kernel/arch/powerpc/include/asm/pkeys.h, branch linux-4.16.y

powerpc: Enable pkey subsystem

2018-01-20T14:06:10Z

PAPR defines 'ibm,processor-storage-keys' property. It exports two values. The first value holds the number of data-access keys and the second holds the number of instruction-access keys. Due to a bug in the firmware, instruction-access keys is always reported as zero. However any key can be configured to disable data-access and/or disable execution-access. The inavailablity of the second value is not a big handicap, though it could have been used to determine if the platform supported disable-execution-access. Non-PAPR platforms do not define this property in the device tree yet. Fortunately power8 is the only released Non-PAPR platform that is supported. Here, we hardcode the number of supported pkey to 32, by consulting the PowerISA3.0 This patch calculates the number of keys supported by the platform. Also it determines the platform support for read/write/execution access support for pkeys. Signed-off-by: Ram Pai [mpe: Use a PVR check instead of CPU_FTR for execute. Restrict to Power7/8/9 for now until older CPUs are tested.] Signed-off-by: Michael Ellerman

powerpc/ptrace: Add memory protection key regset

2018-01-20T11:59:06Z

The AMR/IAMR/UAMOR are part of the program context. Allow it to be accessed via ptrace and through core files. Signed-off-by: Ram Pai Signed-off-by: Thiago Jung Bauermann Signed-off-by: Michael Ellerman

powerpc: helper to validate key-access permissions of a pte

2018-01-20T11:59:03Z

helper function that checks if the read/write/execute is allowed on the pte. Signed-off-by: Ram Pai Signed-off-by: Michael Ellerman

powerpc: Program HPTE key protection bits

2018-01-20T11:59:03Z

Map the PTE protection key bits to the HPTE key protection bits, while creating HPTE entries. Acked-by: Balbir Singh Signed-off-by: Ram Pai Signed-off-by: Michael Ellerman

powerpc: map vma key-protection bits to pte key bits.

2018-01-20T11:59:02Z

Map the key protection bits of the vma to the pkey bits in the PTE. The PTE bits used for pkey are 3,4,5,6 and 57. The first four bits are the same four bits that were freed up initially in this patch series. remember? :-) Without those four bits this patch wouldn't be possible. BUT, on 4k kernel, bit 3, and 4 could not be freed up. remember? Hence we have to be satisfied with 5, 6 and 7. Signed-off-by: Ram Pai Signed-off-by: Michael Ellerman

powerpc: implementation for arch_override_mprotect_pkey()

2018-01-20T11:59:02Z

arch independent code calls arch_override_mprotect_pkey() to return a pkey that best matches the requested protection. This patch provides the implementation. Signed-off-by: Ram Pai Signed-off-by: Michael Ellerman

powerpc: ability to associate pkey to a vma

2018-01-20T11:59:01Z

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: Ram Pai Signed-off-by: Michael Ellerman

powerpc: introduce execute-only pkey

2018-01-20T11:59:01Z

This patch provides the implementation of execute-only pkey. The architecture-independent layer expects the arch-dependent layer, to support the ability to create and enable a special key which has execute-only permission. Acked-by: Balbir Singh Signed-off-by: Ram Pai Signed-off-by: Michael Ellerman

powerpc: store and restore the pkey state across context switches

2018-01-20T11:59:00Z

Store and restore the AMR, IAMR and UAMOR register state of the task before scheduling out and after scheduling in, respectively. Signed-off-by: Ram Pai Signed-off-by: Michael Ellerman

powerpc: implementation for arch_set_user_pkey_access()

2018-01-20T11:58:59Z

This patch provides the detailed implementation for a user to allocate a key and enable it in the hardware. It provides the plumbing, but it cannot be used till the system call is implemented. The next patch will do so. Reviewed-by: Thiago Jung Bauermann Signed-off-by: Ram Pai Signed-off-by: Michael Ellerman