Are there any concerns with merging these into the x86 tree so that they go upstream for 4.8? -- Memory Protection Keys for User pages (pkeys) is a CPU feature which will first appear on Skylake Servers, but will also be supported on future non-server parts. It provides a mechanism for enforcing page-based protections, but without requiring modification of the page tables when an application changes wishes to change permissions. Patches to implement execute-only mapping support using pkeys were merged in to 4.6. But, to do anything else useful with pkeys, an application needs to be able to set the pkey field in the PTE (obviously has to be done in-kernel) and make changes to the "rights" register (using unprivileged instructions). An application also needs to have an an allocator for the keys themselves. If two different parts of an application both want to protect their data with pkeys, they first need to know which key to use for their individual purposes. This set introduces 5 system calls, in 3 logical groups: 1. PTE pkey setting (sys_pkey_mprotect(), patches #1-3) 2. Key allocation (sys_pkey_alloc() / sys_pkey_free(), patch #4) 3. Rights register manipulation (sys_pkey_set/get(), patch #5) These patches build on top of "core" pkeys support already in 4.6, and are based on 4.6 itself with the compat siginfo fix patches applied (includes MPX selftests). I have manpages written for some of these syscalls, and have had multiple rounds of reviews on the manpages list. This set is also available here (including a fix for the compat signal handler code): git://git.kernel.org/pub/scm/linux/kernel/git/daveh/x86-pkeys.git pkeys-v034 I've written a set of unit tests for these interfaces, which is available as the last patch in the series and integrated in to kselftests. Note: this is based on a plain 4.6 kernel and will have a minor merge conflict in the x86 selftests makefile with the new MPX selftest if those get merged first. === diffstat === Dave Hansen (8): x86, pkeys: add fault handling for PF_PK page fault bit mm: implement new pkey_mprotect() system call x86, pkeys: make mprotect_key() mask off additional vm_flags x86: wire up mprotect_key() system call x86, pkeys: allocation/free syscalls x86, pkeys: add pkey set/get syscalls pkeys: add details of system call use to Documentation/ x86, pkeys: add self-tests Documentation/x86/protection-keys.txt | 63 + arch/alpha/include/uapi/asm/mman.h | 5 + arch/mips/include/uapi/asm/mman.h | 5 + arch/parisc/include/uapi/asm/mman.h | 5 + arch/x86/entry/syscalls/syscall_32.tbl | 5 + arch/x86/entry/syscalls/syscall_64.tbl | 5 + arch/x86/include/asm/mmu.h | 8 + arch/x86/include/asm/mmu_context.h | 25 +- arch/x86/include/asm/pkeys.h | 80 +- arch/x86/kernel/fpu/xstate.c | 73 +- arch/x86/mm/fault.c | 9 + arch/x86/mm/pkeys.c | 38 +- arch/xtensa/include/uapi/asm/mman.h | 5 + include/linux/pkeys.h | 39 +- include/uapi/asm-generic/mman-common.h | 5 + mm/mprotect.c | 134 +- tools/testing/selftests/x86/Makefile | 2 +- tools/testing/selftests/x86/pkey-helpers.h | 187 +++ tools/testing/selftests/x86/protection_keys.c | 1249 +++++++++++++++++ 19 files changed, 1912 insertions(+), 30 deletions(-) Cc: linux-api@xxxxxxxxxxxxxxx Cc: linux-arch@xxxxxxxxxxxxxxx Cc: linux-mm@xxxxxxxxx Cc: x86@xxxxxxxxxx Cc: torvalds@xxxxxxxxxxxxxxxxxxxx Cc: akpm@xxxxxxxxxxxxxxxxxxxx -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>