Commit Graph

30924 Commits

Author SHA1 Message Date
Christoph Hellwig 90ae409f9e dma-direct: fix zone selection after an unaddressable CMA allocation
The new dma_alloc_contiguous hides if we allocate CMA or regular
pages, and thus fails to retry a ZONE_NORMAL allocation if the CMA
allocation succeeds but isn't addressable.  That means we either fail
outright or dip into a small zone that might not succeed either.

Thanks to Hillf Danton for debugging this issue.

Fixes: b1d2dc009d ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers")
Reported-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
2019-08-21 07:14:10 +09:00
Linus Torvalds 5bba5c9c86 SPDX fixes for 5.3-rc5
Here are 4 small SPDX fixes for 5.3-rc5.  A few style fixes for some
 SPDX comments, added an SPDX tag for one file, and fix up some GPL
 boilerplate for another file.
 
 All of these have been in linux-next for a few weeks with no reported
 issues (they are comment changes only, so that's to be expected...)
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'spdx-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx

Pull SPDX fixes from Greg KH:
 "Here are four small SPDX fixes for 5.3-rc5.

  A few style fixes for some SPDX comments, added an SPDX tag for one
  file, and fix up some GPL boilerplate for another file.

  All of these have been in linux-next for a few weeks with no reported
  issues (they are comment changes only, so that's to be expected...)"

* tag 'spdx-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx:
  i2c: stm32: Use the correct style for SPDX License Identifier
  intel_th: Use the correct style for SPDX License Identifier
  coccinelle: api/atomic_as_refcounter: add SPDX License Identifier
  kernel/configs: Replace GPL boilerplate code with SPDX identifier
2019-08-18 09:26:16 -07:00
Linus Torvalds 2d63ba3e41 Power management fixes for 5.3-rc5
- Disable NVMe power optimization related to suspend-to-idle added
    recently on systems where PCIe ASPM is not able to put PCIe links
    into low-power states to prevent excess power from being drawn by
    the system while suspended (Rafael Wysocki).
 
  - Make the schedutil governor handle frequency limits changes
    properly in all cases (Viresh Kumar).
 
  - Prevent the cpufreq core from treating positive values returned
    by dev_pm_qos_update_request() as errors (Viresh Kumar).
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Merge tag 'pm-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "These add a check to avoid recent suspend-to-idle power regression on
  systems with NVMe drives where the PCIe ASPM policy is "performance"
  (or when the kernel is built without ASPM support), fix an issue
  related to frequency limits in the schedutil cpufreq governor and fix
  a mistake related to the PM QoS usage in the cpufreq core introduced
  recently.

  Specifics:

   - Disable NVMe power optimization related to suspend-to-idle added
     recently on systems where PCIe ASPM is not able to put PCIe links
     into low-power states to prevent excess power from being drawn by
     the system while suspended (Rafael Wysocki).

   - Make the schedutil governor handle frequency limits changes
     properly in all cases (Viresh Kumar).

   - Prevent the cpufreq core from treating positive values returned by
     dev_pm_qos_update_request() as errors (Viresh Kumar)"

* tag 'pm-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  nvme-pci: Allow PCI bus-level PM to be used if ASPM is disabled
  PCI/ASPM: Add pcie_aspm_enabled()
  cpufreq: schedutil: Don't skip freq update when limits change
  cpufreq: dev_pm_qos_update_request() can return 1 on success
2019-08-16 09:13:16 -07:00
Rafael J. Wysocki a3ee2477c4 Merge branch 'pm-cpufreq'
* pm-cpufreq:
  cpufreq: schedutil: Don't skip freq update when limits change
  cpufreq: dev_pm_qos_update_request() can return 1 on success
2019-08-16 14:24:51 +02:00
Linus Torvalds e83b009c5c dma-mapping fixes for 5.3-rc
- fix the handling of the bus_dma_mask in dma_get_required_mask, which
    caused a regression in this merge window (Lucas Stach)
  - fix a regression in the handling of DMA_ATTR_NO_KERNEL_MAPPING (me)
  - fix dma_mmap_coherent to not cause page attribute mismatches on
    coherent architectures like x86 (me)
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Merge tag 'dma-mapping-5.3-4' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:

 - fix the handling of the bus_dma_mask in dma_get_required_mask, which
   caused a regression in this merge window (Lucas Stach)

 - fix a regression in the handling of DMA_ATTR_NO_KERNEL_MAPPING (me)

 - fix dma_mmap_coherent to not cause page attribute mismatches on
   coherent architectures like x86 (me)

* tag 'dma-mapping-5.3-4' of git://git.infradead.org/users/hch/dma-mapping:
  dma-mapping: fix page attributes for dma_mmap_*
  dma-direct: don't truncate dma_required_mask to bus addressing capabilities
  dma-direct: fix DMA_ATTR_NO_KERNEL_MAPPING
2019-08-14 10:31:11 -07:00
Linus Torvalds dcbb4a1539 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Thomas Gleixner:
 "Three fixlets for the scheduler:

   - Avoid double bandwidth accounting in the push & pull code

   - Use a sane FIFO priority for the Pressure Stall Information (PSI)
     thread.

   - Avoid permission checks when setting the scheduler params for the
     PSI thread"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/psi: Do not require setsched permission from the trigger creator
  sched/psi: Reduce psimon FIFO priority
  sched/deadline: Fix double accounting of rq/running bw in push & pull
2019-08-10 15:48:02 -07:00
Christoph Hellwig 33dcb37cef dma-mapping: fix page attributes for dma_mmap_*
All the way back to introducing dma_common_mmap we've defaulted to mark
the pages as uncached.  But this is wrong for DMA coherent devices.
Later on DMA_ATTR_WRITE_COMBINE also got incorrect treatment as that
flag is only treated special on the alloc side for non-coherent devices.

