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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/tty/tty_mutex.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--drivers/tty/tty_mutex.c60
1 files changed, 60 insertions, 0 deletions
diff --git a/drivers/tty/tty_mutex.c b/drivers/tty/tty_mutex.c
new file mode 100644
index 000000000..2640635ee
--- /dev/null
+++ b/drivers/tty/tty_mutex.c
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/tty.h>
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/semaphore.h>
+#include <linux/sched.h>
+
+/* Legacy tty mutex glue */
+
+/*
+ * Getting the big tty mutex.
+ */
+
+void tty_lock(struct tty_struct *tty)
+{
+ if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty))
+ return;
+ tty_kref_get(tty);
+ mutex_lock(&tty->legacy_mutex);
+}
+EXPORT_SYMBOL(tty_lock);
+
+int tty_lock_interruptible(struct tty_struct *tty)
+{
+ int ret;
+
+ if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty))
+ return -EIO;
+ tty_kref_get(tty);
+ ret = mutex_lock_interruptible(&tty->legacy_mutex);
+ if (ret)
+ tty_kref_put(tty);
+ return ret;
+}
+
+void tty_unlock(struct tty_struct *tty)
+{
+ if (WARN(tty->magic != TTY_MAGIC, "U Bad %p\n", tty))
+ return;
+ mutex_unlock(&tty->legacy_mutex);
+ tty_kref_put(tty);
+}
+EXPORT_SYMBOL(tty_unlock);
+
+void tty_lock_slave(struct tty_struct *tty)
+{
+ if (tty && tty != tty->link)
+ tty_lock(tty);
+}
+
+void tty_unlock_slave(struct tty_struct *tty)
+{
+ if (tty && tty != tty->link)
+ tty_unlock(tty);
+}
+
+void tty_set_lock_subclass(struct tty_struct *tty)
+{
+ lockdep_set_subclass(&tty->legacy_mutex, TTY_LOCK_SLAVE);
+}