ppc64: fix handling of sigaltstack

arch/ppc64/kernel/signal.c

@@ -159,11 +159,10 @@ long sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize, int p3, int p4, int
 	}
 }
 
-
-
-long sys_sigaltstack(const stack_t *uss, stack_t *uoss)
+long sys_sigaltstack(const stack_t *uss, stack_t *uoss, unsigned long r5,
+		     unsigned long r6, unsigned long r7, unsigned long r8,
+		     struct pt_regs *regs)
 {
-	struct pt_regs *regs = (struct pt_regs *)&uss;
 	return do_sigaltstack(uss, uoss, regs->gpr[1]);
 }
 
@@ -250,7 +249,7 @@ int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
 		goto badframe;
 	/* This function sets back the stack flags into
 	   the current task structure.  */
-	sys_sigaltstack(&st, NULL);
+	sys_sigaltstack(&st, NULL, 0, 0, 0, 0, regs);
 
 	return regs->result;
 

arch/ppc64/kernel/signal32.c

@@ -421,7 +421,6 @@ static void setup_frame32(struct pt_regs *regs, struct sigregs32 *frame,
  *        siginfo32to64
  */
 
-
 /*
  * This code executes after the rt signal handler in 32 bit mode has
  * completed and returned  
@@ -438,6 +437,7 @@ long sys32_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
 	sigset_t set; 
 	stack_t st;
 	int i;
+	mm_segment_t old_fs;
 
 	/* Adjust the inputted reg1 to point to the first rt signal frame */
 	rt_sf = (struct rt_sigframe_32 *)(regs->gpr[1] + __SIGNAL_FRAMESIZE32);
@@ -509,10 +509,15 @@ long sys32_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
 	regs->dar = 0; 
 	regs->dsisr = 0;
 	regs->result = (u64)(saved_regs[PT_RESULT]) & 0xFFFFFFFF;
-
 	if (copy_from_user(current->thread.fpr, &sr->fp_regs,
 			   sizeof(sr->fp_regs)))
 		goto badframe;
+	/* This function sets back the stack flags into
+	   the current task structure.  */
+	old_fs = get_fs();
+	set_fs(KERNEL_DS);
+	do_sigaltstack(&st, NULL, regs->gpr[1]);
+	set_fs(old_fs);
 
 	ret = regs->result;
 	return ret;