Introduce a new dma_pgprot helper that deals with the check for coherent
devices so that only the remapping cases ever reach arch_dma_mmap_pgprot
and we thus ensure no aliasing of page attributes happens, which makes
the powerpc version of arch_dma_mmap_pgprot obsolete and simplifies the
remaining ones.

Note that this means arch_dma_mmap_pgprot is a bit misnamed now, but
we'll phase it out soon.

Fixes: 64ccc9c033 ("common: dma-mapping: add support for generic dma_mmap_* calls")
Reported-by: Shawn Anastasio <shawn@anastas.io>
Reported-by: Gavin Li <git@thegavinli.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com> # arm64
2019-08-10 19:52:45 +02:00
Lucas Stach d8ad55538a dma-direct: don't truncate dma_required_mask to bus addressing capabilities
The dma required_mask needs to reflect the actual addressing capabilities
needed to handle the whole system RAM. When truncated down to the bus
addressing capabilities dma_addressing_limited() will incorrectly signal
no limitations for devices which are restricted by the bus_dma_mask.

Fixes: b4ebe60632 (dma-direct: implement complete bus_dma_mask handling)
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-08-10 19:52:45 +02:00
Christoph Hellwig cf14be0b41 dma-direct: fix DMA_ATTR_NO_KERNEL_MAPPING
The new DMA_ATTR_NO_KERNEL_MAPPING needs to actually assign
a dma_addr to work.  Also skip it if the architecture needs
forced decryption handling, as that needs a kernel virtual
address.

Fixes: d98849aff8 (dma-direct: handle DMA_ATTR_NO_KERNEL_MAPPING in common code)
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
2019-08-10 19:52:45 +02:00
Viresh Kumar 600f5badb7 cpufreq: schedutil: Don't skip freq update when limits change
To avoid reducing the frequency of a CPU prematurely, we skip reducing
the frequency if the CPU had been busy recently.

This should not be done when the limits of the policy are changed, for
example due to thermal throttling. We should always get the frequency
within the new limits as soon as possible.

Trying to fix this by using only one flag, i.e. need_freq_update, can
lead to a race condition where the flag gets cleared without forcing us
to change the frequency at least once. And so this patch introduces
another flag to avoid that race condition.

Fixes: ecd2884291 ("cpufreq: schedutil: Don't set next_freq to UINT_MAX")
Cc: v4.18+ <stable@vger.kernel.org> # v4.18+
Reported-by: Doug Smythies <dsmythies@telus.net>
Tested-by: Doug Smythies <dsmythies@telus.net>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-08-10 13:53:19 +02:00
Ming Lei 491beed3b1 genirq/affinity: Create affinity mask for single vector
Since commit c66d4bd110 ("genirq/affinity: Add new callback for
(re)calculating interrupt sets"), irq_create_affinity_masks() returns
NULL in case of single vector. This change has caused regression on some
drivers, such as lpfc.

The problem is that single vector requests can happen in some generic cases:

  1) kdump kernel

  2) irq vectors resource is close to exhaustion.

If in that situation the affinity mask for a single vector is not created,
every caller has to handle the special case.

There is no reason why the mask cannot be created, so remove the check for
a single vector and create the mask.

Fixes: c66d4bd110 ("genirq/affinity: Add new callback for (re)calculating interrupt sets")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190805011906.5020-1-ming.lei@redhat.com
2019-08-08 08:47:55 +02:00
Linus Torvalds 33920f1ec5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:
 "Yeah I should have sent a pull request last week, so there is a lot
  more here than usual:

   1) Fix memory leak in ebtables compat code, from Wenwen Wang.

   2) Several kTLS bug fixes from Jakub Kicinski (circular close on
      disconnect etc.)

   3) Force slave speed check on link state recovery in bonding 802.3ad
      mode, from Thomas Falcon.

   4) Clear RX descriptor bits before assigning buffers to them in
      stmmac, from Jose Abreu.

   5) Several missing of_node_put() calls, mostly wrt. for_each_*() OF
      loops, from Nishka Dasgupta.

   6) Double kfree_skb() in peak_usb can driver, from Stephane Grosjean.

   7) Need to hold sock across skb->destructor invocation, from Cong
      Wang.

   8) IP header length needs to be validated in ipip tunnel xmit, from
      Haishuang Yan.

   9) Use after free in ip6 tunnel driver, also from Haishuang Yan.

  10) Do not use MSI interrupts on r8169 chips before RTL8168d, from
      Heiner Kallweit.

  11) Upon bridge device init failure, we need to delete the local fdb.
      From Nikolay Aleksandrov.

  12) Handle erros from of_get_mac_address() properly in stmmac, from
      Martin Blumenstingl.

  13) Handle concurrent rename vs. dump in netfilter ipset, from Jozsef
      Kadlecsik.

  14) Setting NETIF_F_LLTX on mac80211 causes complete breakage with
      some devices, so revert. From Johannes Berg.

  15) Fix deadlock in rxrpc, from David Howells.

  16) Fix Kconfig deps of enetc driver, we must have PHYLIB. From Yue
      Haibing.

  17) Fix mvpp2 crash on module removal, from Matteo Croce.

  18) Fix race in genphy_update_link, from Heiner Kallweit.

  19) bpf_xdp_adjust_head() stopped working with generic XDP when we
      fixes generic XDP to support stacked devices properly, fix from
      Jesper Dangaard Brouer.

  20) Unbalanced RCU locking in rt6_update_exception_stamp_rt(), from
      David Ahern.

