patch-2.4.0-test11 linux/arch/sparc64/kernel/process.c

• Lines: 40
• Date: Thu Nov 9 15:57:41 2000
• Orig file: v2.4.0-test10/linux/arch/sparc64/kernel/process.c
• Orig date: Thu Sep 7 08:32:00 2000

diff -u --recursive --new-file v2.4.0-test10/linux/arch/sparc64/kernel/process.c linux/arch/sparc64/kernel/process.c
@@ -1,4 +1,4 @@
-/*  $Id: process.c,v 1.112 2000/09/06 00:45:01 davem Exp $
+/*  $Id: process.c,v 1.113 2000/11/08 08:14:58 davem Exp $
  *  arch/sparc64/kernel/process.c
  *
  *  Copyright (C) 1995, 1996 David S. Miller (davem@caip.rutgers.edu)
@@ -647,14 +647,21 @@
 {
 	long retval;
 
-	__asm__ __volatile("mov %1, %%g1\n\t"
+	/* If the parent runs before fn(arg) is called by the child,
+	 * the input registers of this function can be clobbered.
+	 * So we stash 'fn' and 'arg' into global registers which
+	 * will not be modified by the parent.
+	 */
+	__asm__ __volatile("mov %4, %%g2\n\t"	   /* Save FN into global */
+			   "mov %5, %%g3\n\t"	   /* Save ARG into global */
+			   "mov %1, %%g1\n\t"	   /* Clone syscall nr. */
 			   "mov %2, %%o0\n\t"	   /* Clone flags. */
 			   "mov 0, %%o1\n\t"	   /* usp arg == 0 */
 			   "t 0x6d\n\t"		   /* Linux/Sparc clone(). */
 			   "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
 			   " mov %%o0, %0\n\t"
-			   "jmpl %4, %%o7\n\t"	   /* Call the function. */
-			   " mov %5, %%o0\n\t"	   /* Set arg in delay. */
+			   "jmpl %%g2, %%o7\n\t"   /* Call the function. */
+			   " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
 			   "mov %3, %%g1\n\t"
 			   "t 0x6d\n\t"		   /* Linux/Sparc exit(). */
 			   /* Notreached by child. */
@@ -662,7 +669,7 @@
 			   "=r" (retval) :
 			   "i" (__NR_clone), "r" (flags | CLONE_VM),
 			   "i" (__NR_exit),  "r" (fn), "r" (arg) :
-			   "g1", "o0", "o1", "memory", "cc");
+			   "g1", "g2", "g3", "o0", "o1", "memory", "cc");
 	return retval;
 }