linux-stable.git/arch/xtensa, branch v4.0

Merge tag 'asm-generic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

2015-02-18T18:02:24+00:00

Pull asm-generic uaccess.h cleanup from Arnd Bergmann:
 "Like in 3.19, I once more have a multi-stage cleanup for one
  asm-generic header file, this time the work was done by Michael
  Tsirkin and cleans up the uaccess.h file in asm-generic, as well as
  all architectures for which the respective maintainers did not pick up
  his patches directly"

* tag 'asm-generic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (37 commits)
  sparc32: nocheck uaccess coding style tweaks
  sparc64: nocheck uaccess coding style tweaks
  xtensa: macro whitespace fixes
  sh: macro whitespace fixes
  parisc: macro whitespace fixes
  m68k: macro whitespace fixes
  m32r: macro whitespace fixes
  frv: macro whitespace fixes
  cris: macro whitespace fixes
  avr32: macro whitespace fixes
  arm64: macro whitespace fixes
  arm: macro whitespace fixes
  alpha: macro whitespace fixes
  blackfin: macro whitespace fixes
  sparc64: uaccess_64 macro whitespace fixes
  sparc32: uaccess_32 macro whitespace fixes
  avr32: whitespace fix
  sh: fix put_user sparse errors
  metag: fix put_user sparse errors
  ia64: fix put_user sparse errors
  ...

xtensa: use %*pb[l] to print bitmaps including cpumasks and nodemasks

2015-02-14T05:21:37+00:00

printk and friends can now format bitmaps using '%*pb[l]'.  cpumask
and nodemask also provide cpumask_pr_args() and nodemask_pr_args()
respectively which can be used to generate the two printf arguments
necessary to format the specified cpu/nodemask.

Signed-off-by: Tejun Heo 
Cc: Chris Zankel 
Cc: Max Filippov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

all arches, signal: move restart_block to struct task_struct

2015-02-13T02:54:12+00:00

If an attacker can cause a controlled kernel stack overflow, overwriting
the restart block is a very juicy exploit target.  This is because the
restart_block is held in the same memory allocation as the kernel stack.

Moving the restart block to struct task_struct prevents this exploit by
making the restart_block harder to locate.

Note that there are other fields in thread_info that are also easy
targets, at least on some architectures.

It's also a decent simplification, since the restart code is more or less
identical on all architectures.

[james.hogan@imgtec.com: metag: align thread_info::supervisor_stack]
Signed-off-by: Andy Lutomirski 
Cc: Thomas Gleixner 
Cc: Al Viro 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Kees Cook 
Cc: David Miller 
Acked-by: Richard Weinberger 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Cc: Matt Turner 
Cc: Vineet Gupta 
Cc: Russell King 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Haavard Skinnemoen 
Cc: Hans-Christian Egtvedt 
Cc: Steven Miao 
Cc: Mark Salter 
Cc: Aurelien Jacquiot 
Cc: Mikael Starvik 
Cc: Jesper Nilsson 
Cc: David Howells 
Cc: Richard Kuo 
Cc: "Luck, Tony" 
Cc: Geert Uytterhoeven 
Cc: Michal Simek 
Cc: Ralf Baechle 
Cc: Jonas Bonn 
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Acked-by: Michael Ellerman  (powerpc)
Tested-by: Michael Ellerman  (powerpc)
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: Chen Liqin 
Cc: Lennox Wu 
Cc: Chris Metcalf 
Cc: Guan Xuetao 
Cc: Chris Zankel 
Cc: Max Filippov 
Cc: Oleg Nesterov 
Cc: Guenter Roeck 
Signed-off-by: James Hogan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: make FIRST_USER_ADDRESS unsigned long on all archs

2015-02-12T01:06:03+00:00

LKP has triggered a compiler warning after my recent patch "mm: account
pmd page tables to the process":

    mm/mmap.c: In function 'exit_mmap':
 >> mm/mmap.c:2857:2: warning: right shift count >= width of type [enabled by default]

The code:

 > 2857                WARN_ON(mm_nr_pmds(mm) >
   2858                                round_up(FIRST_USER_ADDRESS, PUD_SIZE) >> PUD_SHIFT);

In this, on tile, we have FIRST_USER_ADDRESS defined as 0.  round_up() has
the same type -- int.  PUD_SHIFT.

I think the best way to fix it is to define FIRST_USER_ADDRESS as unsigned
long.  On every arch for consistency.

Signed-off-by: Kirill A. Shutemov 
Reported-by: Wu Fengguang 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

xtensa: drop _PAGE_FILE and pte_file()-related helpers

2015-02-10T22:30:33+00:00

We've replaced remap_file_pages(2) implementation with emulation.  Nobody
creates non-linear mapping anymore.

