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| author |  Daniel Kiss <daniel.kiss@arm.com>
| 2021-06-13 11:26:32 +0200 |
|---|---|---|
| committer |  Will Deacon <will@kernel.org>
| 2021-06-15 11:32:31 +0100 |
| commit | d053e71ac8442d4fd24fb85591489813cdb56365 (patch) | |
| tree | 442db612f4fa71991b35f56b2a3e683da4211702 /arch/arm64/include/asm/asm_pointer_auth.h | |
| parent | arm64: Add ARM64_PTR_AUTH_KERNEL config option (diff) | |
| download | linux-d053e71ac8442d4fd24fb85591489813cdb56365.tar.gz linux-d053e71ac8442d4fd24fb85591489813cdb56365.tar.bz2 linux-d053e71ac8442d4fd24fb85591489813cdb56365.zip | |
arm64: Conditionally configure PTR_AUTH key of the kernel.
If the kernel is not compiled with CONFIG_ARM64_PTR_AUTH_KERNEL=y,
then no PACI/AUTI instructions are expected while the kernel is running
so the kernel's key will not be used. Write of a system registers
is expensive therefore avoid if not required.
Signed-off-by: Daniel Kiss <daniel.kiss@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210613092632.93591-3-daniel.kiss@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/include/asm/asm_pointer_auth.h')
| -rw-r--r-- | arch/arm64/include/asm/asm_pointer_auth.h | 49 |
1 files changed, 29 insertions, 20 deletions
diff --git a/arch/arm64/include/asm/asm_pointer_auth.h b/arch/arm64/include/asm/asm_pointer_auth.h index 8ca2dc0661ee..f1bba5fc61c4 100644 --- a/arch/arm64/include/asm/asm_pointer_auth.h +++ b/arch/arm64/include/asm/asm_pointer_auth.h @@ -7,19 +7,7 @@ #include <asm/cpufeature.h> #include <asm/sysreg.h> -#ifdef CONFIG_ARM64_PTR_AUTH -/* - * thread.keys_user.ap* as offset exceeds the #imm offset range - * so use the base value of ldp as thread.keys_user and offset as - * thread.keys_user.ap*. - */ - .macro __ptrauth_keys_install_user tsk, tmp1, tmp2, tmp3 - mov \tmp1, #THREAD_KEYS_USER - add \tmp1, \tsk, \tmp1 - ldp \tmp2, \tmp3, [\tmp1, #PTRAUTH_USER_KEY_APIA] - msr_s SYS_APIAKEYLO_EL1, \tmp2 - msr_s SYS_APIAKEYHI_EL1, \tmp3 - .endm +#ifdef CONFIG_ARM64_PTR_AUTH_KERNEL .macro __ptrauth_keys_install_kernel_nosync tsk, tmp1, tmp2, tmp3 mov \tmp1, #THREAD_KEYS_KERNEL @@ -42,6 +30,33 @@ alternative_if ARM64_HAS_ADDRESS_AUTH alternative_else_nop_endif .endm +#else /* CONFIG_ARM64_PTR_AUTH_KERNEL */ + + .macro __ptrauth_keys_install_kernel_nosync tsk, tmp1, tmp2, tmp3 + .endm + + .macro ptrauth_keys_install_kernel_nosync tsk, tmp1, tmp2, tmp3 + .endm + + .macro ptrauth_keys_install_kernel tsk, tmp1, tmp2, tmp3 + .endm + +#endif /* CONFIG_ARM64_PTR_AUTH_KERNEL */ + +#ifdef CONFIG_ARM64_PTR_AUTH +/* + * thread.keys_user.ap* as offset exceeds the #imm offset range + * so use the base value of ldp as thread.keys_user and offset as + * thread.keys_user.ap*. + */ + .macro __ptrauth_keys_install_user tsk, tmp1, tmp2, tmp3 + mov \tmp1, #THREAD_KEYS_USER + add \tmp1, \tsk, \tmp1 + ldp \tmp2, \tmp3, [\tmp1, #PTRAUTH_USER_KEY_APIA] + msr_s SYS_APIAKEYLO_EL1, \tmp2 + msr_s SYS_APIAKEYHI_EL1, \tmp3 + .endm + .macro __ptrauth_keys_init_cpu tsk, tmp1, tmp2, tmp3 mrs \tmp1, id_aa64isar1_el1 ubfx \tmp1, \tmp1, #ID_AA64ISAR1_APA_SHIFT, #8 @@ -64,17 +79,11 @@ alternative_else_nop_endif .Lno_addr_auth\@: .endm -#else /* CONFIG_ARM64_PTR_AUTH */ +#else /* !CONFIG_ARM64_PTR_AUTH */ .macro ptrauth_keys_install_user tsk, tmp1, tmp2, tmp3 .endm - .macro ptrauth_keys_install_kernel_nosync 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 */ |