[PATCH 0/6]

PATCH Superseded Peter Hurley 1 participant 14 messages Nov 28, 2015 – Jan 10, 2016

Subsystems (2)

TTY layer and serial drivers SELinux security module

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Peter Hurley

author

2015-11-28 02:38 UTC #0 lore raw

cover [PATCH 0/6]

Hi Greg,

This patch series is part of the ongoing effort to cleanup and reduce the kernel tty interface; specifically removing undefined function declarations, unused macros, encapsulating global data, undefining unused exports, limiting functions and data to file scope, etc.

Regards,

Peter Hurley (6):
tty: Unexport system-wide tty_mutex
tty: Eliminate global symbol tty_ldisc_N_TTY
tty: Remove declarations to non-existent functions
tty: Move tty_check_change() helper
tty: Remove unreferenced tty flags macro TTY_DEBUG
tty: Make tty_files_lock per-tty

 drivers/tty/n_tty.c      | 18 ++++++++----------
 drivers/tty/tty_io.c     | 37 ++++++++++++++++++++-----------------
 drivers/tty/tty_ldisc.c  |  6 ------
 include/linux/tty.h      | 10 ++--------
 security/selinux/hooks.c |  4 ++--
 5 files changed, 32 insertions(+), 43 deletions(-)

Signature · 1 line

2.6.3

Peter Hurley

author

2015-11-28 02:40 UTC #1 lore raw

PATCH 1/6 tty: Unexport system-wide tty_mutex

tty_mutex is a core, system-wide lock; there is no reason for any code outside the tty core to have direct access.

Signed-off-by Peter Hurley <[email protected]>

---
 drivers/tty/tty_io.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

drivers/tty/tty_io.c +1 -3

index 09e8d4f..64c4a7e 100644
@@ -135,10 +135,8 @@ EXPORT_SYMBOL(tty_std_termios);
 
 LIST_HEAD(tty_drivers);			/* linked list of tty drivers */
 
-/* Mutex to protect creating and releasing a tty. This is shared with
-   vt.c for deeply disgusting hack reasons */
+/* Mutex to protect creating and releasing a tty */
 DEFINE_MUTEX(tty_mutex);
-EXPORT_SYMBOL(tty_mutex);
 
 /* Spinlock to protect the tty->tty_files list */
 DEFINE_SPINLOCK(tty_files_lock);

Signature · 1 line

2.6.3

Peter Hurley

author

2015-11-28 02:40 UTC #2 lore raw

PATCH 2/6 tty: Eliminate global symbol tty_ldisc_N_TTY

In reply to Peter Hurley

Reduce global tty symbols; move and rename tty_ldisc_begin() as n_tty_init() and redefine the N_TTY ldisc ops as file scope.

Signed-off-by Peter Hurley <[email protected]>

---
 drivers/tty/n_tty.c     | 12 ++++++++----
 drivers/tty/tty_io.c    |  2 +-
 drivers/tty/tty_ldisc.c |  6 ------
 include/linux/tty.h     |  3 +--
 4 files changed, 10 insertions(+), 13 deletions(-)

drivers/tty/n_tty.c +8 -4

index 4f2b5dc..d294e24 100644
@@ -2499,7 +2499,7 @@ static void n_tty_closing(struct tty_struct *tty)
 	ldata->closing = 1;
 }
 
-struct tty_ldisc_ops tty_ldisc_N_TTY = {
+static struct tty_ldisc_ops n_tty_ops = {
 	.magic           = TTY_LDISC_MAGIC,
 	.name            = "n_tty",
 	.open            = n_tty_open,

@@ -2521,14 +2521,18 @@ struct tty_ldisc_ops tty_ldisc_N_TTY = {
  *	n_tty_inherit_ops	-	inherit N_TTY methods
  *	@ops: struct tty_ldisc_ops where to save N_TTY methods
  *
- *	Enables a 'subclass' line discipline to 'inherit' N_TTY
- *	methods.
+ *	Enables a 'subclass' line discipline to 'inherit' N_TTY methods.
  */
 
 void n_tty_inherit_ops(struct tty_ldisc_ops *ops)
 {
-	*ops = tty_ldisc_N_TTY;
+	*ops = n_tty_ops;
 	ops->owner = NULL;
 	ops->refcount = ops->flags = 0;
 }
 EXPORT_SYMBOL_GPL(n_tty_inherit_ops);
+
+void __init n_tty_init(void)
+{
+	tty_register_ldisc(N_TTY, &n_tty_ops);
+}

drivers/tty/tty_io.c +1 -1

index 64c4a7e..0778fa9 100644
@@ -3566,7 +3566,7 @@ void __init console_init(void)
 	initcall_t *call;
 
