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-rw-r--r--kernel/futex.c49
1 files changed, 9 insertions, 40 deletions
diff --git a/kernel/futex.c b/kernel/futex.c
index 2aa216e..80b5ce7 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1507,7 +1507,6 @@ handle_fault:
#define FLAGS_HAS_TIMEOUT 0x04
static long futex_wait_restart(struct restart_block *restart);
-static long futex_lock_pi_restart(struct restart_block *restart);
/**
* fixup_owner() - Post lock pi_state and corner case management
@@ -1930,21 +1929,6 @@ uaddr_faulted:
goto retry;
}
-static long futex_lock_pi_restart(struct restart_block *restart)
-{
- u32 __user *uaddr = (u32 __user *)restart->futex.uaddr;
- ktime_t t, *tp = NULL;
- int fshared = restart->futex.flags & FLAGS_SHARED;
-
- if (restart->futex.flags & FLAGS_HAS_TIMEOUT) {
- t.tv64 = restart->futex.time;
- tp = &t;
- }
- restart->fn = do_no_restart_syscall;
-
- return (long)futex_lock_pi(uaddr, fshared, restart->futex.val, tp, 0);
-}
-
/*
* Userspace attempted a TID -> 0 atomic transition, and failed.
* This is the in-kernel slowpath: we look up the PI state (if any),
@@ -2141,12 +2125,10 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, int fshared,
struct hrtimer_sleeper timeout, *to = NULL;
struct rt_mutex_waiter rt_waiter;
struct rt_mutex *pi_mutex = NULL;
- struct restart_block *restart;
struct futex_hash_bucket *hb;
union futex_key key2;
struct futex_q q;
int res, ret;
- u32 uval;
if (!bitset)
return -EINVAL;
@@ -2245,30 +2227,17 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, int fshared,
if (rt_mutex_owner(pi_mutex) == current)
rt_mutex_unlock(pi_mutex);
} else if (ret == -EINTR) {
- ret = -EFAULT;
- if (get_user(uval, uaddr2))
- goto out_put_keys;
-
/*
- * We've already been requeued, so restart by calling
- * futex_lock_pi() directly, rather then returning to this
- * function.
+ * We've already been requeued, but we have no way to
+ * restart by calling futex_lock_pi() directly. We
+ * could restart the syscall, but that will look at
+ * the user space value and return right away. So we
+ * drop back with EWOULDBLOCK to tell user space that
+ * "val" has been changed. That's the same what the
+ * restart of the syscall would do in
+ * futex_wait_setup().
*/
- ret = -ERESTART_RESTARTBLOCK;
- restart = &current_thread_info()->restart_block;
- restart->fn = futex_lock_pi_restart;
- restart->futex.uaddr = (u32 *)uaddr2;
- restart->futex.val = uval;
- restart->futex.flags = 0;
- if (abs_time) {
- restart->futex.flags |= FLAGS_HAS_TIMEOUT;
- restart->futex.time = abs_time->tv64;
- }
-
- if (fshared)
- restart->futex.flags |= FLAGS_SHARED;
- if (clockrt)
- restart->futex.flags |= FLAGS_CLOCKRT;
+ ret = -EWOULDBLOCK;
}
out_put_keys:
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