ARC: wireup clone3 syscall

Signed-off-by: Vineet Gupta <[e-mail]>

arch/arc/Kconfig

···
 	select GENERIC_SMP_IDLE_THREAD
 	select HAVE_ARCH_KGDB
 	select HAVE_ARCH_TRACEHOOK
+	select HAVE_COPY_THREAD_TLS
 	select HAVE_DEBUG_STACKOVERFLOW
 	select HAVE_DEBUG_KMEMLEAK
 	select HAVE_FUTEX_CMPXCHG if FUTEX

arch/arc/include/asm/syscalls.h

···
 #include <linux/types.h>
 
 int sys_clone_wrapper(int, int, int, int, int);
+int sys_clone3_wrapper(void *, size_t);
 int sys_cacheflush(uint32_t, uint32_t uint32_t);
 int sys_arc_settls(void *);
 int sys_arc_gettls(void);

arch/arc/include/uapi/asm/unistd.h

···
 #define __ARCH_WANT_SET_GET_RLIMIT
 #define __ARCH_WANT_SYS_EXECVE
 #define __ARCH_WANT_SYS_CLONE
+#define __ARCH_WANT_SYS_CLONE3
 #define __ARCH_WANT_SYS_VFORK
 #define __ARCH_WANT_SYS_FORK
 #define __ARCH_WANT_TIME32_SYSCALLS

arch/arc/kernel/entry.S

···
 	b .Lret_from_system_call
 END(sys_clone_wrapper)
 
+ENTRY(sys_clone3_wrapper)
+	SAVE_CALLEE_SAVED_USER
+	bl  @sys_clone3
+	DISCARD_CALLEE_SAVED_USER
+
+	GET_CURR_THR_INFO_FLAGS   r10
+	btst r10, TIF_SYSCALL_TRACE
+	bnz  tracesys_exit
+
+	b .Lret_from_system_call
+END(sys_clone3_wrapper)
+
 ENTRY(ret_from_fork)
 	; when the forked child comes here from the __switch_to function
 	; r0 has the last task pointer.

arch/arc/kernel/process.c

···
  * |    user_r25    |
  * ------------------  <===== END of PAGE
  */
-int copy_thread(unsigned long clone_flags,
-		unsigned long usp, unsigned long kthread_arg,
-		struct task_struct *p)
+int copy_thread_tls(unsigned long clone_flags, unsigned long usp,
+	unsigned long kthread_arg, struct task_struct *p, unsigned long tls)
 {
 	struct pt_regs *c_regs;        /* child's pt_regs */
 	unsigned long *childksp;       /* to unwind out of __switch_to() */
···
 		 * set task's userland tls data ptr from 4th arg
 		 * clone C-lib call is difft from clone sys-call
 		 */
-		task_thread_info(p)->thr_ptr = regs->r3;
+		task_thread_info(p)->thr_ptr = tls;
 	} else {
 		/* Normal fork case: set parent's TLS ptr in child */
 		task_thread_info(p)->thr_ptr =

arch/arc/kernel/sys.c

···
 #include <asm/syscalls.h>
 
 #define sys_clone	sys_clone_wrapper
+#define sys_clone3	sys_clone3_wrapper
 
 #undef __SYSCALL
 #define __SYSCALL(nr, call) [nr] = (call),