 	/* Setup the default TTY line discipline. */
-	tty_ldisc_begin();
+	n_tty_init();
 
 	/*
 	 * set up the console device so that later boot sequences can

drivers/tty/tty_ldisc.c +0 -6

index 8a960fd..5734c22 100644
@@ -840,9 +840,3 @@ void tty_ldisc_deinit(struct tty_struct *tty)
 		tty_ldisc_put(tty->ldisc);
 	tty->ldisc = NULL;
 }
-
-void tty_ldisc_begin(void)
-{
-	/* Setup the default TTY line discipline. */
-	(void) tty_register_ldisc(N_TTY, &tty_ldisc_N_TTY);
-}

include/linux/tty.h +1 -2

index cc15147..9e3231e 100644
@@ -577,7 +577,6 @@ extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
 extern void tty_ldisc_release(struct tty_struct *tty);
 extern void tty_ldisc_init(struct tty_struct *tty);
 extern void tty_ldisc_deinit(struct tty_struct *tty);
-extern void tty_ldisc_begin(void);
 
 static inline int tty_ldisc_receive_buf(struct tty_ldisc *ld, unsigned char *p,
 					char *f, int count)

@@ -594,8 +593,8 @@ static inline int tty_ldisc_receive_buf(struct tty_ldisc *ld, unsigned char *p,
 
 
 /* n_tty.c */
-extern struct tty_ldisc_ops tty_ldisc_N_TTY;
 extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
+extern void __init n_tty_init(void);
 
 /* tty_audit.c */
 #ifdef CONFIG_AUDIT

Signature · 1 line

2.6.3

Peter Hurley

author

2015-11-28 02:39 UTC #3 lore raw

PATCH 3/6 tty: Remove declarations to non-existent functions

In reply to Peter Hurley

tty_read_raw_data() and tty_signal() no longer exist; remove declarations.

Signed-off-by Peter Hurley <[email protected]>

---
 include/linux/tty.h | 3 ---
 1 file changed, 3 deletions(-)

include/linux/tty.h +0 -3

index 9e3231e..584bf4c 100644
@@ -432,8 +432,6 @@ extern struct device *tty_register_device_attr(struct tty_driver *driver,
 				void *drvdata,
 				const struct attribute_group **attr_grp);
 extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
-extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
-			     int buflen);
 extern void tty_write_message(struct tty_struct *tty, char *msg);
 extern int tty_send_xchar(struct tty_struct *tty, char ch);
 extern int tty_put_char(struct tty_struct *tty, unsigned char c);

@@ -447,7 +445,6 @@ extern int tty_unthrottle_safe(struct tty_struct *tty);
 extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
 extern int is_current_pgrp_orphaned(void);
 extern int is_ignored(int sig);
-extern int tty_signal(int sig, struct tty_struct *tty);
 extern void tty_hangup(struct tty_struct *tty);
 extern void tty_vhangup(struct tty_struct *tty);
 extern int tty_hung_up_p(struct file *filp);

Signature · 1 line

2.6.3

Peter Hurley

author

2015-11-28 02:39 UTC #4 lore raw

PATCH 4/6 tty: Move tty_check_change() helper

In reply to Peter Hurley

Move is_ignored() to drivers/tty/tty_io.c and re-declare in file scope.

