[SPARC64]: Kill bogus set_fs(KERNEL_DS) in do_rt_sigreturn().

From: Oleg Nesterov <oleg@tv-sign.ru>

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 12 deletions

diff --git a/arch/sparc64/kernel/signal.c b/arch/sparc64/kernel/signal.c
index 203e87301005..fb13775b3682 100644
--- a/arch/sparc64/kernel/signal.c
+++ b/arch/sparc64/kernel/signal.c
@@ -289,9 +289,7 @@ void do_rt_sigreturn(struct pt_regs *regs)
         struct rt_signal_frame __user *sf;
         unsigned long tpc, tnpc, tstate;
         __siginfo_fpu_t __user *fpu_save;
-        mm_segment_t old_fs;
         sigset_t set;
-        stack_t st;
         int err;
 
         /* Always make any pending restarted system calls return -EINTR */
@@ -327,20 +325,13 @@ void do_rt_sigreturn(struct pt_regs *regs)
                 err |= restore_fpu_state(regs, &sf->fpu_state);
 
         err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
-        err |= __copy_from_user(&st, &sf->stack, sizeof(stack_t));
-        
+        err |= do_sigaltstack(&sf->stack, NULL, (unsigned long)sf);
+
         if (err)
                 goto segv;
-                
+
         regs->tpc = tpc;
         regs->tnpc = tnpc;
-        
-        /* It is more difficult to avoid calling this function than to
-           call it and ignore errors.  */
-        old_fs = get_fs();
-        set_fs(KERNEL_DS);
-        do_sigaltstack((const stack_t __user *) &st, NULL, (unsigned long)sf);
-        set_fs(old_fs);
 
         sigdelsetmask(&set, ~_BLOCKABLE);
         spin_lock_irq(&current->sighand->siglock);