Index: arch/mips/kernel/ptrace.c
===================================================================
RCS file: /cvsroot/hhl-2.4.2/linux/arch/mips/kernel/ptrace.c,v
retrieving revision 1.3
diff -u -r1.3 ptrace.c
--- arch/mips/kernel/ptrace.c	2001/06/15 00:58:41	1.3
+++ arch/mips/kernel/ptrace.c	2001/06/16 19:06:59
@@ -149,8 +149,19 @@
 					save_fp(child);
 					disable_cp1();
 					last_task_used_math = NULL;
+					regs->cp0_status &= ~ST0_CU1;
 				}
-				tmp = (unsigned long) fregs[(addr - 32)];
+				/* The odd registers are actually the high order bits of the values
+				   stored in the even registers - unless we're using r2k_switch.S. */
+#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_R3912)
+				if (mips_cpu_options & MIPS_CPU_FPU)
+					tmp = *(unsigned long *)(fregs + addr);
+				else
+#endif
+				if (addr & 1)
+					tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
+				else
+					tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
 			} else {
 				tmp = -1;	/* FP not yet used  */
 			}
@@ -238,8 +249,21 @@
 				memset(&child->thread.fpu.hard, ~0,
 				       sizeof(child->thread.fpu.hard));
 				child->thread.fpu.hard.control = 0;
+			}
+			/* The odd registers are actually the high order bits of the values
+			   stored in the even registers - unless we're using r2k_switch.S. */
+#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_R3912)
+			if (mips_cpu_options & MIPS_CPU_FPU)
+				*(unsigned long *)(fregs + addr) = data;
+			else
+#endif
+			if (addr & 1) {
+				fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
+				fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32;
+			} else {
+				fregs[addr - FPR_BASE] &= ~0xffffffffLL;
+				fregs[addr - FPR_BASE] |= data;
 			}
-			fregs[addr - FPR_BASE] = data;
 			break;
 		}
 		case PC:
Index: arch/mips/kernel/signal.c
===================================================================
RCS file: /cvsroot/hhl-2.4.2/linux/arch/mips/kernel/signal.c,v
retrieving revision 1.2
diff -u -r1.2 signal.c
--- arch/mips/kernel/signal.c	2001/05/30 00:08:10	1.2
+++ arch/mips/kernel/signal.c	2001/06/16 19:06:59
@@ -220,8 +220,10 @@
 
 	err |= __get_user(owned_fp, &sc->sc_ownedfp);
 	if (owned_fp) {
+		if (last_task_used_math && (last_task_used_math != current))
+			last_task_used_math->thread.cp0_status &= ~ST0_CU1;
 		err |= restore_fp_context(sc);
 		last_task_used_math = current;
 	}
 
 	return err;
@@ -353,12 +355,11 @@
 	owned_fp = (current == last_task_used_math);
 	err |= __put_user(owned_fp, &sc->sc_ownedfp);
 
-	if (current->used_math) {	/* fp is active.  */
+	if (owned_fp) {	/* fp is active.  */
 		set_cp0_status(ST0_CU1);
 		err |= save_fp_context(sc);
 		last_task_used_math = NULL;
 		regs->cp0_status &= ~ST0_CU1;
-		current->used_math = 0;
 	}
 
 	return err;
Index: include/asm-mips/processor.h
===================================================================
RCS file: /cvsroot/hhl-2.4.2/linux/include/asm-mips/processor.h,v
retrieving revision 1.1.1.2
diff -u -r1.1.1.2 processor.h
--- include/asm-mips/processor.h	2001/03/27 22:01:19	1.1.1.2
+++ include/asm-mips/processor.h	2001/06/16 19:07:05
@@ -235,8 +235,8 @@
  * Do necessary setup to start up a newly executed thread.
  */
 #define start_thread(regs, new_pc, new_sp) do {				\
-	/* New thread looses kernel privileges. */			\
-	regs->cp0_status = (regs->cp0_status & ~(ST0_CU0|ST0_KSU)) | KU_USER;\
+	/* New thread loses kernel and FPU privileges. */		\
+	regs->cp0_status = (regs->cp0_status & ~(ST0_CU0|ST0_KSU|ST0_CU1)) | KU_USER;\
 	regs->cp0_epc = new_pc;						\
 	regs->regs[29] = new_sp;					\
 	current->thread.current_ds = USER_DS;				\