Signed-off-by Peter Hurley <[email protected]>

---
 drivers/tty/n_tty.c  | 6 ------
 drivers/tty/tty_io.c | 6 ++++++
 include/linux/tty.h  | 1 -
 3 files changed, 6 insertions(+), 7 deletions(-)

drivers/tty/n_tty.c +0 -6

index d294e24..f61be24 100644
@@ -1753,12 +1753,6 @@ static int n_tty_receive_buf2(struct tty_struct *tty, const unsigned char *cp,
 	return n_tty_receive_buf_common(tty, cp, fp, count, 1);
 }
 
-int is_ignored(int sig)
-{
-	return (sigismember(&current->blocked, sig) ||
-		current->sighand->action[sig-1].sa.sa_handler == SIG_IGN);
-}
-
 /**
  *	n_tty_set_termios	-	termios data changed
  *	@tty: terminal

drivers/tty/tty_io.c +6 -0

index 0778fa9..a8a1f62 100644
@@ -381,6 +381,12 @@ struct tty_driver *tty_find_polling_driver(char *name, int *line)
 EXPORT_SYMBOL_GPL(tty_find_polling_driver);
 #endif
 
+static int is_ignored(int sig)
+{
+	return (sigismember(&current->blocked, sig) ||
+		current->sighand->action[sig-1].sa.sa_handler == SIG_IGN);
+}
+
 /**
  *	tty_check_change	-	check for POSIX terminal changes
  *	@tty: tty to check

include/linux/tty.h +0 -1

index 584bf4c..8f16d52 100644
@@ -444,7 +444,6 @@ extern int tty_throttle_safe(struct tty_struct *tty);
 extern int tty_unthrottle_safe(struct tty_struct *tty);
 extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
 extern int is_current_pgrp_orphaned(void);
-extern int is_ignored(int sig);
 extern void tty_hangup(struct tty_struct *tty);
 extern void tty_vhangup(struct tty_struct *tty);
 extern int tty_hung_up_p(struct file *filp);

Signature · 1 line

2.6.3

Peter Hurley

author

2015-11-28 02:38 UTC #5 lore raw

PATCH 5/6 tty: Remove unreferenced tty flags macro TTY_DEBUG

In reply to Peter Hurley

The TTY_DEBUG macro is not used; remove.

Signed-off-by Peter Hurley <[email protected]>

---
 include/linux/tty.h | 1 -
 1 file changed, 1 deletion(-)

include/linux/tty.h +0 -1

index 8f16d52..168f198 100644
@@ -335,7 +335,6 @@ struct tty_file_private {
 #define TTY_IO_ERROR 		1	/* Cause an I/O error (may be no ldisc too) */
 #define TTY_OTHER_CLOSED 	2	/* Other side (if any) has closed */
 #define TTY_EXCLUSIVE 		3	/* Exclusive open mode */
-#define TTY_DEBUG 		4	/* Debugging */
 #define TTY_DO_WRITE_WAKEUP 	5	/* Call write_wakeup after queuing new */
 #define TTY_OTHER_DONE		6	/* Closed pty has completed input processing */
 #define TTY_LDISC_OPEN	 	11	/* Line discipline is open */

Signature · 1 line

2.6.3

Peter Hurley

author

2015-11-28 02:39 UTC #6 lore raw

PATCH 6/6 tty: Make tty_files_lock per-tty

In reply to Peter Hurley

Access to tty->tty_files list is always per-tty, never for all ttys simultaneously. Replace global tty_files_lock spinlock with per-tty ->files_lock. Initialize when the ->tty_files list is inited, in alloc_tty_struct().

Signed-off-by Peter Hurley <[email protected]>

---
 drivers/tty/tty_io.c     | 25 ++++++++++++-------------
 include/linux/tty.h      |  2 +-
 security/selinux/hooks.c |  4 ++--
 3 files changed, 15 insertions(+), 16 deletions(-)

drivers/tty/tty_io.c +12 ~~-13~~

index a8a1f62..5c8f519 100644
@@ -138,9 +138,6 @@ LIST_HEAD(tty_drivers);			/* linked list of tty drivers */
 /* Mutex to protect creating and releasing a tty */
 DEFINE_MUTEX(tty_mutex);
 
-/* Spinlock to protect the tty->tty_files list */
-DEFINE_SPINLOCK(tty_files_lock);
-
 static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *);
 static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *);
 ssize_t redirected_tty_write(struct file *, const char __user *,

@@ -202,9 +199,9 @@ void tty_add_file(struct tty_struct *tty, struct file *file)
 	priv->tty = tty;
 	priv->file = file;
 
