[PATCH v2 02/43] alpha: Use set_current_blocked() and block_sigmask()

[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.

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@xxxxxxxxxx>
Cc: Richard Henderson <rth@xxxxxxxxxxx>
Cc: Ivan Kokshaysky <ink@xxxxxxxxxxxxxxxxxxxx>
Cc: Matt Turner <mattst88@xxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Matt Fleming <matt.fleming@xxxxxxxxxxxxxxx>
---

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/alpha/kernel/signal.c |   31 ++++++++++---------------------
 1 files changed, 10 insertions(+), 21 deletions(-)

diff --git a/arch/alpha/kernel/signal.c b/arch/alpha/kernel/signal.c
index 6f7feb5..35f2ef4 100644
--- a/arch/alpha/kernel/signal.c
+++ b/arch/alpha/kernel/signal.c
@@ -120,12 +120,13 @@ SYSCALL_DEFINE5(rt_sigaction, int, sig, const struct sigaction __user *, act,
  */
 SYSCALL_DEFINE1(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();
@@ -238,10 +239,7 @@ do_sigreturn(struct sigcontext __user *sc, struct pt_regs *regs,
 		goto give_sigsegv;
 
 	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(sc, regs, sw))
 		goto give_sigsegv;
@@ -276,10 +274,7 @@ do_rt_sigreturn(struct rt_sigframe __user *frame, struct pt_regs *regs,
 		goto give_sigsegv;
 
 	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(&frame->uc.uc_mcontext, regs, sw))
 		goto give_sigsegv;
@@ -501,14 +496,8 @@ handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info,
 	else
 		ret = setup_frame(sig, ka, oldset, regs, sw);
 
-	if (ret == 0) {
-		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,sig);
-		recalc_sigpending();
-		spin_unlock_irq(&current->sighand->siglock);
-	}
+	if (ret == 0)
+		block_sigmask(ka, sig);
 
 	return ret;
 }
-- 
1.7.4.4

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