linux-stable.git/drivers/tty, branch v6.1.96 Linux kernel stable tree tty: add the option to have a tty reject a new ldisc 2024-06-27T11:46:17+00:00 Linus Torvalds torvalds@linux-foundation.org 2024-04-23T16:33:39+00:00 3c6332f3bb1578b5b10ac2561247b1d6272ae937 [ Upstream commit 6bd23e0c2bb6c65d4f5754d1456bc9a4427fc59b ] ... and use it to limit the virtual terminals to just N_TTY. They are kind of special, and in particular, the "con_write()" routine violates the "writes cannot sleep" rule that some ldiscs rely on. This avoids the BUG: sleeping function called from invalid context at kernel/printk/printk.c:2659 when N_GSM has been attached to a virtual console, and gsmld_write() calls con_write() while holding a spinlock, and con_write() then tries to get the console lock. Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Daniel Starke <daniel.starke@siemens.com> Reported-by: syzbot <syzbot+dbac96d8e73b61aa559c@syzkaller.appspotmail.com> Closes: https://syzkaller.appspot.com/bug?extid=dbac96d8e73b61aa559c Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20240423163339.59780-1-torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 6bd23e0c2bb6c65d4f5754d1456bc9a4427fc59b ]

... and use it to limit the virtual terminals to just N_TTY.  They are
kind of special, and in particular, the "con_write()" routine violates
the "writes cannot sleep" rule that some ldiscs rely on.

This avoids the

   BUG: sleeping function called from invalid context at kernel/printk/printk.c:2659

when N_GSM has been attached to a virtual console, and gsmld_write()
calls con_write() while holding a spinlock, and con_write() then tries
to get the console lock.

Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Daniel Starke <daniel.starke@siemens.com>
Reported-by: syzbot <syzbot+dbac96d8e73b61aa559c@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=dbac96d8e73b61aa559c
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240423163339.59780-1-torvalds@linux-foundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
serial: exar: adding missing CTI and Exar PCI ids 2024-06-27T11:46:17+00:00 Parker Newman pnewman@connecttech.com 2024-04-16T12:55:28+00:00 3b3655a1d3a4ed621ee5c4fe1d9b833b74d92f59 [ Upstream commit b86ae40ffcf5a16b9569b1016da4a08c4f352ca2 ] - Added Connect Tech and Exar IDs not already in pci_ids.h Signed-off-by: Parker Newman <pnewman@connecttech.com> Link: https://lore.kernel.org/r/7c3d8e795a864dd9b0a00353b722060dc27c4e09.1713270624.git.pnewman@connecttech.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit b86ae40ffcf5a16b9569b1016da4a08c4f352ca2 ]

- Added Connect Tech and Exar IDs not already in pci_ids.h

Signed-off-by: Parker Newman <pnewman@connecttech.com>
Link: https://lore.kernel.org/r/7c3d8e795a864dd9b0a00353b722060dc27c4e09.1713270624.git.pnewman@connecttech.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
serial: imx: Introduce timeout when waiting on transmitter empty 2024-06-27T11:46:17+00:00 Esben Haabendal esben@geanix.com 2024-04-11T12:19:23+00:00 7f9e70c68b7ace0141fe3bc94bf7b61296b71916 [ Upstream commit e533e4c62e9993e62e947ae9bbec34e4c7ae81c2 ] By waiting at most 1 second for USR2_TXDC to be set, we avoid a potential deadlock. In case of the timeout, there is not much we can do, so we simply ignore the transmitter state and optimistically try to continue. Signed-off-by: Esben Haabendal <esben@geanix.com> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> Link: https://lore.kernel.org/r/919647898c337a46604edcabaf13d42d80c0915d.1712837613.git.esben@geanix.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e533e4c62e9993e62e947ae9bbec34e4c7ae81c2 ]

By waiting at most 1 second for USR2_TXDC to be set, we avoid a potential
deadlock.

In case of the timeout, there is not much we can do, so we simply ignore
the transmitter state and optimistically try to continue.

