--- zzzz-none-000/linux-3.10.107/include/linux/tty.h 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/include/linux/tty.h 2021-02-04 17:41:59.000000000 +0000 @@ -10,8 +10,33 @@ #include #include #include +#include +#include +/* + * Lock subclasses for tty locks + * + * TTY_LOCK_NORMAL is for normal ttys and master ptys. + * TTY_LOCK_SLAVE is for slave ptys only. + * + * Lock subclasses are necessary for handling nested locking with pty pairs. + * tty locks which use nested locking: + * + * legacy_mutex - Nested tty locks are necessary for releasing pty pairs. + * The stable lock order is master pty first, then slave pty. + * termios_rwsem - The stable lock order is tty_buffer lock->termios_rwsem. + * Subclassing this lock enables the slave pty to hold its + * termios_rwsem when claiming the master tty_buffer lock. + * tty_buffer lock - slave ptys can claim nested buffer lock when handling + * signal chars. The stable lock order is slave pty, then + * master. + */ + +enum { + TTY_LOCK_NORMAL = 0, + TTY_LOCK_SLAVE, +}; /* * (Note: the *_driver.minor_start values 1, 64, 128, 192 are @@ -29,36 +54,42 @@ #define __DISABLED_CHAR '\0' struct tty_buffer { - struct tty_buffer *next; - char *char_buf_ptr; - unsigned char *flag_buf_ptr; + union { + struct tty_buffer *next; + struct llist_node free; + }; int used; int size; int commit; int read; + int flags; /* Data points here */ unsigned long data[0]; }; -/* - * We default to dicing tty buffer allocations to this many characters - * in order to avoid multiple page allocations. We know the size of - * tty_buffer itself but it must also be taken into account that the - * the buffer is 256 byte aligned. See tty_buffer_find for the allocation - * logic this must match - */ +/* Values for .flags field of tty_buffer */ +#define TTYB_NORMAL 1 /* buffer has no flags buffer */ -#define TTY_BUFFER_PAGE (((PAGE_SIZE - sizeof(struct tty_buffer)) / 2) & ~0xFF) +static inline unsigned char *char_buf_ptr(struct tty_buffer *b, int ofs) +{ + return ((unsigned char *)b->data) + ofs; +} +static inline char *flag_buf_ptr(struct tty_buffer *b, int ofs) +{ + return (char *)char_buf_ptr(b, ofs) + b->size; +} struct tty_bufhead { - struct work_struct work; - spinlock_t lock; struct tty_buffer *head; /* Queue head */ + struct work_struct work; + struct mutex lock; + atomic_t priority; + struct tty_buffer sentinel; + struct llist_head free; /* Free queue head */ + atomic_t mem_used; /* In-use buffers excluding free list */ + int mem_limit; struct tty_buffer *tail; /* Active buffer */ - struct tty_buffer *free; /* Free queue head */ - int memory_used; /* Buffer space used excluding - free queue */ }; /* * When a break, frame error, or parity error happens, these codes are @@ -134,6 +165,7 @@ #define C_CLOCAL(tty) _C_FLAG((tty), CLOCAL) #define C_CIBAUD(tty) _C_FLAG((tty), CIBAUD) #define C_CRTSCTS(tty) _C_FLAG((tty), CRTSCTS) +#define C_CMSPAR(tty) _C_FLAG((tty), CMSPAR) #define L_ISIG(tty) _L_FLAG((tty), ISIG) #define L_ICANON(tty) _L_FLAG((tty), ICANON) @@ -177,7 +209,6 @@ IFF the port was initialized. Do not use to free resources. Called under the port mutex to serialize against activate/shutdowns */ void (*shutdown)(struct tty_port *port); - void (*drop)(struct tty_port *port); /* Called under the port mutex from tty_port_open, serialized using the port mutex */ /* FIXME: long term getting the tty argument *out* of this would be @@ -196,14 +227,10 @@ int blocked_open; /* Waiting to open */ int count; /* Usage count */ wait_queue_head_t open_wait; /* Open waiters */ - wait_queue_head_t close_wait; /* Close waiters */ wait_queue_head_t delta_msr_wait; /* Modem status change */ unsigned long flags; /* TTY flags ASY_*/ - unsigned long iflags; /* TTYP_ internal flags */ -#define TTYP_FLUSHING 1 /* Flushing to ldisc in progress */ -#define TTYP_FLUSHPENDING 2 /* Queued buffer flush pending */ unsigned char console:1, /* port is a console */ - low_latency:1; /* direct buffer flush */ + low_latency:1; /* optional: tune for latency */ struct mutex mutex; /* Locking */ struct mutex buf_mutex; /* Buffer alloc lock */ unsigned char *xmit_buf; /* Optional buffer */ @@ -238,14 +265,17 @@ int index; /* Protects ldisc changes: Lock tty not pty */ - struct mutex ldisc_mutex; + struct ld_semaphore ldisc_sem; struct tty_ldisc *ldisc; struct mutex atomic_write_lock; struct mutex legacy_mutex; - struct mutex termios_mutex; + struct mutex throttle_mutex; + struct rw_semaphore termios_rwsem; + struct mutex winsize_mutex; spinlock_t ctrl_lock; - /* Termios values are protected by the termios mutex */ + spinlock_t flow_lock; + /* Termios values are protected by the termios rwsem */ struct ktermios termios, termios_locked; struct termiox *termiox; /* May be NULL for unsupported */ char name[64]; @@ -253,9 +283,14 @@ struct pid *session; unsigned long flags; int count; - struct winsize winsize; /* termios mutex */ - unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1; - unsigned char ctrl_status; /* ctrl_lock */ + struct winsize winsize; /* winsize_mutex */ + unsigned long stopped:1, /* flow_lock */ + flow_stopped:1, + unused:BITS_PER_LONG - 2; + int hw_stopped; + unsigned long ctrl_status:8, /* ctrl_lock */ + packet:1, + unused_ctrl:BITS_PER_LONG - 9; unsigned int receive_room; /* Bytes free for queue */ int flow_change; @@ -271,8 +306,7 @@ #define N_TTY_BUF_SIZE 4096 - unsigned char closing:1; - unsigned short minimum_to_wake; + int closing; unsigned char *write_buf; int write_cnt; /* If the tty has a pending do_SAK, queue it here - akpm */ @@ -304,17 +338,10 @@ #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_PUSH 6 /* n_tty private */ -#define TTY_CLOSING 7 /* ->close() in progress */ -#define TTY_LDISC 9 /* Line discipline attached */ -#define TTY_LDISC_CHANGING 10 /* Line discipline changing */ #define TTY_LDISC_OPEN 11 /* Line discipline is open */ -#define TTY_HW_COOK_OUT 14 /* Hardware can do output cooking */ -#define TTY_HW_COOK_IN 15 /* Hardware can do input cooking */ #define TTY_PTY_LOCK 16 /* pty private */ #define TTY_NO_WRITE_SPLIT 17 /* Preserve write boundaries to driver */ #define TTY_HUPPED 18 /* Post driver->hangup() */ -#define TTY_HUPPING 21 /* ->hangup() in progress */ #define TTY_LDISC_HALTED 22 /* Line discipline is halted */ #define TTY_WRITE_FLUSH(tty) tty_write_flush((tty)) @@ -393,10 +420,13 @@ extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, const char *routine); -extern char *tty_name(struct tty_struct *tty, char *buf); +extern const char *tty_name(const struct tty_struct *tty); extern void tty_wait_until_sent(struct tty_struct *tty, long timeout); +extern int __tty_check_change(struct tty_struct *tty, int sig); extern int tty_check_change(struct tty_struct *tty); +extern void __stop_tty(struct tty_struct *tty); extern void stop_tty(struct tty_struct *tty); +extern void __start_tty(struct tty_struct *tty); extern void start_tty(struct tty_struct *tty); extern int tty_register_driver(struct tty_driver *driver); extern int tty_unregister_driver(struct tty_driver *driver); @@ -410,6 +440,7 @@ 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); extern int tty_chars_in_buffer(struct tty_struct *tty); extern int tty_write_room(struct tty_struct *tty); @@ -427,16 +458,17 @@ 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 void tty_vhangup_locked(struct tty_struct *tty); -extern void tty_unhangup(struct file *filp); extern int tty_hung_up_p(struct file *filp); extern void do_SAK(struct tty_struct *tty); extern void __do_SAK(struct tty_struct *tty); extern void no_tty(void); -extern void tty_flush_to_ldisc(struct tty_struct *tty); extern void tty_buffer_free_all(struct tty_port *port); -extern void tty_buffer_flush(struct tty_struct *tty); +extern void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld); extern void tty_buffer_init(struct tty_port *port); +extern void tty_buffer_set_lock_subclass(struct tty_port *port); +extern bool tty_buffer_restart_work(struct tty_port *port); +extern bool tty_buffer_cancel_work(struct tty_port *port); +extern void tty_buffer_flush_work(struct tty_port *port); extern speed_t tty_termios_baud_rate(struct ktermios *termios); extern speed_t tty_termios_input_baud_rate(struct ktermios *termios); extern void tty_termios_encode_baud_rate(struct ktermios *termios, @@ -477,13 +509,11 @@ unsigned int cmd, unsigned long arg); extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg); extern void tty_default_fops(struct file_operations *fops); -extern struct tty_struct *alloc_tty_struct(void); +extern struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx); extern int tty_alloc_file(struct file *file); extern void tty_add_file(struct tty_struct *tty, struct file *file); extern void tty_free_file(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); extern void deinitialize_tty_struct(struct tty_struct *tty); extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx); extern int tty_release(struct inode *inode, struct file *filp); @@ -491,14 +521,9 @@ extern int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty); -extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty); -extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty); - extern struct mutex tty_mutex; extern spinlock_t tty_files_lock; -extern void tty_write_unlock(struct tty_struct *tty); -extern