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authorKristina Martsenko <kristina.martsenko@arm.com>2020-03-13 14:34:51 +0530
committerCatalin Marinas <catalin.marinas@arm.com>2020-03-18 09:50:19 +0000
commitbe129842566599f2c6f8fbba277c098802cd4b3d (patch)
tree99ba6277bb813d8d239e52bfebad736d707a4080 /arch/arm64/include/asm/asm_pointer_auth.h
parent91a1b6ccff323e60615e3118eceb2d8cbc4f69ab (diff)
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.h49
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 */