diff options
Diffstat (limited to 'fs/userfaultfd.c')
| -rw-r--r-- | fs/userfaultfd.c | 43 |
1 files changed, 3 insertions, 40 deletions
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 52de29000c7e..0e4a3837da52 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -61,7 +61,7 @@ struct userfaultfd_ctx { /* waitqueue head for events */ wait_queue_head_t event_wqh; /* a refile sequence protected by fault_pending_wqh lock */ - struct seqcount refile_seq; + seqcount_spinlock_t refile_seq; /* pseudo fd refcounting */ refcount_t refcount; /* userfaultfd syscall flags */ @@ -339,7 +339,6 @@ out: return ret; } -/* Should pair with userfaultfd_signal_pending() */ static inline long userfaultfd_get_blocking_state(unsigned int flags) { if (flags & FAULT_FLAG_INTERRUPTIBLE) @@ -351,18 +350,6 @@ static inline long userfaultfd_get_blocking_state(unsigned int flags) return TASK_UNINTERRUPTIBLE; } -/* Should pair with userfaultfd_get_blocking_state() */ -static inline bool userfaultfd_signal_pending(unsigned int flags) -{ - if (flags & FAULT_FLAG_INTERRUPTIBLE) - return signal_pending(current); - - if (flags & FAULT_FLAG_KILLABLE) - return fatal_signal_pending(current); - - return false; -} - /* * The locking rules involved in returning VM_FAULT_RETRY depending on * FAULT_FLAG_ALLOW_RETRY, FAULT_FLAG_RETRY_NOWAIT and @@ -516,33 +503,9 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason) vmf->flags, reason); mmap_read_unlock(mm); - if (likely(must_wait && !READ_ONCE(ctx->released) && - !userfaultfd_signal_pending(vmf->flags))) { + if (likely(must_wait && !READ_ONCE(ctx->released))) { wake_up_poll(&ctx->fd_wqh, EPOLLIN); schedule(); - ret |= VM_FAULT_MAJOR; - - /* - * False wakeups can orginate even from rwsem before - * up_read() however userfaults will wait either for a - * targeted wakeup on the specific uwq waitqueue from - * wake_userfault() or for signals or for uffd - * release. - */ - while (!READ_ONCE(uwq.waken)) { - /* - * This needs the full smp_store_mb() - * guarantee as the state write must be - * visible to other CPUs before reading - * uwq.waken from other CPUs. - */ - set_current_state(blocking_state); - if (READ_ONCE(uwq.waken) || - READ_ONCE(ctx->released) || - userfaultfd_signal_pending(vmf->flags)) - break; - schedule(); - } } __set_current_state(TASK_RUNNING); @@ -1998,7 +1961,7 @@ static void init_once_userfaultfd_ctx(void *mem) init_waitqueue_head(&ctx->fault_wqh); init_waitqueue_head(&ctx->event_wqh); init_waitqueue_head(&ctx->fd_wqh); - seqcount_init(&ctx->refile_seq); + seqcount_spinlock_init(&ctx->refile_seq, &ctx->fault_pending_wqh.lock); } SYSCALL_DEFINE1(userfaultfd, int, flags) |