Signed-off-by: Esben Haabendal <esben@geanix.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Link: https://lore.kernel.org/r/919647898c337a46604edcabaf13d42d80c0915d.1712837613.git.esben@geanix.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
serial: 8250_dw: fall back to poll if there's no interrupt 2024-06-21T12:36:00+00:00 Jisheng Zhang jszhang@kernel.org 2023-08-06T09:20:56+00:00 29d35f0b53d4bd82ebc37c500a8dd73da61318ff [ Upstream commit 22130dae0533c474e4e0db930a88caa9b397d083 ] When there's no irq(this can be due to various reasons, for example, no irq from HW support, or we just want to use poll solution, and so on), falling back to poll is still better than no support at all. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Link: https://lore.kernel.org/r/20230806092056.2467-3-jszhang@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Stable-dep-of: 87d80bfbd577 ("serial: 8250_dw: Don't use struct dw8250_data outside of 8250_dw") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 22130dae0533c474e4e0db930a88caa9b397d083 ]

When there's no irq(this can be due to various reasons, for example,
no irq from HW support, or we just want to use poll solution, and so
on), falling back to poll is still better than no support at all.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Link: https://lore.kernel.org/r/20230806092056.2467-3-jszhang@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 87d80bfbd577 ("serial: 8250_dw: Don't use struct dw8250_data outside of 8250_dw")
Signed-off-by: Sasha Levin <sashal@kernel.org>
serial: 8250_pxa: Configure tx_loadsz to match FIFO IRQ level 2024-06-21T12:35:59+00:00 Doug Brown doug@schmorgal.com 2024-05-19T19:19:30+00:00 51861fc086f22c92fa5c74e854181919d8321093 commit 5208e7ced520a813b4f4774451fbac4e517e78b2 upstream. The FIFO is 64 bytes, but the FCR is configured to fire the TX interrupt when the FIFO is half empty (bit 3 = 0). Thus, we should only write 32 bytes when a TX interrupt occurs. This fixes a problem observed on the PXA168 that dropped a bunch of TX bytes during large transmissions. Fixes: ab28f51c77cd ("serial: rewrite pxa2xx-uart to use 8250_core") Signed-off-by: Doug Brown <doug@schmorgal.com> Link: https://lore.kernel.org/r/20240519191929.122202-1-doug@schmorgal.com Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 5208e7ced520a813b4f4774451fbac4e517e78b2 upstream.

The FIFO is 64 bytes, but the FCR is configured to fire the TX interrupt
when the FIFO is half empty (bit 3 = 0). Thus, we should only write 32
bytes when a TX interrupt occurs.

This fixes a problem observed on the PXA168 that dropped a bunch of TX
bytes during large transmissions.

Fixes: ab28f51c77cd ("serial: rewrite pxa2xx-uart to use 8250_core")
Signed-off-by: Doug Brown <doug@schmorgal.com>
Link: https://lore.kernel.org/r/20240519191929.122202-1-doug@schmorgal.com
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: n_tty: Fix buffer offsets when lookahead is used 2024-06-21T12:35:43+00:00 Ilpo Järvinen ilpo.jarvinen@linux.intel.com 2024-05-14T14:04:29+00:00 03f916e56afd7bba8b8f34e190ac4ab461b5ea86 commit b19ab7ee2c4c1ec5f27c18413c3ab63907f7d55c upstream. When lookahead has "consumed" some characters (la_count > 0), n_tty_receive_buf_standard() and n_tty_receive_buf_closing() for characters beyond the la_count are given wrong cp/fp offsets which leads to duplicating and losing some characters. If la_count > 0, correct buffer pointers and make count consistent too (the latter is not strictly necessary to fix the issue but seems more logical to adjust all variables immediately to keep state consistent). Reported-by: Vadym Krevs <vkrevs@yahoo.com> Fixes: 6bb6fa6908eb ("tty: Implement lookahead to process XON/XOFF timely") Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218834 Tested-by: Vadym Krevs <vkrevs@yahoo.com> Cc: stable@vger.kernel.org Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20240514140429.12087-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit b19ab7ee2c4c1ec5f27c18413c3ab63907f7d55c upstream.

