[ALPHA] Add restart_syscall support.

arch/alpha/kernel/signal.c

@@ -587,6 +587,10 @@ syscall_restart(unsigned long r0, unsigned long r19,
 		regs->r19 = r19;
 		regs->pc -= 4;
 		break;
+	case ERESTART_RESTARTBLOCK:
+		current_thread_info()->restart_block.fn = do_no_restart_syscall;
+		regs->r0 = EINTR;
+		break;
 	}
 }
 
@@ -628,13 +632,22 @@ do_signal(sigset_t *oldset, struct pt_regs * regs, struct switch_stack * sw,
 		return 1;
 	}
 
-	if (r0 &&
-	    (regs->r0 == ERESTARTNOHAND ||
-	     regs->r0 == ERESTARTSYS ||
-	     regs->r0 == ERESTARTNOINTR)) {
-		regs->r0 = r0;	/* reset v0 and a3 and replay syscall */
+	if (r0) {
+	  	switch (regs->r0) {
+		case ERESTARTNOHAND:
+		case ERESTARTSYS:
+		case ERESTARTNOINTR:
+			/* Reset v0 and a3 and replay syscall.  */
+			regs->r0 = r0;
 			regs->r19 = r19;
 			regs->pc -= 4;
+			break;
+		case ERESTART_RESTARTBLOCK:
+			/* Force v0 to the restart syscall and reply.  */
+			regs->r0 = __NR_restart_syscall;
+			regs->pc -= 4;
+			break;
+		}
 	}
 	if (single_stepping)
 		ptrace_set_bpt(current);	/* re-set breakpoint */

arch/alpha/kernel/systbls.S

@@ -431,6 +431,7 @@ sys_call_table:
 	.quad sys_epoll_wait
 	.quad sys_remap_file_pages		/* 410 */
 	.quad sys_set_tid_address
+	.quad sys_restart_syscall
 
 	.size sys_call_table, . - sys_call_table
 	.type sys_call_table, @object

include/asm-alpha/current.h

 #ifndef _ALPHA_CURRENT_H
 #define _ALPHA_CURRENT_H
 
-#include <asm/thread_info.h>
+#include <linux/thread_info.h>
 
 #define get_current()	(current_thread_info()->task + 0)
 #define current		get_current()

include/asm-alpha/thread_info.h

@@ -25,6 +25,8 @@ struct thread_info {
 	int bpt_nsaved;
 	unsigned long bpt_addr[2];		/* breakpoint handling  */
 	unsigned int bpt_insn[2];
+
+	struct restart_block	restart_block;
 };
 
 /*
@@ -35,6 +37,9 @@ struct thread_info {
 	task:		&tsk,			\
 	exec_domain:	&default_exec_domain,	\
 	addr_limit:	KERNEL_DS,		\
+	.restart_block = {			\
+		.fn = do_no_restart_syscall,	\
+	},					\
 }
 
 #define init_thread_info	(init_thread_union.thread_info)

include/asm-alpha/unistd.h

@@ -349,7 +349,8 @@
 #define __NR_sys_epoll_wait		409
 #define __NR_remap_file_pages		410
 #define __NR_set_tid_address		411
-#define NR_SYSCALLS			412
+#define __NR_restart_syscall		412
+#define NR_SYSCALLS			413
 
 #if defined(__GNUC__)