Reported-by: NDavid Binderman <dcb314@hotmail.com>
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

pr_err() has a KERN_ERR built in.  Smatch complains about these nowadays.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

All other Ethernet drivers are builtin, for NFS root.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

We have a central copy of the GPL for that, and the FSF may change
address again in the future.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Core mm expects __PAGETABLE_{PUD,PMD}_FOLDED to be defined if these page
table levels folded.  Usually, these defines are provided by
<asm-generic/pgtable-nopmd.h> and <asm-generic/pgtable-nopud.h>.

But some architectures fold page table levels in a custom way.  They
need to define these macros themself.  This patch adds missing defines.

The patch fixes mm->nr_pmds underflow and eliminates dead __pmd_alloc()
and __pud_alloc() on architectures without these page table levels.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NAndy Lutomirski <luto@amacapital.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Miller <davem@davemloft.net>
Acked-by: NRichard Weinberger <richard@nod.at>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: NWu Fengguang <fengguang.wu@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We've replaced remap_file_pages(2) implementation with emulation.  Nobody
creates non-linear mapping anymore.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove the function BSP_set_clock_mmss() that is not used anywhere.

This was partially found by using a static code analysis program called cppcheck.
Signed-off-by: NRickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: NGreg Ungerer <gerg@uclinux.org>

Compilation of arch/m68k/68360/commproc.c fails with the following errors:

arch/m68k/68360/commproc.c:75:1: error: function declaration isn’t a prototype
arch/m68k/68360/commproc.c:211:1: error: function declaration isn’t a prototype
arch/m68k/68360/commproc.c: In function ‘cpm_install_handler’:
arch/m68k/68360/commproc.c:214:2: warning: passing argument 2 of ‘request_irq’ from incompatible pointer type
include/linux/interrupt.h:128:1: note: expected ‘irq_handler_t’ but argument is of type ‘void (*)()’

It should be using the proper irq hander type, irq_handler_t. Modify it
to use that.
Signed-off-by: NGreg Ungerer <gerg@uclinux.org>

There used to be a Kconfig symbol BSEIP. It was PPC specific and was
removed in v2.6.27. So the check for CONFIG_BSEIP can be removed. This
means a few defines will be removed. None of the macros involved are
used, so no one should care.
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Signed-off-by: NGreg Ungerer <gerg@uclinux.org>

Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Enable support for Atari EtherNAT (SMC91X) and EtherNEC (NE2000)
Ethernet support in the Atari and multiplatform defconfig files.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Enable CONFIG_DEVTMPFS_MOUNT, as it's useful for initrd-less kernels.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Enable CONFIG_EARLY_PRINTK on all platforms where it's available (all
but Sun-3) and not yet enabled.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

It doesn't hurt to have CONFIG_TEST_* enabled as modules.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

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 fee7e49d ("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: NTakashi Iwai <tiwai@suse.de>
Tested-by: NJan Engelhardt <jengelh@inai.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # "s390 still compiles and boots"
Cc: linux-arch@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

IRQ_TYPE_SLOW, IRQ_TYPE_FAST, and IRQ_TYPE_PRIO are no longer used by
the Atari platform interrupt code since commit 73408565
("[PATCH] m68k: convert atari irq code") in v2.6.18-rc1, so drop them.

Note that their values have been reused for different purposes
(IRQ_TYPE_NONE, IRQ_TYPE_EDGE_RISING, and IRQ_TYPE_EDGE_FALLING) since
commit 6a6de9ef ("[PATCH] genirq: core") in v2.6.18-rc1.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

While working on arch/m68k/include/asm/uaccess.h, I noticed
that one macro within this header is made harder to read because it
violates a coding style rule: space is missing after comma.

Fix it up.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>

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: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>

If CONFIG_VT=n:

arch/m68k/atari/built-in.o: In function `atari_keyboard_interrupt':
atakeyb.c:(.text+0x1846): undefined reference to `keyboard_tasklet'
atakeyb.c:(.text+0x1852): undefined reference to `keyboard_tasklet'

I think the keyboard_tasklet scheduling is no longer needed, as I
believe it's handled by drivers/tty/vt/keyboard.c based on events
received from the input subsystem. So just remove it.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Tested-by: NMichael Schmitz <schmitz@debian.org>

Designing Cards and Drivers for the Macintosh Family, 3rd ed. on page 310
says that the I/O address space for the Mac LC is $50F0 0000 - $50FF FFFF.
The developer notes for the Classic II, LC III and IIvx/IIvi give the same
I/O address space.

That means I've assigned the wrong platform resources to those Mac models.
Fix the scsi_type initialization for the affected models, to restore the
SCSI base address to its value prior to Linux 3.18.