-	spin_lock(&tty_files_lock);
+	spin_lock(&tty->files_lock);
 	list_add(&priv->list, &tty->tty_files);
-	spin_unlock(&tty_files_lock);
+	spin_unlock(&tty->files_lock);
 }
 
 /**

@@ -225,10 +222,11 @@ void tty_free_file(struct file *file)
 static void tty_del_file(struct file *file)
 {
 	struct tty_file_private *priv = file->private_data;
+	struct tty_struct *tty = priv->tty;
 
-	spin_lock(&tty_files_lock);
+	spin_lock(&tty->files_lock);
 	list_del(&priv->list);
-	spin_unlock(&tty_files_lock);
+	spin_unlock(&tty->files_lock);
 	tty_free_file(file);
 }

@@ -286,11 +284,11 @@ static int check_tty_count(struct tty_struct *tty, const char *routine)
 	struct list_head *p;
 	int count = 0;
 
-	spin_lock(&tty_files_lock);
+	spin_lock(&tty->files_lock);
 	list_for_each(p, &tty->tty_files) {
 		count++;
 	}
-	spin_unlock(&tty_files_lock);
+	spin_unlock(&tty->files_lock);
 	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
 	    tty->driver->subtype == PTY_TYPE_SLAVE &&
 	    tty->link && tty->link->count)

@@ -713,7 +711,7 @@ static void __tty_hangup(struct tty_struct *tty, int exit_session)
 	   workqueue with the lock held */
 	check_tty_count(tty, "tty_hangup");
 
-	spin_lock(&tty_files_lock);
+	spin_lock(&tty->files_lock);
 	/* This breaks for file handles being sent over AF_UNIX sockets ? */
 	list_for_each_entry(priv, &tty->tty_files, list) {
 		filp = priv->file;

@@ -725,7 +723,7 @@ static void __tty_hangup(struct tty_struct *tty, int exit_session)
 		__tty_fasync(-1, filp, 0);	/* can't block */
 		filp->f_op = &hung_up_tty_fops;
 	}
-	spin_unlock(&tty_files_lock);
+	spin_unlock(&tty->files_lock);
 
 	refs = tty_signal_session_leader(tty, exit_session);
 	/* Account for the p->signal references we killed */

@@ -1641,9 +1639,9 @@ static void release_one_tty(struct work_struct *work)
 	tty_driver_kref_put(driver);
 	module_put(owner);
 
-	spin_lock(&tty_files_lock);
+	spin_lock(&tty->files_lock);
 	list_del_init(&tty->tty_files);
-	spin_unlock(&tty_files_lock);
+	spin_unlock(&tty->files_lock);
 
 	put_pid(tty->pgrp);
 	put_pid(tty->session);

@@ -3166,6 +3164,7 @@ struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx)
 	mutex_init(&tty->atomic_write_lock);
 	spin_lock_init(&tty->ctrl_lock);
 	spin_lock_init(&tty->flow_lock);
+	spin_lock_init(&tty->files_lock);
 	INIT_LIST_HEAD(&tty->tty_files);
 	INIT_WORK(&tty->SAK_work, do_SAK_work);

include/linux/tty.h +1 -1

index 168f198..a2d167e 100644
@@ -302,6 +302,7 @@ struct tty_struct {
 	struct work_struct hangup_work;
 	void *disc_data;
 	void *driver_data;
+	spinlock_t files_lock;		/* protects tty_files list */
 	struct list_head tty_files;
 
 #define N_TTY_BUF_SIZE 4096

@@ -509,7 +510,6 @@ extern int tty_standard_install(struct tty_driver *driver,
 		struct tty_struct *tty);
 
 extern struct mutex tty_mutex;
-extern spinlock_t tty_files_lock;
 
 #define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))

security/selinux/hooks.c +2 -2

index d0cfaa9..ae6dbc75 100644
@@ -2352,7 +2352,7 @@ static inline void flush_unauthorized_files(const struct cred *cred,
 
 	tty = get_current_tty();
 	if (tty) {
-		spin_lock(&tty_files_lock);
+		spin_lock(&tty->files_lock);
 		if (!list_empty(&tty->tty_files)) {
 			struct tty_file_private *file_priv;