  21) Several memory leaks in new sja1105 driver, from Vladimir Oltean"

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (214 commits)
  net: dsa: sja1105: Fix memory leak on meta state machine error path
  net: dsa: sja1105: Fix memory leak on meta state machine normal path
  net: dsa: sja1105: Really fix panic on unregistering PTP clock
  net: dsa: sja1105: Use the LOCKEDS bit for SJA1105 E/T as well
  net: dsa: sja1105: Fix broken learning with vlan_filtering disabled
  net: dsa: qca8k: Add of_node_put() in qca8k_setup_mdio_bus()
  net: sched: sample: allow accessing psample_group with rtnl
  net: sched: police: allow accessing police->params with rtnl
  net: hisilicon: Fix dma_map_single failed on arm64
  net: hisilicon: fix hip04-xmit never return TX_BUSY
  net: hisilicon: make hip04_tx_reclaim non-reentrant
  tc-testing: updated vlan action tests with batch create/delete
  net sched: update vlan action for batched events operations
  net: stmmac: tc: Do not return a fragment entry
  net: stmmac: Fix issues when number of Queues >= 4
  net: stmmac: xgmac: Fix XGMAC selftests
  be2net: disable bh with spin_lock in be_process_mcc
  net: cxgb3_main: Fix a resource leak in a error path in 'init_one()'
  net: ethernet: sun4i-emac: Support phy-handle property for finding PHYs
  net: bridge: move default pvid init/deinit to NETDEV_REGISTER/UNREGISTER
  ...
2019-08-06 17:11:59 -07:00
Suren Baghdasaryan 04e048cf09 sched/psi: Do not require setsched permission from the trigger creator
When a process creates a new trigger by writing into /proc/pressure/*
files, permissions to write such a file should be used to determine whether
the process is allowed to do so or not. Current implementation would also
require such a process to have setsched capability. Setting of psi trigger
thread's scheduling policy is an implementation detail and should not be
exposed to the user level. Remove the permission check by using _nocheck
version of the function.

Suggested-by: Nick Kralevich <nnk@google.com>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: lizefan@huawei.com
Cc: mingo@redhat.com
Cc: akpm@linux-foundation.org
Cc: kernel-team@android.com
Cc: dennisszhou@gmail.com
Cc: dennis@kernel.org
Cc: hannes@cmpxchg.org
Cc: axboe@kernel.dk
Link: https://lkml.kernel.org/r/20190730013310.162367-1-surenb@google.com
2019-08-06 12:49:18 +02:00
Peter Zijlstra 14f5c7b46a sched/psi: Reduce psimon FIFO priority
PSI defaults to a FIFO-99 thread, reduce this to FIFO-1.

FIFO-99 is the very highest priority available to SCHED_FIFO and
it not a suitable default; it would indicate the psi work is the
most important work on the machine.

Since Real-Time tasks will have pre-allocated memory and locked it in
place, Real-Time tasks do not care about PSI. All it needs is to be
above OTHER.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Tested-by: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
2019-08-06 12:49:18 +02:00
Dietmar Eggemann f4904815f9 sched/deadline: Fix double accounting of rq/running bw in push & pull
{push,pull}_dl_task() always calls {de,}activate_task() with .flags=0
which sets p->on_rq=TASK_ON_RQ_MIGRATING.

{push,pull}_dl_task()->{de,}activate_task()->{de,en}queue_task()->
{de,en}queue_task_dl() calls {sub,add}_{running,rq}_bw() since
p->on_rq==TASK_ON_RQ_MIGRATING.
So {sub,add}_{running,rq}_bw() in {push,pull}_dl_task() is
double-accounting for that task.

Fix it by removing rq/running bw accounting in [push/pull]_dl_task().

Fixes: 7dd7788411 ("sched/core: Unify p->on_rq updates")
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Luca Abeni <luca.abeni@santannapisa.it>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Qais Yousef <qais.yousef@arm.com>
Link: https://lkml.kernel.org/r/20190802145945.18702-2-dietmar.eggemann@arm.com
2019-08-06 12:49:18 +02:00
Christoph Hellwig 14c5cebad5 memremap: move from kernel/ to mm/
memremap.c implements MM functionality for ZONE_DEVICE, so it really
should be in the mm/ directory, not the kernel/ one.

Link: http://lkml.kernel.org/r/20190722094143.18387-1-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-08-03 07:02:01 -07:00
Mauro Carvalho Chehab 68d8681e97 kernel/signal.c: fix a kernel-doc markup
The kernel-doc parser doesn't handle expressions with %foo*.  Instead,
when an asterisk should be part of a constant, it uses an alternative
notation: `foo*`.

Link: http://lkml.kernel.org/r/7f18c2e0b5e39e6b7eb55ddeb043b8b260b49f2d.1563361575.git.mchehab+samsung@kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-08-03 07:02:00 -07:00
Linus Torvalds 234172f6bb add swiotlb support to arm
This fixes a cascade of regressions that originally started with
 the addition of the ia64 port, but only got fatal once we removed
 most uses of block layer bounce buffering in Linux 4.18.
 
 The reason is that while the original i386/PAE code that was the first
 architecture that supported > 4GB of memory without an iommu decided to
 leave bounce buffering to the subsystems, which in those days just mean
 block and networking as no one else consumer arbitrary userspace memory.
 
 Later with ia64, x86_64 and other ports we assumed that either an iommu
 or something that fakes it up ("software IOTLB" in beautiful Intel
 speak) is present and that subsystems can rely on that for dealing with
 addressing limitations in devices.   Except that the ARM LPAE scheme
 that added larger physical address to 32-bit ARM did not follow that
 scheme and thus only worked by chance and only for block and networking
 I/O directly to highmem.
 
 Long story, short fix - add swiotlb support to arm when build for LPAE
 platforms, which actuallys turns out to be pretty trivial with the
 modern dma-direct / swiotlb code to fix the Linux 4.18-ish regression.
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Merge tag 'arm-swiotlb-5.3' of git://git.infradead.org/users/hch/dma-mapping

Pull arm swiotlb support from Christoph Hellwig:
 "This fixes a cascade of regressions that originally started with the
  addition of the ia64 port, but only got fatal once we removed most
  uses of block layer bounce buffering in Linux 4.18.

  The reason is that while the original i386/PAE code that was the first
  architecture that supported > 4GB of memory without an iommu decided
  to leave bounce buffering to the subsystems, which in those days just
  mean block and networking as no one else consumed arbitrary userspace
  memory.

