linux-stable.git/arch/mips, branch v4.14.78

MIPS: VDSO: Always map near top of user memory

2018-10-18T07:16:23+00:00

commit ea7e0480a4b695d0aa6b3fa99bd658a003122113 upstream.

When using the legacy mmap layout, for example triggered using ulimit -s
unlimited, get_unmapped_area() fills memory from bottom to top starting
from a fairly low address near TASK_UNMAPPED_BASE.

This placement is suboptimal if the user application wishes to allocate
large amounts of heap memory using the brk syscall. With the VDSO being
located low in the user's virtual address space, the amount of space
available for access using brk is limited much more than it was prior to
the introduction of the VDSO.

For example:

  # ulimit -s unlimited; cat /proc/self/maps
  00400000-004ec000 r-xp 00000000 08:00 71436      /usr/bin/coreutils
  004fc000-004fd000 rwxp 000ec000 08:00 71436      /usr/bin/coreutils
  004fd000-0050f000 rwxp 00000000 00:00 0
  00cc3000-00ce4000 rwxp 00000000 00:00 0          [heap]
  2ab96000-2ab98000 r--p 00000000 00:00 0          [vvar]
  2ab98000-2ab99000 r-xp 00000000 00:00 0          [vdso]
  2ab99000-2ab9d000 rwxp 00000000 00:00 0
  ...

Resolve this by adjusting STACK_TOP to reserve space for the VDSO &
providing an address hint to get_unmapped_area() causing it to use this
space even when using the legacy mmap layout.

We reserve enough space for the VDSO, plus 1MB or 256MB for 32 bit & 64
bit systems respectively within which we randomize the VDSO base
address. Previously this randomization was taken care of by the mmap
base address randomization performed by arch_mmap_rnd(). The 1MB & 256MB
sizes are somewhat arbitrary but chosen such that we have some
randomization without taking up too much of the user's virtual address
space, which is often in short supply for 32 bit systems.

With this the VDSO is always mapped at a high address, leaving lots of
space for statically linked programs to make use of brk:

  # ulimit -s unlimited; cat /proc/self/maps
  00400000-004ec000 r-xp 00000000 08:00 71436      /usr/bin/coreutils
  004fc000-004fd000 rwxp 000ec000 08:00 71436      /usr/bin/coreutils
  004fd000-0050f000 rwxp 00000000 00:00 0
  00c28000-00c49000 rwxp 00000000 00:00 0          [heap]
  ...
  7f67c000-7f69d000 rwxp 00000000 00:00 0          [stack]
  7f7fc000-7f7fd000 rwxp 00000000 00:00 0
  7fcf1000-7fcf3000 r--p 00000000 00:00 0          [vvar]
  7fcf3000-7fcf4000 r-xp 00000000 00:00 0          [vdso]

Signed-off-by: Paul Burton 
Reported-by: Huacai Chen 
Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO")
Cc: Huacai Chen 
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org # v4.4+
Signed-off-by: Greg Kroah-Hartman

MIPS: boot: fix build rule of vmlinux.its.S

2018-10-04T00:00:52+00:00

[ Upstream commit 67e09db507db3e1642ddce512a4313d20addd6e5 ]

As Documentation/kbuild/makefile.txt says, it is a typical mistake
to forget the FORCE prerequisite for the rule invoked by if_changed.

Add the FORCE to the prerequisite, but it must be filtered-out from
the files passed to the 'cat' command.  Because this rule generates
.vmlinux.its.S.cmd, vmlinux.its.S must be specified as targets so
that the .cmd file is included.

Signed-off-by: Masahiro Yamada 
Patchwork: https://patchwork.linux-mips.org/patch/19097/
Signed-off-by: Paul Burton 
Cc: Kees Cook 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

MIPS: loongson64: cs5536: Fix PCI_OHCI_INT_REG reads

2018-09-26T06:38:10+00:00

[ Upstream commit cd87668d601f622e0ebcfea4f78d116d5f572f4d ]

The PCI_OHCI_INT_REG case in pci_ohci_read_reg() contains the following
if statement:

  if ((lo & 0x00000f00) == CS5536_USB_INTR)

CS5536_USB_INTR expands to the constant 11, which gives us the following
condition which can never evaluate true:

  if ((lo & 0xf00) == 11)

At least when using GCC 8.1.0 this falls foul of the tautoligcal-compare
warning, and since the code is built with the -Werror flag the build
fails.

Fix this by shifting lo right by 8 bits in order to match the
corresponding PCI_OHCI_INT_REG case in pci_ohci_write_reg().

Signed-off-by: Paul Burton 
Patchwork: https://patchwork.linux-mips.org/patch/19861/
Cc: Huacai Chen 
Cc: James Hogan 
Cc: Ralf Baechle 
Cc: linux-mips@linux-mips.org
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

MIPS: jz4740: Bump zload address

2018-09-26T06:38:03+00:00

[ Upstream commit c6ea7e9747318e5a6774995f4f8e3e0f7c0fa8ba ]

Having the zload address at 0x8060.0000 means the size of the
uncompressed kernel cannot be bigger than around 6 MiB, as it is
deflated at address 0x8001.0000.

