linux-kernel - [PATCH v2 25/43] powerpc: Use set_current_blocked() and block

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Date:	Fri, 19 Aug 2011 17:46:41 +0100
From:	Matt Fleming <matt@...sole-pimps.org>
To:	Oleg Nesterov <oleg@...hat.com>
Cc:	linux-kernel@...r.kernel.org,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Paul Mackerras <paulus@...ba.org>
Subject: [PATCH v2 25/43] powerpc: Use set_current_blocked() and block_sigmask()

From: Matt Fleming <matt.fleming@...el.com>

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 block_sigmask() 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@...hat.com>
Cc: Benjamin Herrenschmidt <benh@...nel.crashing.org>
Cc: Paul Mackerras <paulus@...ba.org>
Signed-off-by: Matt Fleming <matt.fleming@...el.com>
---

v2 of this patch depends on "[PATCH 01/43] signal: Add block_sigmask()
for adding sigmask to current->blocked" so they need to go through the
same tree but this patch would benefit from some maintainer ACK's.

 arch/powerpc/kernel/signal.c    |   13 ++-----------
 arch/powerpc/kernel/signal_32.c |   11 ++++++-----
 2 files changed, 8 insertions(+), 16 deletions(-)

diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index 2300426..3867f7b 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -56,10 +56,7 @@ void __user * get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
 void restore_sigmask(sigset_t *set)
 {
 	sigdelsetmask(set, ~_BLOCKABLE);
-	spin_lock_irq(&current->sighand->siglock);
-	current->blocked = *set;
-	recalc_sigpending();
-	spin_unlock_irq(&current->sighand->siglock);
+	set_current_blocked(set);
 }
 
 static void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka,
@@ -167,13 +164,7 @@ static int do_signal_pending(sigset_t *oldset, struct pt_regs *regs)
 
 	regs->trap = 0;
 	if (ret) {
-		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);
+		block_sigmask(&ka, signr);
 
 		/*
 		 * A signal was successfully delivered; the saved sigmask is in
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 78b76dc..5fc9d19 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -242,12 +242,13 @@ static inline int restore_general_regs(struct pt_regs *regs,
  */
 long sys_sigsuspend(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_blocked(&blocked);
 
  	current->state = TASK_INTERRUPTIBLE;
  	schedule();
-- 
1.7.4.4

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