  Later with ia64, x86_64 and other ports we assumed that either an
  iommu or something that fakes it up ("software IOTLB" in beautiful
  Intel speak) is present and that subsystems can rely on that for
  dealing with addressing limitations in devices. Except that the ARM
  LPAE scheme that added larger physical address to 32-bit ARM did not
  follow that scheme and thus only worked by chance and only for block
  and networking I/O directly to highmem.

  Long story, short fix - add swiotlb support to arm when build for LPAE
  platforms, which actuallys turns out to be pretty trivial with the
  modern dma-direct / swiotlb code to fix the Linux 4.18-ish regression"

* tag 'arm-swiotlb-5.3' of git://git.infradead.org/users/hch/dma-mapping:
  arm: use swiotlb for bounce buffering on LPAE configs
  dma-mapping: check pfn validity in dma_common_{mmap,get_sgtable}
2019-08-02 08:44:33 -07:00
Linus Torvalds 35fca9f8a9 dma-mapping regression fixes for 5.3
- fix alignment issues introduced in the CMA allocation rework
    (Nicolin Chen)
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Merge tag 'dma-mapping-5.3-3' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping regression fixes from Christoph Hellwig:
 "Two related regression fixes for changes from this merge window to fix
  alignment issues introduced in the CMA allocation rework (Nicolin
  Chen)"

* tag 'dma-mapping-5.3-3' of git://git.infradead.org/users/hch/dma-mapping:
  dma-contiguous: page-align the size in dma_free_contiguous()
  dma-contiguous: do not overwrite align in dma_alloc_contiguous()
2019-08-02 08:41:11 -07:00
Linus Torvalds d2eee9fca1 Two minor fixes:
- Fix trace event header include guards, as several did not match
    the #define to the #ifdef
 
  - Remove a redundant test to ftrace_graph_notrace_addr() that
    was accidentally added.
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Merge tag 'trace-v5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Two minor fixes:

   - Fix trace event header include guards, as several did not match the
     #define to the #ifdef

   - Remove a redundant test to ftrace_graph_notrace_addr() that was
     accidentally added"

* tag 'trace-v5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  fgraph: Remove redundant ftrace_graph_notrace_addr() test
  tracing: Fix header include guards in trace event headers
2019-07-31 10:26:59 -07:00
Changbin Du 6c77221df9 fgraph: Remove redundant ftrace_graph_notrace_addr() test
We already have tested it before. The second one should be removed.
With this change, the performance should have little improvement.

Link: http://lkml.kernel.org/r/20190730140850.7927-1-changbin.du@gmail.com

Cc: stable@vger.kernel.org
Fixes: 9cd2992f2d ("fgraph: Have set_graph_notrace only affect function_graph tracer")
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-07-30 21:50:03 -04:00
Christian Brauner 30b692d3b3
exit: make setting exit_state consistent
Since commit b191d6491b ("pidfd: fix a poll race when setting exit_state")
we unconditionally set exit_state to EXIT_ZOMBIE before calling into
do_notify_parent(). This was done to eliminate a race when querying
exit_state in do_notify_pidfd().
Back then we decided to do the absolute minimal thing to fix this and
not touch the rest of the exit_notify() function where exit_state is
set.
Since this fix has not caused any issues change the setting of
exit_state to EXIT_DEAD in the autoreap case to account for the fact hat
exit_state is set to EXIT_ZOMBIE unconditionally. This fix was planned
but also explicitly requested in [1] and makes the whole code more
consistent.

/* References */
[1]: https://lore.kernel.org/lkml/CAHk-=wigcxGFR2szue4wavJtH5cYTTeNES=toUBVGsmX0rzX+g@mail.gmail.com

Signed-off-by: Christian Brauner <christian@brauner.io>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-30 19:57:14 +02:00
Thomas Huth 2b089bf8d1 kernel/configs: Replace GPL boilerplate code with SPDX identifier
The FSF does not reside in "675 Mass Ave, Cambridge" anymore...
let's replace the old GPL boilerplate code with a proper SPDX
identifier instead.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-30 18:34:15 +02:00
Joel Fernandes (Google) 1caf7d50f4 pidfd: Add warning if exit_state is 0 during notification
Previously a condition got missed where the pidfd waiters are awakened
before the exit_state gets set. This can result in a missed notification
[1] and the polling thread waiting forever.

It is fixed now, however it would be nice to avoid this kind of issue
going unnoticed in the future. So just add a warning to catch it in the
future.

/* References */
[1]: https://lore.kernel.org/lkml/20190717172100.261204-1-joel@joelfernandes.org/

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Link: https://lore.kernel.org/r/20190724164816.201099-1-joel@joelfernandes.org
Signed-off-by: Christian Brauner <christian@brauner.io>
2019-07-29 17:20:19 +02:00
Nicolin Chen f46cc01525 dma-contiguous: page-align the size in dma_free_contiguous()
According to the original dma_direct_alloc_pages() code:
{
	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;

	if (!dma_release_from_contiguous(dev, page, count))
		__free_pages(page, get_order(size));
}

The count parameter for dma_release_from_contiguous() was page
aligned before the right-shifting operation, while the new API
dma_free_contiguous() forgets to have PAGE_ALIGN() at the size.

So this patch simply adds it to prevent any corner case.

Fixes: fdaeec198ada ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers")
Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-07-29 09:50:04 +03:00
Nicolin Chen c6622a425a dma-contiguous: do not overwrite align in dma_alloc_contiguous()
The dma_alloc_contiguous() limits align at CONFIG_CMA_ALIGNMENT for
cma_alloc() however it does not restore it for the fallback routine.
This will result in a size mismatch between the allocation and free
when running into the fallback routines after cma_alloc() fails, if
the align is larger than CONFIG_CMA_ALIGNMENT.

