3 files changed, 34 insertions, 9 deletions

diff --git a/arch/sparc/kernel/process.c b/arch/sparc/kernel/process.c
index e7f35198ae34..36431f377dee 100644
--- a/arch/sparc/kernel/process.c
+++ b/arch/sparc/kernel/process.c
@@ -419,14 +419,26 @@ asmlinkage int sparc_do_fork(unsigned long clone_flags,
                              unsigned long stack_size)
 {
 	unsigned long parent_tid_ptr, child_tid_ptr;
+	unsigned long orig_i1 = regs->u_regs[UREG_I1];
+	long ret;
 
 	parent_tid_ptr = regs->u_regs[UREG_I2];
 	child_tid_ptr = regs->u_regs[UREG_I4];
 
-	return do_fork(clone_flags, stack_start,
-		       regs, stack_size,
-		       (int __user *) parent_tid_ptr,
-		       (int __user *) child_tid_ptr);
+	ret = do_fork(clone_flags, stack_start,
+		      regs, stack_size,
+		      (int __user *) parent_tid_ptr,
+		      (int __user *) child_tid_ptr);
+
+	/* If we get an error and potentially restart the system
+	 * call, we're screwed because copy_thread() clobbered
+	 * the parent's %o1.  So detect that case and restore it
+	 * here.
+	 */
+	if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
+		regs->u_regs[UREG_I1] = orig_i1;
+
+	return ret;
 }
 
 /* Copy a Sparc thread.  The fork() return value conventions
diff --git a/arch/sparc/kernel/signal.c b/arch/sparc/kernel/signal.c
index 3c312290c3c2..368157926d24 100644
--- a/arch/sparc/kernel/signal.c
+++ b/arch/sparc/kernel/signal.c
@@ -245,15 +245,29 @@ static inline int invalid_frame_pointer(void __user *fp, int fplen)
 
 static inline void __user *get_sigframe(struct sigaction *sa, struct pt_regs *regs, unsigned long framesize)
 {
-	unsigned long sp;
+	unsigned long sp = regs->u_regs[UREG_FP];
 
-	sp = regs->u_regs[UREG_FP];
+	/*
+	 * If we are on the alternate signal stack and would overflow it, don't.
+	 * Return an always-bogus address instead so we will die with SIGSEGV.
+	 */
+	if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
+		return (void __user *) -1L;
 
 	/* This is the X/Open sanctioned signal stack switching.  */
 	if (sa->sa_flags & SA_ONSTACK) {
-		if (!on_sig_stack(sp) && !((current->sas_ss_sp + current->sas_ss_size) & 7))
+		if (sas_ss_flags(sp) == 0)
 			sp = current->sas_ss_sp + current->sas_ss_size;
 	}
+
+	/* Always align the stack frame.  This handles two cases.  First,
+	 * sigaltstack need not be mindful of platform specific stack
+	 * alignment.  Second, if we took this signal because the stack
+	 * is not aligned properly, we'd like to take the signal cleanly
+	 * and report that.
+	 */
+	sp &= ~7UL;
+
 	return (void __user *)(sp - framesize);
 }
 
diff --git a/arch/sparc/kernel/sys_sparc.c b/arch/sparc/kernel/sys_sparc.c
index f188b5dc9fd0..e995491c4436 100644
--- a/arch/sparc/kernel/sys_sparc.c
+++ b/arch/sparc/kernel/sys_sparc.c
@@ -223,8 +223,7 @@ int sparc_mmap_check(unsigned long addr, unsigned long len, unsigned long flags)
 {
 	if (ARCH_SUN4C_SUN4 &&
 	    (len > 0x20000000 ||
-	     ((flags & MAP_FIXED) &&
-	      addr < 0xe0000000 && addr + len > 0x20000000)))
+	     (addr < 0xe0000000 && addr + len > 0x20000000)))
 		return -EINVAL;
 
 	/* See asm-sparc/uaccess.h */