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authorXindong Xu <xindong.xu@amlogic.com>2018-04-10 09:30:58 (GMT)
committer Gerrit Code Review <gituser@droid04>2018-04-10 09:30:58 (GMT)
commitd764be38bbe19cb954e9b4f32c290806ad014be5 (patch)
tree66155dd6bc4833bf93682d73804eb4322db5a70b
parent73e8b07a72fbb8da3ac02ec81f2c386d9d39184d (diff)
parent1efaae5ed4c136b75f5a0e224d30e324c984463c (diff)
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Merge "tty: fix data race between tty_init_dev and flush of buf" into ampere-20180311
Diffstat
-rw-r--r--drivers/tty/tty_io.c8
-rw-r--r--drivers/tty/tty_ldisc.c4
-rw-r--r--include/linux/tty.h2
3 files changed, 11 insertions, 3 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 734a635..8d9f9a8 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -1543,6 +1543,9 @@ struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx)
"%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n",
__func__, tty->driver->name);
+ retval = tty_ldisc_lock(tty, 5 * HZ);
+ if (retval)
+ goto err_release_lock;
tty->port->itty = tty;
/*
@@ -1553,6 +1556,7 @@ struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx)
retval = tty_ldisc_setup(tty, tty->link);
if (retval)
goto err_release_tty;
+ tty_ldisc_unlock(tty);
/* Return the tty locked so that it cannot vanish under the caller */
return tty;
@@ -1565,9 +1569,11 @@ err_module_put:
/* call the tty release_tty routine to clean out this slot */
err_release_tty:
- tty_unlock(tty);
+ tty_ldisc_unlock(tty);
tty_info_ratelimited(tty, "ldisc open failed (%d), clearing slot %d\n",
retval, idx);
+err_release_lock:
+ tty_unlock(tty);
release_tty(tty, idx);
return ERR_PTR(retval);
}
diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index 68947f6..9f0b062 100644
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -333,7 +333,7 @@ static inline void __tty_ldisc_unlock(struct tty_struct *tty)
ldsem_up_write(&tty->ldisc_sem);
}
-static int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout)
+int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout)
{
int ret;
@@ -344,7 +344,7 @@ static int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout)
return 0;
}
-static void tty_ldisc_unlock(struct tty_struct *tty)
+void tty_ldisc_unlock(struct tty_struct *tty)
{
clear_bit(TTY_LDISC_HALTED, &tty->flags);
__tty_ldisc_unlock(tty);
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 40144f3..a41244f 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -394,6 +394,8 @@ extern struct tty_struct *get_current_tty(void);
/* tty_io.c */
extern int __init tty_init(void);
extern const char *tty_name(const struct tty_struct *tty);
+extern int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout);
+extern void tty_ldisc_unlock(struct tty_struct *tty);
#else
static inline void console_init(void)
{ }