[parisc-linux-cvs] linux-2.6 tausq

[Randolph Chung]

In reference to a message from Randolph Chung, dated Nov 01:
> CVSROOT:	/var/cvs
> Module name:	linux-2.6
> Changes by:	tausq	03/11/01 21:40:50
> 
> Modified files:
> 	.              : Makefile 
> 	arch/parisc/kernel: syscall_table.S signal.c 
> 	include/asm-parisc: unistd.h 
> 
> Log message:
> 2.6.0-test9-pa4
> Support for restarting syscalls via the restart block


Index: arch/parisc/kernel/syscall_table.S
===================================================================
RCS file: /var/cvs/linux-2.6/arch/parisc/kernel/syscall_table.S,v
retrieving revision 1.1
diff -u -p -r1.1 syscall_table.S
--- arch/parisc/kernel/syscall_table.S	21 Sep 2003 14:33:58 -0000	1.1
+++ arch/parisc/kernel/syscall_table.S	2 Nov 2003 04:39:23 -0000
@@ -28,7 +28,7 @@
 #define ENTRY_COMP(_name_) .word sys_##_name_
 #endif
 
-	ENTRY_SAME(ni_syscall)	/* 0  -  old "setup()" system call*/
+	ENTRY_SAME(restart_syscall)	/* 0 */
 	ENTRY_SAME(exit)
 	ENTRY_SAME(fork_wrapper)
 	ENTRY_SAME(read)
Index: arch/parisc/kernel/signal.c
===================================================================
RCS file: /var/cvs/linux-2.6/arch/parisc/kernel/signal.c,v
retrieving revision 1.11
diff -u -p -r1.11 signal.c
--- arch/parisc/kernel/signal.c	24 Sep 2003 17:54:31 -0000	1.11
+++ arch/parisc/kernel/signal.c	2 Nov 2003 04:39:24 -0000
@@ -486,6 +486,7 @@ do_signal(sigset_t *oldset, struct pt_re
 
 
 	signr = get_signal_to_deliver(&info, regs, NULL);
+	/* printk("do_signal: signr = %d, regs->gr[28] = %ld\n", signr, regs->gr[28]); */
 	if (signr > 0) {
 		/* Restart a system call if necessary. */
 		if (in_syscall) {
@@ -530,10 +531,42 @@ do_signal(sigset_t *oldset, struct pt_re
 	/* Did we come from a system call? */
 	if (in_syscall) {
 		/* Restart the system call - no handlers present */
-		if (regs->gr[28] == -ERESTART_RESTARTBLOCK ||
-		    regs->gr[28] == -ERESTARTNOHAND ||
-		    regs->gr[28] == -ERESTARTSYS ||
-		    regs->gr[28] == -ERESTARTNOINTR) {
+		if (regs->gr[28] == -ERESTART_RESTARTBLOCK) {
+			unsigned int *usp = (unsigned int *)regs->gr[30];
+
+			/* Setup a trampoline to restart the syscall
+			 * with __NR_restart_syscall
+			 *
+			 *  0: <return address (orig r31)>
+			 *  8: <2nd half for 64-bit>
+			 * 12: ldw 0(%sp), %r31
+			 * 16: be 0x100(%sr2, %r0)
+			 * 20: ldi __NR_restart_syscall, %r20
+			 */
+#ifndef __LP64__
+			put_user(regs->gr[31], &usp[0]);
+			put_user(0x0fc0109f, &usp[2]);
+#else
+			put_user(regs->gr[31] >> 32, &usp[0]);
+			put_user(regs->gr[31] & 0xffffffff, &usp[1]);
+			put_user(0x0fc010df, &usp[2]);
+#endif
+			put_user(0xe0008200, &usp[3]);
+			put_user(0x34140000, &usp[4]);
+
+			/* Stack is 64-byte aligned, and we only 
+			 * need to flush 1 cache line */
+			asm("fdc 0(%%sr3, %0)\n"
+			    "fic 0(%%sr3, %0)\n"
+			    "sync\n"
+			    : : "r"(regs->gr[30]));
+
+			regs->gr[31] = regs->gr[30] + 8;
+			/* Preserve original r28. */
+			regs->gr[28] = regs->orig_r28;
+		} else if (regs->gr[28] == -ERESTARTNOHAND ||
+		           regs->gr[28] == -ERESTARTSYS ||
+		           regs->gr[28] == -ERESTARTNOINTR) {
 			/* Hooray for delayed branching.  We don't
                            have to restore %r20 (the system call
                            number) because it gets loaded in the delay
Index: include/asm-parisc/unistd.h
===================================================================
RCS file: /var/cvs/linux-2.6/include/asm-parisc/unistd.h,v
retrieving revision 1.1
diff -u -p -r1.1 unistd.h
--- include/asm-parisc/unistd.h	29 Jul 2003 17:02:04 -0000	1.1
+++ include/asm-parisc/unistd.h	2 Nov 2003 04:39:24 -0000
@@ -490,7 +490,7 @@
  */
 
 #define __NR_Linux                0
-#define __NR_syscall              (__NR_Linux + 0)
+#define __NR_restart_syscall      (__NR_Linux + 0)
 #define __NR_exit                 (__NR_Linux + 1)
 #define __NR_fork                 (__NR_Linux + 2)
 #define __NR_read                 (__NR_Linux + 3)