kernel/linux.git/arch/powerpc/mm/pkeys.c, branch linux-4.16.y

powerpc: Enable pkey subsystem

2018-01-20T14:06:10+00:00

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: implementation for arch_vma_access_permitted()

2018-01-20T11:59:04+00:00

This patch provides the implementation for arch_vma_access_permitted(). Returns true if the requested access is allowed by pkey associated with the vma. Signed-off-by: Ram Pai Signed-off-by: Michael Ellerman

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

2018-01-20T11:59:03+00:00

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: implementation for arch_override_mprotect_pkey()

2018-01-20T11:59:02+00:00

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

2018-01-20T11:59:01+00:00

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

2018-01-20T11:59:01+00:00

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

2018-01-20T11:59:00+00:00

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: ability to create execute-disabled pkeys

2018-01-20T11:59:00+00:00

powerpc has hardware support to disable execute on a pkey. This patch enables the ability to create execute-disabled keys. Signed-off-by: Ram Pai Signed-off-by: Michael Ellerman

powerpc: implementation for arch_set_user_pkey_access()

2018-01-20T11:58:59+00:00

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

powerpc: helper functions to initialize AMR, IAMR and UAMOR registers

2018-01-20T11:58:58+00:00

Introduce helper functions that can initialize the bits in the AMR, IAMR and UAMOR register; the bits that correspond to the given pkey. Reviewed-by: Thiago Jung Bauermann Signed-off-by: Ram Pai Signed-off-by: Michael Ellerman