Merge tag 'io_uring-5.6-2020-02-05' of git://git.kernel.dk/linux-block

Pull io_uring updates from Jens Axboe:
 "Some later fixes for io_uring:

   - Small cleanup series from Pavel

   - Belt and suspenders build time check of sqe size and layout
     (Stefan)

   - Addition of ->show_fdinfo() on request of Jann Horn, to aid in
     understanding mapped personalities

   - eventfd recursion/deadlock fix, for both io_uring and aio

   - Fixup for send/recv handling

   - Fixup for double deferral of read/write request

   - Fix for potential double completion event for close request

   - Adjust fadvise advice async/inline behavior

   - Fix for shutdown hang with SQPOLL thread

   - Fix for potential use-after-free of fixed file table"

* tag 'io_uring-5.6-2020-02-05' of git://git.kernel.dk/linux-block:
  io_uring: cleanup fixed file data table references
  io_uring: spin for sq thread to idle on shutdown
  aio: prevent potential eventfd recursion on poll
  io_uring: put the flag changing code in the same spot
  io_uring: iterate req cache backwards
  io_uring: punt even fadvise() WILLNEED to async context
  io_uring: fix sporadic double CQE entry for close
  io_uring: remove extra ->file check
  io_uring: don't map read/write iovec potentially twice
  io_uring: use the proper helpers for io_send/recv
  io_uring: prevent potential eventfd recursion on poll
  eventfd: track eventfd_signal() recursion depth
  io_uring: add BUILD_BUG_ON() to assert the layout of struct io_uring_sqe
  io_uring: add ->show_fdinfo() for the io_uring file descriptor

1 files changed, 14 insertions, 0 deletions

diff --git a/include/linux/eventfd.h b/include/linux/eventfd.h
index ffcc7724ca21..dc4fd8a6644d 100644
--- a/include/linux/eventfd.h
+++ b/include/linux/eventfd.h
@@ -12,6 +12,8 @@
 #include <linux/fcntl.h>
 #include <linux/wait.h>
 #include <linux/err.h>
+#include <linux/percpu-defs.h>
+#include <linux/percpu.h>
 
 /*
  * CAREFUL: Check include/uapi/asm-generic/fcntl.h when defining
@@ -40,6 +42,13 @@ __u64 eventfd_signal(struct eventfd_ctx *ctx, __u64 n);
 int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_entry_t *wait,
 				  __u64 *cnt);
 
+DECLARE_PER_CPU(int, eventfd_wake_count);
+
+static inline bool eventfd_signal_count(void)
+{
+	return this_cpu_read(eventfd_wake_count);
+}
+
 #else /* CONFIG_EVENTFD */
 
 /*
@@ -68,6 +77,11 @@ static inline int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx,
 	return -ENOSYS;
 }
 
+static inline bool eventfd_signal_count(void)
+{
+	return false;
+}
+
 #endif
 
 #endif /* _LINUX_EVENTFD_H */