linux.git/arch/parisc/kernel, branch v4.12

arch: remove unused macro/function thread_saved_pc()

2017-06-28T23:13:57+00:00

The only user of thread_saved_pc() in non-arch-specific code was removed
in commit 8243d5597793 ("sched/core: Remove pointless printout in
sched_show_task()").  Remove the implementations as well.

Some architectures use thread_saved_pc() in their arch-specific code.
Leave their thread_saved_pc() intact.

Signed-off-by: Tobias Klauser 
Acked-by: Geert Uytterhoeven 
Cc: Ingo Molnar 
Signed-off-by: Linus Torvalds

mm: larger stack guard gap, between vmas

2017-06-19T13:50:20+00:00

Stack guard page is a useful feature to reduce a risk of stack smashing
into a different mapping. We have been using a single page gap which
is sufficient to prevent having stack adjacent to a different mapping.
But this seems to be insufficient in the light of the stack usage in
userspace. E.g. glibc uses as large as 64kB alloca() in many commonly
used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX]
which is 256kB or stack strings with MAX_ARG_STRLEN.

This will become especially dangerous for suid binaries and the default
no limit for the stack size limit because those applications can be
tricked to consume a large portion of the stack and a single glibc call
could jump over the guard page. These attacks are not theoretical,
unfortunatelly.

Make those attacks less probable by increasing the stack guard gap
to 1MB (on systems with 4k pages; but make it depend on the page size
because systems with larger base pages might cap stack allocations in
the PAGE_SIZE units) which should cover larger alloca() and VLA stack
allocations. It is obviously not a full fix because the problem is
somehow inherent, but it should reduce attack space a lot.

One could argue that the gap size should be configurable from userspace,
but that can be done later when somebody finds that the new 1MB is wrong
for some special case applications.  For now, add a kernel command line
option (stack_guard_gap) to specify the stack gap size (in page units).

Implementation wise, first delete all the old code for stack guard page:
because although we could get away with accounting one extra page in a
stack vma, accounting a larger gap can break userspace - case in point,
a program run with "ulimit -S -v 20000" failed when the 1MB gap was
counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK
and strict non-overcommit mode.

Instead of keeping gap inside the stack vma, maintain the stack guard
gap as a gap between vmas: using vm_start_gap() in place of vm_start
(or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few
places which need to respect the gap - mainly arch_get_unmapped_area(),
and and the vma tree's subtree_gap support for that.

Original-patch-by: Oleg Nesterov 
Original-patch-by: Michal Hocko 
Signed-off-by: Hugh Dickins 
Acked-by: Michal Hocko 
Tested-by: Helge Deller  # parisc
Signed-off-by: Linus Torvalds

Merge tag 'pci-v4.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

2017-05-09T02:03:25+00:00

Pull PCI updates from Bjorn Helgaas:

 - add framework for supporting PCIe devices in Endpoint mode (Kishon
   Vijay Abraham I)

 - use non-postable PCI config space mappings when possible (Lorenzo
   Pieralisi)

 - clean up and unify mmap of PCI BARs (David Woodhouse)

 - export and unify Function Level Reset support (Christoph Hellwig)

 - avoid FLR for Intel 82579 NICs (Sasha Neftin)

 - add pci_request_irq() and pci_free_irq() helpers (Christoph Hellwig)

 - short-circuit config access failures for disconnected devices (Keith
   Busch)

 - remove D3 sleep delay when possible (Adrian Hunter)

 - freeze PME scan before suspending devices (Lukas Wunner)

 - stop disabling MSI/MSI-X in pci_device_shutdown() (Prarit Bhargava)

 - disable boot interrupt quirk for ASUS M2N-LR (Stefan Assmann)

 - add arch-specific alignment control to improve device passthrough by
   avoiding multiple BARs in a page (Yongji Xie)

 - add sysfs sriov_drivers_autoprobe to control VF driver binding
   (Bodong Wang)

 - allow slots below PCI-to-PCIe "reverse bridges" (Bjorn Helgaas)

 - fix crashes when unbinding host controllers that don't support
   removal (Brian Norris)

 - add driver for MicroSemi Switchtec management interface (Logan
   Gunthorpe)

 - add driver for Faraday Technology FTPCI100 host bridge (Linus
   Walleij)

 - add i.MX7D support (Andrey Smirnov)

 - use generic MSI support for Aardvark (Thomas Petazzoni)

 - make Rockchip driver modular (Brian Norris)

 - advertise 128-byte Read Completion Boundary support for Rockchip
   (Shawn Lin)

 - advertise PCI_EXP_LNKSTA_SLC for Rockchip root port (Shawn Lin)

 - convert atomic_t to refcount_t in HV driver (Elena Reshetova)

 - add CPU IRQ affinity in HV driver (K. Y. Srinivasan)

 - fix PCI bus removal in HV driver (Long Li)

 - add support for ThunderX2 DMA alias topology (Jayachandran C)

 - add ThunderX pass2.x 2nd node MCFG quirk (Tomasz Nowicki)

 - add ITE 8893 bridge DMA alias quirk (Jarod Wilson)

 - restrict Cavium ACS quirk only to CN81xx/CN83xx/CN88xx devices
   (Manish Jaggi)

