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2015-12-03arm64: kernel: Add support for Privileged Access Neverv3.18/topic/PANJames Morse
commit 338d4f49d6f7114a017d294ccf7374df4f998edc upstream. 'Privileged Access Never' is a new arm8.1 feature which prevents privileged code from accessing any virtual address where read or write access is also permitted at EL0. This patch enables the PAN feature on all CPUs, and modifies {get,put}_user helpers temporarily to permit access. This will catch kernel bugs where user memory is accessed directly. 'Unprivileged loads and stores' using ldtrb et al are unaffected by PAN. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: James Morse <james.morse@arm.com> [will: use ALTERNATIVE in asm and tidy up pan_enable check] Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: David Brown <david.brown@linaro.org>
2015-12-03arm64: lib: use pair accessors for copy_*_user routinesWill Deacon
commit 23e94994464a7281838785675e09c8ed1055f62f upstream. The AArch64 instruction set contains load/store pair memory accessors, so use these in our copy_*_user routines to transfer 16 bytes per iteration. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: David Brown <david.brown@linaro.org>
2012-09-17arm64: User access library functionsCatalin Marinas
This patch add support for various user access functions. These functions use the standard LDR/STR instructions and not the LDRT/STRT variants in order to allow kernel addresses (after set_fs(KERNEL_DS)). Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>