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 */