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author | Kristina Martsenko <kristina.martsenko@arm.com> | 2020-03-13 14:34:51 +0530 |
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committer | Catalin Marinas <catalin.marinas@arm.com> | 2020-03-18 09:50:19 +0000 |
commit | be129842566599f2c6f8fbba277c098802cd4b3d (patch) | |
tree | 99ba6277bb813d8d239e52bfebad736d707a4080 /arch/arm64/include/asm/asm_pointer_auth.h | |
parent | 91a1b6ccff323e60615e3118eceb2d8cbc4f69ab (diff) | |
download | linux-be129842566599f2c6f8fbba277c098802cd4b3d.tar.gz linux-be129842566599f2c6f8fbba277c098802cd4b3d.tar.bz2 linux-be129842566599f2c6f8fbba277c098802cd4b3d.zip |
arm64: install user ptrauth keys at kernel exit time
As we're going to enable pointer auth within the kernel and use a
different APIAKey for the kernel itself, so move the user APIAKey
switch to EL0 exception return.
The other 4 keys could remain switched during task switch, but are also
moved to keep things consistent.
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
[Amit: commit msg, re-positioned the patch, comments]
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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, 49 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/asm_pointer_auth.h b/arch/arm64/include/asm/asm_pointer_auth.h new file mode 100644 index 000000000000..3482348ec07f --- /dev/null +++ b/arch/arm64/include/asm/asm_pointer_auth.h @@ -0,0 +1,49 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_ASM_POINTER_AUTH_H +#define __ASM_ASM_POINTER_AUTH_H + +#include <asm/alternative.h> +#include <asm/asm-offsets.h> +#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 +alternative_if_not ARM64_HAS_ADDRESS_AUTH + b .Laddr_auth_skip_\@ +alternative_else_nop_endif + ldp \tmp2, \tmp3, [\tmp1, #PTRAUTH_USER_KEY_APIA] + msr_s SYS_APIAKEYLO_EL1, \tmp2 + msr_s SYS_APIAKEYHI_EL1, \tmp3 + ldp \tmp2, \tmp3, [\tmp1, #PTRAUTH_USER_KEY_APIB] + msr_s SYS_APIBKEYLO_EL1, \tmp2 + msr_s SYS_APIBKEYHI_EL1, \tmp3 + ldp \tmp2, \tmp3, [\tmp1, #PTRAUTH_USER_KEY_APDA] + msr_s SYS_APDAKEYLO_EL1, \tmp2 + msr_s SYS_APDAKEYHI_EL1, \tmp3 + ldp \tmp2, \tmp3, [\tmp1, #PTRAUTH_USER_KEY_APDB] + msr_s SYS_APDBKEYLO_EL1, \tmp2 + msr_s SYS_APDBKEYHI_EL1, \tmp3 +.Laddr_auth_skip_\@: +alternative_if ARM64_HAS_GENERIC_AUTH + ldp \tmp2, \tmp3, [\tmp1, #PTRAUTH_USER_KEY_APGA] + msr_s SYS_APGAKEYLO_EL1, \tmp2 + msr_s SYS_APGAKEYHI_EL1, \tmp3 +alternative_else_nop_endif + .endm + +#else /* CONFIG_ARM64_PTR_AUTH */ + + .macro ptrauth_keys_install_user tsk, tmp1, tmp2, tmp3 + .endm + +#endif /* CONFIG_ARM64_PTR_AUTH */ + +#endif /* __ASM_ASM_POINTER_AUTH_H */ |