* tag 'pci-v4.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (146 commits)
  PCI: Don't allow unbinding host controllers that aren't prepared
  ARM: DRA7: clockdomain: Change the CLKTRCTRL of CM_PCIE_CLKSTCTRL to SW_WKUP
  MAINTAINERS: Add PCI Endpoint maintainer
  Documentation: PCI: Add userguide for PCI endpoint test function
  tools: PCI: Add sample test script to invoke pcitest
  tools: PCI: Add a userspace tool to test PCI endpoint
  Documentation: misc-devices: Add Documentation for pci-endpoint-test driver
  misc: Add host side PCI driver for PCI test function device
  PCI: Add device IDs for DRA74x and DRA72x
  dt-bindings: PCI: dra7xx: Add DT bindings to enable unaligned access
  PCI: dwc: dra7xx: Workaround for errata id i870
  dt-bindings: PCI: dra7xx: Add DT bindings for PCI dra7xx EP mode
  PCI: dwc: dra7xx: Add EP mode support
  PCI: dwc: dra7xx: Facilitate wrapper and MSI interrupts to be enabled independently
  dt-bindings: PCI: Add DT bindings for PCI designware EP mode
  PCI: dwc: designware: Add EP mode support
  Documentation: PCI: Add binding documentation for pci-test endpoint function
  ixgbe: Use pcie_flr() instead of duplicating it
  IB/hfi1: Use pcie_flr() instead of duplicating it
  PCI: imx6: Fix spelling mistake: "contol" -> "control"
  ...

scripts/spelling.txt: add regsiter -> register spelling mistake

2017-05-09T00:15:13+00:00

This typo is quite common.  Fix it and add it to the spelling file so
that checkpatch catches it earlier.

Link: http://lkml.kernel.org/r/20170317011131.6881-2-sboyd@codeaurora.org
Signed-off-by: Stephen Boyd 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm, vmalloc: use __GFP_HIGHMEM implicitly

2017-05-09T00:15:13+00:00

__vmalloc* allows users to provide gfp flags for the underlying
allocation.  This API is quite popular

  $ git grep "=[[:space:]]__vmalloc\|return[[:space:]]*__vmalloc" | wc -l
  77

The only problem is that many people are not aware that they really want
to give __GFP_HIGHMEM along with other flags because there is really no
reason to consume precious lowmemory on CONFIG_HIGHMEM systems for pages
which are mapped to the kernel vmalloc space.  About half of users don't
use this flag, though.  This signals that we make the API unnecessarily
too complex.

This patch simply uses __GFP_HIGHMEM implicitly when allocating pages to
be mapped to the vmalloc space.  Current users which add __GFP_HIGHMEM
are simplified and drop the flag.

Link: http://lkml.kernel.org/r/20170307141020.29107-1-mhocko@kernel.org
Signed-off-by: Michal Hocko 
Reviewed-by: Matthew Wilcox 
Cc: Al Viro 
Cc: Vlastimil Babka 
Cc: David Rientjes 
Cc: Cristopher Lameter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

parisc: Use generic pci_mmap_resource_range()

2017-04-20T13:47:47+00:00

Signed-off-by: David Woodhouse 
Signed-off-by: Bjorn Helgaas

PCI: Add BAR index argument to pci_mmap_page_range()

2017-04-20T13:47:47+00:00

In all cases we know which BAR it is.  Passing it in means that arch code
(or generic code; watch this space) won't have to go looking for it again.

Signed-off-by: David Woodhouse 
Signed-off-by: Bjorn Helgaas

parisc: Avoid stalled CPU warnings after system shutdown

2017-03-29T19:50:38+00:00

Commit 73580dac7618 ("parisc: Fix system shutdown halt") introduced an endless
loop for systems which don't provide a software power off function.  But the
soft lockup detector will detect this and report stalled CPUs after some time.
Avoid those unwanted warnings by disabling the soft lockup detector.

Fixes: 73580dac7618 ("parisc: Fix system shutdown halt")
Signed-off-by: Helge Deller 
Cc: stable@vger.kernel.org # 4.9+

parisc: Clean up fixup routines for get_user()/put_user()

2017-03-29T19:50:36+00:00

Al Viro noticed that userspace accesses via get_user()/put_user() can be
simplified a lot with regard to usage of the exception handling.

This patch implements a fixup routine for get_user() and put_user() in such
that the exception handler will automatically load -EFAULT into the register
%r8 (the error value) in case on a fault on userspace.  Additionally the fixup
routine will zero the target register on fault in case of a get_user() call.
The target register is extracted out of the faulting assembly instruction.

This patch brings a few benefits over the old implementation:
1. Exception handling gets much cleaner, easier and smaller in size.
2. Helper functions like fixup_get_user_skip_1 (all of fixup.S) can be dropped.
3. No need to hardcode %r9 as target register for get_user() any longer. This
   helps the compiler register allocator and thus creates less assembler
   statements.
4. No dependency on the exception_data contents any longer.
5. Nested faults will be handled cleanly.

Reported-by: Al Viro 
Cc:  # v4.9+
Signed-off-by: Helge Deller

parisc: Fix system shutdown halt

2017-03-18T16:27:45+00:00

On those parisc machines which don't provide a software power off
function, the system currently kills the init process at the end of a
shutdown and unexpectedly restarts insteads of halting.
Fix it by adding a loop which will not return.

Signed-off-by: Helge Deller 
Cc: stable@vger.kernel.org # 4.9+