There are places in the kernel where we look up files in fd tables and
access the file structure without holding refereces to the file.  So, we
need special care to avoid the race between looking up files in the fd
table and tearing down of the file in another CPU.  Otherwise, one might
see a NULL f_dentry or such torn down version of the file.  This patch
fixes those special places where such a race may happen.
Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com>
Acked-by: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

We were missing __volatile__ on some bits of asm in the segfault handlers.
On x86_64, this was messing up the move from %rdx to uc because that was
moved to after the GET_FAULTINFO_FROM_SC, which changed %rdx.

Also changed the other bit of asm and the one in the i386 handler to
prevent any similar occurrences.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

UML really wants shared memory semantics form its physical memory map file,
and the place for that is /dev/shm.  So move the default, and fix the error
messages to recognize that this value can be overridden.
Signed-off-by: Rob Landley <rob@landley.net>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

bits of uml __user annotations lost in merge
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Clean up the jmpbuf code.  Since softints, we no longer use sig_setjmp, so
the UML_SIGSETJMP wrapper now has a misleading name.  Also, I forgot to
change the buffers from sigjmp_buf to jmp_buf.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

- Remove unnecessary push/pop's of the switch_to() macro
  for performance tuning.
- Cosmetic updates: change __inline__ to inline, etc.
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Cc: NIIBE Yutaka <gniibe@fsij.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

  /project/m32r-linux/kernel/linux-2.6.17-rc1-mm2/linux-2.6.17-rc1-mm2/drivers/serial/m32r_sio.c: In function 'm32r_sio_console_write':
  /project/m32r-linux/kernel/linux-2.6.17-rc1-mm2/linux-2.6.17-rc1-mm2/drivers/serial/m32r_sio.c:1060: warning: unused variable 'i'
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Here is a patch to support a reboot function for M3A-2170(Mappi-III)
evaluation board.
Signed-off-by: Hayato Fujiwara <fujiwara@linux-m32r.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This patch updates include/asm-m32r/semaphore.h for good readability and
maintainability.
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This modification is required to fix debugging function for m32r targets
with !CONFIG_ISA_DSP_LEVEL2, by unifying 'struct pt_regs' and 'struct
sigcontext' size for all M32R ISA.

Some m32r processor core with !CONFIG_ISA_DSP_LEVEL2 configuration has only
single accumulator a0 (ex.  VDEC2 core, M32102 core, etc.), the others with
CONFIG_ISA_DSP_LEVEL2 has two accumulators, a0 and a1.

This means there are two variations of thread context.  So far, we reduced
and changed stackframe size at a syscall for their context size.  However,
this causes a problem that a GDB for processors with CONFIG_ISA_DSP_LEVEL2
cannot be used for processors with !CONFIG_ISA_DSP_LEVEL2.

From the viewpoint of GDB support, we should reduce such variation of
stackframe size for simplicity.

In this patch, dummy members are added to 'struct pt_regs' and 'struct
sigcontext' to adjust their size for !CONFIG_ISA_DSP_LEVEL2.

This modification is also a one step for a GDB update in future.
Currently, on the m32r, GDB can access process's context by using ptrace
functions in a simple way of register by register access.  By unifying
stackframe size, we have a possibility to make use of ptrace functions of
not only a single register access but also block register access,
PTRACE_{GETREGS,PUTREGS}.

However, for this purpose, we might have to modify stackframe structure
some more; for example, PSW (processor status word) register should be
pre-processed before pushing to stack at a syscall, and so on.  In this
case, we must update carefully both kernel and GDB at a time...
Signed-off-by: Hayato Fujiwara <fujiwara@linux-m32r.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Cc: Kei Sakamoto <ksakamot@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Fix section mismatch warnings in x86 cpuid and msr notifier callback
functions.  We can't have these as init (discarded) code.

WARNING: arch/x86_64/kernel/cpuid.o - Section mismatch: reference to .init.text: from .data between 'cpuid_class_cpu_notifier' (at offset 0x0) and 'cpuid_fops'
WARNING: arch/x86_64/kernel/msr.o - Section mismatch: reference to .init.text: from .data between 'msr_class_cpu_notifier' (at offset 0x0) and 'msr_fops'
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

atomic_add_return() if CONFIG_M386 can accidentally enable local interrupts.
Signed-off-by: Lepton Wu <ytht.net@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Fix an off-by-one error in the MLS compatibility code that was causing
contexts with a MLS suffix to be rejected, preventing sharing partitions
between FC4 and FC5.  Bug reported in

   https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=188068Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: James Morris <jmorris@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

