kernel/linux.git/drivers/tty/tty_io.c, branch v6.1.168

usb: cdc-acm: return correct error code on unsupported break

2024-01-25T23:27:47+00:00

[ Upstream commit 66aad7d8d3ec5a3a8ec2023841bcec2ded5f65c9 ] In ACM support for sending breaks to devices is optional. If a device says that it doenot support sending breaks, the host must respect that. Given the number of optional features providing tty operations for each combination is not practical and errors need to be returned dynamically if unsupported features are requested. In case a device does not support break, we want the tty layer to treat that like it treats drivers that statically cannot support sending a break. It ignores the inability and does nothing. This patch uses EOPNOTSUPP to indicate that. Signed-off-by: Oliver Neukum Fixes: 9e98966c7bb94 ("tty: rework break handling") Link: https://lore.kernel.org/r/20231207132639.18250-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

tty: use 'if' in send_break() instead of 'goto'

2024-01-25T23:27:47+00:00

[ Upstream commit 24f2cd019946fc2e88e632d2e24a34c2cc3f2be4 ] Now, the "jumped-over" code is simple enough to be put inside an 'if'. Do so to make it 'goto'-less. Signed-off-by: "Jiri Slaby (SUSE)" Link: https://lore.kernel.org/r/20230919085156.1578-16-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman Stable-dep-of: 66aad7d8d3ec ("usb: cdc-acm: return correct error code on unsupported break") Signed-off-by: Sasha Levin

tty: don't check for signal_pending() in send_break()

2024-01-25T23:27:47+00:00

[ Upstream commit fd99392b643b824813df2edbaebe26a2136d31e6 ] msleep_interruptible() will check on its own. So no need to do the check in send_break() before calling the above. Signed-off-by: "Jiri Slaby (SUSE)" Link: https://lore.kernel.org/r/20230919085156.1578-15-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman Stable-dep-of: 66aad7d8d3ec ("usb: cdc-acm: return correct error code on unsupported break") Signed-off-by: Sasha Levin

tty: early return from send_break() on TTY_DRIVER_HARDWARE_BREAK

2024-01-25T23:27:47+00:00

[ Upstream commit 66619686d187b4a6395316b7f39881e945dce4bc ] If the driver sets TTY_DRIVER_HARDWARE_BREAK, we leave ops->break_ctl() to the driver and return from send_break(). But we do it using a local variable and keep the code flowing through the end of the function. Instead, do 'return' immediately with the ops->break_ctl()'s return value. This way, we don't have to stuff the 'else' branch of the 'if' with the software break handling. And we can re-indent the function too. Signed-off-by: "Jiri Slaby (SUSE)" Link: https://lore.kernel.org/r/20230919085156.1578-14-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman Stable-dep-of: 66aad7d8d3ec ("usb: cdc-acm: return correct error code on unsupported break") Signed-off-by: Sasha Levin

tty: change tty_write_lock()'s ndelay parameter to bool

2024-01-25T23:27:47+00:00

[ Upstream commit af815336556df28f800669c58ab3bdad7d786b98 ] It's a yes-no parameter, so convert it to bool to be obvious. Signed-off-by: "Jiri Slaby (SUSE)" Link: https://lore.kernel.org/r/20230810091510.13006-6-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman Stable-dep-of: 66aad7d8d3ec ("usb: cdc-acm: return correct error code on unsupported break") Signed-off-by: Sasha Levin

tty: Prevent writing chars during tcsetattr TCSADRAIN/FLUSH

2023-05-11T14:03:01+00:00

commit 094fb49a2d0d6827c86d2e0840873e6db0c491d2 upstream. If userspace races tcsetattr() with a write, the drained condition might not be guaranteed by the kernel. There is a race window after checking Tx is empty before tty_set_termios() takes termios_rwsem for write. During that race window, more characters can be queued by a racing writer. Any ongoing transmission might produce garbage during HW's ->set_termios() call. The intent of TCSADRAIN/FLUSH seems to be preventing such a character corruption. If those flags are set, take tty's write lock to stop any writer before performing the lower layer Tx empty check and wait for the pending characters to be sent (if any). The initial wait for all-writers-done must be placed outside of tty's write lock to avoid deadlock which makes it impossible to use tty_wait_until_sent(). The write lock is retried if a racing write is detected. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20230317113318.31327-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

tty: fix out-of-bounds access in tty_driver_lookup_tty()

