We must use the "a" (allocate) attribute every time we
emit an entry into the __ex_table section.

For consistency, use "a" instead of #alloc which is some
Solaris compat cruft GNU as provides on Sparc.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We were not calling kernel_mna_trap_fault() correctly.
Instead of being fancy, just return 0 vs. -EFAULT from
the assembler stubs, and handle that return value as
appropriate.

Create an "__retl_efault" stub for assembler exception
table entries and use it where possible.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Because we use byte loads/stores to cons up the value
in and out of registers, we can't expect the ASI endianness
setting to take care of this for us.  So do it by hand.

This case is triggered by drivers/block/aoe/aoecmd.c in the
ataid_complete() function where it goes:

		/* word 100: number lba48 sectors */
		ssize = le64_to_cpup((__le64 *) &id[100<<1]);

This &id[100<<1] address is 4 byte, rather than 8 byte aligned,
thus triggering the unaligned exception.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

GCC 4.x really dislikes the games we are playing in
unaligned.c, and the cleanest way to fix this is to
move things into assembler.

Noted by Al Viro.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>