[PATCH 35/40] um: Use set_current_blocked() and block_sigmask()

[Matt Fleming]

From: Matt Fleming <matt.fleming@xxxxxxxxx>

As described in e6fa16ab ("signal: sigprocmask() should do
retarget_shared_pending()") the modification of current->blocked is
incorrect as we need to check whether the signal we're about to block
is pending in the shared queue.

Also, use the new helper function introduced in commit 5e6292c0f28f
("signal: add block_sigmask() for adding sigmask to current->blocked")
which centralises the code for updating current->blocked after
successfully delivering a signal and reduces the amount of duplicate
code across architectures. In the past some architectures got this
code wrong, so using this helper function should stop that from
happening again.

Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Richard Weinberger <richard@xxxxxx>
Cc: user-mode-linux-devel@xxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Matt Fleming <matt.fleming@xxxxxxxxx>
---
 arch/um/kernel/signal.c |   20 ++++++--------------
 1 files changed, 6 insertions(+), 14 deletions(-)

diff --git a/arch/um/kernel/signal.c b/arch/um/kernel/signal.c
index 8382e0b..fb12f4c 100644
--- a/arch/um/kernel/signal.c
+++ b/arch/um/kernel/signal.c
@@ -67,15 +67,8 @@ static int handle_signal(struct pt_regs *regs, unsigned long signr,
 
 	if (err)
 		force_sigsegv(signr, current);
-	else {
-		spin_lock_irq(&current->sighand->siglock);
-		sigorsets(&current->blocked, &current->blocked,
-			  &ka->sa.sa_mask);
-		if (!(ka->sa.sa_flags & SA_NODEFER))
-			sigaddset(&current->blocked, signr);
-		recalc_sigpending();
-		spin_unlock_irq(&current->sighand->siglock);
-	}
+	else
+		block_sigmask(ka, signr);
 
 	return err;
 }
@@ -158,12 +151,11 @@ int do_signal(void)
  */
 long sys_sigsuspend(int history0, int history1, old_sigset_t mask)
 {
+	sigset_t blocked;
+
 	mask &= _BLOCKABLE;
-	spin_lock_irq(&current->sighand->siglock);
-	current->saved_sigmask = current->blocked;
-	siginitset(&current->blocked, mask);
-	recalc_sigpending();
-	spin_unlock_irq(&current->sighand->siglock);
+	siginitset(&blocked, mask);
+	set_current_blocked(&blocked);
 
 	current->state = TASK_INTERRUPTIBLE;
 	schedule();
-- 
1.7.4.4

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