linux/arch/powerpc/mm
Ram Pai 07f522d203 powerpc/pkeys: make protection key 0 less special
Applications need the ability to associate an address-range with some
key and latter revert to its initial default key. Pkey-0 comes close to
providing this function but falls short, because the current
implementation disallows applications to explicitly associate pkey-0 to
the address range.

Lets make pkey-0 less special and treat it almost like any other key.
Thus it can be explicitly associated with any address range, and can be
freed. This gives the application more flexibility and power.  The
ability to free pkey-0 must be used responsibily, since pkey-0 is
associated with almost all address-range by default.

Even with this change pkey-0 continues to be slightly more special
from the following point of view.
(a) it is implicitly allocated.
(b) it is the default key assigned to any address-range.
(c) its permissions cannot be modified by userspace.

NOTE: (c) is specific to powerpc only. pkey-0 is associated by default
with all pages including kernel pages, and pkeys are also active in
kernel mode. If any permission is denied on pkey-0, the kernel running
in the context of the application will be unable to operate.

Tested on powerpc.

Signed-off-by: Ram Pai <linuxram@us.ibm.com>
[mpe: Drop #define PKEY_0 0 in favour of plain old 0]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-24 21:43:24 +10:00
..
8xx_mmu.c powerpc/mm/slice: Fix hugepage allocation at hint address on 8xx 2018-03-06 09:21:23 +11:00
40x_mmu.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
44x_mmu.c
copro_fault.c powerpc/mm: Add support for handling > 512TB address in SLB miss 2018-03-31 00:10:38 +11:00
dma-noncoherent.c powerpc/mm: Rename map_page() to map_kernel_page() on 32-bit 2017-06-05 19:59:03 +10:00
drmem.c powerpc/mm/drmem: Fix unexpected flag value in ibm,dynamic-memory-v2 2018-02-23 16:45:51 +11:00
dump_hashpagetable.c powerpc/64s: Replace CONFIG_PPC_STD_MMU_64 with CONFIG_PPC_BOOK3S_64 2017-11-06 16:48:14 +11:00
dump_linuxpagetables.c powerpc/mm: Introduce _PAGE_NA 2018-01-16 23:47:14 +11:00
fault.c powerpc updates for 4.18 2018-06-07 10:23:33 -07:00
fsl_booke_mmu.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
hash64_4k.c powerpc/mm/hash64: Store the slot information at the right offset for hugetlb 2018-02-13 22:37:48 +11:00
hash64_64k.c powerpc/mm/hash64: Store the slot information at the right offset for hugetlb 2018-02-13 22:37:48 +11:00
hash_low_32.S powerpc: fix location of two EXPORT_SYMBOL 2017-09-01 16:42:45 +10:00
hash_native_64.c Merge branch 'fixes' into next 2018-03-28 22:59:50 +11:00
hash_utils_64.c powerpc/64s: Remove POWER9 DD1 support 2018-07-16 11:37:21 +10:00
highmem.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hugepage-hash64.c powerpc/mm: Move hash table ops to a separate structure 2016-07-21 18:59:09 +10:00
hugetlbpage-book3e.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hugetlbpage-hash64.c powerpc/mm/hash64: Store the slot information at the right offset for hugetlb 2018-02-13 22:37:48 +11:00
hugetlbpage-radix.c powerpc updates for 4.15 2017-11-16 12:47:46 -08:00
hugetlbpage.c powerpc/hugetlbpage: Rmove unhelpful HUGEPD_*_SHIFT macros 2018-07-19 14:38:46 +10:00
init_32.c powerpc/mm/32: Remove the reserved memory hack 2018-04-01 00:47:44 +11:00
init_64.c powerpc/mm/radix: Parse disable_radix commandline correctly. 2018-04-04 16:59:36 +10:00
init-common.c powerpc/mm: Fix crashes with 16G huge pages 2018-02-13 22:37:47 +11:00
Makefile powerpc: initial pkey plumbing 2018-01-20 21:45:03 +11:00
mem.c treewide: use PHYS_ADDR_MAX to avoid type casting ULLONG_MAX 2018-06-15 07:55:25 +09:00
mmap.c exec: pass stack rlimit into mm layout functions 2018-04-11 10:28:37 -07:00
mmu_context_book3s64.c powerpc/64s: Remove POWER9 DD1 support 2018-07-16 11:37:21 +10:00
mmu_context_hash32.c powerpc: Remove power3 from comments 2014-07-28 14:10:26 +10:00
mmu_context_iommu.c treewide: Use array_size() in vzalloc() 2018-06-12 16:19:22 -07:00
mmu_context_nohash.c powerpc/mm: Remove stale_map[] handling on non SMP processors 2018-06-04 00:39:16 +10:00
mmu_context.c powerpc/64s/radix: optimise pte_update 2018-06-03 20:40:36 +10:00
mmu_decl.h powerpc/mm/32: Remove the reserved memory hack 2018-04-01 00:47:44 +11:00
numa.c treewide: kzalloc() -> kcalloc() 2018-06-12 16:19:22 -07:00
pgtable_32.c powerpc/mm/32: Remove the reserved memory hack 2018-04-01 00:47:44 +11:00
pgtable_64.c powerpc/mm: Use page fragments for allocation page table at PMD level 2018-05-15 22:29:12 +10:00
pgtable-book3e.c powerpc/mm: Make page table size a variable 2016-05-01 18:32:48 +10:00
pgtable-book3s64.c powerpc/mm/hash/4k: Free hugetlb page table caches correctly. 2018-06-20 09:13:25 +10:00
pgtable-hash64.c powerpc/mm: Use pmd_lockptr instead of opencoding it 2018-05-15 22:29:09 +10:00
pgtable-radix.c powerpc/64s: Remove POWER9 DD1 support 2018-07-16 11:37:21 +10:00
pgtable.c powerpc/mm/hugetlb: Update hugetlb related locks 2018-06-03 20:40:37 +10:00
pkeys.c powerpc/pkeys: make protection key 0 less special 2018-07-24 21:43:24 +10:00
ppc_mmu_32.c powerpc/sparse: Fix plain integer as NULL pointer warning 2018-05-25 12:04:38 +10:00
slb_low.S powerpc/mm: Add support for handling > 512TB address in SLB miss 2018-03-31 00:10:38 +11:00
slb.c powerpc/mm/hash: hard disable irq in the SLB insert path 2018-06-03 20:40:38 +10:00
slice.c powerpc/8xx: Fix build with hugetlbfs enabled 2018-04-11 12:00:23 +10:00
subpage-prot.c powerpc: Remove -Wattribute-alias pragmas 2018-06-25 23:21:13 +09:00
tlb_hash32.c powerpc/sparse: Fix plain integer as NULL pointer warning 2018-05-25 12:04:38 +10:00
tlb_hash64.c powerpc/mm: Add support for handling > 512TB address in SLB miss 2018-03-31 00:10:38 +11:00
tlb_low_64e.S powerpc: Fix misspellings in comments. 2016-03-01 19:27:20 +11:00
tlb_nohash_low.S powerpc/8xx: Getting rid of remaining use of CONFIG_8xx 2017-08-10 23:32:12 +10:00
tlb_nohash.c powerpc/mm/nohash: do not flush the entire mm when range is a single page 2018-01-27 20:24:44 +11:00
tlb-radix.c Merge branch 'topic/ppc-kvm' into next 2018-07-19 14:37:57 +10:00
vphn.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
vphn.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00