Sorry please ignore this series. It was a duplication mistake. I aborted the send midway, but a few escaped into the cyber. RP On Mon, Jan 22, 2018 at 10:26:29AM -0800, Ram Pai wrote: > Memory protection keys enable applications to protect its > address space from inadvertent access from or corruption > by itself. > > These patches along with the pte-bit freeing patch series > enables the protection key feature on powerpc; 4k and 64k > hashpage kernels. > > Will send the documentation and selftest patches separately > > All patches can be found at -- > https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_rampai_memorykeys.git&d=DwIBAg&c=jf_iaSHvJObTbx-siA1ZOg&r=m-UrKChQVkZtnPpjbF6YY99NbT8FBByQ-E-ygV8luxw&m=Swwnka5M5weiMNnxmx35NOJUSSC3s8iQYEH4hsrCNSw&s=h7BFHYo7gWvagk3xbtcifI_3xFOO1CyWzfOtLBjWLcQ&e= memkey.v10 > > > The overall idea: > ----------------- > A process allocates a key and associates it with > an address range within its address space. > The process then can dynamically set read/write > permissions on the key without involving the > kernel. Any code that violates the permissions > of the address space; as defined by its associated > key, will receive a segmentation fault. > > This patch series enables the feature on PPC64 HPTE > platform. > > ISA3.0 section 5.7.13 describes the detailed > specifications. > > > Highlevel view of the design: > --------------------------- > When an application associates a key with a address > address range, program the key in the Linux PTE. > When the MMU detects a page fault, allocate a hash > page and program the key into HPTE. And finally > when the MMU detects a key violation; due to > invalid application access, invoke the registered > signal handler and provide the violated key number. > > > Testing: > ------- > This patch series has passed all the protection key > tests available in the selftest directory.The > tests are updated to work on both x86 and powerpc. > The selftests have passed on x86 and powerpc hardware. > > History: > ------- > version v10: > (1) key-fault in page-fault handler > is handled as normal fault > and not as a bad fault. > (2) changed device tree scanning to > unflattened device tree. > (3) fixed a bug in the logic that detected > the total number of available pkeys. > (4) dropped two patches. (i) sysfs interface > (ii) sys_pkey_modif() syscall > > version v9: > (1) used jump-labels to optimize code > -- Balbir > (2) fixed a register initialization bug noted > by Balbir > (3) fixed inappropriate use of paca to pass > siginfo and keys to signal handler > (4) Cleanup of comment style not to be right > justified -- mpe > (5) restructured the patches to depend on the > availability of VM_PKEY_BIT4 in > include/linux/mm.h > (6) Incorporated comments from Dave Hansen > towards changes to selftest and got > them tested on x86. > > version v8: > (1) Contents of the AMR register withdrawn from > the siginfo structure. Applications can always > read the AMR register. > (2) AMR/IAMR/UAMOR are now available through > ptrace system call. -- thanks to Thiago > (3) code changes to handle legacy power cpus > that do not support execute-disable. > (4) incorporates many code improvement > suggestions. > > version v7: > (1) refers to device tree property to enable > protection keys. > (2) adds 4K PTE support. > (3) fixes a couple of bugs noticed by Thiago > (4) decouples this patch series from arch- > independent code. This patch series can > now stand by itself, with one kludge > patch(2). > version v7: > (1) refers to device tree property to enable > protection keys. > (2) adds 4K PTE support. > (3) fixes a couple of bugs noticed by Thiago > (4) decouples this patch series from arch- > independent code. This patch series can > now stand by itself, with one kludge > patch(2). > > version v6: > (1) selftest changes are broken down into 20 > incremental patches. > (2) A separate key allocation mask that > includes PKEY_DISABLE_EXECUTE is > added for powerpc > (3) pkey feature is enabled for 64K HPT case > only. RPT and 4k HPT is disabled. > (4) Documentation is updated to better > capture the semantics. > (5) introduced arch_pkeys_enabled() to find > if an arch enables pkeys. Correspond- > ing change the logic that displays > key value in smaps. > (6) code rearranged in many places based on > comments from Dave Hansen, Balbir, > Anshuman. > (7) fixed one bug where a bogus key could be > associated successfully in > pkey_mprotect(). > > version v5: > (1) reverted back to the old design -- store > the key in the pte, instead of bypassing > it. The v4 design slowed down the hash > page path. > (2) detects key violation when kernel is told > to access user pages. > (3) further refined the patches into smaller > consumable units > (4) page faults handlers captures the fault- > ing key > from the pte instead of the vma. This > closes a race between where