5.4-stable patches

added patches:
	epoll-add-synchronous-wakeup-support-for-ep_poll_callback.patch

diff --git a/queue-5.4/epoll-add-synchronous-wakeup-support-for-ep_poll_callback.patch b/queue-5.4/epoll-add-synchronous-wakeup-support-for-ep_poll_callback.patch
new file mode 100644 (file)
index 0000000..1b2a127
--- /dev/null
+++ b/queue-5.4/epoll-add-synchronous-wakeup-support-for-ep_poll_callback.patch
@@ -0,0 +1,55 @@
+From 900bbaae67e980945dec74d36f8afe0de7556d5a Mon Sep 17 00:00:00 2001
+From: Xuewen Yan <xuewen.yan@unisoc.com>
+Date: Fri, 26 Apr 2024 16:05:48 +0800
+Subject: epoll: Add synchronous wakeup support for ep_poll_callback
+
+From: Xuewen Yan <xuewen.yan@unisoc.com>
+
+commit 900bbaae67e980945dec74d36f8afe0de7556d5a upstream.
+
+Now, the epoll only use wake_up() interface to wake up task.
+However, sometimes, there are epoll users which want to use
+the synchronous wakeup flag to hint the scheduler, such as
+Android binder driver.
+So add a wake_up_sync() define, and use the wake_up_sync()
+when the sync is true in ep_poll_callback().
+
+Co-developed-by: Jing Xia <jing.xia@unisoc.com>
+Signed-off-by: Jing Xia <jing.xia@unisoc.com>
+Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com>
+Link: https://lore.kernel.org/r/20240426080548.8203-1-xuewen.yan@unisoc.com
+Tested-by: Brian Geffon <bgeffon@google.com>
+Reviewed-by: Brian Geffon <bgeffon@google.com>
+Reported-by: Benoit Lize <lizeb@google.com>
+Signed-off-by: Christian Brauner <brauner@kernel.org>
+Cc: Brian Geffon <bgeffon@google.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ fs/eventpoll.c       |    5 ++++-
+ include/linux/wait.h |    1 +
+ 2 files changed, 5 insertions(+), 1 deletion(-)
+
+--- a/fs/eventpoll.c
++++ b/fs/eventpoll.c
+@@ -1273,7 +1273,10 @@ static int ep_poll_callback(wait_queue_e
+                               break;
+                       }
+               }
+-              wake_up(&ep->wq);
++              if (sync)
++                      wake_up_sync(&ep->wq);
++              else
++                      wake_up(&ep->wq);
+       }
+       if (waitqueue_active(&ep->poll_wait))
+               pwake++;
+--- a/include/linux/wait.h
++++ b/include/linux/wait.h
+@@ -213,6 +213,7 @@ void __wake_up_pollfree(struct wait_queu
+ #define wake_up_all(x)                        __wake_up(x, TASK_NORMAL, 0, NULL)
+ #define wake_up_locked(x)             __wake_up_locked((x), TASK_NORMAL, 1)
+ #define wake_up_all_locked(x)         __wake_up_locked((x), TASK_NORMAL, 0)
++#define wake_up_sync(x)                       __wake_up_sync(x, TASK_NORMAL)
+ 
+ #define wake_up_interruptible(x)      __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
+ #define wake_up_interruptible_nr(x, nr)       __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)

diff --git a/queue-5.4/series b/queue-5.4/series
index f4208f9642cbf08af845b369628381441ba04b60..c1e2a15397cc42ab7ad1b1d9808d2633757acd92 100644 (file)
--- a/queue-5.4/series
+++ b/queue-5.4/series
@@ -30,3 +30,4 @@ nilfs2-prevent-use-of-deleted-inode.patch
 udmabuf-also-check-for-f_seal_future_write.patch
 of-fix-error-path-in-of_parse_phandle_with_args_map.patch
 of-fix-refcount-leakage-for-of-node-returned-by-__of_get_dma_parent.patch
+epoll-add-synchronous-wakeup-support-for-ep_poll_callback.patch