@@ -2367,7 +2367,7 @@ static inline void flush_unauthorized_files(const struct cred *cred,
 			if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE))
 				drop_tty = 1;
 		}
-		spin_unlock(&tty_files_lock);
+		spin_unlock(&tty->files_lock);
 		tty_kref_put(tty);
 	}
 	/* Reset controlling tty. */

Signature · 1 line

2.6.3

Peter Hurley

author

2016-01-10 05:35 UTC #7 lore raw

v2 cover tty globals cleanup (cont'd)

In reply to Peter Hurley

Changes from v2: rebased on top of current tty-next

original message follows:

Hi Greg,

Regards,

 drivers/tty/n_tty.c      | 18 ++++++++----------
 drivers/tty/tty_io.c     | 37 ++++++++++++++++++++-----------------
 drivers/tty/tty_ldisc.c  |  6 ------
 include/linux/tty.h      | 10 ++--------
 security/selinux/hooks.c |  4 ++--
 5 files changed, 32 insertions(+), 43 deletions(-)

Signature · 1 line

2.7.0

Peter Hurley

author

2016-01-10 05:36 UTC #8 lore raw

PATCH v2 1/6 tty: Unexport system-wide tty_mutex

tty_mutex is a core, system-wide lock; there is no reason for any code outside the tty core to have direct access.

Signed-off-by Peter Hurley <[email protected]>

---
 drivers/tty/tty_io.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

drivers/tty/tty_io.c +1 -3

index cef913c..0650a34 100644
@@ -135,10 +135,8 @@ EXPORT_SYMBOL(tty_std_termios);
 
 LIST_HEAD(tty_drivers);			/* linked list of tty drivers */
 
-/* Mutex to protect creating and releasing a tty. This is shared with
-   vt.c for deeply disgusting hack reasons */
+/* Mutex to protect creating and releasing a tty */
 DEFINE_MUTEX(tty_mutex);
-EXPORT_SYMBOL(tty_mutex);
 
 /* Spinlock to protect the tty->tty_files list */
 DEFINE_SPINLOCK(tty_files_lock);

Signature · 1 line

2.7.0

Peter Hurley

author

2016-01-10 05:35 UTC #9 lore raw

PATCH v2 2/6 tty: Eliminate global symbol tty_ldisc_N_TTY

In reply to Peter Hurley

Reduce global tty symbols; move and rename tty_ldisc_begin() as n_tty_init() and redefine the N_TTY ldisc ops as file scope.

Signed-off-by Peter Hurley <[email protected]>

---
 drivers/tty/n_tty.c     | 12 ++++++++----
 drivers/tty/tty_io.c    |  2 +-
 drivers/tty/tty_ldisc.c |  6 ------
 include/linux/tty.h     |  3 +--
 4 files changed, 10 insertions(+), 13 deletions(-)

drivers/tty/n_tty.c +8 -4

index 6bab08a..5315d1a 100644
@@ -2488,7 +2488,7 @@ static void n_tty_fasync(struct tty_struct *tty, int on)
 	}
 }
 
-struct tty_ldisc_ops tty_ldisc_N_TTY = {
+static struct tty_ldisc_ops n_tty_ops = {
 	.magic           = TTY_LDISC_MAGIC,
 	.name            = "n_tty",
 	.open            = n_tty_open,

@@ -2509,14 +2509,18 @@ struct tty_ldisc_ops tty_ldisc_N_TTY = {
  *	n_tty_inherit_ops	-	inherit N_TTY methods
  *	@ops: struct tty_ldisc_ops where to save N_TTY methods
  *
- *	Enables a 'subclass' line discipline to 'inherit' N_TTY
- *	methods.
+ *	Enables a 'subclass' line discipline to 'inherit' N_TTY methods.
  */
 
 void n_tty_inherit_ops(struct tty_ldisc_ops *ops)
 {
-	*ops = tty_ldisc_N_TTY;
+	*ops = n_tty_ops;
 	ops->owner = NULL;
 	ops->refcount = ops->flags = 0;
 }
 EXPORT_SYMBOL_GPL(n_tty_inherit_ops);
+
+void __init n_tty_init(void)
+{
+	tty_register_ldisc(N_TTY, &n_tty_ops);
+}

drivers/tty/tty_io.c +1 -1

index 0650a34..8b4e7cd 100644
@@ -3576,7 +3576,7 @@ void __init console_init(void)
 	initcall_t *call;
 
