From 7503197562567b57ec14feb3a9d5400ebc56812f Mon Sep 17 00:00:00 2001
From: Mark Rutland <mark.rutland@arm.com>
Date: Fri, 7 Dec 2018 18:39:25 +0000
Subject: arm64: add basic pointer authentication support

This patch adds basic support for pointer authentication, allowing
userspace to make use of APIAKey, APIBKey, APDAKey, APDBKey, and
APGAKey. The kernel maintains key values for each process (shared by all
threads within), which are initialised to random values at exec() time.

The ID_AA64ISAR1_EL1.{APA,API,GPA,GPI} fields are exposed to userspace,
to describe that pointer authentication instructions are available and
that the kernel is managing the keys. Two new hwcaps are added for the
same reason: PACA (for address authentication) and PACG (for generic
authentication).

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
Tested-by: Adam Wallis <awallis@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ramana Radhakrishnan <ramana.radhakrishnan@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
[will: Fix sizeof() usage and unroll address key initialisation]
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/include/asm/thread_info.h | 4 ++++
 1 file changed, 4 insertions(+)

(limited to 'arch/arm64/include/asm/thread_info.h')

diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index bbca68b54732..f8f66ad9dd8f 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -28,6 +28,7 @@
 struct task_struct;
 
 #include <asm/memory.h>
+#include <asm/pointer_auth.h>
 #include <asm/stack_pointer.h>
 #include <asm/types.h>
 
@@ -54,6 +55,9 @@ struct thread_info {
 #endif
 		} preempt;
 	};
+#ifdef CONFIG_ARM64_PTR_AUTH
+	struct ptrauth_keys	keys_user;
+#endif
 };
 
 #define thread_saved_pc(tsk)	\
-- 
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