2023-03-11T12:55:34+00:00

[ Upstream commit db4df8e9d79e7d37732c1a1b560958e8dadfefa1 ] When specifying an invalid console= device like console=tty3270, tty_driver_lookup_tty() returns the tty struct without checking whether index is a valid number. To reproduce: qemu-system-x86_64 -enable-kvm -nographic -serial mon:stdio \ -kernel ../linux-build-x86/arch/x86/boot/bzImage \ -append "console=ttyS0 console=tty3270" This crashes with: [ 0.770599] BUG: kernel NULL pointer dereference, address: 00000000000000ef [ 0.771265] #PF: supervisor read access in kernel mode [ 0.771773] #PF: error_code(0x0000) - not-present page [ 0.772609] Oops: 0000 [#1] PREEMPT SMP PTI [ 0.774878] RIP: 0010:tty_open+0x268/0x6f0 [ 0.784013] chrdev_open+0xbd/0x230 [ 0.784444] ? cdev_device_add+0x80/0x80 [ 0.784920] do_dentry_open+0x1e0/0x410 [ 0.785389] path_openat+0xca9/0x1050 [ 0.785813] do_filp_open+0xaa/0x150 [ 0.786240] file_open_name+0x133/0x1b0 [ 0.786746] filp_open+0x27/0x50 [ 0.787244] console_on_rootfs+0x14/0x4d [ 0.787800] kernel_init_freeable+0x1e4/0x20d [ 0.788383] ? rest_init+0xc0/0xc0 [ 0.788881] kernel_init+0x11/0x120 [ 0.789356] ret_from_fork+0x22/0x30 Signed-off-by: Sven Schnelle Reviewed-by: Jiri Slaby Link: https://lore.kernel.org/r/20221209112737.3222509-2-svens@linux.ibm.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

tty: remove TTY_DRIVER_MAGIC

2022-09-22T14:12:34+00:00

According to Greg, in the context of magic numbers as defined in magic-number.rst, "the tty layer should not need this and I'll gladly take patches" Acked-by: Jiri Slaby Signed-off-by: Ahelenia Ziemiańska Ref: https://lore.kernel.org/linux-doc/YyMlovoskUcHLEb7@kroah.com/ Link: https://lore.kernel.org/r/723478a270a3858f27843cbec621df4d5d44efcc.1663288066.git.nabijaczleweli@nabijaczleweli.xyz Signed-off-by: Greg Kroah-Hartman

tty: remove TTY_MAGIC

2022-09-22T14:12:34+00:00

According to Greg, in the context of magic numbers as defined in magic-number.rst, "the tty layer should not need this and I'll gladly take patches" Acked-by: Jiri Slaby Signed-off-by: Ahelenia Ziemiańska Ref: https://lore.kernel.org/linux-doc/YyMlovoskUcHLEb7@kroah.com/ Link: https://lore.kernel.org/r/476d024cd6b04160a5de381ea2b9856b60088cbd.1663288066.git.nabijaczleweli@nabijaczleweli.xyz Signed-off-by: Greg Kroah-Hartman

termios: start unifying non-UAPI parts of asm/termios.h

2022-09-09T08:44:34+00:00

* new header (linut/termios_internal.h), pulled by the users of those suckers * defaults for INIT_C_CC and externs for conversion helpers moved over there * remove termios-base.h (empty now) Signed-off-by: Al Viro Link: https://lore.kernel.org/r/YxDmptU7dNGZ+/Hn@ZenIV Signed-off-by: Greg Kroah-Hartman