nios2: define syscall_get_arch()

syscall_get_arch() is required to be implemented on all architectures
in addition to already implemented syscall_get_nr(),
syscall_get_arguments(), syscall_get_error(), and
syscall_get_return_value() functions in order to extend the generic
ptrace API with PTRACE_GET_SYSCALL_INFO request.
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Elvira Khabirova <lineprinter@altlinux.org>
Cc: Eugene Syromyatnikov <esyr@redhat.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: nios2-dev@lists.rocketboards.org
Cc: linux-audit@redhat.com
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>

arch/nios2/include/asm/syscall.h

@@ -17,6 +17,7 @@
 #ifndef __ASM_NIOS2_SYSCALL_H__
 #define __ASM_NIOS2_SYSCALL_H__
 
+#include <uapi/linux/audit.h>
 #include <linux/err.h>
 #include <linux/sched.h>
 
@@ -135,4 +136,9 @@ static inline void syscall_set_arguments(struct task_struct *task,
 	}
 }
 
+static inline int syscall_get_arch(void)
+{
+	return AUDIT_ARCH_NIOS2;
+}
+
 #endif

include/uapi/linux/audit.h

@@ -403,6 +403,7 @@ enum {
 				 __AUDIT_ARCH_CONVENTION_MIPS64_N32)
 #define AUDIT_ARCH_NDS32	(EM_NDS32|__AUDIT_ARCH_LE)
 #define AUDIT_ARCH_NDS32BE	(EM_NDS32)
+#define AUDIT_ARCH_NIOS2	(EM_ALTERA_NIOS2|__AUDIT_ARCH_LE)
 #define AUDIT_ARCH_OPENRISC	(EM_OPENRISC)
 #define AUDIT_ARCH_PARISC	(EM_PARISC)
 #define AUDIT_ARCH_PARISC64	(EM_PARISC|__AUDIT_ARCH_64BIT)