linux-stable.git/arch/score, branch linux-3.4.y

vm: add VM_FAULT_SIGSEGV handling support

2015-04-14T09:33:57+00:00

commit 33692f27597fcab536d7cbbcc8f52905133e4aa7 upstream.

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
Signed-off-by: Linus Torvalds 
[bwh: Backported to 3.2:
 - Adjust filenames, context
 - Drop arc, metag, nios2 and lustre changes
 - For sh, patch both 32-bit and 64-bit implementations to use goto bad_area
 - For s390, pass int_code and trans_exc_code as arguments to do_no_context()
   and do_sigsegv()]
Signed-off-by: Ben Hutchings 
[lizf: Backported to 3.4:
 - adjust context in arch/power/mm/fault.c
 - apply the original change in upstream commit for s390]
Signed-off-by: Zefan Li

score: Add missing RCU idle APIs on idle loop

2012-10-12T20:38:55+00:00

commit 0ee23fda59740767324b4340247ca41a2f498ca6 upstream.

In the old times, the whole idle task was considered
as an RCU quiescent state. But as RCU became more and
more successful overtime, some RCU read side critical
section have been added even in the code of some
architectures idle tasks, for tracing for example.

So nowadays, rcu_idle_enter() and rcu_idle_exit() must
be called by the architecture to tell RCU about the part
in the idle loop that doesn't make use of rcu read side
critical sections, typically the part that puts the CPU
in low power mode.

This is necessary for RCU to find the quiescent states in
idle in order to complete grace periods.

Add this missing pair of calls in scores's idle loop.

Reported-by: Paul E. McKenney 
Signed-off-by: Frederic Weisbecker 
Cc: Chen Liqin 
Cc: Lennox Wu 
Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett 
Signed-off-by: Greg Kroah-Hartman

Delete all instances of asm/system.h

2012-03-28T17:30:03+00:00

Delete all instances of asm/system.h as they should be redundant by this
point.

Signed-off-by: David Howells

Disintegrate asm/system.h for Score

2012-03-28T17:30:02+00:00

Disintegrate asm/system.h for Score.  Not compiled.

Signed-off-by: David Howells 
cc: Chen Liqin

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial

2012-03-21T04:12:50+00:00

Pull trivial tree from Jiri Kosina:
 "It's indeed trivial -- mostly documentation updates and a bunch of
  typo fixes from Masanari.

  There are also several linux/version.h include removals from Jesper."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (101 commits)
  kcore: fix spelling in read_kcore() comment
  constify struct pci_dev * in obvious cases
  Revert "char: Fix typo in viotape.c"
  init: fix wording error in mm_init comment
  usb: gadget: Kconfig: fix typo for 'different'
  Revert "power, max8998: Include linux/module.h just once in drivers/power/max8998_charger.c"
  writeback: fix fn name in writeback_inodes_sb_nr_if_idle() comment header
  writeback: fix typo in the writeback_control comment
  Documentation: Fix multiple typo in Documentation
  tpm_tis: fix tis_lock with respect to RCU
  Revert "media: Fix typo in mixer_drv.c and hdmi_drv.c"
  Doc: Update numastat.txt
  qla4xxx: Add missing spaces to error messages
  compiler.h: Fix typo
  security: struct security_operations kerneldoc fix
  Documentation: broken URL in libata.tmpl
  Documentation: broken URL in filesystems.tmpl
  mtd: simplify return logic in do_map_probe()
  mm: fix comment typo of truncate_inode_pages_range
  power: bq27x00: Fix typos in comment
  ...

sched/rt: Use schedule_preempt_disabled()

2012-03-01T09:28:03+00:00

Coccinelle based conversion.

Signed-off-by: Thomas Gleixner 
Acked-by: Peter Zijlstra 
Link: http://lkml.kernel.org/n/tip-24swm5zut3h9c4a6s46x8rws@git.kernel.org
Signed-off-by: Ingo Molnar

score: Fix typo in Kconfig.debug

2012-02-05T16:14:48+00:00

Correct spelling "debuging" to "debugging" in
arch/score/Kconfig.debug

Signed-off-by: Masanari Iida 
Signed-off-by: Jiri Kosina

score: fix off-by-one index into syscall table

2012-01-23T16:38:49+00:00

If the provided system call number is equal to __NR_syscalls, the
current check will pass and a function pointer just after the system
call table may be called, since sys_call_table is an array with total
size __NR_syscalls.

Whether or not this is a security bug depends on what the compiler puts
immediately after the system call table.  It's likely that this won't do
anything bad because there is an additional NULL check on the syscall
entry, but if there happens to be a non-NULL value immediately after the
system call table, this may result in local privilege escalation.

Signed-off-by: Dan Rosenberg 
Cc: 
Cc: Chen Liqin 
Cc: Lennox Wu 
Cc: Eugene Teo 
Cc: Arnd Bergmann 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

cpu: Register a generic CPU device on architectures that currently do not

2012-01-11T23:50:11+00:00

frv, h8300, m68k, microblaze, openrisc, score, um and xtensa currently
do not register a CPU device.  Add the config option GENERIC_CPU_DEVICES
which causes a generic CPU device to be registered for each present CPU,
and make all these architectures select it.

Richard Weinberger  covered UML and suggested using
per_cpu.

Signed-off-by: Ben Hutchings 
Signed-off-by: Linus Torvalds

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

2012-01-11T02:04:27+00:00

lib: use generic pci_iomap on all architectures

Many architectures don't want to pull in iomap.c,
so they ended up duplicating pci_iomap from that file.
That function isn't trivial, and we are going to modify it
https://lkml.org/lkml/2011/11/14/183
so the duplication hurts.

This reduces the scope of the problem significantly,
by moving pci_iomap to a separate file and
referencing that from all architectures.

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  alpha: drop pci_iomap/pci_iounmap from pci-noop.c
  mn10300: switch to GENERIC_PCI_IOMAP
  mn10300: add missing __iomap markers
  frv: switch to GENERIC_PCI_IOMAP
  tile: switch to GENERIC_PCI_IOMAP
  tile: don't panic on iomap
  sparc: switch to GENERIC_PCI_IOMAP
  sh: switch to GENERIC_PCI_IOMAP
  powerpc: switch to GENERIC_PCI_IOMAP
  parisc: switch to GENERIC_PCI_IOMAP
  mips: switch to GENERIC_PCI_IOMAP
  microblaze: switch to GENERIC_PCI_IOMAP
  arm: switch to GENERIC_PCI_IOMAP
  alpha: switch to GENERIC_PCI_IOMAP
  lib: add GENERIC_PCI_IOMAP
  lib: move GENERIC_IOMAP to lib/Kconfig

Fix up trivial conflicts due to changes nearby in arch/{m68k,score}/Kconfig