arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections

arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections

KASAN needs to know whether the allocation happens in an IRQ handler.
This lets us strip everything below the IRQ entry point to reduce the
number of unique stack traces needed to be stored.

Move the definition of __irq_entry to <linux/interrupt.h> so that the
users don't need to pull in <linux/ftrace.h>.  Also introduce the
__softirq_entry macro which is similar to __irq_entry, but puts the
corresponding functions to the .softirqentry.text section.

Signed-off-by: Alexander Potapenko <[email protected]>
Acked-by: Steven Rostedt <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Andrey Konovalov <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Konstantin Serebryany <[email protected]>
Cc: Dmitry Chernenkov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>