3.12.38-rt53-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Gleixner <tglx@xxxxxxxxxxxxx> upstream commit: bd1dbcc67cd2c1181e2c01daac51eabf1b964dd8 No point in open coding the same function again. Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Reviewed-by: Darren Hart <darren@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Davidlohr Bueso <davidlohr@xxxxxx> Cc: Kees Cook <kees@xxxxxxxxxxx> Cc: wad@xxxxxxxxxxxx Link: http://lkml.kernel.org/r/20140611204237.092947239@xxxxxxxxxxxxx Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx> --- kernel/futex.c | 127 +++++++++++++++++++++++++++------------------------------ 1 file changed, 61 insertions(+), 66 deletions(-) diff --git a/kernel/futex.c b/kernel/futex.c index 4dfbd5d57c5c..b85c07028be1 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -649,90 +649,85 @@ static int lookup_pi_state(u32 uval, struct futex_hash_bucket *hb, union futex_key *key, struct futex_pi_state **ps) { + struct futex_q *match = futex_top_waiter(hb, key); struct futex_pi_state *pi_state = NULL; - struct futex_q *this, *next; - struct plist_head *head; struct task_struct *p; pid_t pid = uval & FUTEX_TID_MASK; - head = &hb->chain; - - plist_for_each_entry_safe(this, next, head, list) { - if (match_futex(&this->key, key)) { - /* - * Sanity check the waiter before increasing - * the refcount and attaching to it. - */ - pi_state = this->pi_state; - /* - * Userspace might have messed up non-PI and - * PI futexes [3] - */ - if (unlikely(!pi_state)) - return -EINVAL; + if (match) { + /* + * Sanity check the waiter before increasing the + * refcount and attaching to it. + */ + pi_state = match->pi_state; + /* + * Userspace might have messed up non-PI and PI + * futexes [3] + */ + if (unlikely(!pi_state)) + return -EINVAL; - WARN_ON(!atomic_read(&pi_state->refcount)); + WARN_ON(!atomic_read(&pi_state->refcount)); + /* + * Handle the owner died case: + */ + if (uval & FUTEX_OWNER_DIED) { /* - * Handle the owner died case: + * exit_pi_state_list sets owner to NULL and + * wakes the topmost waiter. The task which + * acquires the pi_state->rt_mutex will fixup + * owner. */ - if (uval & FUTEX_OWNER_DIED) { + if (!pi_state->owner) { /* - * exit_pi_state_list sets owner to NULL and - * wakes the topmost waiter. The task which - * acquires the pi_state->rt_mutex will fixup - * owner. + * No pi state owner, but the user + * space TID is not 0. Inconsistent + * state. [5] */ - if (!pi_state->owner) { - /* - * No pi state owner, but the user - * space TID is not 0. Inconsistent - * state. [5] - */ - if (pid) - return -EINVAL; - /* - * Take a ref on the state and - * return. [4] - */ - goto out_state; - } - - /* - * If TID is 0, then either the dying owner - * has not yet executed exit_pi_state_list() - * or some waiter acquired the rtmutex in the - * pi state, but did not yet fixup the TID in - * user space. - * - * Take a ref on the state and return. [6] - */ - if (!pid) - goto out_state; - } else { + if (pid) + return -EINVAL; /* - * If the owner died bit is not set, - * then the pi_state must have an - * owner. [7] + * Take a ref on the state and + * return. [4] */ - if (!pi_state->owner) - return -EINVAL; + goto out_state; } /* - * Bail out if user space manipulated the - * futex value. If pi state exists then the - * owner TID must be the same as the user - * space TID. [9/10] + * If TID is 0, then either the dying owner + * has not yet executed exit_pi_state_list() + * or some waiter acquired the rtmutex in the + * pi state, but did not yet fixup the TID in + * user space. + * + * Take a ref on the state and return. [6] + */ + if (!pid) + goto out_state; + } else { + /* + * If the owner died bit is not set, + * then the pi_state must have an + * owner. [7] */ - if (pid != task_pid_vnr(pi_state->owner)) + if (!pi_state->owner) return -EINVAL; - - out_state: - atomic_inc(&pi_state->refcount); - *ps = pi_state; - return 0; } + + /* + * Bail out if user space manipulated the + * futex value. If pi state exists then the + * owner TID must be the same as the user + * space TID. [9/10] + */ + if (pid != task_pid_vnr(pi_state->owner)) + return -EINVAL; + + out_state: + atomic_inc(&pi_state->refcount); + *ps = pi_state; + return 0; } /* -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