Also rename MAC_SCSI_CCL as MAC_SCSI_LC for the sake of correct chronology.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

As of commit 00f634bc ("asm-generic: add generic futex for
!CONFIG_SMP") asm-generic follows the m68k futex implementation.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Remove the function mvme147_init_console_port() that is not used
anywhere.

This was partially found by using a static code analysis program called
cppcheck.
Signed-off-by: NRickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
[geert: Also remove now unused m147_scc_write(), scc_write(), scc_delay()]
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Remove some functions that are not used anywhere:
atari_kbd_leds() ikbd_exec() ikbd_mem_read() ikbd_mem_write()
ikbd_clock_get() ikbd_clock_set() ikbd_pause() ikbd_resume()

This was partially found by using a static code analysis program called
cppcheck.
Signed-off-by: NRickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

The rtc.o is built for obj-y, i.e. always built in.  It will
never be modular, so using module_init as an alias for __initcall
can be somewhat misleading.

Fix this up now, so that we can relocate module_init from
init.h into module.h in the future.  If we don't do this, we'd
have to add module.h to obviously non-modular code, and that
would be a worse thing.

Note that direct use of __initcall is discouraged, vs. one
of the priority categorized subgroups.  As __initcall gets
mapped onto device_initcall, our use of device_initcall
directly in this change means that the runtime impact is
zero -- it will remain at level 6 in initcall ordering.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Check success of execveat(3, '../execveat', 0)... [OK]
Check success of execveat(5, 'execveat', 0)... [OK]
Check success of execveat(6, 'execveat', 0)... [OK]
Check success of execveat(-100, '/root/selftest-exec/exec/execveat', 0)... [OK]
Check success of execveat(99, '/root/selftest-exec/exec/execveat', 0)... [OK]
Check success of execveat(8, '', 4096)... [OK]
Check success of execveat(17, '', 4096)... [OK]
Check success of execveat(9, '', 4096)... [OK]
Check success of execveat(14, '', 4096)... [OK]
Check success of execveat(14, '', 4096)... [OK]
Check success of execveat(15, '', 4096)... [OK]
Check failure of execveat(8, '', 0) with ENOENT... [OK]
Check failure of execveat(8, '(null)', 4096) with EFAULT... [OK]
Check success of execveat(5, 'execveat.symlink', 0)... [OK]
Check success of execveat(6, 'execveat.symlink', 0)... [OK]
Check success of execveat(-100, '/root/selftest-exec/...xec/execveat.symlink', 0)... [OK]
Check success of execveat(10, '', 4096)... [OK]
Check success of execveat(10, '', 4352)... [OK]
Check failure of execveat(5, 'execveat.symlink', 256) with ELOOP... [OK]
Check failure of execveat(6, 'execveat.symlink', 256) with ELOOP... [OK]
Check failure of execveat(-100, '/root/selftest-exec/exec/execveat.symlink', 256) with ELOOP... [OK]
Check success of execveat(3, '../script', 0)... [OK]
Check success of execveat(5, 'script', 0)... [OK]
Check success of execveat(6, 'script', 0)... [OK]
Check success of execveat(-100, '/root/selftest-exec/exec/script', 0)... [OK]
Check success of execveat(13, '', 4096)... [OK]
Check success of execveat(13, '', 4352)... [OK]
Check failure of execveat(18, '', 4096) with ENOENT... [OK]
Check failure of execveat(7, 'script', 0) with ENOENT... [OK]
Check success of execveat(16, '', 4096)... [OK]
Check success of execveat(16, '', 4096)... [OK]
Check success of execveat(4, '../script', 0)... [OK]
Check success of execveat(4, 'script', 0)... [OK]
Check success of execveat(4, '../script', 0)... [OK]
Check failure of execveat(4, 'script', 0) with ENOENT... [OK]
Check failure of execveat(5, 'execveat', 65535) with EINVAL... [OK]
Check failure of execveat(5, 'no-such-file', 0) with ENOENT... [OK]
Check failure of execveat(6, 'no-such-file', 0) with ENOENT... [OK]
Check failure of execveat(-100, 'no-such-file', 0) with ENOENT... [OK]
Check failure of execveat(5, '', 4096) with EACCES... [OK]
Check failure of execveat(5, 'Makefile', 0) with EACCES... [OK]
Check failure of execveat(11, '', 4096) with EACCES... [OK]
Check failure of execveat(12, '', 4096) with EACCES... [OK]
Check failure of execveat(99, '', 4096) with EBADF... [OK]
Check failure of execveat(99, 'execveat', 0) with EBADF... [OK]
Check failure of execveat(8, 'execveat', 0) with ENOTDIR... [OK]
Invoke copy of 'execveat' via filename of length 4093:
Check success of execveat(19, '', 4096)... [OK]
Check success of execveat(5, 'xxxxxxxxxxxxxxxxxxxx...yyyyyyyyyyyyyyyyyyyy', 0)... [OK]
Invoke copy of 'script' via filename of length 4093:
Check success of execveat(20, '', 4096)... [OK]
Check success of execveat(5, 'xxxxxxxxxxxxxxxxxxxx...yyyyyyyyyyyyyyyyyyyy', 0)... [OK]
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

