4.4-stable patches

added patches:
	misc-panel-properly-restore-atomic-counter-on-error-path.patch

diff --git a/queue-4.4/misc-panel-properly-restore-atomic-counter-on-error-path.patch b/queue-4.4/misc-panel-properly-restore-atomic-counter-on-error-path.patch
new file mode 100644 (file)
index 0000000..d222eeb
--- /dev/null
+++ b/queue-4.4/misc-panel-properly-restore-atomic-counter-on-error-path.patch
@@ -0,0 +1,78 @@
+From 29e391ca59d60b7902b09ed11edbc5c95c372f09 Mon Sep 17 00:00:00 2001
+From: Willy Tarreau <w@1wt.eu>
+Date: Thu, 7 Sep 2017 11:56:40 +0200
+Subject: misc: panel: properly restore atomic counter on error path
+
+commit 93dc1774d2a4c7a298d5cdf78cc8acdcb7b1428d upstream.
+
+Commit f4757af ("staging: panel: Fix single-open policy race condition")
+introduced in 3.19-rc1 attempted to fix a race condition on the open, but
+failed to properly do it and used to exit without restoring the semaphore.
+
+This results in -EBUSY being returned after the first open error until
+the module is reloaded or the system restarted (ie: consecutive to a
+dual open resulting in -EBUSY or to a permission error).
+
+Fixes: f4757af85 # 3.19-rc1
+Cc: Mariusz Gorski <marius.gorski@gmail.com>
+Signed-off-by: Willy Tarreau <w@1wt.eu>
+[wt: driver is in staging/panel in 4.4]
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/staging/panel/panel.c |   23 +++++++++++++++++++----
+ 1 file changed, 19 insertions(+), 4 deletions(-)
+
+--- a/drivers/staging/panel/panel.c
++++ b/drivers/staging/panel/panel.c
+@@ -1431,17 +1431,25 @@ static ssize_t lcd_write(struct file *fi
+ 
+ static int lcd_open(struct inode *inode, struct file *file)
+ {
++      int ret;
++
++      ret = -EBUSY;
+       if (!atomic_dec_and_test(&lcd_available))
+-              return -EBUSY;  /* open only once at a time */
++              goto fail; /* open only once at a time */
+ 
++      ret = -EPERM;
+       if (file->f_mode & FMODE_READ)  /* device is write-only */
+-              return -EPERM;
++              goto fail;
+ 
+       if (lcd.must_clear) {
+               lcd_clear_display();
+               lcd.must_clear = false;
+       }
+       return nonseekable_open(inode, file);
++
++ fail:
++      atomic_inc(&lcd_available);
++      return ret;
+ }
+ 
+ static int lcd_release(struct inode *inode, struct file *file)
+@@ -1704,14 +1712,21 @@ static ssize_t keypad_read(struct file *
+ 
+ static int keypad_open(struct inode *inode, struct file *file)
+ {
++      int ret;
++
++      ret = -EBUSY;
+       if (!atomic_dec_and_test(&keypad_available))
+-              return -EBUSY;  /* open only once at a time */
++              goto fail;      /* open only once at a time */
+ 
++      ret = -EPERM;
+       if (file->f_mode & FMODE_WRITE) /* device is read-only */
+-              return -EPERM;
++              goto fail;
+ 
+       keypad_buflen = 0;      /* flush the buffer on opening */
+       return 0;
++ fail:
++      atomic_inc(&keypad_available);
++      return ret;
+ }
+ 
+ static int keypad_release(struct inode *inode, struct file *file)

diff --git a/queue-4.4/series b/queue-4.4/series
index e687e3c706a134967f0f4a8fd3dd102c3780ae2d..6612d651ea6792a11db79c30f493b5c274cdc95c 100644 (file)
--- a/queue-4.4/series
+++ b/queue-4.4/series
@@ -25,3 +25,4 @@ tipc-fix-link-attribute-propagation-bug.patch
 brcmfmac-remove-setting-ibss-mode-when-stopping-ap.patch
 target-iscsi-fix-iscsi-task-reassignment-handling.patch
 target-fix-node_acl-demo-mode-uncached-dynamic-shutdown-regression.patch
+misc-panel-properly-restore-atomic-counter-on-error-path.patch