perf/x86: Fix offcore_rsp valid mask for SNB/IVB

The valid mask for both offcore_response_0 and
offcore_response_1 was wrong for SNB/SNB-EP,
IVB/IVB-EP. It was possible to write to
reserved bit and cause a GP fault crashing
the kernel.

This patch fixes the problem by correctly marking the
reserved bits in the valid mask for all the processors
mentioned above.

A distinction between desktop and server parts is introduced
because bits 24-30 are only available on the server parts.

This version of the  patch is just a rebase to perf/urgent tree
and should apply to older kernels as well.

Signed-off-by: Stephane Eranian <eranian@google.com>
Cc: peterz@infradead.org
Cc: jolsa@redhat.com
Cc: gregkh@linuxfoundation.org
Cc: security@kernel.org
Cc: ak@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
struct intel_shared_regs *allocate_shared_regs(int cpu)
{
	struct intel_shared_regs *regs;
	int i;

	regs = kzalloc_node(sizeof(struct intel_shared_regs),
			    GFP_KERNEL, cpu_to_node(cpu));
	if (regs) {
		/*
		 * initialize the locks to keep lockdep happy
		 */
		for (i = 0; i < EXTRA_REG_MAX; i++)
			raw_spin_lock_init(&regs->regs[i].lock);

		regs->core_id = -1;
	}
	return regs;
}

struct intel_shared_regs *allocate_shared_regs(int cpu)
{
	struct intel_shared_regs *regs;
	int i;

	regs = kzalloc_node(sizeof(struct intel_shared_regs),
			    GFP_KERNEL, cpu_to_node(cpu));
	if (regs) {
		/*
		 * initialize the locks to keep lockdep happy
		 */
		for (i = 0; i < EXTRA_REG_MAX; i++)
			raw_spin_lock_init(&regs->regs[i].lock);

		regs->core_id = -1;
	}
	return regs;
}
