Evolution-X-Devices/kernel_google_wahoo
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

futex: Simplify fixup_pi_state_owner()

Browse Source 
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>
This commit is contained in:
Lee Jones
2021-02-04 17:29:02 +00:00
committed by Greg Kroah-Hartman
parent f08a4af5cc
commit 47e452fcf2
1 changed files with 27 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

41
kernel/futex.c
View File

@@ -2237,18 +2237,16 @@ 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;
@@ -2289,7 +2287,7 @@ retry:
if (__rt_mutex_futex_trylock(&pi_state->pi_mutex)) {
/* We got the lock after all, nothing to fix. */
return 0;
return 1;
}
/*
@@ -2304,7 +2302,7 @@ retry:
* We raced against a concurrent self; things are
* already fixed up. Nothing to do.
*/
return 0;
return 1;
}
newowner = argowner;
}
@@ -2345,7 +2343,7 @@ 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);
@@ -2353,12 +2351,27 @@ 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);