kernel/arch/powerpc/include/asm/pkeys.h, branch linux-6.2.y

powerpc/pkeys: Remove unused code

2021-02-08T14:09:44Z

This removes arch_supports_pkeys(), arch_usable_pkeys() and thread_pkey_regs_*() which are remnants from the following: commit 06bb53b33804 ("powerpc: store and restore the pkey state across context switches") commit 2cd4bd192ee9 ("powerpc/pkeys: Fix handling of pkey state across fork()") commit cf43d3b26452 ("powerpc: Enable pkey subsystem") arch_supports_pkeys() and arch_usable_pkeys() were unused since their introduction while thread_pkey_regs_*() became unused after the introduction of the following: commit d5fa30e6993f ("powerpc/book3s64/pkeys: Reset userspace AMR correctly on exec") commit 48a8ab4eeb82 ("powerpc/book3s64/pkeys: Don't update SPRN_AMR when in kernel mode") Signed-off-by: Sandipan Das Reviewed-by: Ram Pai Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210202150050.75335-1-sandipan@linux.ibm.com

powerpc/book3s64/pkeys: Use MMU_FTR_PKEY instead of pkey_disabled static key

2020-07-20T12:57:59Z

Instead of pkey_disabled static key use mmu feature MMU_FTR_PKEY. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200709032946.881753-17-aneesh.kumar@linux.ibm.com

powerpc/book3s64/pkeys: Use pkey_execute_disable_supported

2020-07-20T12:57:59Z

Use pkey_execute_disable_supported to check for execute key support instead of pkey_disabled. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200709032946.881753-16-aneesh.kumar@linux.ibm.com

powerpc/book3s64/pkeys: Make initial_allocation_mask static

2020-07-20T12:57:58Z

initial_allocation_mask is not used outside this file. Also mark reserved_allocation_mask and initial_allocation_mask __ro_after_init; Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200709032946.881753-12-aneesh.kumar@linux.ibm.com

powerpc/book3s64/pkeys: Convert pkey_total to num_pkey

2020-07-20T12:57:58Z

num_pkey now represents max number of keys supported such that we return to userspace 0 - num_pkey - 1. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200709032946.881753-11-aneesh.kumar@linux.ibm.com

powerpc/book3s64/pkeys: Simplify pkey disable branch

2020-07-20T12:57:58Z

Make the default value FALSE (pkey enabled) and set to TRUE when we find the total number of keys supported to be zero. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200709032946.881753-10-aneesh.kumar@linux.ibm.com

powerpc/book3s64/pkeys: pkeys are supported only on hash on book3s.

2020-07-20T12:57:57Z

Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200709032946.881753-4-aneesh.kumar@linux.ibm.com

powerpc/book3s64/pkeys: Fixup bit numbering

2020-07-20T12:57:57Z

This number the pkey bit such that it is easy to follow. PKEY_BIT0 is the lower order bit. This makes further changes easy to follow. No functional change in this patch other than linux page table for hash translation now maps pkeys differently. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200709032946.881753-3-aneesh.kumar@linux.ibm.com

mmap locking API: convert mmap_sem comments

2020-06-09T16:39:14Z

Convert comments that reference mmap_sem to reference mmap_lock instead. [akpm@linux-foundation.org: fix up linux-next leftovers] [akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil] [akpm@linux-foundation.org: more linux-next fixups, per Michel] Signed-off-by: Michel Lespinasse Signed-off-by: Andrew Morton Reviewed-by: Vlastimil Babka Reviewed-by: Daniel Jordan Cc: Davidlohr Bueso Cc: David Rientjes Cc: Hugh Dickins Cc: Jason Gunthorpe Cc: Jerome Glisse Cc: John Hubbard Cc: Laurent Dufour Cc: Liam Howlett Cc: Matthew Wilcox Cc: Peter Zijlstra Cc: Ying Han Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com Signed-off-by: Linus Torvalds

powerpc/pkeys: make protection key 0 less special

2018-07-24T11:43:24Z

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 [mpe: Drop #define PKEY_0 0 in favour of plain old 0] Signed-off-by: Michael Ellerman