In kernel bugzilla #6248 (http://bugzilla.kernel.org/show_bug.cgi?id=6248),
Adrian Bunk <bunk@stusta.de> notes that CONFIG_HUGETLBFS is missing Kconfig
help text.
Signed-off-by: Arthur Othieno <apgo@patchbomb.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Fix up some whitespace damage.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Fix oom_kill_task() so it doesn't call mmput() (which may sleep) while
holding tasklist_lock.
Signed-off-by: David S. Peterson <dsp@llnl.gov>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Dave Peterson <dsp@llnl.gov> points out that badness() is playing with
mm_structs without taking a reference on them.

mmput() can sleep, so taking a reference here (inside tasklist_lock) is
hard.  Fix it up via task_lock() instead.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Convert for-loops that explicitly reference "NR_CPUS" into the
potentially more efficient for_each_possible_cpu() construct.
Signed-off-by: John Hawkes <hawkes@sgi.com>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

The function free_pagedir() used by swsusp for freeing its internal data
structures clears the PG_nosave and PG_nosave_free flags for each page
being freed.

However, during resume PG_nosave_free set means that the page in
question is "unsafe" (ie.  it will be overwritten in the process of
restoring the saved system state from the image), so it should not be
used for the image data.

Therefore free_pagedir() should not clear PG_nosave_free if it's called
during resume (otherwise "unsafe" pages freed by it may be used for
storing the image data and the data may get corrupted later on).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Fix the bitmasks used when writing to the M41T00 registers.

The original code used a mask of 0x7f when writing to each register,
this is incorrect and probably the result of a copy-paste error.  As a
result years from 1980 to 1999 will be read back as 2000 to 2019.
Signed-off-by: David Barksdale <amatus@ocgnet.org>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

MADV_REMOVE fixes - change the test mapping to be MAP_SHARED instead of
MAP_PRIVATE, as MADV_REMOVE on MAP_PRIVATE maps won't work.  Also, use
the kernel's definition of MADV_REMOVE instead of hardcoding it if there
isn't a libc definition.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

for_each_cpu() actually iterates across all possible CPUs.  We've had
mistakes in the past where people were using for_each_cpu() where they
should have been iterating across only online or present CPUs.  This is
inefficient and possibly buggy.

We're renaming for_each_cpu() to for_each_possible_cpu() to avoid this
in the future.

This patch replaces for_each_cpu with for_each_possible_cpu.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

While we can currently walk through thread groups, process groups, and
sessions with just the rcu_read_lock, this opens the door to walking the
entire task list.

We already have all of the other RCU guarantees so there is no cost in
doing this, this should be enough so that proc can stop taking the
tasklist lock during readdir.

prev_task was killed because it has no users, and using it will miss new
tasks when doing an rcu traversal.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This is the minimal fix to make 64-bit UML binaries create 32-bit
compatible COW files and read them.

I've indeed tested that current code doesn't do this - the code gets
SIGFPE for a division by a value read at the wrong place, where 0 is
found.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus: (47 commits)
  [MAINTAINERS] The ham radio code now has website at http://www.linux-ax25.org.
  [MIPS] Use __ffs() instead of ffs() for waybit calculation.
  [MIPS] Fix Makefile bugs for MIPS32/MIPS64 R1 and R2.
  [MIPS] Handle IDE PIO cache aliases on SMP.
  [MIPS] Make mips_srs_init static.
  [MIPS] MIPS boards: Set HZ to 100.
  [MIPS] kgdb: Let gcc compute the array size itself.
  [MIPS] FPU affinity for MT ASE.
  [MIPS] MT: Improved multithreading support.
  [MIPS] kpsd and other AP/SP improvements.
  [MIPS] R2: Instruction hazard barrier.
  [MIPS] Fix genrtc compilation.
  [MIPS] R2: Implement shadow register allocation without spinlock.
  [MIPS] Fix VR41xx build errors.
  [MIPS] Fix tx49_blast_icache32_page_indexed.
  [MIPS] Enable SCHED_NO_NO_OMIT_FRAME_POINTER for MIPS.
  [MIPS] Use "R" constraint for cache_op.
  [MIPS] Rewrite all the assembler interrupt handlers to C.
  [MIPS] Fix the crime against humanity that mipsIRQ.S is.
  [MIPS] Fixup damage done by 22a9835c.
  ...

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

This fixes kernel builds with gcc 3.2 (not 64-bit, that is looking like
it is beyond recovery) and 3.3.  With these bugs fixed we now also can
get undo 3b4c4996a0c24da9e6f8be764e3950b756b18cc0 and similar bits for
SMTC that were added in 79cc8007b93838a670b164b8a55ab3e735a12a8b.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Nothing outside traps.c uses it.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1000Hz will bring an FPGA CPU down on it's knees and it's even worse on
multithreaded cores.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

This is the same method as used in the serial driver.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Signed-off-by: Ralf Roesch <ralf.roesch@rw-gmbh.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>