support for thin devices if pool's is disabled")
Reported-by: Mike Gerber <mike@sprachgewalt.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 4.1+
2015-11-23 14:54:46 -05:00
Linus Torvalds
1ec218373b Linux 4.4-rc2 2015-11-22 16:45:59 -08:00
Linus Torvalds
104e2a6f8b Merge branch 'akpm' (patches from Andrew)
Merge slub bulk allocator updates from Andrew Morton:
 "This missed the merge window because I was waiting for some repairs to
  come in.  Nothing actually uses the bulk allocator yet and the changes
  to other code paths are pretty small.  And the net guys are waiting
  for this so they can start merging the client code"

More comments from Jesper Dangaard Brouer:
 "The kmem_cache_alloc_bulk() call, in mm/slub.c, were included in
  previous kernel.  The present version contains a bug.  Vladimir
  Davydov noticed it contained a bug, when kernel is compiled with
  CONFIG_MEMCG_KMEM (see commit 03ec0ed57f: "slub: fix kmem cgroup
  bug in kmem_cache_alloc_bulk").  Plus the mem cgroup counterpart in
  kmem_cache_free_bulk() were missing (see commit 033745189b "slub:
  add missing kmem cgroup support to kmem_cache_free_bulk").

  I don't consider the fix stable-material because there are no in-tree
  users of the API.

  But with known bugs (for memcg) I cannot start using the API in the
  net-tree"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  slab/slub: adjust kmem_cache_alloc_bulk API
  slub: add missing kmem cgroup support to kmem_cache_free_bulk
  slub: fix kmem cgroup bug in kmem_cache_alloc_bulk
  slub: optimize bulk slowpath free by detached freelist
  slub: support for bulk free with SLUB freelists
2015-11-22 15:21:40 -08:00
Linus Torvalds
dcfeda9d5f TTY/Serial fixes for 4.4-rc2
Here are a few small tty/serial driver fixes for 4.4-rc2 that resolve
 some reported problems.
 
 All have been in linux-next, full details are in the shortlog below.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iEYEABECAAYFAlZSCjgACgkQMUfUDdst+yl4kQCgyYYsaVVUcG2i3HQUpio4CAJg
 EFQAn03Z0OD/EGNHKw7FtsICSgAhSatG
 =JRcn
 -----END PGP SIGNATURE-----

Merge tag 'tty-4.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial fixes from Greg KH:
 "Here are a few small tty/serial driver fixes for 4.4-rc2 that resolve
  some reported problems.

  All have been in linux-next, full details are in the shortlog below"

* tag 'tty-4.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: export fsl8250_handle_irq
  serial: 8250_mid: Add missing dependency
  tty: audit: Fix audit source
  serial: etraxfs-uart: Fix crash
  serial: fsl_lpuart: Fix earlycon support
  bcm63xx_uart: Use the device name when registering an interrupt
  tty: Fix direct use of tty buffer work
  tty: Fix tty_send_xchar() lock order inversion
2015-11-22 15:10:57 -08:00
Linus Torvalds
7f21739301 Staging/IIO fixes for 4.4-rc2
Here are some staging and iio driver fixes for 4.4-rc2.  All of these
 are in response to issues that have been reported and have been in
 linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iEYEABECAAYFAlZSCfgACgkQMUfUDdst+yn0cwCeI7I/i1MUaiequc4gSOoElqfa
 RCYAnj+PTk+BcbACs0mgZKbYuEEd1eVT
 =nUNA
 -----END PGP SIGNATURE-----

Merge tag 'staging-4.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging/IIO fixes from Greg KH:
 "Here are some staging and iio driver fixes for 4.4-rc2.  All of these
  are in response to issues that have been reported and have been in
  linux-next for a while"