This patch adds a cma_align to take care of cma_alloc() and prevent
the align from being overwritten.

Fixes: fdaeec198ada ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers")
Reported-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-07-29 09:50:04 +03:00
Linus Torvalds e24ce84e85 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Thomas Gleixner:
 "Two fixes for the fair scheduling class:

   - Prevent freeing memory which is accessible by concurrent readers

   - Make the RCU annotations for numa groups consistent"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Use RCU accessors consistently for ->numa_group
  sched/fair: Don't free p->numa_faults with concurrent readers
2019-07-27 21:22:33 -07:00
Linus Torvalds 750991f9af Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
 "A pile of perf related fixes:

  Kernel:
   - Fix SLOTS PEBS event constraints for Icelake CPUs

   - Add the missing mask bit to allow counting hardware generated
     prefetches on L3 for Icelake CPUs

   - Make the test for hypervisor platforms more accurate (as far as
     possible)

   - Handle PMUs correctly which override event->cpu

   - Yet another missing fallthrough annotation

  Tools:
     perf.data:
        - Fix loading of compressed data split across adjacent records
        - Fix buffer size setting for processing CPU topology perf.data
          header.

     perf stat:
        - Fix segfault for event group in repeat mode
        - Always separate "stalled cycles per insn" line, it was being
          appended to the "instructions" line.

     perf script:
        - Fix --max-blocks man page description.
        - Improve man page description of metrics.
        - Fix off by one in brstackinsn IPC computation.

     perf probe:
        - Avoid calling freeing routine multiple times for same pointer.

     perf build:
        - Do not use -Wshadow on gcc < 4.8, avoiding too strict warnings
          treated as errors, breaking the build"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Mark expected switch fall-throughs
  perf/core: Fix creating kernel counters for PMUs that override event->cpu
  perf/x86: Apply more accurate check on hypervisor platform
  perf/x86/intel: Fix invalid Bit 13 for Icelake MSR_OFFCORE_RSP_x register
  perf/x86/intel: Fix SLOTS PEBS event constraint
  perf build: Do not use -Wshadow on gcc < 4.8
  perf probe: Avoid calling freeing routine multiple times for same pointer
  perf probe: Set pev->nargs to zero after freeing pev->args entries
  perf session: Fix loading of compressed data split across adjacent records
  perf stat: Always separate stalled cycles per insn
  perf stat: Fix segfault for event group in repeat mode
  perf tools: Fix proper buffer size for feature processing
  perf script: Fix off by one in brstackinsn IPC computation
  perf script: Improve man page description of metrics
  perf script: Fix --max-blocks man page description
2019-07-27 21:17:56 -07:00
Linus Torvalds 431f288ed7 Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Thomas Gleixner:
 "A set of locking fixes:

   - Address the fallout of the rwsem rework. Missing ACQUIREs and a
     sanity check to prevent a use-after-free

   - Add missing checks for unitialized mutexes when mutex debugging is
     enabled.

   - Remove the bogus code in the generic SMP variant of
     arch_futex_atomic_op_inuser()

   - Fixup the #ifdeffery in lockdep to prevent compile warnings"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/mutex: Test for initialized mutex
  locking/lockdep: Clean up #ifdef checks
  locking/lockdep: Hide unused 'class' variable
  locking/rwsem: Add ACQUIRE comments
  tty/ldsem, locking/rwsem: Add missing ACQUIRE to read_failed sleep loop
  lcoking/rwsem: Add missing ACQUIRE to read_slowpath sleep loop
  locking/rwsem: Add missing ACQUIRE to read_slowpath exit when queue is empty
  locking/rwsem: Don't call owner_on_cpu() on read-owner
  futex: Cleanup generic SMP variant of arch_futex_atomic_op_inuser()
2019-07-27 21:10:26 -07:00
David S. Miller 28ba934d28 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Alexei Starovoitov says:

====================
pull-request: bpf 2019-07-25

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) fix segfault in libbpf, from Andrii.

2) fix gso_segs access, from Eric.

3) tls/sockmap fixes, from Jakub and John.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-25 17:35:03 -07:00
Linus Torvalds a29a0a467e Merge branch 'access-creds'
The access() (and faccessat()) credentials change can cause an
unnecessary load on the RCU machinery because every access() call ends
up freeing the temporary access credential using RCU.

This isn't really noticeable on small machines, but if you have hundreds
of cores you can cause huge slowdowns due to RCU storms.

It's easy to avoid: the temporary access crededntials aren't actually
normally accessed using RCU at all, so we can avoid the whole issue by
just marking them as such.

* access-creds:
  access: avoid the RCU grace period for the temporary subjective credentials
2019-07-25 08:36:29 -07:00
Leonard Crestez 4ce54af8b3 perf/core: Fix creating kernel counters for PMUs that override event->cpu
Some hardware PMU drivers will override perf_event.cpu inside their
event_init callback. This causes a lockdep splat when initialized through
the kernel API:

 WARNING: CPU: 0 PID: 250 at kernel/events/core.c:2917 ctx_sched_out+0x78/0x208
 pc : ctx_sched_out+0x78/0x208
 Call trace:
  ctx_sched_out+0x78/0x208
  __perf_install_in_context+0x160/0x248
  remote_function+0x58/0x68
  generic_exec_single+0x100/0x180
  smp_call_function_single+0x174/0x1b8
  perf_install_in_context+0x178/0x188
  perf_event_create_kernel_counter+0x118/0x160

Fix this by calling perf_install_in_context with event->cpu, just like
perf_event_open

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Frank Li <Frank.li@nxp.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Link: https://lkml.kernel.org/r/c4ebe0503623066896d7046def4d6b1e06e0eb2e.1563972056.git.leonard.crestez@nxp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-25 15:41:31 +02:00
Sebastian Andrzej Siewior 6c11c6e3d5 locking/mutex: Test for initialized mutex
An uninitialized/ zeroed mutex will go unnoticed because there is no
check for it. There is a magic check in the unlock's slowpath path which
might go unnoticed if the unlock happens in the fastpath.

