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* arm64: don't pull uaccess.h into *.SAl Viro2016-12-261-1/+1
| | | | | | | Split asm-only parts of arm64 uaccess.h into a new header and use that from *.S. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds2016-12-241-1/+1
| | | | | | | | | | | | | This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* arm64: Factor out PAN enabling/disabling into separate uaccess_* macrosCatalin Marinas2016-11-211-8/+3Star
| | | | | | | | | | | | | | | | This patch moves the directly coded alternatives for turning PAN on/off into separate uaccess_{enable,disable} macros or functions. The asm macros take a few arguments which will be used in subsequent patches. Note that any (unlikely) access that the compiler might generate between uaccess_enable() and uaccess_disable(), other than those explicitly specified by the user access code, will not be protected by PAN. Cc: Will Deacon <will.deacon@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Kees Cook <keescook@chromium.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: don't zero in __copy_from_user{,_inatomic}Al Viro2016-09-161-6/+1Star
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* arm64: kasan: instrument user memory access APIYang Shi2016-06-211-2/+2
| | | | | | | | | | | | | | | | | The upstream commit 1771c6e1a567ea0ba2cccc0a4ffe68a1419fd8ef ("x86/kasan: instrument user memory access API") added KASAN instrument to x86 user memory access API, so added such instrument to ARM64 too. Define __copy_to/from_user in C in order to add kasan_check_read/write call, rename assembly implementation to __arch_copy_to/from_user. Tested by test_kasan module. Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Yang Shi <yang.shi@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: kernel: Don't toggle PAN on systems with UAOJames Morse2016-02-181-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | If a CPU supports both Privileged Access Never (PAN) and User Access Override (UAO), we don't need to disable/re-enable PAN round all copy_to_user() like calls. UAO alternatives cause these calls to use the 'unprivileged' load/store instructions, which are overridden to be the privileged kind when fs==KERNEL_DS. This patch changes the copy_to_user() calls to have their PAN toggling depend on a new composite 'feature' ARM64_ALT_PAN_NOT_UAO. If both features are detected, PAN will be enabled, but the copy_to_user() alternatives will not be applied. This means PAN will be enabled all the time for these functions. If only PAN is detected, the toggling will be enabled as normal. This will save the time taken to disable/re-enable PAN, and allow us to catch copy_to_user() accesses that occur with fs==KERNEL_DS. Futex and swp-emulation code continue to hang their PAN toggling code on ARM64_HAS_PAN. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: kernel: Add support for User Access OverrideJames Morse2016-02-181-4/+4
| | | | | | | | | | | | | | | | | | 'User Access Override' is a new ARMv8.2 feature which allows the unprivileged load and store instructions to be overridden to behave in the normal way. This patch converts {get,put}_user() and friends to use ldtr*/sttr* instructions - so that they can only access EL0 memory, then enables UAO when fs==KERNEL_DS so that these functions can access kernel memory. This allows user space's read/write permissions to be checked against the page tables, instead of testing addr<USER_DS, then using the kernel's read/write permissions. Signed-off-by: James Morse <james.morse@arm.com> [catalin.marinas@arm.com: move uao_thread_switch() above dsb()] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: copy_to-from-in_user optimization using copy templateFeng Kan2015-10-071-34/+44
| | | | | | | | | | This patch optimize copy_to-from-in_user for arm 64bit architecture. The copy template is used as template file for all the copy*.S files. Minor change was made to it to accommodate the copy to/from/in user files. Signed-off-by: Feng Kan <fkan@apm.com> Signed-off-by: Balamurugan Shanmugam <bshanmugam@apm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: kernel: Add support for Privileged Access NeverJames Morse2015-07-271-0/+8
| | | | | | | | | | | | | | | | | '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>
* arm64: lib: use pair accessors for copy_*_user routinesWill Deacon2015-07-271-6/+11
| | | | | | | | | 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>
* arm64: User access library functionsCatalin Marinas2012-09-171-0/+66
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>