!8237 x86: profiling: Using generic unwinding in profile_pc

#include <asm/timer.h>

#include <asm/hpet.h>

#include <asm/time.h>

#include <asm/unwind.h>

unsigned long profile_pc(struct pt_regs *regs)

{

	unsigned long pc = instruction_pointer(regs);

	if (!user_mode(regs) && in_lock_functions(pc)) {

#ifdef CONFIG_FRAME_POINTER

		return *(unsigned long *)(regs->bp + sizeof(long));

#else

		unsigned long *sp = (unsigned long *)regs->sp;

		/*

		 * Return address is either directly at stack pointer

		 * or above a saved flags. Eflags has bits 22-31 zero,

		 * kernel addresses don't.

		 */

		if (sp[0] >> 22)

			return sp[0];

		if (sp[1] >> 22)

			return sp[1];

#endif

		struct unwind_state state;

		/* unwind_start will skip the first regs frame */

		unwind_start(&state, current, regs, NULL);

		pc = unwind_get_return_address(&state);

	}

	return pc;

}