This limit is too small; a kernel with some built-in drivers and things
like debugfs enabled will already be over 6 MiB in size, and so will
fail to extract properly.

To fix this, we bump the zload address from 0x8060.0000 to 0x8100.0000.

This is fine, as all the boards featuring Ingenic JZ SoCs have at least
32 MiB of RAM, and use u-boot or compatible bootloaders which won't
hardcode the load address but read it from the uImage's header.

Signed-off-by: Paul Cercueil 
Signed-off-by: Paul Burton 
Patchwork: https://patchwork.linux-mips.org/patch/19787/
Cc: Ralf Baechle 
Cc: James Hogan 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

MIPS: ath79: fix system restart

2018-09-26T06:38:00+00:00

[ Upstream commit f8a7bfe1cb2c1ebfa07775c9c8ac0ad3ba8e5ff5 ]

This patch disables irq on reboot to fix hang issues that were observed
due to pending interrupts.

Signed-off-by: Felix Fietkau 
Signed-off-by: John Crispin 
Signed-off-by: Paul Burton 
Patchwork: https://patchwork.linux-mips.org/patch/19913/
Cc: James Hogan 
Cc: Ralf Baechle 
Cc: linux-mips@linux-mips.org
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

MIPS: WARN_ON invalid DMA cache maintenance, not BUG_ON

2018-09-19T20:43:44+00:00

[ Upstream commit d4da0e97baea8768b3d66ccef3967bebd50dfc3b ]

If a driver causes DMA cache maintenance with a zero length then we
currently BUG and kill the kernel. As this is a scenario that we may
well be able to recover from, WARN & return in the condition instead.

Signed-off-by: Paul Burton 
Acked-by: Florian Fainelli 
Patchwork: https://patchwork.linux-mips.org/patch/14623/
Cc: Ralf Baechle 
Cc: linux-mips@linux-mips.org
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

MIPS: generic: fix missing of_node_put()

2018-09-19T20:43:43+00:00

[ Upstream commit 28ec2238f37e72a3a40a7eb46893e7651bcc40a6 ]

of_find_compatible_node() returns a device_node pointer with refcount
incremented and must be decremented explicitly.
 As this code is using the result only to check presence of the interrupt
controller (!NULL) but not actually using the result otherwise the
refcount can be decremented here immediately again.

Signed-off-by: Nicholas Mc Guire 
Signed-off-by: Paul Burton 
Patchwork: https://patchwork.linux-mips.org/patch/19820/
Cc: Ralf Baechle 
Cc: James Hogan 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

MIPS: Octeon: add missing of_node_put()

2018-09-19T20:43:43+00:00

[ Upstream commit b1259519e618d479ede8a0db5474b3aff99f5056 ]

The call to of_find_node_by_name returns a node pointer with refcount
incremented thus it must be explicitly decremented here after the last
usage.

Signed-off-by: Nicholas Mc Guire 
Signed-off-by: Paul Burton 
Patchwork: https://patchwork.linux-mips.org/patch/19558/
Cc: Ralf Baechle 
Cc: James Hogan 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

MIPS: Fix ISA virt/bus conversion for non-zero PHYS_OFFSET

2018-09-19T20:43:41+00:00

[ Upstream commit 0494d7ffdcebc6935410ea0719b24ab626675351 ]

isa_virt_to_bus() & isa_bus_to_virt() claim to treat ISA bus addresses
as being identical to physical addresses, but they fail to do so in the
presence of a non-zero PHYS_OFFSET.

Correct this by having them use virt_to_phys() & phys_to_virt(), which
consolidates the calculations to one place & ensures that ISA bus
addresses do indeed match physical addresses.

Signed-off-by: Paul Burton 
Patchwork: https://patchwork.linux-mips.org/patch/20047/
Cc: James Hogan 
Cc: Ralf Baechle 
Cc: linux-mips@linux-mips.org
Cc: Vladimir Kondratiev 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

MIPS: VDSO: Match data page cache colouring when D$ aliases

2018-09-19T20:43:35+00:00

commit 0f02cfbc3d9e413d450d8d0fd660077c23f67eff upstream.

When a system suffers from dcache aliasing a user program may observe
stale VDSO data from an aliased cache line. Notably this can break the
expectation that clock_gettime(CLOCK_MONOTONIC, ...) is, as its name
suggests, monotonic.

In order to ensure that users observe updates to the VDSO data page as
intended, align the user mappings of the VDSO data page such that their
cache colouring matches that of the virtual address range which the
kernel will use to update the data page - typically its unmapped address
within kseg0.

This ensures that we don't introduce aliasing cache lines for the VDSO
data page, and therefore that userland will observe updates without
requiring cache invalidation.

Signed-off-by: Paul Burton 
Reported-by: Hauke Mehrtens 
Reported-by: Rene Nielsen 
Reported-by: Alexandre Belloni 
Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO")
Patchwork: https://patchwork.linux-mips.org/patch/20344/
Tested-by: Alexandre Belloni 
Tested-by: Hauke Mehrtens 
Cc: James Hogan 
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org # v4.4+
Signed-off-by: Greg Kroah-Hartman