kernel/linux.git/drivers/tty/tty_io.c, branch v5.15.7

tty: Fix data race between tiocsti() and flush_to_ldisc()

2021-08-26T12:51:38+00:00

The ops->receive_buf() may be accessed concurrently from these two functions. If the driver flushes data to the line discipline receive_buf() method while tiocsti() is waiting for the ops->receive_buf() to finish its work, the data race will happen. For example: tty_ioctl |tty_ldisc_receive_buf ->tioctsi | ->tty_port_default_receive_buf | ->tty_ldisc_receive_buf ->hci_uart_tty_receive | ->hci_uart_tty_receive ->h4_recv | ->h4_recv In this case, the h4 receive buffer will be overwritten by the latecomer, and we will lost the data. Hence, change tioctsi() function to use the exclusive lock interface from tty_buffer to avoid the data race. Reported-by: syzbot+97388eb9d31b997fe1d0@syzkaller.appspotmail.com Reviewed-by: Jiri Slaby Signed-off-by: Nguyen Dinh Phi Link: https://lore.kernel.org/r/20210823000641.2082292-1-phind.uet@gmail.com Cc: stable Signed-off-by: Greg Kroah-Hartman

tty: drop put_tty_driver

2021-07-27T10:17:21+00:00

put_tty_driver() is an alias for tty_driver_kref_put(). There is no need for two exported identical functions, therefore switch all users of old put_tty_driver() to new tty_driver_kref_put() and remove the former for good. Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Cc: Geert Uytterhoeven Cc: Jeff Dike Cc: Richard Weinberger Cc: Anton Ivanov Cc: Chris Zankel Cc: Max Filippov Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Cc: Samuel Iglesias Gonsalvez Cc: Jens Taprogge Cc: Karsten Keil Cc: Scott Branden Cc: Ulf Hansson Cc: "David S. Miller" Cc: Jakub Kicinski Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger Cc: David Lin Cc: Johan Hovold Cc: Alex Elder Cc: Jiri Slaby Cc: Laurentiu Tudor Cc: Jiri Kosina Cc: David Sterba Cc: Shawn Guo Cc: Sascha Hauer Cc: Pengutronix Kernel Team Cc: Fabio Estevam Cc: NXP Linux Team Cc: Oliver Neukum Cc: Felipe Balbi Cc: Mathias Nyman Cc: Marcel Holtmann Cc: Johan Hedberg Cc: Luiz Augusto von Dentz Acked-by: Alex Elder Acked-by: Christian Borntraeger Acked-by: Max Filippov Acked-by: David Sterba Acked-by: Samuel Iglesias Gonsálvez Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20210723074317.32690-8-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman

tty: make tty_set_operations an inline

2021-07-27T10:17:21+00:00

Since commit f34d7a5b7010 (tty: The big operations rework) in 2008, tty_set_operations() is a simple one-line assignment. There is no reason for this to be an exported function, hence move it to a header and make an inline from that. Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20210723074317.32690-7-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman

tty: fix kernel-doc for {start,stop}_tty

2021-05-20T14:59:14+00:00

Commit f9e053dcfc02 (tty: Serialize tty flow control changes with flow_lock) renamed start_tty to __start_tty and stop_tty to __stop_tty and introduced new start_tty and stop_tty. But it left kernel-doc comments on the old locations: tty_io.c:785: warning: expecting prototype for stop_tty(). Prototype was for __stop_tty() instead tty_io.c:816: warning: expecting prototype for start_tty(). Prototype was for __start_tty() instead Fix that by moving the comments to appropriate locations. Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20210519072153.3859-4-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman

tty: fix kernel-doc for tty_{read,write}

2021-05-20T14:59:14+00:00

After commits a9cbbb80e3e7 (tty: avoid using vfs_iocb_iter_write() for redirected console writes) and dd78b0c483e3 (tty: implement read_iter), the tty_read and tty_write kernel-doc comments don't match the code: tty_io.c:931: warning: Function parameter or member 'iocb' not described in 'tty_read' tty_io.c:931: warning: Function parameter or member 'to' not described in 'tty_read' tty_io.c:931: warning: Excess function parameter 'file' description in 'tty_read' tty_io.c:931: warning: Excess function parameter 'buf' description in 'tty_read' tty_io.c:931: warning: Excess function parameter 'count' description in 'tty_read' tty_io.c:931: warning: Excess function parameter 'ppos' description in 'tty_read' tty_io.c:1115: warning: Function parameter or member 'iocb' not described in 'file_tty_write' tty_io.c:1115: warning: Function parameter or member 'from' not described in 'file_tty_write' tty_io.c:1115: warning: expecting prototype for tty_write(). Prototype was for file_tty_write() instead Fix them to correspond the reality, i.e. the switch from read/write to read_iter/write_iter. Cc: Linus Torvalds Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20210519072153.3859-3-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman

tty: tty_io: Remove return in void function

2021-05-13T16:29:13+00:00

Remove return in void function, reported by checkpatch.pl. Signed-off-by: Xiaofei Tan Link: https://lore.kernel.org/r/1620811585-18582-15-git-send-email-tanxiaofei@huawei.com Signed-off-by: Greg Kroah-Hartman

tty: tty_io: Delete a blank line before EXPORT_SYMBOL(foo)

2021-05-13T16:29:13+00:00

Delete a blank line before EXPORT_SYMBOL(foo) so that EXPORT_SYMBOL(foo) immediately follow its function/variable, reported by checkpatch.pl. Signed-off-by: Xiaofei Tan Link: https://lore.kernel.org/r/1620811585-18582-14-git-send-email-tanxiaofei@huawei.com Signed-off-by: Greg Kroah-Hartman

tty: tty_io: Fix an issue of code indent for conditional statements

2021-05-13T16:29:13+00:00

Fix an issue of code indent for conditional statements,reported by checkpatch.pl. Signed-off-by: Xiaofei Tan Link: https://lore.kernel.org/r/1620811585-18582-13-git-send-email-tanxiaofei@huawei.com Signed-off-by: Greg Kroah-Hartman

tty: tty_io: Remove the repeated word 'can'

2021-05-13T16:29:13+00:00

Remove the repeated word 'can' following advice of checkpatch.pl Signed-off-by: Xiaofei Tan Link: https://lore.kernel.org/r/1620811585-18582-12-git-send-email-tanxiaofei@huawei.com Signed-off-by: Greg Kroah-Hartman

tty: tty_io: Fix coding style issues of block comments

2021-05-13T16:29:13+00:00

Fix coding style issues of block comments, reported by checkpatch.pl. Besides, add a period at the end of the sentenses. Signed-off-by: Xiaofei Tan Link: https://lore.kernel.org/r/1620811585-18582-11-git-send-email-tanxiaofei@huawei.com Signed-off-by: Greg Kroah-Hartman