powerpc/mm: Fix spurrious segfaults on radix with autonuma

When autonuma (Automatic NUMA balancing) marks a PTE inaccessible it
clears all the protection bits but leave the PTE valid.

With the Radix MMU, an attempt at executing from such a PTE will
take a fault with bit 35 of SRR1 set "SRR1_ISI_N_OR_G".

It is thus incorrect to treat all such faults as errors. We should
pass them to handle_mm_fault() for autonuma to deal with. The case
of pages that are really not executable is handled by the existing
test for VM_EXEC further down.

That leaves us with catching the kernel attempts at executing user
pages. We can catch that earlier, even before we do find_vma.

It is never valid on powerpc for the kernel to take an exec fault
to begin with. So fold that test with the existing test for the
kernel faulting on kernel addresses to bail out early.

Fixes: 1d18ad026844 ("powerpc/mm: Detect instruction fetch denied and report")
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

path: root/include/acpi/acpi_numa.h

#ifndef __ACPI_NUMA_H
#define __ACPI_NUMA_H

#ifdef CONFIG_ACPI_NUMA
#include <linux/kernel.h>

/* Proximity bitmap length */
#if MAX_NUMNODES > 256
#define MAX_PXM_DOMAINS MAX_NUMNODES
#else
#define MAX_PXM_DOMAINS (256)	/* Old pxm spec is defined 8 bit */
#endif

extern int pxm_to_node(int);
extern int node_to_pxm(int);
extern int acpi_map_pxm_to_node(int);
extern unsigned char acpi_srat_revision;
extern int acpi_numa __initdata;

extern void bad_srat(void);
extern int srat_disabled(void);

#endif				/* CONFIG_ACPI_NUMA */
#endif				/* __ACP_NUMA_H */