Patch from Daniel Jacobowitz

The ARM kernel has several uses of asm("foo%?").  %? is a GCC internal
modifier used to output conditional execution predicates.  However, no
version of GCC supports conditionalizing asm statements.  GCC 4.2 will
correctly expand %? to the empty string in user asms.  Earlier versions may
reuse the condition from the previous instruction.  In 'if (foo) asm
("bar%?");' this is somewhat likely to be right... but not reliable.

So, the only safe thing to do is to remove the uses of %?.  I believe
the tlbflush.h occurances were supposed to be removed before, based
on the comment about %? not working at the top of that file.

Old versions of GCC could omit branches around user asms if the asm didn't
mark the condition codes as clobbered.  This problem hasn't been seen on any
recent (3.x or 4.x) GCC, but it could theoretically happen.  So, where
%? was removed a cc clobber was added.

Signed-off-by: Daniel Jacobowitz <dan@codesourcery.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Previously the message was "Fatal exception: panic_on_oops", as introduced
in a recent patch whith removed a somewhat dangerous call to ssleep() in
the panic_on_oops path.  However, Paul Mackerras suggested that this was
somewhat confusing, leadind people to believe that it was panic_on_oops
that was the root cause of the fatal exception.  On his suggestion, this
patch changes the message to simply "Fatal exception".  A suitable oops
message should already have been displayed.

Signed-off-by: Simon Horman <horms@verge.net.au>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

This patch is part of an effort to unify the panic_on_oops behaviour across
all architectures that implement it.

It was pointed out to me by Andi Kleen that if an oops has occured in
interrupt context, then calling sleep() in the oops path will only cause a
panic, and that it would be really better for it not to be in the path at
all.

This patch removes the ssleep() call and reworks the console message
accordinly.  I have a slght concern that the resulting console message is
too long, feedback welcome.

For powerpc it also unifies the 32bit and 64bit behaviour.

Fror x86_64, this patch only updates the console message, as ssleep() is
already not present.

Signed-off-by: Horms <horms@verge.net.au>
Acked-by: Paul Mackerras <paulus@samba.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

The high page vector (0xFFFF0000) does not supported in nommu mode.
This patch allows the vectors to be 0x00000000 or the begining of DRAM
in nommu mode.

Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Patch from Nicolas Pitre

Quoting RMK:

|pte_write() just says that the page _may_ be writable. It doesn't say
|that the MMU is programmed to allow writes. If pte_dirty() doesn't
|return true, that means that the page is _not_ writable from userspace.
|If you write to it from kernel mode (without using put_user) you'll
|bypass the MMU read-only protection and may end up writing to a page
|owned by two separate processes.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Although you could ask the kernel for panic-on-oops, it remained
non-functional because the architecture specific code fragment had
not been implemented.  Add it, so it works as advertised.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Patch from Nicolas Pitre

For a while we wanted to change the way syscalls were called on ARM.
Instead of encoding the syscall number in the swi instruction which
requires reading back the instruction from memory to extract that number
and polluting the data cache, it was decided that simply storing the
syscall number into r7 would be more efficient. Since this represents
an ABI change then making that change at the same time as EABI support
is the right thing to do.

It is now expected that EABI user space binaries put the syscall number
into r7 and use "swi 0" to call the kernel. Syscall register argument
are also expected to have "EABI arrangement" i.e. 64-bit arguments
should be put in a pair of registers from an even register number.

Example with long ftruncate64(unsigned int fd, loff_t length):

	legacy ABI:
	- put fd into r0
	- put length into r1-r2
	- use "swi #(0x900000 + 194)" to call the kernel

	new ARM EABI:
	- put fd into r0
	- put length into r2-r3 (skipping over r1)
	- put 194 into r7
	- use "swi 0" to call the kernel

Note that it is important to use 0 for the swi argument as backward
compatibility with legacy ABI user space relies on this.
The syscall macros in asm-arm/unistd.h were also updated to support
both ABIs and implement the right call method automatically.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>