1 files changed, 41 insertions, 70 deletions

diff --git a/arch/m68k/kernel/signal.c b/arch/m68k/kernel/signal.c
index cd11eb101eac..338817d0cb3f 100644
--- a/arch/m68k/kernel/signal.c
+++ b/arch/m68k/kernel/signal.c
@@ -641,56 +641,35 @@ static inline void siginfo_build_tests(void)
 static int mangle_kernel_stack(struct pt_regs *regs, int formatvec,
 			       void __user *fp)
 {
-	int fsize = frame_extra_sizes(formatvec >> 12);
-	if (fsize < 0) {
+	int extra = frame_extra_sizes(formatvec >> 12);
+	char buf[sizeof_field(struct frame, un)];
+
+	if (extra < 0) {
 		/*
 		 * user process trying to return with weird frame format
 		 */
 		pr_debug("user process returning with weird frame format\n");
-		return 1;
+		return -1;
 	}
-	if (!fsize) {
-		regs->format = formatvec >> 12;
-		regs->vector = formatvec & 0xfff;
-	} else {
-		struct switch_stack *sw = (struct switch_stack *)regs - 1;
-		/* yes, twice as much as max(sizeof(frame.un.fmt<x>)) */
-		unsigned long buf[sizeof_field(struct frame, un) / 2];
-
-		/* that'll make sure that expansion won't crap over data */
-		if (copy_from_user(buf + fsize / 4, fp, fsize))
-			return 1;
-
-		/* point of no return */
-		regs->format = formatvec >> 12;
-		regs->vector = formatvec & 0xfff;
-#define frame_offset (sizeof(struct pt_regs)+sizeof(struct switch_stack))
-		__asm__ __volatile__ (
-#ifdef CONFIG_COLDFIRE
-			 "   movel %0,%/sp\n\t"
-			 "   bra ret_from_signal\n"
-#else
-			 "   movel %0,%/a0\n\t"
-			 "   subl %1,%/a0\n\t"     /* make room on stack */
-			 "   movel %/a0,%/sp\n\t"  /* set stack pointer */
-			 /* move switch_stack and pt_regs */
-			 "1: movel %0@+,%/a0@+\n\t"
-			 "   dbra %2,1b\n\t"
-			 "   lea %/sp@(%c3),%/a0\n\t" /* add offset of fmt */
-			 "   lsrl  #2,%1\n\t"
-			 "   subql #1,%1\n\t"
-			 /* copy to the gap we'd made */
-			 "2: movel %4@+,%/a0@+\n\t"
-			 "   dbra %1,2b\n\t"
-			 "   bral ret_from_signal\n"
+	if (extra && copy_from_user(buf, fp, extra))
+		return -1;
+	regs->format = formatvec >> 12;
+	regs->vector = formatvec & 0xfff;
+	if (extra) {
+		void *p = (struct switch_stack *)regs - 1;
+		struct frame *new = (void *)regs - extra;
+		int size = sizeof(struct pt_regs)+sizeof(struct switch_stack);
+
+		memmove(p - extra, p, size);
+		memcpy(p - extra + size, buf, extra);
+		current->thread.esp0 = (unsigned long)&new->ptregs;
+#ifdef CONFIG_M68040
+		/* on 68040 complete pending writebacks if any */
+		if (new->ptregs.format == 7) // bus error frame
+			berr_040cleanup(new);
 #endif
-			 : /* no outputs, it doesn't ever return */
-			 : "a" (sw), "d" (fsize), "d" (frame_offset/4-1),
-			   "n" (frame_offset), "a" (buf + fsize/4)
-			 : "a0");
-#undef frame_offset
 	}
-	return 0;
+	return extra;
 }
 
 static inline int
@@ -698,7 +677,6 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *usc, void __u
 {
 	int formatvec;
 	struct sigcontext context;
-	int err = 0;
 
 	siginfo_build_tests();
 
@@ -707,7 +685,7 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *usc, void __u
 
 	/* get previous context */
 	if (copy_from_user(&context, usc, sizeof(context)))
-		goto badframe;
+		return -1;
 
 	/* restore passed registers */
 	regs->d0 = context.sc_d0;
@@ -720,15 +698,10 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *usc, void __u
 	wrusp(context.sc_usp);
 	formatvec = context.sc_formatvec;
 
-	err = restore_fpu_state(&context);
-
-	if (err || mangle_kernel_stack(regs, formatvec, fp))
-		goto badframe;
-
-	return 0;
+	if (restore_fpu_state(&context))
+		return -1;
 
-badframe:
-	return 1;
+	return mangle_kernel_stack(regs, formatvec, fp);
 }
 
 static inline int
@@ -745,7 +718,7 @@ rt_restore_ucontext(struct pt_regs *regs, struct switch_stack *sw,
 
 	err = __get_user(temp, &uc->uc_mcontext.version);
 	if (temp != MCONTEXT_VERSION)
-		goto badframe;
+		return -1;
 	/* restore passed registers */
 	err |= __get_user(regs->d0, &gregs[0]);
 	err |= __get_user(regs->d1, &gregs[1]);
@@ -774,22 +747,17 @@ rt_restore_ucontext(struct pt_regs *regs, struct switch_stack *sw,
 	err |= restore_altstack(&uc->uc_stack);
 
 	if (err)
-		goto badframe;
-
-	if (mangle_kernel_stack(regs, temp, &uc->uc_extra))
-		goto badframe;
+		return -1;
 
-	return 0;
-
-badframe:
-	return 1;
+	return mangle_kernel_stack(regs, temp, &uc->uc_extra);
 }
 
-asmlinkage int do_sigreturn(struct pt_regs *regs, struct switch_stack *sw)
+asmlinkage void *do_sigreturn(struct pt_regs *regs, struct switch_stack *sw)
 {
 	unsigned long usp = rdusp();
 	struct sigframe __user *frame = (struct sigframe __user *)(usp - 4);
 	sigset_t set;
+	int size;
 
 	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
@@ -801,20 +769,22 @@ asmlinkage int do_sigreturn(struct pt_regs *regs, struct switch_stack *sw)
 
 	set_current_blocked(&set);
 
-	if (restore_sigcontext(regs, &frame->sc, frame + 1))
+	size = restore_sigcontext(regs, &frame->sc, frame + 1);
+	if (size < 0)
 		goto badframe;
-	return regs->d0;
+	return (void *)sw - size;
 
 badframe:
 	force_sig(SIGSEGV);
-	return 0;
+	return sw;
 }
 
-asmlinkage int do_rt_sigreturn(struct pt_regs *regs, struct switch_stack *sw)
+asmlinkage void *do_rt_sigreturn(struct pt_regs *regs, struct switch_stack *sw)
 {
 	unsigned long usp = rdusp();
 	struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(usp - 4);
 	sigset_t set;
+	int size;
 
 	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;
@@ -823,13 +793,14 @@ asmlinkage int do_rt_sigreturn(struct pt_regs *regs, struct switch_stack *sw)
 
 	set_current_blocked(&set);
 
-	if (rt_restore_ucontext(regs, sw, &frame->uc))
+	size = rt_restore_ucontext(regs, sw, &frame->uc);
+	if (size < 0)
 		goto badframe;
-	return regs->d0;
+	return (void *)sw - size;
 
 badframe:
 	force_sig(SIGSEGV);
-	return 0;
+	return sw;
 }
 
 static inline struct pt_regs *rte_regs(struct pt_regs *regs)