linux-stable.git/arch/frv, 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

frv: Use core allocator for task_struct

2013-08-20T15:26:28+00:00

commit c6ae063aaf3786b9db7f19a90bf4ed8aaebb7f90 upstream.

There is no point having a copy of the core allocator.

Signed-off-by: Thomas Gleixner 
Acked-by: David Howells 
Link: http://lkml.kernel.org/r/20120503085033.967140188@linutronix.de
Cc: Guenter Roeck 
Signed-off-by: Greg Kroah-Hartman

frv: Use correct size for task_struct allocation

2013-08-20T15:26:28+00:00

commit cce4517f33384c3794c759e206cc8e1bb6df146b upstream.

alloc_task_struct_node() allocates THREAD_SIZE and maintains some
weird refcount in the allocated memory. This never blew up as
task_struct size on 32bit machines was always less than THREAD_SIZE

Allocate just sizeof(struct task_struct) and get rid of the magic
refcounting.

Signed-off-by: Thomas Gleixner 
Acked-by: David Howells 
Link: http://lkml.kernel.org/r/20120503085033.898475542@linutronix.de
Cc: Guenter Roeck 
Signed-off-by: Greg Kroah-Hartman

frv: Add missing RCU idle APIs on idle loop

2012-10-12T20:38:54+00:00

commit 41d8fe5bb3cf91ce2716ac8f43e4b40d802a99c8 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 the Frv's idle loop.

Reported-by: Paul E. McKenney 
Signed-off-by: Frederic Weisbecker 
Cc: David Howells 
Acked-by: David Howells 
Reviewed-by: Josh Triplett 
Signed-off-by: Greg Kroah-Hartman

frv: delete incorrect task prototypes causing compile fail

2012-05-18T01:00:51+00:00

Commit 41101809a865 ("fork: Provide weak arch_release_[task_struct|
thread_info] functions") in -tip highlights a problem in the frv arch,
where it has needles prototypes for alloc_task_struct_node and
free_task_struct.  This now shows up as:

  kernel/fork.c:120:66: error: static declaration of 'alloc_task_struct_node' follows non-static declaration
  kernel/fork.c:127:51: error: static declaration of 'free_task_struct' follows non-static declaration

since that commit turned them into real functions.  Since arch/frv does
does not define define __HAVE_ARCH_TASK_STRUCT_ALLOCATOR (i.e.  it just
uses the generic ones) it shouldn't list these at all.

Signed-off-by: Paul Gortmaker 
Cc: David Howells 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

frv: fix warnings in mb93090-mb00/pci-dma.c about implicit EXPORT_SYMBOL

2012-04-02T21:41:26+00:00

To fix:

    arch/frv/mb93090-mb00/pci-dma.c:31:1: warning: data definition has no type or storage class [enabled by default]
    arch/frv/mb93090-mb00/pci-dma.c:31:1: warning: type defaults to 'int' in declaration of 'EXPORT_SYMBOL' [-Wimplicit-int]
    arch/frv/mb93090-mb00/pci-dma.c:31:1: warning: parameter names (without types) in function declaration [enabled by default]
    arch/frv/mb93090-mb00/pci-dma.c:38:1: warning: data definition has no type or storage class [enabled by default]

Signed-off-by: Paul Gortmaker 
Acked-by: David Howells 
Signed-off-by: Linus Torvalds

Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2012-03-30T01:12:23+00:00

Pull x32 support for x86-64 from Ingo Molnar:
 "This tree introduces the X32 binary format and execution mode for x86:
  32-bit data space binaries using 64-bit instructions and 64-bit kernel
  syscalls.

  This allows applications whose working set fits into a 32 bits address
  space to make use of 64-bit instructions while using a 32-bit address
  space with shorter pointers, more compressed data structures, etc."

Fix up trivial context conflicts in arch/x86/{Kconfig,vdso/vma.c}

* 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits)
  x32: Fix alignment fail in struct compat_siginfo
  x32: Fix stupid ia32/x32 inversion in the siginfo format
  x32: Add ptrace for x32
  x32: Switch to a 64-bit clock_t
  x32: Provide separate is_ia32_task() and is_x32_task() predicates
  x86, mtrr: Use explicit sizing and padding for the 64-bit ioctls
  x86/x32: Fix the binutils auto-detect
  x32: Warn and disable rather than error if binutils too old
  x32: Only clear TIF_X32 flag once
  x32: Make sure TS_COMPAT is cleared for x32 tasks
  fs: Remove missed ->fds_bits from cessation use of fd_set structs internally
  fs: Fix close_on_exec pointer in alloc_fdtable
  x32: Drop non-__vdso weak symbols from the x32 VDSO
  x32: Fix coding style violations in the x32 VDSO code
  x32: Add x32 VDSO support
  x32: Allow x32 to be configured
  x32: If configured, add x32 system calls to system call tables
  x32: Handle process creation
  x32: Signal-related system calls
  x86: Add #ifdef CONFIG_COMPAT to 
  ...

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

Move all declarations of free_initmem() to linux/mm.h

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

Move all declarations of free_initmem() to linux/mm.h so that there's only one
and it's used by everything.

Signed-off-by: David Howells 
cc: linux-c6x-dev@linux-c6x.org
cc: microblaze-uclinux@itee.uq.edu.au
cc: linux-sh@vger.kernel.org
cc: sparclinux@vger.kernel.org
cc: x86@kernel.org
cc: linux-mm@kvack.org

Disintegrate asm/system.h for FRV

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

Disintegrate asm/system.h for FRV.

Signed-off-by: David Howells