int tty_write_lock(struct tty_struct *tty, int ndelay); #define tty_is_writelocked(tty) (mutex_is_locked(&tty->atomic_write_lock)) extern void tty_port_init(struct tty_port *port); @@ -518,9 +543,9 @@ static inline struct tty_port *tty_port_get(struct tty_port *port) { - if (port) - kref_get(&port->kref); - return port; + if (port && kref_get_unless_zero(&port->kref)) + return port; + return NULL; } /* If the cts flow control is enabled, return true. */ @@ -557,11 +582,24 @@ extern int tty_unregister_ldisc(int disc); extern int tty_set_ldisc(struct tty_struct *tty, int ldisc); extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty); -extern void tty_ldisc_release(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) +{ + if (ld->ops->receive_buf2) + count = ld->ops->receive_buf2(ld->tty, p, f, count); + else { + count = min_t(int, count, ld->tty->receive_room); + if (count && ld->ops->receive_buf) + ld->ops->receive_buf(ld->tty, p, f, count); + } + return count; +} + /* n_tty.c */ extern struct tty_ldisc_ops tty_ldisc_N_TTY; @@ -569,7 +607,7 @@ /* tty_audit.c */ #ifdef CONFIG_AUDIT -extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data, +extern void tty_audit_add_data(struct tty_struct *tty, const void *data, size_t size, unsigned icanon); extern void tty_audit_exit(void); extern void tty_audit_fork(struct signal_struct *sig); @@ -577,8 +615,8 @@ extern void tty_audit_push(struct tty_struct *tty); extern int tty_audit_push_current(void); #else -static inline void tty_audit_add_data(struct tty_struct *tty, - unsigned char *data, size_t size, unsigned icanon) +static inline void tty_audit_add_data(struct tty_struct *tty, const void *data, + size_t size, unsigned icanon) { } static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch) @@ -605,14 +643,6 @@ extern long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned long arg); -/* serial.c */ - -extern void serial_console_init(void); - -/* pcxx.c */ - -extern int pcxe_open(struct tty_struct *tty, struct file *filp); - /* vt.c */ extern int vt_ioctl(struct tty_struct *tty, @@ -624,70 +654,11 @@ /* tty_mutex.c */ /* functions for preparation of BKL removal */ extern void __lockfunc tty_lock(struct tty_struct *tty); +extern int tty_lock_interruptible(struct tty_struct *tty); extern void __lockfunc tty_unlock(struct tty_struct *tty); -extern void __lockfunc tty_lock_pair(struct tty_struct *tty, - struct tty_struct *tty2); -extern void __lockfunc tty_unlock_pair(struct tty_struct *tty, - struct tty_struct *tty2); - -/* - * this shall be called only from where BTM is held (like close) - * - * We need this to ensure nobody waits for us to finish while we are waiting. - * Without this we were encountering system stalls. - * - * This should be indeed removed with BTM removal later. - * - * Locking: BTM required. Nobody is allowed to hold port->mutex. - */ -static inline void tty_wait_until_sent_from_close(struct tty_struct *tty, - long timeout) -{ - tty_unlock(tty); /* tty->ops->close holds the BTM, drop it while waiting */ - tty_wait_until_sent(tty, timeout); - tty_lock(tty); -} - -/* - * wait_event_interruptible_tty -- wait for a condition with the tty lock held - * - * The condition we are waiting for might take a long time to - * become true, or might depend on another thread taking the - * BTM. In either case, we need to drop the BTM to guarantee - * forward progress. This is a leftover from the conversion - * from the BKL and should eventually get removed as the BTM - * falls out of use. - * - * Do not use in new code. - */ -#define wait_event_interruptible_tty(tty, wq, condition) \ -({ \ - int __ret = 0; \ - if (!(condition)) { \ - __wait_event_interruptible_tty(tty, wq, condition, __ret); \ - } \ - __ret; \ -}) - -#define __wait_event_interruptible_tty(tty, wq, condition, ret) \ -do { \ - DEFINE_WAIT(__wait); \ - \ - for (;;) { \ - prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \ - if (condition) \ - break; \ - if (!signal_pending(current)) { \ - tty_unlock(tty); \ - schedule(); \ - tty_lock(tty); \ - continue; \ - } \ - ret = -ERESTARTSYS; \ - break; \ - } \ - finish_wait(&wq, &__wait); \ -} while (0) +extern void __lockfunc tty_lock_slave(struct tty_struct *tty); +extern void __lockfunc tty_unlock_slave(struct tty_struct *tty); +extern void tty_set_lock_subclass(struct tty_struct *tty); #ifdef CONFIG_PROC_FS extern void proc_tty_register_driver(struct tty_driver *); @@ -697,4 +668,10 @@ static inline void proc_tty_unregister_driver(struct tty_driver *d) {} #endif +#define tty_debug(tty, f, args...) \ + do { \ + printk(KERN_DEBUG "%s: %s: " f, __func__, \ + tty_name(tty), ##args); \ + } while (0) + #endif