Signed-off-by: Kirill A. Shutemov 
Acked-by: Max Filippov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

vm: add VM_FAULT_SIGSEGV handling support

2015-01-29T18:51:32+00:00

The core VM already knows about VM_FAULT_SIGBUS, but cannot return a
"you should SIGSEGV" error, because the SIGSEGV case was generally
handled by the caller - usually the architecture fault handler.

That results in lots of duplication - all the architecture fault
handlers end up doing very similar "look up vma, check permissions, do
retries etc" - but it generally works.  However, there are cases where
the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV.

In particular, when accessing the stack guard page, libsigsegv expects a
SIGSEGV.  And it usually got one, because the stack growth is handled by
that duplicated architecture fault handler.

However, when the generic VM layer started propagating the error return
from the stack expansion in commit fee7e49d4514 ("mm: propagate error
from stack expansion even for guard page"), that now exposed the
existing VM_FAULT_SIGBUS result to user space.  And user space really
expected SIGSEGV, not SIGBUS.

To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those
duplicate architecture fault handlers about it.  They all already have
the code to handle SIGSEGV, so it's about just tying that new return
value to the existing code, but it's all a bit annoying.

This is the mindless minimal patch to do this.  A more extensive patch
would be to try to gather up the mostly shared fault handling logic into
one generic helper routine, and long-term we really should do that
cleanup.

Just from this patch, you can generally see that most architectures just
copied (directly or indirectly) the old x86 way of doing things, but in
the meantime that original x86 model has been improved to hold the VM
semaphore for shorter times etc and to handle VM_FAULT_RETRY and other
"newer" things, so it would be a good idea to bring all those
improvements to the generic case and teach other architectures about
them too.

Reported-and-tested-by: Takashi Iwai 
Tested-by: Jan Engelhardt 
Acked-by: Heiko Carstens  # "s390 still compiles and boots"
Cc: linux-arch@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds

xtensa: macro whitespace fixes

2015-01-13T13:24:10+00:00

While working on arch/xtensa/include/asm/uaccess.h, I noticed
that some macros within this header are made harder to read because they
violate a coding style rule: space is missing after comma.

Fix it up.

Signed-off-by: Michael S. Tsirkin 
Acked-by: Max Filippov

Merge tag 'xtensa-next-20141215' of git://github.com/czankel/xtensa-linux

2014-12-16T22:08:53+00:00

Pull Xtensa fixes from Chris Zankel:
 - fix nommu support
 - remove s6000 variant and s6105 platform
 - fix permissions for kmapped pages so that copy_to_user_page works with them
 - add power management menu to Kconfig to allow use of runtime PM
 - disable linker optimizations because of a linker bug
 - fix sparse error

* tag 'xtensa-next-20141215' of git://github.com/czankel/xtensa-linux:
  xtensa: disable link optimization
  xtensa/uaccess: fix sparse errors
  xtensa: fix kmap_prot definition
  xtensa: add power management menu to Kconfig
  xtensa: remove s6000 variant and s6105 platform
  xtensa: make PLATFORM_DEFAULT_MEM parameters configurable
  xtensa: nommu: clean up memory map dump
  xtensa: nommu: reserve memory below PLATFORM_DEFAULT_MEM_START
  xtensa: nommu: set up cache and atomctl in initialize_mmu
  xtensa: move vecbase SR initialization to _startup
  xtensa: nommu: fix uImage load address
  xtensa: nommu: fix load address definitions
  xtensa: nommu: fix Image.elf reset code and ld script
  xtensa: nommu: add MMU dependency to DEBUG_TLB_SANITY
  xtensa: nommu: don't build most of the cache flushing code
  xtensa: nommu: don't provide arch_get_unmapped_area
  xtensa: nommu: provide MAP_UNINITIALIZED definition
  xtensa: nommu: provide _PAGE_CHG_MASK definition
  xtensa: nommu: provide __invalidate_dcache_page_alias stub
  xtensa: nommu: move init_mmu stub to nommu_context.h

xtensa: disable link optimization

2014-12-16T07:47:24+00:00

The default linker behavior is to optimize identical literal values
and remove unnecessary overhead. However, because of a bug in the
linker, this currently results in an error ('call target out of range').

Disable link-time optimizations per default until there is a fix
for the linker and add the option to iss_defconfig.

Signed-off-by: Chris Zankel

xtensa/uaccess: fix sparse errors

2014-12-16T04:14:26+00:00

virtio wants to read bitwise types from userspace using get_user.  At the
moment this triggers sparse errors, since the value is passed through an
integer.

Fix that up using __force.

Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Chris Zankel