arm64: Add audit support

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

Acked-by Will Deacon <will.deacon@arm.com>
Acked-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

3 files changed, 17 insertions, 0 deletions

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 1cb806529393..ce6e733e0c05 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -10,6 +10,7 @@ config ARM64
         select ARM_AMBA
         select ARM_ARCH_TIMER
         select ARM_GIC
+        select AUDIT_ARCH_COMPAT_GENERIC
         select BUILDTIME_EXTABLE_SORT
         select CLONE_BACKWARDS
         select COMMON_CLK
@@ -28,6 +29,7 @@ config ARM64
         select GENERIC_STRNLEN_USER
         select GENERIC_TIME_VSYSCALL
         select HARDIRQS_SW_RESEND
+        select HAVE_ARCH_AUDITSYSCALL
         select HAVE_ARCH_JUMP_LABEL
         select HAVE_ARCH_KGDB
         select HAVE_ARCH_TRACEHOOK
diff --git a/arch/arm64/include/asm/syscall.h b/arch/arm64/include/asm/syscall.h
index 383771eb0b87..709a574468f0 100644
--- a/arch/arm64/include/asm/syscall.h
+++ b/arch/arm64/include/asm/syscall.h
@@ -16,6 +16,8 @@
 #ifndef __ASM_SYSCALL_H
 #define __ASM_SYSCALL_H
 
+#include <uapi/linux/audit.h>
+#include <linux/compat.h>
 #include <linux/err.h>
 
 extern const void *sys_call_table[];
@@ -105,4 +107,16 @@ 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(void)
+{
+        if (is_compat_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 cf6714752b69..3b9ff33e1768 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -342,6 +342,7 @@ enum {
 #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)