Commit 013a91b3 authored by Ram Pai's avatar Ram Pai Committed by Michael Ellerman
Browse files

powerpc: ability to associate pkey to a vma 



arch-independent code expects the arch to  map
a  pkey  into the vma's protection bit setting.
The patch provides that ability.

Signed-off-by: default avatarRam Pai <linuxram@us.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 5586cf61

arch/powerpc/include/asm/mman.h

+6 −1
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 


#include <asm/cputable.h>

#include <linux/mm.h>

#include <linux/pkeys.h>

#include <asm/cpu_has_feature.h>



/*
@@ -22,7 +23,11 @@ 
static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot,

		unsigned long pkey)

{

	return (prot & PROT_SAO) ? VM_SAO : 0;

#ifdef CONFIG_PPC_MEM_KEYS

	return (((prot & PROT_SAO) ? VM_SAO : 0) | pkey_to_vmflag_bits(pkey));

#else

	return ((prot & PROT_SAO) ? VM_SAO : 0);

#endif

}

#define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)

arch/powerpc/include/asm/pkeys.h

+11 −0
Original line number Diff line number Diff line
@@ -30,6 +30,17 @@ extern u32 initial_allocation_mask; /* bits set for reserved keys */ 
#define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | \

			    VM_PKEY_BIT3 | VM_PKEY_BIT4)



/* Override any generic PKEY permission defines */

#define PKEY_DISABLE_EXECUTE   0x4

#define PKEY_ACCESS_MASK       (PKEY_DISABLE_ACCESS | \

				PKEY_DISABLE_WRITE  | \

				PKEY_DISABLE_EXECUTE)



static inline u64 pkey_to_vmflag_bits(u16 pkey)

{

	return (((u64)pkey << VM_PKEY_SHIFT) & ARCH_VM_PKEY_FLAGS);

}



#define arch_max_pkey() pkeys_total



#define pkey_alloc_mask(pkey) (0x1 << pkey)

arch/powerpc/mm/pkeys.c

+8 −0
Original line number Diff line number Diff line
@@ -34,6 +34,14 @@ int pkey_initialize(void) 
	BUILD_BUG_ON(PKEY_DISABLE_EXECUTE &

		     (PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE));



	/*

	 * pkey_to_vmflag_bits() assumes that the pkey bits are contiguous

	 * in the vmaflag. Make sure that is really the case.

	 */

	BUILD_BUG_ON(__builtin_clzl(ARCH_VM_PKEY_FLAGS >> VM_PKEY_SHIFT) +

		     __builtin_popcountl(ARCH_VM_PKEY_FLAGS >> VM_PKEY_SHIFT)

				!= (sizeof(u64) * BITS_PER_BYTE));



	/*

	 * Disable the pkey system till everything is in place. A subsequent

	 * patch will enable it.