* tag 'staging-4.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  Revert "Staging: wilc1000: coreconfigurator: Drop unneeded wrapper functions"
  iio: adc: xilinx: Fix VREFN scale
  iio: si7020: Swap data byte order
  iio: adc: vf610_adc: Fix division by zero error
  iio:ad7793: Fix ad7785 product ID
  iio: ad5064: Fix ad5629/ad5669 shift
  iio:ad5064: Make sure ad5064_i2c_write() returns 0 on success
  iio: lpc32xx_adc: fix warnings caused by enabling unprepared clock
  staging: iio: select IRQ_WORK for IIO_DUMMY_EVGEN
  vf610_adc: Fix internal temperature calculation
2015-11-22 13:26:24 -08:00
Linus Torvalds
6d2d91b3e4 USB fixes for 4.4-rc2
Here are a number of USB fixes and new device ids for 4.4-rc2.  All have
 been in linux-next and the details are in the shortlog.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iEYEABECAAYFAlZSDW4ACgkQMUfUDdst+ymrlwCgha5PobWYrhVnhC/w5ODZxRaF
 oAQAn2tOK94L9sADvjbQlFUy+/Zaxxbj
 =x9f4
 -----END PGP SIGNATURE-----

Merge tag 'usb-4.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

Pull USB fixes from Greg KH:
 "Here are a number of USB fixes and new device ids for 4.4-rc2.  All
  have been in linux-next and the details are in the shortlog"

* tag 'usb-4.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (28 commits)
  usblp: do not set TASK_INTERRUPTIBLE before lock
  USB: MAINTAINERS: cxacru
  usb: kconfig: fix warning of select USB_OTG
  USB: option: add XS Stick W100-2 from 4G Systems
  xhci: Fix a race in usb2 LPM resume, blocking U3 for usb2 devices
  usb: xhci: fix checking ep busy for CFC
  xhci: Workaround to get Intel xHCI reset working more reliably
  usb: chipidea: imx: fix a possible NULL dereference
  usb: chipidea: usbmisc_imx: fix a possible NULL dereference
  usb: chipidea: otg: gadget module load and unload support
  usb: chipidea: debug: disable usb irq while role switch
  ARM: dts: imx27.dtsi: change the clock information for usb
  usb: chipidea: imx: refine clock operations to adapt for all platforms
  usb: gadget: atmel_usba_udc: Expose correct device speed
  usb: musb: enable usb_dma parameter
  usb: phy: phy-mxs-usb: fix a possible NULL dereference
  usb: dwc3: gadget: let us set lower max_speed
  usb: musb: fix tx fifo flush handling
  usb: gadget: f_loopback: fix the warning during the enumeration
  usb: dwc2: host: Fix remote wakeup when not in DWC2_L2
  ...
2015-11-22 13:15:05 -08:00
Linus Torvalds
0ec7dc8d19 Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS fixes from Ralf Baechle:

 - Fix a flood of annoying build warnings

 - A number of fixes for Atheros 79xx platforms

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: ath79: Add a machine entry for booting OF machines
  MIPS: ath79: Fix the size of the MISC INTC registers in ar9132.dtsi
  MIPS: ath79: Fix the DDR control initialization on ar71xx and ar934x
  MIPS: Fix flood of warnings about comparsion being always true.
2015-11-22 12:59:46 -08:00
Linus Torvalds
94521b2fd2 Merge branch 'parisc-4.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull parisc update from Helge Deller:
 "This patchset adds Huge Page and HUGETLBFS support for parisc"

Honestly, the hugepage support should have gone through in the merge
window, and is not really an rc-time fix.  But it only touches
arch/parisc, and I cannot find it in myself to care.  If one of the
three parisc users notices a breakage, I will point at Helge and make
rude farting noises.