Add a ->magic check early in the mutex_lock() and mutex_trylock() path.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190703092125.lsdf4gpsh2plhavb@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-25 15:39:27 +02:00
Arnd Bergmann 30a35f79fa locking/lockdep: Clean up #ifdef checks
As Will Deacon points out, CONFIG_PROVE_LOCKING implies TRACE_IRQFLAGS,
so the conditions I added in the previous patch, and some others in the
same file can be simplified by only checking for the former.

No functional change.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Frederic Weisbecker <frederic@kernel.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: Waiman Long <longman@redhat.com>
Cc: Yuyang Du <duyuyang@gmail.com>
Fixes: 886532aee3 ("locking/lockdep: Move mark_lock() inside CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING")
Link: https://lkml.kernel.org/r/20190628102919.2345242-1-arnd@arndb.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-25 15:39:26 +02:00
Arnd Bergmann 68037aa782 locking/lockdep: Hide unused 'class' variable
The usage is now hidden in an #ifdef, so we need to move
the variable itself in there as well to avoid this warning:

  kernel/locking/lockdep_proc.c:203:21: error: unused variable 'class' [-Werror,-Wunused-variable]

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qian Cai <cai@lca.pw>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yuyang Du <duyuyang@gmail.com>
Cc: frederic@kernel.org
Fixes: 68d41d8c94 ("locking/lockdep: Fix lock used or unused stats error")
Link: https://lkml.kernel.org/r/20190715092809.736834-1-arnd@arndb.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-25 15:39:25 +02:00
Peter Zijlstra 6ffddfb9e1 locking/rwsem: Add ACQUIRE comments
Since we just reviewed read_slowpath for ACQUIRE correctness, add a
few coments to retain our findings.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-25 15:39:25 +02:00
Peter Zijlstra 99143f82a2 lcoking/rwsem: Add missing ACQUIRE to read_slowpath sleep loop
While reviewing another read_slowpath patch, both Will and I noticed
another missing ACQUIRE, namely:

  X = 0;

  CPU0			CPU1

  rwsem_down_read()
    for (;;) {
      set_current_state(TASK_UNINTERRUPTIBLE);

                        X = 1;
                        rwsem_up_write();
                          rwsem_mark_wake()
                            atomic_long_add(adjustment, &sem->count);
                            smp_store_release(&waiter->task, NULL);

      if (!waiter.task)
        break;

      ...
    }

  r = X;

Allows 'r == 0'.

Reported-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reported-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-25 15:39:24 +02:00
Jan Stancek e1b98fa316 locking/rwsem: Add missing ACQUIRE to read_slowpath exit when queue is empty
LTP mtest06 has been observed to occasionally hit "still mapped when
deleted" and following BUG_ON on arm64.

The extra mapcount originated from pagefault handler, which handled
pagefault for vma that has already been detached. vma is detached
under mmap_sem write lock by detach_vmas_to_be_unmapped(), which
also invalidates vmacache.

When the pagefault handler (under mmap_sem read lock) calls
find_vma(), vmacache_valid() wrongly reports vmacache as valid.

After rwsem down_read() returns via 'queue empty' path (as of v5.2),
it does so without an ACQUIRE on sem->count:

  down_read()
    __down_read()
      rwsem_down_read_failed()
        __rwsem_down_read_failed_common()
          raw_spin_lock_irq(&sem->wait_lock);
          if (list_empty(&sem->wait_list)) {
            if (atomic_long_read(&sem->count) >= 0) {
              raw_spin_unlock_irq(&sem->wait_lock);
              return sem;

The problem can be reproduced by running LTP mtest06 in a loop and
building the kernel (-j $NCPUS) in parallel. It does reproduces since
v4.20 on arm64 HPE Apollo 70 (224 CPUs, 256GB RAM, 2 nodes). It
triggers reliably in about an hour.

The patched kernel ran fine for 10+ hours.

Signed-off-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Waiman Long <longman@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dbueso@suse.de
Fixes: 4b486b535c ("locking/rwsem: Exit read lock slowpath if queue empty & no writer")
Link: https://lkml.kernel.org/r/50b8914e20d1d62bb2dee42d342836c2c16ebee7.1563438048.git.jstancek@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-25 15:39:23 +02:00
Waiman Long 7813430057 locking/rwsem: Don't call owner_on_cpu() on read-owner
For writer, the owner value is cleared on unlock. For reader, it is
left intact on unlock for providing better debugging aid on crash dump
and the unlock of one reader may not mean the lock is free.

As a result, the owner_on_cpu() shouldn't be used on read-owner
as the task pointer value may not be valid and it might have
been freed. That is the case in rwsem_spin_on_owner(), but not in
rwsem_can_spin_on_owner(). This can lead to use-after-free error from
KASAN. For example,

  BUG: KASAN: use-after-free in rwsem_down_write_slowpath
  (/home/miguel/kernel/linux/kernel/locking/rwsem.c:669
  /home/miguel/kernel/linux/kernel/locking/rwsem.c:1125)

Fix this by checking for RWSEM_READER_OWNED flag before calling
owner_on_cpu().

Reported-by: Luis Henriques <lhenriques@suse.com>
Tested-by: Luis Henriques <lhenriques@suse.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: huang ying <huang.ying.caritas@gmail.com>
Fixes: 94a9717b3c ("locking/rwsem: Make rwsem->owner an atomic_long_t")
Link: https://lkml.kernel.org/r/81e82d5b-5074-77e8-7204-28479bbe0df0@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-25 15:39:22 +02:00
Jann Horn cb361d8cde sched/fair: Use RCU accessors consistently for ->numa_group
The old code used RCU annotations and accessors inconsistently for
->numa_group, which can lead to use-after-frees and NULL dereferences.

