linux-toradex.git/arch/score, branch v4.0

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

score: 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.

This patch also increase number of bits availble for swap offset.

Signed-off-by: Kirill A. Shutemov 
Cc: Chen Liqin 
Cc: Lennox Wu 
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

net, lib: kill arch_fast_hash library bits

2014-12-10T20:17:46+00:00

As there are now no remaining users of arch_fast_hash(), lets kill
it entirely.

This basically reverts commit 71ae8aac3e19 ("lib: introduce arch
optimized hash library") and follow-up work, that is f.e., commit
237217546d44 ("lib: hash: follow-up fixups for arch hash"),
commit e3fec2f74f7f ("lib: Add missing arch generic-y entries for
asm-generic/hash.h") and last but not least commit 6a02652df511
("perf tools: Fix include for non x86 architectures").

Cc: Francesco Fusco 
Cc: Thomas Graf 
Cc: Arnaldo Carvalho de Melo 
Signed-off-by: Daniel Borkmann 
Signed-off-by: David S. Miller

score: use Kbuild logic to include

2014-10-10T02:25:46+00:00

Signed-off-by: Geert Uytterhoeven 
Acked-by: Lennox Wu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2014-10-09T10:30:57+00:00

Pull timer fixes from Ingo Molnar:
 "Main changes:

  - Fix the deadlock reported by Dave Jones et al
  - Clean up and fix nohz_full interaction with arch abilities
  - nohz init code consolidation/cleanup"

* 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  nohz: nohz full depends on irq work self IPI support
  nohz: Consolidate nohz full init code
  arm64: Tell irq work about self IPI support
  arm: Tell irq work about self IPI support
  x86: Tell irq work about self IPI support
  irq_work: Force raised irq work to run on irq work interrupt
  irq_work: Introduce arch_irq_work_has_interrupt()
  nohz: Move nohz full init call to tick init

score: Remove GENERIC_HAS_IOMAP

2014-10-04T20:38:08+00:00

The symbol is an orphan, get rid of it.

Signed-off-by: Richard Weinberger 
Acked-by: Lennox Wu 
Cc: Paul Bolle 
[Guenter Roeck: Merge with 3.17-rc3; update headline]
Signed-off-by: Guenter Roeck

arch/score/include/asm/Kbuild: Add generic "serial.h"

2014-10-04T17:18:17+00:00

The related error (with allmodconfig under score):

    CC [M]  drivers/staging/speakup/speakup_acntpc.o
  In file included from drivers/staging/speakup/speakup_acntpc.c:33:0:
  drivers/staging/speakup/serialio.h:7:24: fatal error: asm/serial.h: No such file or directory
   #include 
                          ^
  compilation terminated.
  make[3]: *** [drivers/staging/speakup/speakup_acntpc.o] Error 1
  make[2]: *** [drivers/staging/speakup] Error 2
  make[1]: *** [drivers/staging] Error 2
  make: *** [drivers] Error 2

Acked-by: Lennox Wu 
Signed-off-by: Chen Gang

score: remove deprecated IRQF_DISABLED

2014-10-04T17:18:17+00:00

This patch removes the use of the IRQF_DISABLED flag
from arch/score/kernel/time.c

It's a NOOP since 2.6.35 and it will be removed one day.

Signed-off-by: Michael Opdenacker 
Acked-by: Lennox Wu