tty: Remove __GFP_NOFAIL from tty_add_file()

PATCH Superseded Pekka Enberg 2 participants 2 messages Aug 23, 2010

Subsystems (2)

TTY layer and serial drivers Char and misc drivers

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Pekka Enberg

author

2010-08-23 20:22 UTC #0 lore raw

PATCH 1/1 tty: Remove __GFP_NOFAIL from tty_add_file()

This patch removes __GFP_NOFAIL use from tty_add_file() and adds proper error handling to the call-sites of the function.

Cc Andrew Morton <[email protected]>

Cc Alan Cox <[email protected]>

Cc Arnd Bergmann <[email protected]>

Cc David Rientjes <[email protected]>

Signed-off-by Pekka Enberg <[email protected]>

---
 drivers/char/pty.c    |    4 +++-
 drivers/char/tty_io.c |   15 +++++++++++----
 include/linux/tty.h   |    2 +-
 3 files changed, 15 insertions(+), 6 deletions(-)

drivers/char/pty.c +3 -1

index c350d01..bc577ac 100644
@@ -676,7 +676,9 @@ static int ptmx_open(struct inode *inode, struct file *filp)
 
 	set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
 
-	tty_add_file(tty, filp);
+	retval = tty_add_file(tty, filp);
+	if (retval)
+		goto out1;
 
 	retval = devpts_pty_new(inode, tty->link);
 	if (retval)

drivers/char/tty_io.c +11 -4

index 949067a..1587f93 100644
@@ -194,12 +194,13 @@ static inline struct tty_struct *file_tty(struct file *file)
 }
 
 /* Associate a new file with the tty structure */
-void tty_add_file(struct tty_struct *tty, struct file *file)
+int tty_add_file(struct tty_struct *tty, struct file *file)
 {
 	struct tty_file_private *priv;
 
-	/* XXX: must implement proper error handling in callers */
-	priv = kmalloc(sizeof(*priv), GFP_KERNEL|__GFP_NOFAIL);
+	priv = kmalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
 
 	priv->tty = tty;
 	priv->file = file;

@@ -208,6 +209,8 @@ void tty_add_file(struct tty_struct *tty, struct file *file)
 	spin_lock(&tty_files_lock);
 	list_add(&priv->list, &tty->tty_files);
 	spin_unlock(&tty_files_lock);
+
+	return 0;
 }
 
 /* Delete file from its tty */

@@ -1875,7 +1878,11 @@ got_driver:
 		return PTR_ERR(tty);
 	}
 
-	tty_add_file(tty, filp);
+	retval = tty_add_file(tty, filp);
+	if (retval) {
+		tty_unlock();
+		return retval;
+	}
 
 	check_tty_count(tty, "tty_open");
 	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&

include/linux/tty.h +1 -1

index 67d64e6..a3f4388 100644
@@ -465,7 +465,7 @@ extern void proc_clear_tty(struct task_struct *p);
 extern struct tty_struct *get_current_tty(void);
 extern void tty_default_fops(struct file_operations *fops);
 extern struct tty_struct *alloc_tty_struct(void);
-extern void tty_add_file(struct tty_struct *tty, struct file *file);
+extern int tty_add_file(struct tty_struct *tty, struct file *file);
 extern void free_tty_struct(struct tty_struct *tty);
 extern void initialize_tty_struct(struct tty_struct *tty,
 		struct tty_driver *driver, int idx);

Signature · 1 line

1.6.3.3

David Rientjes

2010-08-23 21:07 UTC #1 lore raw

Quoted 5 lines · Pekka Enberg

drivers/char/pty.c +0 -0
index c350d01..bc577ac 100644

drivers/char/pty.c static int ptmx_open(struct inode *inode, struct file *filp) · line 684

Quoted 10 lines

drivers/char/pty.c +3 -1

@@ -676,7 +676,9 @@ static int ptmx_open(struct inode *inode, struct file *filp)
 
 	set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
 
-	tty_add_file(tty, filp);
+	retval = tty_add_file(tty, filp);
+	if (retval)
+		goto out1;
 
 	retval = devpts_pty_new(inode, tty->link);
 	if (retval)

This needs devpts_kill_index() to reverse the successful devpts_new_index(), so I think it should be "goto out" and not "goto out1".