Let all accesses to ->numa_group use proper RCU helpers to prevent such
issues.

Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Fixes: 8c8a743c50 ("sched/numa: Use {cpu, pid} to create task groups for shared faults")
Link: https://lkml.kernel.org/r/20190716152047.14424-3-jannh@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-25 15:37:05 +02:00
Jann Horn 16d51a590a sched/fair: Don't free p->numa_faults with concurrent readers
When going through execve(), zero out the NUMA fault statistics instead of
freeing them.

During execve, the task is reachable through procfs and the scheduler. A
concurrent /proc/*/sched reader can read data from a freed ->numa_faults
allocation (confirmed by KASAN) and write it back to userspace.
I believe that it would also be possible for a use-after-free read to occur
through a race between a NUMA fault and execve(): task_numa_fault() can
lead to task_numa_compare(), which invokes task_weight() on the currently
running task of a different CPU.

Another way to fix this would be to make ->numa_faults RCU-managed or add
extra locking, but it seems easier to wipe the NUMA fault statistics on
execve.

Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Fixes: 82727018b0 ("sched/numa: Call task_numa_free() from do_execve()")
Link: https://lkml.kernel.org/r/20190716152047.14424-1-jannh@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-25 15:37:04 +02:00
Linus Torvalds d7852fbd0f access: avoid the RCU grace period for the temporary subjective credentials
It turns out that 'access()' (and 'faccessat()') can cause a lot of RCU
work because it installs a temporary credential that gets allocated and
freed for each system call.

The allocation and freeing overhead is mostly benign, but because
credentials can be accessed under the RCU read lock, the freeing
involves a RCU grace period.

Which is not a huge deal normally, but if you have a lot of access()
calls, this causes a fair amount of seconday damage: instead of having a
nice alloc/free patterns that hits in hot per-CPU slab caches, you have
all those delayed free's, and on big machines with hundreds of cores,
the RCU overhead can end up being enormous.

But it turns out that all of this is entirely unnecessary.  Exactly
because access() only installs the credential as the thread-local
subjective credential, the temporary cred pointer doesn't actually need
to be RCU free'd at all.  Once we're done using it, we can just free it
synchronously and avoid all the RCU overhead.

So add a 'non_rcu' flag to 'struct cred', which can be set by users that
know they only use it in non-RCU context (there are other potential
users for this).  We can make it a union with the rcu freeing list head
that we need for the RCU case, so this doesn't need any extra storage.

Note that this also makes 'get_current_cred()' clear the new non_rcu
flag, in case we have filesystems that take a long-term reference to the
cred and then expect the RCU delayed freeing afterwards.  It's not
entirely clear that this is required, but it makes for clear semantics:
the subjective cred remains non-RCU as long as you only access it
synchronously using the thread-local accessors, but you _can_ use it as
a generic cred if you want to.

It is possible that we should just remove the whole RCU markings for
->cred entirely.  Only ->real_cred is really supposed to be accessed
through RCU, and the long-term cred copies that nfs uses might want to
explicitly re-enable RCU freeing if required, rather than have
get_current_cred() do it implicitly.

But this is a "minimal semantic changes" change for the immediate
problem.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jan Glauber <jglauber@marvell.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Jayachandran Chandrasekharan Nair <jnair@marvell.com>
Cc: Greg KH <greg@kroah.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-24 10:12:09 -07:00
Christoph Hellwig 66d7780f18 dma-mapping: check pfn validity in dma_common_{mmap,get_sgtable}
Check that the pfn returned from arch_dma_coherent_to_pfn refers to
a valid page and reject the mmap / get_sgtable requests otherwise.

Based on the arm implementation of the mmap and get_sgtable methods.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Vignesh Raghavendra <vigneshr@ti.com>
2019-07-24 17:28:54 +02:00
Ilya Leoshkevich d9b8aadaff bpf: fix narrower loads on s390
The very first check in test_pkt_md_access is failing on s390, which
happens because loading a part of a struct __sk_buff field produces
an incorrect result.

The preprocessed code of the check is:

{
	__u8 tmp = *((volatile __u8 *)&skb->len +
		((sizeof(skb->len) - sizeof(__u8)) / sizeof(__u8)));
	if (tmp != ((*(volatile __u32 *)&skb->len) & 0xFF)) return 2;
};

clang generates the following code for it:

      0:	71 21 00 03 00 00 00 00	r2 = *(u8 *)(r1 + 3)
      1:	61 31 00 00 00 00 00 00	r3 = *(u32 *)(r1 + 0)
      2:	57 30 00 00 00 00 00 ff	r3 &= 255
      3:	5d 23 00 1d 00 00 00 00	if r2 != r3 goto +29 <LBB0_10>

Finally, verifier transforms it to:

  0: (61) r2 = *(u32 *)(r1 +104)
  1: (bc) w2 = w2
  2: (74) w2 >>= 24
  3: (bc) w2 = w2
  4: (54) w2 &= 255
  5: (bc) w2 = w2

The problem is that when verifier emits the code to replace a partial
load of a struct __sk_buff field (*(u8 *)(r1 + 3)) with a full load of
struct sk_buff field (*(u32 *)(r1 + 104)), an optional shift and a
bitwise AND, it assumes that the machine is little endian and
incorrectly decides to use a shift.

Adjust shift count calculation to account for endianness.

Fixes: 31fd85816d ("bpf: permits narrower load from bpf program context fields")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-07-23 13:59:33 -07:00
Linus Torvalds 7b5cf701ea Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull preemption Kconfig fix from Thomas Gleixner:
 "The PREEMPT_RT stub config renamed PREEMPT to PREEMPT_LL and defined
  PREEMPT outside of the menu and made it selectable by both PREEMPT_LL
  and PREEMPT_RT.

  Stupid me missed that 114 defconfigs select CONFIG_PREEMPT which
  obviously can't work anymore. oldconfig builds are affected as well,
  but it's more obvious as the user gets asked. [old]defconfig silently
  fixes it up and selects PREEMPT_NONE.

