[PATCH 02/41] arm: Use set_current_blocked()

[Matt Fleming]

From: Matt Fleming <matt.fleming@xxxxxxxxxxxxxxx>

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

Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd.bergmann@xxxxxxxxxx>
Cc: Dave Martin <dave.martin@xxxxxxxxxx>
Cc: Nicolas Pitre <nicolas.pitre@xxxxxxxxxx>
CC: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Matt Fleming <matt.fleming@xxxxxxxxxxxxxxx>
---
 arch/arm/kernel/signal.c |   25 +++++++++++--------------
 1 files changed, 11 insertions(+), 14 deletions(-)

diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 0340224..b97668a 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -66,12 +66,13 @@ const unsigned long syscall_restart_code[2] = {
  */
 asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask)
 {
-	mask &= _BLOCKABLE;
-	spin_lock_irq(&current->sighand->siglock);
+	sigset_t blocked;
+
 	current->saved_sigmask = current->blocked;
-	siginitset(&current->blocked, mask);
-	recalc_sigpending();
-	spin_unlock_irq(&current->sighand->siglock);
+
+	mask &= _BLOCKABLE;
+	siginitset(&blocked, mask);
+	set_current_block(&blocked);
 
 	current->state = TASK_INTERRUPTIBLE;
 	schedule();
@@ -281,10 +282,7 @@ static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf)
 	err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
 	if (err == 0) {
 		sigdelsetmask(&set, ~_BLOCKABLE);
-		spin_lock_irq(&current->sighand->siglock);
-		current->blocked = set;
-		recalc_sigpending();
-		spin_unlock_irq(&current->sighand->siglock);
+		set_current_blocked(&set);
 	}
 
 	__get_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
@@ -607,6 +605,7 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,
 {
 	struct thread_info *thread = current_thread_info();
 	struct task_struct *tsk = current;
+	sigset_t blocked;
 	int usig = sig;
 	int ret;
 
@@ -637,13 +636,11 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,
 	/*
 	 * Block the signal if we were successful.
 	 */
-	spin_lock_irq(&tsk->sighand->siglock);
-	sigorsets(&tsk->blocked, &tsk->blocked,
+	sigorsets(&blocked, &tsk->blocked,
 		  &ka->sa.sa_mask);
 	if (!(ka->sa.sa_flags & SA_NODEFER))
-		sigaddset(&tsk->blocked, sig);
-	recalc_sigpending();
-	spin_unlock_irq(&tsk->sighand->siglock);
+		sigaddset(&blocked, sig);
+	set_current_blocked(&blocked);
 
 	return 0;
 }
-- 
1.7.4.4

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