* 'parisc-4.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Map kernel text and data on huge pages
  parisc: Add Huge Page and HUGETLBFS support
  parisc: Use long branch to do_syscall_trace_exit
  parisc: Increase initial kernel mapping to 32MB on 64bit kernel
  parisc: Initialize the fault vector earlier in the boot process.
  parisc: Add defines for Huge page support
  parisc: Drop unused MADV_xxxK_PAGES flags from asm/mman.h
  parisc: Drop definition of start_thread_som for HP-UX SOM binaries
  parisc: Fix wrong comment regarding first pmd entry flags
2015-11-22 12:50:58 -08:00
Linus Torvalds
727cde6c3a Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf tool fixes from Thomas Gleixner:
 "A couple of fixes for perf tools:

   - Build system updates

   - Plug a memory leak in an error path of perf probe

   - Tear down probes correctly when adding fails

   - Fixes to the perf symbol handling

   - Fix ordering of event processing in buildid-list

   - Fix per DSO filtering in the histogram browser"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf probe: Clear probe_trace_event when add_probe_trace_event() fails
  perf probe: Fix memory leaking on failure by clearing all probe_trace_events
  perf inject: Also re-pipe lost_samples event
  perf buildid-list: Requires ordered events
  perf symbols: Fix dso lookup by long name and missing buildids
  perf symbols: Allow forcing reading of non-root owned files by root
  perf hists browser: The dso can be obtained from popup_action->ms.map->dso
  perf hists browser: Fix 'd' hotkey action to filter by DSO
  perf symbols: Rebuild rbtree when adjusting symbols for kcore
  tools: Add a "make all" rule
  tools: Actually install tmon in the install rule
2015-11-22 12:37:20 -08:00
Linus Torvalds
069ec22915 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
 "This update contains:

   - MPX updates for handling 32bit processes

   - A fix for a long standing bug in 32bit signal frame handling
     related to FPU/XSAVE state

   - Handle get_xsave_addr() correctly in KVM

   - Fix SMAP check under paravirtualization

   - Add a comment to the static function trace entry to avoid further
     confusion about the difference to dynamic tracing"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Fix SMAP check in PVOPS environments
  x86/ftrace: Add comment on static function tracing
  x86/fpu: Fix get_xsave_addr() behavior under virtualization
  x86/fpu: Fix 32-bit signal frame handling
  x86/mpx: Fix 32-bit address space calculation
  x86/mpx: Do proper get_user() when running 32-bit binaries on 64-bit kernels
2015-11-22 12:00:12 -08:00
Jesper Dangaard Brouer
865762a811 slab/slub: adjust kmem_cache_alloc_bulk API
Adjust kmem_cache_alloc_bulk API before we have any real users.

Adjust API to return type 'int' instead of previously type 'bool'.  This
is done to allow future extension of the bulk alloc API.

A future extension could be to allow SLUB to stop at a page boundary, when
specified by a flag, and then return the number of objects.

The advantage of this approach, would make it easier to make bulk alloc
run without local IRQs disabled.  With an approach of cmpxchg "stealing"
the entire c->freelist or page->freelist.  To avoid overshooting we would
stop processing at a slab-page boundary.  Else we always end up returning
some objects at the cost of another cmpxchg.

To keep compatible with future users of this API linking against an older
kernel when using the new flag, we need to return the number of allocated
objects with this API change.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-22 11:58:44 -08:00
Jesper Dangaard Brouer
033745189b slub: add missing kmem cgroup support to kmem_cache_free_bulk
Initial implementation missed support for kmem cgroup support in
kmem_cache_free_bulk() call, add this.

If CONFIG_MEMCG_KMEM is not enabled, the compiler should be smart enough
to not add any asm code.

Incoming bulk free objects can belong to different kmem cgroups, and
object free call can happen at a later point outside memcg context.  Thus,
we need to keep the orig kmem_cache, to correctly verify if a memcg object
match against its "root_cache" (s->memcg_params.root_cache).

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-22 11:58:44 -08:00
Jesper Dangaard Brouer
03ec0ed57f slub: fix kmem cgroup bug in kmem_cache_alloc_bulk
The call slab_pre_alloc_hook() interacts with kmemgc and is not allowed to
be called several times inside the bulk alloc for loop, due to the call to
memcg_kmem_get_cache().

