[PATCH v3 2/3] arm64: Add audit support

[AKASHI Takahiro <takahiro.akashi@linaro.org>]

On AArch64, audit is supported through generic lib/audit.c and
compat_audit.c, and so this patch adds arch specific definitions required.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
---
 arch/arm64/Kconfig               |    1 +
 arch/arm64/include/asm/syscall.h |   15 +++++++++++++++
 include/uapi/linux/audit.h       |    1 +
 3 files changed, 17 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 6d4dd22..3c21405 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -19,6 +19,7 @@ config ARM64
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_TIME_VSYSCALL
 	select HARDIRQS_SW_RESEND
+	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_DEBUG_BUGVERBOSE
 	select HAVE_DEBUG_KMEMLEAK
diff --git a/arch/arm64/include/asm/syscall.h b/arch/arm64/include/asm/syscall.h
index 70ba9d4..6900183 100644
--- a/arch/arm64/include/asm/syscall.h
+++ b/arch/arm64/include/asm/syscall.h
@@ -16,7 +16,9 @@
 #ifndef __ASM_SYSCALL_H
 #define __ASM_SYSCALL_H
 
+#include <linux/audit.h>
 #include <linux/err.h>
+#include <asm/compat.h>
 
 
 static inline int syscall_get_nr(struct task_struct *task,
@@ -104,4 +106,17 @@ static inline void syscall_set_arguments(struct task_struct *task,
 	memcpy(&regs->regs[i], args, n * sizeof(args[0]));
 }
 
+/*
+ * We don't care about endianness (__AUDIT_ARCH_LE bit) here because
+ * AArch64 has the same system calls both on little- and big- endian.
+ */
+static inline int syscall_get_arch(struct task_struct *task,
+				   struct pt_regs *regs)
+{
+	if (is_compat_thread(task_thread_info(task)))
+		return AUDIT_ARCH_ARM;
+
+	return AUDIT_ARCH_AARCH64;
+}
+
 #endif	/* __ASM_SYSCALL_H */
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index 0a73cf3..cf27cae 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -327,6 +327,7 @@ enum {
 /* distinguish syscall tables */
 #define __AUDIT_ARCH_64BIT 0x80000000
 #define __AUDIT_ARCH_LE	   0x40000000
+#define AUDIT_ARCH_AARCH64	(EM_AARCH64|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE)
 #define AUDIT_ARCH_ALPHA	(EM_ALPHA|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE)
 #define AUDIT_ARCH_ARM		(EM_ARM|__AUDIT_ARCH_LE)
 #define AUDIT_ARCH_ARMEB	(EM_ARM)
-- 
1.7.9.5