arm64: introduce AUDIT_ARCH_AARCH64ILP32 for ilp32

maillist inclusion
category: feature
bugzilla: 46790
CVE: NA

Reference: https://github.com/norov/linux/commits/ilp32-5.2

--------------------------------

syscall_get_arch() currently makes no difference between arm64 and
arm64/ilp32. Fix it by adding AUDIT_ARCH_AARCH64ILP32.
Reported-by: NAndy Lutomirski <luto@amacapital.net>
Signed-off-by: NYury Norov <ynorov@marvell.com>
Signed-off-by: NXiongfeng Wang <wangxiongfeng2@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>

arch/arm64/include/asm/syscall.h

@@ -91,6 +91,9 @@ static inline int syscall_get_arch(struct task_struct *task)
 	if (is_a32_compat_thread(task_thread_info(task)))
 		return AUDIT_ARCH_ARM;
 
+	else if (is_ilp32_compat_task())
+		return AUDIT_ARCH_AARCH64ILP32;
+
 	return AUDIT_ARCH_AARCH64;
 }
 

include/uapi/linux/audit.h

@@ -381,6 +381,7 @@ enum {
 #define __AUDIT_ARCH_LE	   0x40000000
 
 #define AUDIT_ARCH_AARCH64	(EM_AARCH64|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE)
+#define AUDIT_ARCH_AARCH64ILP32	(EM_AARCH64|__AUDIT_ARCH_LE)
 #define AUDIT_ARCH_ALPHA	(EM_ALPHA|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE)
 #define AUDIT_ARCH_ARCOMPACT	(EM_ARCOMPACT|__AUDIT_ARCH_LE)
 #define AUDIT_ARCH_ARCOMPACTBE	(EM_ARCOMPACT)