diff options
| author | Lee Jones <lee.jones@linaro.org> | 2021-02-04 17:29:02 +0000 |
|---|---|---|
| committer | Panwar Vijay Kumar <pvijayku@codeaurora.org> | 2021-09-28 11:29:26 +0530 |
| commit | a436b73e9032cdc9731255d950bb524739db037e (patch) | |
| tree | 574222259e36eedb571eb5ad6fdb6d8351ced685 /kernel | |
| parent | 11b99dbe32215bd92e0d417dad927673988f36a6 (diff) | |
futex: Simplify fixup_pi_state_owner()
From: Thomas Gleixner <tglx@linutronix.de>
[ Upstream commit f2dac39d93987f7de1e20b3988c8685523247ae2 ]
Too many gotos already and an upcoming fix would make it even more
unreadable.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Git-commit: 47e452fcf2f50645247aa0240ae26e0d14d6d3ad
Git-repo: https://android.googlesource.com/kernel/common/
Change-Id: Idf8902712a59e0c830fe0582a5b97a2ca54e1320
Signed-off-by: pvijayku <pvijayku@codeaurora.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/futex.c | 41 |
1 files changed, 27 insertions, 14 deletions
diff --git a/kernel/futex.c b/kernel/futex.c index d40884af7121..8b67e66210c0 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -2135,18 +2135,16 @@ static void unqueue_me_pi(struct futex_q *q) spin_unlock(q->lock_ptr); } -static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q, - struct task_struct *argowner) +static int __fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q, + struct task_struct *argowner) { struct futex_pi_state *pi_state = q->pi_state; - u32 uval, uninitialized_var(curval), newval; struct task_struct *oldowner, *newowner; - u32 newtid; - int ret; - - lockdep_assert_held(q->lock_ptr); + u32 uval, curval, newval, newtid; + int err = 0; oldowner = pi_state->owner; + /* Owner died? */ if (!pi_state->owner) newtid |= FUTEX_OWNER_DIED; @@ -2187,7 +2185,7 @@ retry: if (__rt_mutex_futex_trylock(&pi_state->pi_mutex)) { /* We got the lock after all, nothing to fix. */ - return 0; + return 1; } /* @@ -2202,7 +2200,7 @@ retry: * We raced against a concurrent self; things are * already fixed up. Nothing to do. */ - return 0; + return 1; } newowner = argowner; } @@ -2243,7 +2241,7 @@ retry: handle_fault: spin_unlock(q->lock_ptr); - ret = fault_in_user_writeable(uaddr); + err = fault_in_user_writeable(uaddr); spin_lock(q->lock_ptr); @@ -2251,12 +2249,27 @@ handle_fault: * Check if someone else fixed it for us: */ if (pi_state->owner != oldowner) - return 0; + return argowner == current; - if (ret) - return ret; + /* Retry if err was -EAGAIN or the fault in succeeded */ + if (!err) + goto retry; - goto retry; + return err; +} + +static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q, + struct task_struct *argowner) +{ + struct futex_pi_state *pi_state = q->pi_state; + int ret; + + lockdep_assert_held(q->lock_ptr); + + raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock); + ret = __fixup_pi_state_owner(uaddr, q, argowner); + raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock); + return ret; } static long futex_wait_restart(struct restart_block *restart); |