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

This basically reverts commit 71ae8aac ("lib: introduce arch
optimized hash library") and follow-up work, that is f.e., commit
23721754 ("lib: hash: follow-up fixups for arch hash"),
commit e3fec2f7 ("lib: Add missing arch generic-y entries for
asm-generic/hash.h") and last but not least commit 6a02652d
("perf tools: Fix include for non x86 architectures").

Cc: Francesco Fusco <fusco@ntop.org>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NDaniel Borkmann <dborkman@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Convert sun3_scsi to platform device and eliminate scsi_register().
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Convert atari_scsi to platform device and eliminate scsi_register().

Validate __setup options later on so that module options are checked as well.

Remove the comment about the scsi mid-layer disabling the host irq as it
is no longer true (AFAICT). Also remove the obsolete slow interrupt stuff
(IRQ_TYPE_SLOW == 0 anyway).
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Tested-by: NMichael Schmitz <schmitzmic@gmail.com>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Don't disable irqs when waiting for the ST DMA "lock"; its release may
require an interrupt.

Introduce stdma_try_lock() for use in soft irq context. atari_scsi now tells
the SCSI mid-layer to defer queueing a command if the ST DMA lock is not
available, as per Michael's patch:
http://marc.info/?l=linux-m68k&m=139095335824863&w=2

The falcon_got_lock variable is race prone: we can't disable IRQs while
waiting to acquire the lock, so after acquiring it there must be some
interval during which falcon_got_lock remains false. Introduce
stdma_is_locked_by() to replace falcon_got_lock.

The falcon_got_lock tests in the EH handlers are incorrect these days. It
can happen that an EH handler is called after a command completes normally.
Remove these checks along with falcon_got_lock.

Also remove the complicated and racy fairness wait queues. If fairness is an
issue (when SCSI competes with IDE for the ST DMA interrupt), the solution
is likely to be a lower value for host->can_queue.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Tested-by: NMichael Schmitz <schmitzmic@gmail.com>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Convert mac_scsi to platform device and eliminate scsi_register().

Platform resources for chip registers now follow the documentation. This
should fix issues with the Mac IIci (and possibly other models too).
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

alloc_bootmem and related functions always return a zeroed region of memory.
Thus a memset after calls to these functions is unnecessary.

The following Coccinelle semantic patch was used for making the change:

@@
expression E,E1;
@@

E = \(alloc_bootmem\|alloc_bootmem_low\|alloc_bootmem_pages\|alloc_bootmem_low_pages\)(...)
... when != E
- memset(E,0,E1);
Signed-off-by: NHimangi Saraogi <himangi774@gmail.com>
Acked-by: NJulia Lawall <julia.lawall@lip6.fr>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Acked-by: NAlexei Starovoitov <ast@plumgrid.com>

write{b,w,l}_relaxed are implemented by some architectures in order to
permit memory-mapped I/O accesses with weaker barrier semantics than the
non-relaxed variants.

This patch adds dummy macros for the write accessors to m68k, in the
same vein as the dummy definitions for the relaxed read accessors.
Additionally, the existing relaxed read accessors are moved into
asm/io.h, so that they can be used by m68k targets with an MMU.
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Performing vma lookups without taking the mm->mmap_sem is asking for
trouble.  While doing the search, the vma in question can be modified or
even removed before returning to the caller.  Take the lock (shared) in
order to avoid races while iterating through the vmacache and/or rbtree.
In addition, this guarantees that the address space will remain intact
during the CPU flushing.
Signed-off-by: NDavidlohr Bueso <davidlohr@hp.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

No functional changes
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

hwreg_present() and hwreg_write() temporarily change the VBR register to
another vector table. This table contains a valid bus error handler
only, all other entries point to arbitrary addresses.

If an interrupt comes in while the temporary table is active, the
processor will start executing at such an arbitrary address, and the
kernel will crash.

While most callers run early, before interrupts are enabled, or
explicitly disable interrupts, Finn Thain pointed out that macsonic has
one callsite that doesn't, causing intermittent boot crashes.
There's another unsafe callsite in hilkbd.

Fix this for good by disabling and restoring interrupts inside
hwreg_present() and hwreg_write().

Explicitly disabling interrupts can be removed from the callsites later.
Reported-by: NFinn Thain <fthain@telegraphics.com.au>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@vger.kernel.org