x86: signal: sys_rt_sigreturn() should use set_current_blocked()

Normally sys_rt_sigreturn() restores the old current->blocked which was
changed by handle_signal(), and unblocking is always fine.

But the debugger or application itself can change frame->uc_sigmask and
thus we need set_current_blocked()->retarget_shared_pending().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Matt Fleming <matt.fleming@linux.intel.com>
Acked-by: Tejun Heo <tj@kernel.org>

1 files changed, 1 insertions, 4 deletions

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 5a8f5e68bb61..40a24932a8a1 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -601,10 +601,7 @@ long sys_rt_sigreturn(struct pt_regs *regs)
                 goto badframe;
 
         sigdelsetmask(&set, ~_BLOCKABLE);
-        spin_lock_irq(&current->sighand->siglock);
-        current->blocked = set;
-        recalc_sigpending();
-        spin_unlock_irq(&current->sighand->siglock);
+        set_current_blocked(&set);
 
         if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
                 goto badframe;