 	/* Setup the default TTY line discipline. */
-	tty_ldisc_begin();
+	n_tty_init();
 
 	/*
 	 * set up the console device so that later boot sequences can

drivers/tty/tty_ldisc.c +0 -6

index 4cb5e572..68947f6 100644
@@ -824,9 +824,3 @@ void tty_ldisc_deinit(struct tty_struct *tty)
 		tty_ldisc_put(tty->ldisc);
 	tty->ldisc = NULL;
 }
-
-void tty_ldisc_begin(void)
-{
-	/* Setup the default TTY line discipline. */
-	(void) tty_register_ldisc(N_TTY, &tty_ldisc_N_TTY);
-}

include/linux/tty.h +1 -2

index 1b31736..328a7b8 100644
@@ -576,7 +576,6 @@ extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
 extern void tty_ldisc_release(struct tty_struct *tty);
 extern void tty_ldisc_init(struct tty_struct *tty);
 extern void tty_ldisc_deinit(struct tty_struct *tty);
-extern void tty_ldisc_begin(void);
 
 static inline int tty_ldisc_receive_buf(struct tty_ldisc *ld, unsigned char *p,
 					char *f, int count)

@@ -593,8 +592,8 @@ static inline int tty_ldisc_receive_buf(struct tty_ldisc *ld, unsigned char *p,
 
 
 /* n_tty.c */
-extern struct tty_ldisc_ops tty_ldisc_N_TTY;
 extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
+extern void __init n_tty_init(void);
 
 /* tty_audit.c */
 #ifdef CONFIG_AUDIT

Signature · 1 line

2.7.0

Peter Hurley

author

2016-01-10 05:36 UTC #10 lore raw

PATCH v2 3/6 tty: Remove declarations to non-existent functions

In reply to Peter Hurley

tty_read_raw_data() and tty_signal() no longer exist; remove declarations.

Signed-off-by Peter Hurley <[email protected]>

---
 include/linux/tty.h | 3 ---
 1 file changed, 3 deletions(-)

include/linux/tty.h +0 -3

index 328a7b8..fecfe92 100644
@@ -433,8 +433,6 @@ extern struct device *tty_register_device_attr(struct tty_driver *driver,
 				void *drvdata,
 				const struct attribute_group **attr_grp);
 extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
-extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
-			     int buflen);
 extern void tty_write_message(struct tty_struct *tty, char *msg);
 extern int tty_send_xchar(struct tty_struct *tty, char ch);
 extern int tty_put_char(struct tty_struct *tty, unsigned char c);

@@ -448,7 +446,6 @@ extern int tty_unthrottle_safe(struct tty_struct *tty);
 extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
 extern int is_current_pgrp_orphaned(void);
 extern int is_ignored(int sig);
-extern int tty_signal(int sig, struct tty_struct *tty);
 extern void tty_hangup(struct tty_struct *tty);
 extern void tty_vhangup(struct tty_struct *tty);
 extern int tty_hung_up_p(struct file *filp);

Signature · 1 line

2.7.0

Peter Hurley

author

2016-01-10 05:36 UTC #11 lore raw

PATCH v2 4/6 tty: Move tty_check_change() helper

In reply to Peter Hurley

Move is_ignored() to drivers/tty/tty_io.c and re-declare in file scope.

