[PATCH 5/5] futex: Silence uninitialized warnings

Davidlohr Bueso
2014-01-12T23:32:25Z

From: Davidlohr Bueso <davidlohr@hp.com>

Callers of cmpxchg_futex_value_locked() can trigger the following:

kernel/futex.c: In function ‘futex_lock_pi_atomic’:
kernel/futex.c:725: warning: ‘curval’ may be used uninitialized in this function

This was initially addressed by commit 7cfdaf38, but others still remain. Silence
these messages once and for all as the variables really aren't uninitialized.

Cc: Ingo Molnar <mingo@kernel.org>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Scott Norton <scott.norton@hp.com>
Cc: Tom Vaden <tom.vaden@hp.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Waiman Long <Waiman.Long@hp.com>
Cc: Jason Low <jason.low2@hp.com>
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
---
kernel/futex.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/futex.c b/kernel/futex.c
index be6399a..8d40953 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -838,7 +838,7 @@ static int futex_lock_pi_atomic(u32 __user *uaddr, struct futex_hash_bucket *hb,
struct task_struct *task, int set_waiters)
{
int lock_taken, ret, force_take = 0;
- u32 uval, newval, curval, vpid = task_pid_vnr(task);
+ u32 uval, newval, uninitialized_var(curval), vpid = task_pid_vnr(task);

retry:
ret = lock_taken = 0;
@@ -2227,7 +2227,7 @@ static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags)
struct futex_hash_bucket *hb;
struct futex_q *this, *next;
union futex_key key = FUTEX_KEY_INIT;
- u32 uval, vpid = task_pid_vnr(current);
+ u32 uninitialized_var(uval), vpid = task_pid_vnr(current);
int ret;

retry:
@@ -2843,7 +2843,7 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,

static int __init futex_init(void)
{
- u32 curval;
+ u32 uninitialized_var(curval);
unsigned long i;

#if CONFIG_BASE_SMALL
--
1.8.1.4