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arm64: initialize and switch ptrauth kernel keys

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Set up keys to use pointer authentication within the kernel. The kernel
will be compiled with APIAKey instructions, the other keys are currently
unused. Each task is given its own APIAKey, which is initialized during
fork. The key is changed during context switch and on kernel entry from
EL0.

The keys for idle threads need to be set before calling any C functions,
because it is not possible to enter and exit a function with different
keys.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
[Amit: Modified secondary cores key structure, comments]
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Kristina Martsenko
2020-03-13 14:34:56 +05:30
committed by Catalin Marinas
parent 6982934e19
commit 33e4523498
9 changed files with 62 additions and 0 deletions
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14
arch/arm64/include/asm/asm_pointer_auth.h
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@@ -39,11 +39,25 @@ alternative_if ARM64_HAS_GENERIC_AUTH
alternative_else_nop_endif
.endm
.macro ptrauth_keys_install_kernel tsk, tmp1, tmp2, tmp3
alternative_if ARM64_HAS_ADDRESS_AUTH
mov \tmp1, #THREAD_KEYS_KERNEL
add \tmp1, \tsk, \tmp1
ldp \tmp2, \tmp3, [\tmp1, #PTRAUTH_KERNEL_KEY_APIA]
msr_s SYS_APIAKEYLO_EL1, \tmp2
msr_s SYS_APIAKEYHI_EL1, \tmp3
isb
alternative_else_nop_endif
.endm
#else /* CONFIG_ARM64_PTR_AUTH */
.macro ptrauth_keys_install_user tsk, tmp1, tmp2, tmp3
.endm
.macro ptrauth_keys_install_kernel tsk, tmp1, tmp2, tmp3
.endm
#endif /* CONFIG_ARM64_PTR_AUTH */
#endif /* __ASM_ASM_POINTER_AUTH_H */