  Unbreak it by undoing the rename and adding a intermediate config
  symbol which is selected by both PREEMPT and PREEMPT_RT. That requires
  to chase down a few #ifdefs, but it's better than tweaking 114
  defconfigs and annoying users"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/rt, Kconfig: Unbreak def/oldconfig with CONFIG_PREEMPT=y
2019-07-22 09:30:34 -07:00
Thomas Gleixner b8d3349803 sched/rt, Kconfig: Unbreak def/oldconfig with CONFIG_PREEMPT=y
The merge of the CONFIG_PREEMPT_RT stub renamed CONFIG_PREEMPT to
CONFIG_PREEMPT_LL which causes all defconfigs which have CONFIG_PREEMPT=y
set to fall back to CONFIG_PREEMPT_NONE because CONFIG_PREEMPT depends on
the preemption mode choice wich defaults to NONE. This also affects
oldconfig builds.

So rather than changing 114 defconfig files and being an annoyance to
users, revert the rename and select a new config symbol PREEMPTION. That
keeps everything working smoothly and the revelant ifdef's are going to be
fixed up step by step.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Fixes: a50a3f4b6a ("sched/rt, Kconfig: Introduce CONFIG_PREEMPT_RT")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2019-07-22 18:05:11 +02:00
Suren Baghdasaryan b191d6491b
pidfd: fix a poll race when setting exit_state
There is a race between reading task->exit_state in pidfd_poll and
writing it after do_notify_parent calls do_notify_pidfd. Expected
sequence of events is:

CPU 0                            CPU 1
------------------------------------------------
exit_notify
  do_notify_parent
    do_notify_pidfd
  tsk->exit_state = EXIT_DEAD
                                  pidfd_poll
                                     if (tsk->exit_state)

However nothing prevents the following sequence:

CPU 0                            CPU 1
------------------------------------------------
exit_notify
  do_notify_parent
    do_notify_pidfd
                                   pidfd_poll
                                      if (tsk->exit_state)
  tsk->exit_state = EXIT_DEAD

This causes a polling task to wait forever, since poll blocks because
exit_state is 0 and the waiting task is not notified again. A stress
test continuously doing pidfd poll and process exits uncovered this bug.

To fix it, we make sure that the task's exit_state is always set before
calling do_notify_pidfd.

Fixes: b53b0b9d9a ("pidfd: add polling support")
Cc: kernel-team@android.com
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Link: https://lore.kernel.org/r/20190717172100.261204-1-joel@joelfernandes.org
[christian@brauner.io: adapt commit message and drop unneeded changes from wait_task_zombie]
Signed-off-by: Christian Brauner <christian@brauner.io>
2019-07-22 16:02:03 +02:00
Linus Torvalds ac60602a6d dma-mapping fixes for 5.3-rc1
Fix various regressions:
 
  - force unencrypted dma-coherent buffers if encryption bit can't fit
    into the dma coherent mask (Tom Lendacky)
  - avoid limiting request size if swiotlb is not used (me)
  - fix swiotlb handling in dma_direct_sync_sg_for_cpu/device
    (Fugang Duan)
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Merge tag 'dma-mapping-5.3-1' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:
 "Fix various regressions:

   - force unencrypted dma-coherent buffers if encryption bit can't fit
     into the dma coherent mask (Tom Lendacky)

   - avoid limiting request size if swiotlb is not used (me)

   - fix swiotlb handling in dma_direct_sync_sg_for_cpu/device (Fugang
     Duan)"

* tag 'dma-mapping-5.3-1' of git://git.infradead.org/users/hch/dma-mapping:
  dma-direct: correct the physical addr in dma_direct_sync_sg_for_cpu/device
  dma-direct: only limit the mapping size if swiotlb could be used
  dma-mapping: add a dma_addressing_limited helper
  dma-direct: Force unencrypted DMA under SME for certain DMA masks
2019-07-20 12:09:52 -07:00
Linus Torvalds e6023adc5c Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core fixes from Thomas Gleixner:

 - A collection of objtool fixes which address recent fallout partially
   exposed by newer toolchains, clang, BPF and general code changes.

 - Force USER_DS for user stack traces

[ Note: the "objtool fixes" are not all to objtool itself, but for
  kernel code that triggers objtool warnings.

  Things like missing function size annotations, or code that confuses
  the unwinder etc.   - Linus]

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
  objtool: Support conditional retpolines
  objtool: Convert insn type to enum
  objtool: Fix seg fault on bad switch table entry
  objtool: Support repeated uses of the same C jump table
  objtool: Refactor jump table code
  objtool: Refactor sibling call detection logic
  objtool: Do frame pointer check before dead end check
  objtool: Change dead_end_function() to return boolean
  objtool: Warn on zero-length functions
  objtool: Refactor function alias logic
  objtool: Track original function across branches
  objtool: Add mcsafe_handle_tail() to the uaccess safe list
  bpf: Disable GCC -fgcse optimization for ___bpf_prog_run()
  x86/uaccess: Remove redundant CLACs in getuser/putuser error paths
  x86/uaccess: Don't leak AC flag into fentry from mcsafe_handle_tail()
  x86/uaccess: Remove ELF function annotation from copy_user_handle_tail()
  x86/head/64: Annotate start_cpu0() as non-callable
  x86/entry: Fix thunk function ELF sizes
  x86/kvm: Don't call kvm_spurious_fault() from .fixup
  x86/kvm: Replace vmx_vmenter()'s call to kvm_spurious_fault() with UD2
  ...
2019-07-20 10:45:15 -07:00
Linus Torvalds 4b01f5a4c9 Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull smp fix from Thomas Gleixner:
 "Add warnings to the smp function calls so callers from wrong contexts
  get detected"

* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  smp: Warn on function calls from softirq context
2019-07-20 10:43:03 -07:00