Signed-off-by Peter Hurley <[email protected]>

---
 drivers/tty/n_tty.c  | 6 ------
 drivers/tty/tty_io.c | 6 ++++++
 include/linux/tty.h  | 1 -
 3 files changed, 6 insertions(+), 7 deletions(-)

drivers/tty/n_tty.c +0 -6

index 5315d1a..8272069 100644
@@ -1754,12 +1754,6 @@ static int n_tty_receive_buf2(struct tty_struct *tty, const unsigned char *cp,
 	return n_tty_receive_buf_common(tty, cp, fp, count, 1);
 }
 
-int is_ignored(int sig)
-{
-	return (sigismember(&current->blocked, sig) ||
-		current->sighand->action[sig-1].sa.sa_handler == SIG_IGN);
-}
-
 /**
  *	n_tty_set_termios	-	termios data changed
  *	@tty: terminal

drivers/tty/tty_io.c +6 -0

index 8b4e7cd..b89c0a5 100644
@@ -381,6 +381,12 @@ struct tty_driver *tty_find_polling_driver(char *name, int *line)
 EXPORT_SYMBOL_GPL(tty_find_polling_driver);
 #endif
 
+static int is_ignored(int sig)
+{
+	return (sigismember(&current->blocked, sig) ||
+		current->sighand->action[sig-1].sa.sa_handler == SIG_IGN);
+}
+
 /**
  *	tty_check_change	-	check for POSIX terminal changes
  *	@tty: tty to check

include/linux/tty.h +0 -1

index fecfe92..a01f9dd 100644
@@ -445,7 +445,6 @@ extern int tty_throttle_safe(struct tty_struct *tty);
 extern int tty_unthrottle_safe(struct tty_struct *tty);
 extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
 extern int is_current_pgrp_orphaned(void);
-extern int is_ignored(int sig);
 extern void tty_hangup(struct tty_struct *tty);
 extern void tty_vhangup(struct tty_struct *tty);
 extern int tty_hung_up_p(struct file *filp);

Signature · 1 line

2.7.0

Peter Hurley

author

2016-01-10 05:36 UTC #12 lore raw

PATCH v2 5/6 tty: Remove unreferenced tty flags macro TTY_DEBUG

In reply to Peter Hurley

The TTY_DEBUG macro is not used; remove.

Signed-off-by Peter Hurley <[email protected]>

---
 include/linux/tty.h | 1 -
 1 file changed, 1 deletion(-)

include/linux/tty.h +0 -1

index a01f9dd..8ed795d 100644
@@ -336,7 +336,6 @@ struct tty_file_private {
 #define TTY_IO_ERROR 		1	/* Cause an I/O error (may be no ldisc too) */
 #define TTY_OTHER_CLOSED 	2	/* Other side (if any) has closed */
 #define TTY_EXCLUSIVE 		3	/* Exclusive open mode */
-#define TTY_DEBUG 		4	/* Debugging */
 #define TTY_DO_WRITE_WAKEUP 	5	/* Call write_wakeup after queuing new */
 #define TTY_OTHER_DONE		6	/* Closed pty has completed input processing */
 #define TTY_LDISC_OPEN	 	11	/* Line discipline is open */

Signature · 1 line

2.7.0

Peter Hurley

author

2016-01-10 05:35 UTC #13 lore raw

PATCH v2 6/6 tty: Make tty_files_lock per-tty

In reply to Peter Hurley

Signed-off-by Peter Hurley <[email protected]>

---
 drivers/tty/tty_io.c     | 25 ++++++++++++-------------
 include/linux/tty.h      |  2 +-
 security/selinux/hooks.c |  4 ++--
 3 files changed, 15 insertions(+), 16 deletions(-)

drivers/tty/tty_io.c +12 ~~-13~~

index b89c0a5..48281a5 100644
@@ -138,9 +138,6 @@ LIST_HEAD(tty_drivers);			/* linked list of tty drivers */
 /* Mutex to protect creating and releasing a tty */
 DEFINE_MUTEX(tty_mutex);
 
-/* Spinlock to protect the tty->tty_files list */
-DEFINE_SPINLOCK(tty_files_lock);
-
 static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *);
 static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *);
 ssize_t redirected_tty_write(struct file *, const char __user *,

@@ -202,9 +199,9 @@ void tty_add_file(struct tty_struct *tty, struct file *file)
 	priv->tty = tty;
 	priv->file = file;
 
-	spin_lock(&tty_files_lock);
+	spin_lock(&tty->files_lock);
 	list_add(&priv->list, &tty->tty_files);
-	spin_unlock(&tty_files_lock);
+	spin_unlock(&tty->files_lock);
 }
 
 /**

@@ -225,10 +222,11 @@ void tty_free_file(struct file *file)
 static void tty_del_file(struct file *file)
 {
 	struct tty_file_private *priv = file->private_data;
+	struct tty_struct *tty = priv->tty;
 