This would result in hitting the VM_BUG_ON in __memcg_kmem_get_cache.

As suggested by Vladimir Davydov, change slab_post_alloc_hook() to be able
to handle an array of objects.

A subtle detail is, loop iterator "i" in slab_post_alloc_hook() must have
same type (size_t) as size argument.  This helps the compiler to easier
realize that it can remove the loop, when all debug statements inside loop
evaluates to nothing.  Note, this is only an issue because the kernel is
compiled with GCC option: -fno-strict-overflow

In slab_alloc_node() the compiler inlines and optimizes the invocation of
slab_post_alloc_hook(s, flags, 1, &object) by removing the loop and access
object directly.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Reported-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Suggested-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-22 11:58:44 -08:00
Jesper Dangaard Brouer
d0ecd894e3 slub: optimize bulk slowpath free by detached freelist
This change focus on improving the speed of object freeing in the
"slowpath" of kmem_cache_free_bulk.

The calls slab_free (fastpath) and __slab_free (slowpath) have been
extended with support for bulk free, which amortize the overhead of
the (locked) cmpxchg_double.

To use the new bulking feature, we build what I call a detached
freelist.  The detached freelist takes advantage of three properties:

 1) the free function call owns the object that is about to be freed,
    thus writing into this memory is synchronization-free.

 2) many freelist's can co-exist side-by-side in the same slab-page
    each with a separate head pointer.

 3) it is the visibility of the head pointer that needs synchronization.

Given these properties, the brilliant part is that the detached
freelist can be constructed without any need for synchronization.  The
freelist is constructed directly in the page objects, without any
synchronization needed.  The detached freelist is allocated on the
stack of the function call kmem_cache_free_bulk.  Thus, the freelist
head pointer is not visible to other CPUs.

All objects in a SLUB freelist must belong to the same slab-page.
Thus, constructing the detached freelist is about matching objects
that belong to the same slab-page.  The bulk free array is scanned is
a progressive manor with a limited look-ahead facility.

Kmem debug support is handled in call of slab_free().

Notice kmem_cache_free_bulk no longer need to disable IRQs. This
only slowed down single free bulk with approx 3 cycles.

Performance data:
 Benchmarked[1] obj size 256 bytes on CPU i7-4790K @ 4.00GHz

SLUB fastpath single object quick reuse: 47 cycles(tsc) 11.931 ns

To get stable and comparable numbers, the kernel have been booted with
"slab_merge" (this also improve performance for larger bulk sizes).

Performance data, compared against fallback bulking:

bulk -  fallback bulk            - improvement with this patch
   1 -  62 cycles(tsc) 15.662 ns - 49 cycles(tsc) 12.407 ns- improved 21.0%
   2 -  55 cycles(tsc) 13.935 ns - 30 cycles(tsc) 7.506 ns - improved 45.5%
   3 -  53 cycles(tsc) 13.341 ns - 23 cycles(tsc) 5.865 ns - improved 56.6%
   4 -  52 cycles(tsc) 13.081 ns - 20 cycles(tsc) 5.048 ns - improved 61.5%
   8 -  50 cycles(tsc) 12.627 ns - 18 cycles(tsc) 4.659 ns - improved 64.0%
  16 -  49 cycles(tsc) 12.412 ns - 17 cycles(tsc) 4.495 ns - improved 65.3%
  30 -  49 cycles(tsc) 12.484 ns - 18 cycles(tsc) 4.533 ns - improved 63.3%
  32 -  50 cycles(tsc) 12.627 ns - 18 cycles(tsc) 4.707 ns - improved 64.0%
  34 -  96 cycles(tsc) 24.243 ns - 23 cycles(tsc) 5.976 ns - improved 76.0%
  48 -  83 cycles(tsc) 20.818 ns - 21 cycles(tsc) 5.329 ns - improved 74.7%
  64 -  74 cycles(tsc) 18.700 ns - 20 cycles(tsc) 5.127 ns - improved 73.0%
 128 -  90 cycles(tsc) 22.734 ns - 27 cycles(tsc) 6.833 ns - improved 70.0%
 158 -  99 cycles(tsc) 24.776 ns - 30 cycles(tsc) 7.583 ns - improved 69.7%
 250 - 104 cycles(tsc) 26.089 ns - 37 cycles(tsc) 9.280 ns - improved 64.4%