the key > update in the vma and a key fault caused > by the key programmed in the pte. > (5) a key created with access-denied should > also set it up to deny write. Fixed it. > (6) protection-key number is displayed in > smaps the x86 way. > > version v4: > (1) patches no more depend on the pte bits > to program the hpte > -- comment by Balbir > (2) documentation updates > (3) fixed a bug in the selftest. > (4) unlike x86, powerpc lets signal handler > change key permission bits; the > change will persist across signal > handler boundaries. Earlier we > allowed the signal handler to > modify a field in the siginfo > structure which would than be used > by the kernel to program the key > protection register (AMR) > -- resolves a issue raised by Ben. > "Calls to sys_swapcontext with a > made-up context will end up with a > crap AMR if done by code who didn't > know about that register". > (5) these changes enable protection keys on > 4k-page kernel aswell. > > version v3: > (1) split the patches into smaller consumable > patches. > (2) added the ability to disable execute > permission on a key at creation. > (3) rename calc_pte_to_hpte_pkey_bits() to > pte_to_hpte_pkey_bits() > -- suggested by Anshuman > (4) some code optimization and clarity in > do_page_fault() > (5) A bug fix while invalidating a hpte slot > in __hash_page_4K() > -- noticed by Aneesh > > > version v2: > (1) documentation and selftest added. > (2) fixed a bug in 4k hpte backed 64k pte > where page invalidation was not > done correctly, and initialization > of second-part-of-the-pte was not > done correctly if the pte was not > yet Hashed with a hpte. > -- Reported by Aneesh. > (3) Fixed ABI breakage caused in siginfo > structure. > -- Reported by Anshuman. > > > version v1: Initial version > > > Ram Pai (26): > mm, powerpc, x86: define VM_PKEY_BITx bits if CONFIG_ARCH_HAS_PKEYS > is enabled > mm, powerpc, x86: introduce an additional vma bit for powerpc pkey > powerpc: initial pkey plumbing > powerpc: track allocation status of all pkeys > powerpc: helper function to read,write AMR,IAMR,UAMOR registers > powerpc: helper functions to initialize AMR, IAMR and UAMOR registers > powerpc: cleanup AMR, IAMR when a key is allocated or freed > powerpc: implementation for arch_set_user_pkey_access() > powerpc: ability to create execute-disabled pkeys > powerpc: store and restore the pkey state across context switches > powerpc: introduce execute-only pkey > powerpc: ability to associate pkey to a vma > powerpc: implementation for arch_override_mprotect_pkey() > powerpc: map vma key-protection bits to pte key bits. > powerpc: Program HPTE key protection bits > powerpc: helper to validate key-access permissions of a pte > powerpc: check key protection for user page access > powerpc: implementation for arch_vma_access_permitted() > powerpc: Handle exceptions caused by pkey violation > powerpc: introduce get_mm_addr_key() helper > powerpc: Deliver SEGV signal on pkey violation > powerpc: Enable pkey subsystem > powerpc: sys_pkey_alloc() and sys_pkey_free() system calls > powerpc: sys_pkey_mprotect() system call > mm, x86 : introduce arch_pkeys_enabled() > mm: display pkey in smaps if arch_pkeys_enabled() is true > > Thiago Jung Bauermann (1): > powerpc/ptrace: Add memory protection key regset > > arch/powerpc/Kconfig | 15 + > arch/powerpc/include/asm/book3s/64/mmu-hash.h | 5 + > arch/powerpc/include/asm/book3s/64/mmu.h | 10 + > arch/powerpc/include/asm/book3s/64/pgtable.h | 48 +++- > arch/powerpc/include/asm/bug.h | 1 + > arch/powerpc/include/asm/cputable.h | 16 +- > arch/powerpc/include/asm/mman.h | 13 +- > arch/powerpc/include/asm/mmu.h | 9 + > arch/powerpc/include/asm/mmu_context.h | 22 ++ > arch/powerpc/include/asm/pkeys.h | 229 ++++++++++++ > arch/powerpc/include/asm/processor.h | 5 + > arch/powerpc/include/asm/reg.h | 1 - > arch/powerpc/include/asm/systbl.h | 3 + > arch/powerpc/include/asm/unistd.h | 6 +- > arch/powerpc/include/uapi/asm/elf.h | 1 + > arch/powerpc/include/uapi/asm/mman.h | 6 + > arch/powerpc/include/uapi/asm/unistd.h | 3 + > arch/powerpc/kernel/exceptions-64s.S | 2 +- > arch/powerpc/kernel/process.c | 7 + > arch/powerpc/kernel/ptrace.c | 66 ++++ > arch/powerpc/kernel/traps.c | 19 +- > arch/powerpc/mm/Makefile | 1 + > arch/powerpc/mm/fault.c | 49 +++- > arch/powerpc/mm/hash_utils_64.c | 26 ++ > arch/powerpc/mm/mmu_context_book3s64.c | 2 + > arch/powerpc/mm/pkeys.c | 469 +++++++++++++++++++++++++ > arch/x86/include/asm/pkeys.h | 1 + > arch/x86/kernel/fpu/xstate.c | 5 + > arch/x86/kernel/setup.c | 8 - > fs/proc/task_mmu.c | 16 +- > include/linux/mm.h | 12 +- > include/linux/pkeys.h | 5 + > include/uapi/linux/elf.h | 1 + > 33 files changed, 1040 insertions(+), 42 deletions(-) > create mode 100644 arch/powerpc/include/asm/pkeys.h > create mode 100644 arch/powerpc/mm/pkeys.c -- Ram Pai -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