-	spin_lock(&tty_files_lock);
+	spin_lock(&tty->files_lock);
 	list_del(&priv->list);
-	spin_unlock(&tty_files_lock);
+	spin_unlock(&tty->files_lock);
 	tty_free_file(file);
 }

@@ -286,11 +284,11 @@ static int check_tty_count(struct tty_struct *tty, const char *routine)
 	struct list_head *p;
 	int count = 0;
 
-	spin_lock(&tty_files_lock);
+	spin_lock(&tty->files_lock);
 	list_for_each(p, &tty->tty_files) {
 		count++;
 	}
-	spin_unlock(&tty_files_lock);
+	spin_unlock(&tty->files_lock);
 	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
 	    tty->driver->subtype == PTY_TYPE_SLAVE &&
 	    tty->link && tty->link->count)

@@ -713,7 +711,7 @@ static void __tty_hangup(struct tty_struct *tty, int exit_session)
 	   workqueue with the lock held */
 	check_tty_count(tty, "tty_hangup");
 
-	spin_lock(&tty_files_lock);
+	spin_lock(&tty->files_lock);
 	/* This breaks for file handles being sent over AF_UNIX sockets ? */
 	list_for_each_entry(priv, &tty->tty_files, list) {
 		filp = priv->file;

@@ -725,7 +723,7 @@ static void __tty_hangup(struct tty_struct *tty, int exit_session)
 		__tty_fasync(-1, filp, 0);	/* can't block */
 		filp->f_op = &hung_up_tty_fops;
 	}
-	spin_unlock(&tty_files_lock);
+	spin_unlock(&tty->files_lock);
 
 	refs = tty_signal_session_leader(tty, exit_session);
 	/* Account for the p->signal references we killed */

@@ -1637,9 +1635,9 @@ static void release_one_tty(struct work_struct *work)
 	tty_driver_kref_put(driver);
 	module_put(owner);
 
-	spin_lock(&tty_files_lock);
+	spin_lock(&tty->files_lock);
 	list_del_init(&tty->tty_files);
-	spin_unlock(&tty_files_lock);
+	spin_unlock(&tty->files_lock);
 
 	put_pid(tty->pgrp);
 	put_pid(tty->session);

@@ -3176,6 +3174,7 @@ struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx)
 	mutex_init(&tty->atomic_write_lock);
 	spin_lock_init(&tty->ctrl_lock);
 	spin_lock_init(&tty->flow_lock);
+	spin_lock_init(&tty->files_lock);
 	INIT_LIST_HEAD(&tty->tty_files);
 	INIT_WORK(&tty->SAK_work, do_SAK_work);

include/linux/tty.h +1 -1

index 8ed795d..dea7d54 100644
@@ -302,6 +302,7 @@ struct tty_struct {
 	struct work_struct hangup_work;
 	void *disc_data;
 	void *driver_data;
+	spinlock_t files_lock;		/* protects tty_files list */
 	struct list_head tty_files;
 
 #define N_TTY_BUF_SIZE 4096

@@ -508,7 +509,6 @@ extern int tty_standard_install(struct tty_driver *driver,
 		struct tty_struct *tty);
 
 extern struct mutex tty_mutex;
-extern spinlock_t tty_files_lock;
 
 #define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))

security/selinux/hooks.c +2 -2

index d0cfaa9..ae6dbc75 100644
@@ -2352,7 +2352,7 @@ static inline void flush_unauthorized_files(const struct cred *cred,
 
 	tty = get_current_tty();
 	if (tty) {
-		spin_lock(&tty_files_lock);
+		spin_lock(&tty->files_lock);
 		if (!list_empty(&tty->tty_files)) {
 			struct tty_file_private *file_priv;

@@ -2367,7 +2367,7 @@ static inline void flush_unauthorized_files(const struct cred *cred,
 			if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE))
 				drop_tty = 1;
 		}
-		spin_unlock(&tty_files_lock);
+		spin_unlock(&tty->files_lock);
 		tty_kref_put(tty);
 	}
 	/* Reset controlling tty. */

Signature · 1 line

2.7.0