Performance data, compared current in-kernel bulking:

bulk - curr in-kernel  - improvement with this patch
   1 -  46 cycles(tsc) - 49 cycles(tsc) - improved (cycles:-3) -6.5%
   2 -  27 cycles(tsc) - 30 cycles(tsc) - improved (cycles:-3) -11.1%
   3 -  21 cycles(tsc) - 23 cycles(tsc) - improved (cycles:-2) -9.5%
   4 -  18 cycles(tsc) - 20 cycles(tsc) - improved (cycles:-2) -11.1%
   8 -  17 cycles(tsc) - 18 cycles(tsc) - improved (cycles:-1) -5.9%
  16 -  18 cycles(tsc) - 17 cycles(tsc) - improved (cycles: 1)  5.6%
  30 -  18 cycles(tsc) - 18 cycles(tsc) - improved (cycles: 0)  0.0%
  32 -  18 cycles(tsc) - 18 cycles(tsc) - improved (cycles: 0)  0.0%
  34 -  78 cycles(tsc) - 23 cycles(tsc) - improved (cycles:55) 70.5%
  48 -  60 cycles(tsc) - 21 cycles(tsc) - improved (cycles:39) 65.0%
  64 -  49 cycles(tsc) - 20 cycles(tsc) - improved (cycles:29) 59.2%
 128 -  69 cycles(tsc) - 27 cycles(tsc) - improved (cycles:42) 60.9%
 158 -  79 cycles(tsc) - 30 cycles(tsc) - improved (cycles:49) 62.0%
 250 -  86 cycles(tsc) - 37 cycles(tsc) - improved (cycles:49) 57.0%

Performance with normal SLUB merging is significantly slower for
larger bulking.  This is believed to (primarily) be an effect of not
having to share the per-CPU data-structures, as tuning per-CPU size
can achieve similar performance.

bulk - slab_nomerge   -  normal SLUB merge
   1 -  49 cycles(tsc) - 49 cycles(tsc) - merge slower with cycles:0
   2 -  30 cycles(tsc) - 30 cycles(tsc) - merge slower with cycles:0
   3 -  23 cycles(tsc) - 23 cycles(tsc) - merge slower with cycles:0
   4 -  20 cycles(tsc) - 20 cycles(tsc) - merge slower with cycles:0
   8 -  18 cycles(tsc) - 18 cycles(tsc) - merge slower with cycles:0
  16 -  17 cycles(tsc) - 17 cycles(tsc) - merge slower with cycles:0
  30 -  18 cycles(tsc) - 23 cycles(tsc) - merge slower with cycles:5
  32 -  18 cycles(tsc) - 22 cycles(tsc) - merge slower with cycles:4
  34 -  23 cycles(tsc) - 22 cycles(tsc) - merge slower with cycles:-1
  48 -  21 cycles(tsc) - 22 cycles(tsc) - merge slower with cycles:1
  64 -  20 cycles(tsc) - 48 cycles(tsc) - merge slower with cycles:28
 128 -  27 cycles(tsc) - 57 cycles(tsc) - merge slower with cycles:30
 158 -  30 cycles(tsc) - 59 cycles(tsc) - merge slower with cycles:29
 250 -  37 cycles(tsc) - 56 cycles(tsc) - merge slower with cycles:19

Joint work with Alexander Duyck.

