The patch titled
RTC: assure proper memory ordering with respect to RTC_DEV_BUSY flag
has been added to the -mm tree. Its filename is
rtc-assure-proper-memory-ordering-with-respect-to-rtc_dev_busy-flag.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: RTC: assure proper memory ordering with respect to RTC_DEV_BUSY flag
From: Jiri Kosina <jkosina@xxxxxxx>
We must make sure that the RTC_DEV_BUSY flag has proper lock semantics,
i.e. that the RTC_DEV_BUSY stores clearing the flag don't get reordered
before the preceeding stores and loads and vice versa.
Spotted by Nick Piggin.
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Cc: Nick Piggin <nickpiggin@xxxxxxxxxxxx>
Cc: David Brownell <david-b@xxxxxxxxxxx>
Cc: Alessandro Zummo <a.zummo@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/rtc/interface.c | 4 ++--
drivers/rtc/rtc-dev.c | 6 +++---
2 files changed, 5 insertions(+), 5 deletions(-)
diff -puN drivers/rtc/interface.c~rtc-assure-proper-memory-ordering-with-respect-to-rtc_dev_busy-flag drivers/rtc/interface.c
--- a/drivers/rtc/interface.c~rtc-assure-proper-memory-ordering-with-respect-to-rtc_dev_busy-flag
+++ a/drivers/rtc/interface.c
@@ -293,7 +293,7 @@ int rtc_irq_register(struct rtc_device *
return -EINVAL;
/* Cannot register while the char dev is in use */
- if (test_and_set_bit(RTC_DEV_BUSY, &rtc->flags))
+ if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
return -EBUSY;
spin_lock_irq(&rtc->irq_task_lock);
@@ -303,7 +303,7 @@ int rtc_irq_register(struct rtc_device *
}
spin_unlock_irq(&rtc->irq_task_lock);
- clear_bit(RTC_DEV_BUSY, &rtc->flags);
+ clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
return retval;
}
diff -puN drivers/rtc/rtc-dev.c~rtc-assure-proper-memory-ordering-with-respect-to-rtc_dev_busy-flag drivers/rtc/rtc-dev.c
--- a/drivers/rtc/rtc-dev.c~rtc-assure-proper-memory-ordering-with-respect-to-rtc_dev_busy-flag
+++ a/drivers/rtc/rtc-dev.c
@@ -26,7 +26,7 @@ static int rtc_dev_open(struct inode *in
struct rtc_device, char_dev);
const struct rtc_class_ops *ops = rtc->ops;
- if (test_and_set_bit(RTC_DEV_BUSY, &rtc->flags))
+ if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
return -EBUSY;
file->private_data = rtc;
@@ -41,7 +41,7 @@ static int rtc_dev_open(struct inode *in
}
/* something has gone wrong */
- clear_bit(RTC_DEV_BUSY, &rtc->flags);
+ clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
return err;
}
@@ -402,7 +402,7 @@ static int rtc_dev_release(struct inode
if (rtc->ops->release)
rtc->ops->release(rtc->dev.parent);
- clear_bit(RTC_DEV_BUSY, &rtc->flags);
+ clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
return 0;
}
_
Patches currently in -mm which might be from jkosina@xxxxxxx are
origin.patch
rtc-assure-proper-memory-ordering-with-respect-to-rtc_dev_busy-flag.patch
git-hid.patch
fujitsu-application-panel-driver.patch
elantech-touchpad-driver.patch
git-ipwireless_cs.patch
git-x86.patch
pie-executable-randomization.patch
pie-executable-randomization-uninlining.patch
pie-executable-randomization-checkpatch-fixes.patch
-
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