[1] https://github.com/netoptimizer/prototype-kernel/blob/master/kernel/mm/slab_bulk_test01.c

[akpm@linux-foundation.org: BUG_ON -> WARN_ON;return]
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-22 11:58:43 -08:00
Jesper Dangaard Brouer
81084651d7 slub: support for bulk free with SLUB freelists
Make it possible to free a freelist with several objects by adjusting API
of slab_free() and __slab_free() to have head, tail and an objects counter
(cnt).

Tail being NULL indicate single object free of head object.  This allow
compiler inline constant propagation in slab_free() and
slab_free_freelist_hook() to avoid adding any overhead in case of single
object free.

This allows a freelist with several objects (all within the same
slab-page) to be free'ed using a single locked cmpxchg_double in
__slab_free() and with an unlocked cmpxchg_double in slab_free().

Object debugging on the free path is also extended to handle these
freelists.  When CONFIG_SLUB_DEBUG is enabled it will also detect if
objects don't belong to the same slab-page.

These changes are needed for the next patch to bulk free the detached
freelists it introduces and constructs.

Micro benchmarking showed no performance reduction due to this change,
when debugging is turned off (compiled with CONFIG_SLUB_DEBUG).

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-22 11:58:41 -08:00
Helge Deller
41b85a1163 parisc: Map kernel text and data on huge pages
Adjust the linker script and map_pages() to map kernel text and data on
physical 1MB huge/large pages.

Signed-off-by: Helge Deller <deller@gmx.de>
2015-11-22 12:23:19 +01:00
Helge Deller
736d216933 parisc: Add Huge Page and HUGETLBFS support
This patch adds huge page support to allow userspace to allocate huge
pages and to use hugetlbfs filesystem on 32- and 64-bit Linux kernels.
A later patch will add kernel support to map kernel text and data on
huge pages.

The only requirement is, that the kernel needs to be compiled for a
PA8X00 CPU (PA2.0 architecture). Older PA1.X CPUs do not support
variable page sizes. 64bit Kernels are compiled for PA2.0 by default.

Technically on parisc multiple physical huge pages may be needed to
emulate standard 2MB huge pages.

Signed-off-by: Helge Deller <deller@gmx.de>
2015-11-22 12:23:10 +01:00
Helge Deller
337685e556 parisc: Use long branch to do_syscall_trace_exit
Use the 22bit instead of the 17bit branch instruction on a 64bit kernel
to reach the do_syscall_trace_exit function from the gateway page.
A huge page enabled kernel may need the additional branch distance bits.

Signed-off-by: Helge Deller <deller@gmx.de>
2015-11-22 12:23:02 +01:00
Helge Deller
332b42e4eb parisc: Increase initial kernel mapping to 32MB on 64bit kernel
For the 64bit kernel the initially 16 MB kernel memory might become too
small if you build a kernel with many modules built-in and with kernel
text and data areas mapped on huge pages.

This patch increases the initial mapping to 32MB for 64bit kernels and
keeps 16MB for 32bit kernels.

Signed-off-by: Helge Deller <deller@gmx.de>
2015-11-22 12:22:53 +01:00
Helge Deller
4182d0cdf8 parisc: Initialize the fault vector earlier in the boot process.
A fault vector on parisc needs to be 2K aligned.  Furthermore the
checksum of the fault vector needs to sum up to 0 which is being
calculated and written at runtime.

Up to now we aligned both PA20 and PA11 fault vectors on the same 4K
page in order to easily write the checksum after having mapped the
kernel read-only (by mapping this page only as read-write).
But when we want to map the kernel text and data on huge pages this
makes things harder.
So, simplify it by aligning both fault vectors on 2K boundries and write
the checksum before we map the page read-only.

Signed-off-by: Helge Deller <deller@gmx.de>
2015-11-22 12:22:43 +01:00