When lookahead has "consumed" some characters (la_count > 0),
n_tty_receive_buf_standard() and n_tty_receive_buf_closing() for
characters beyond the la_count are given wrong cp/fp offsets which
leads to duplicating and losing some characters.

If la_count > 0, correct buffer pointers and make count consistent too
(the latter is not strictly necessary to fix the issue but seems more
logical to adjust all variables immediately to keep state consistent).

Reported-by: Vadym Krevs <vkrevs@yahoo.com>
Fixes: 6bb6fa6908eb ("tty: Implement lookahead to process XON/XOFF timely")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218834
Tested-by: Vadym Krevs <vkrevs@yahoo.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20240514140429.12087-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: sc16is7xx: fix bug in sc16is7xx_set_baud() when using prescaler 2024-06-21T12:35:40+00:00 Hugo Villeneuve hvilleneuve@dimonoff.com 2024-04-30T20:04:30+00:00 c3d39fdc337b3cdaa116740cd631c5b27211d8ec [ Upstream commit 8492bd91aa055907c67ef04f2b56f6dadd1f44bf ] When using a high speed clock with a low baud rate, the 4x prescaler is automatically selected if required. In that case, sc16is7xx_set_baud() properly configures the chip registers, but returns an incorrect baud rate by not taking into account the prescaler value. This incorrect baud rate is then fed to uart_update_timeout(). For example, with an input clock of 80MHz, and a selected baud rate of 50, sc16is7xx_set_baud() will return 200 instead of 50. Fix this by first changing the prescaler variable to hold the selected prescaler value instead of the MCR bitfield. Then properly take into account the selected prescaler value in the return value computation. Also add better documentation about the divisor value computation. Fixes: dfeae619d781 ("serial: sc16is7xx") Cc: stable@vger.kernel.org Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20240430200431.4102923-1-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 8492bd91aa055907c67ef04f2b56f6dadd1f44bf ]

When using a high speed clock with a low baud rate, the 4x prescaler is
automatically selected if required. In that case, sc16is7xx_set_baud()
properly configures the chip registers, but returns an incorrect baud
rate by not taking into account the prescaler value. This incorrect baud
rate is then fed to uart_update_timeout().

For example, with an input clock of 80MHz, and a selected baud rate of 50,
sc16is7xx_set_baud() will return 200 instead of 50.

Fix this by first changing the prescaler variable to hold the selected
prescaler value instead of the MCR bitfield. Then properly take into
account the selected prescaler value in the return value computation.

Also add better documentation about the divisor value computation.

Fixes: dfeae619d781 ("serial: sc16is7xx")
Cc: stable@vger.kernel.org
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240430200431.4102923-1-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
serial: sc16is7xx: replace hardcoded divisor value with BIT() macro 2024-06-21T12:35:40+00:00 Hugo Villeneuve hvilleneuve@dimonoff.com 2023-12-21T23:18:19+00:00 aeb2b22e4fda6d192e7fef5b5f5dab955aa92613 [ Upstream commit 2e57cefc4477659527f7adab1f87cdbf60ef1ae6 ] To better show why the limit is what it is, since we have only 16 bits for the divisor. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20231221231823.2327894-13-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Stable-dep-of: 8492bd91aa05 ("serial: sc16is7xx: fix bug in sc16is7xx_set_baud() when using prescaler") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 2e57cefc4477659527f7adab1f87cdbf60ef1ae6 ]

To better show why the limit is what it is, since we have only 16 bits for
the divisor.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20231221231823.2327894-13-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 8492bd91aa05 ("serial: sc16is7xx: fix bug in sc16is7xx_set_baud() when using prescaler")
Signed-off-by: Sasha Levin <sashal@kernel.org>
serial: sh-sci: protect invalidating RXDMA on shutdown 2024-06-12T09:03:42+00:00 Wolfram Sang wsa+renesas@sang-engineering.com 2024-05-06T11:40:17+00:00 3cb6516b84ab1ca8e1cf58e8a8500b80709c3acf [ Upstream commit aae20f6e34cd0cbd67a1d0e5877561c40109a81b ] The to-be-fixed commit removed locking when invalidating the DMA RX descriptors on shutdown. It overlooked that there is still a rx_timer running which may still access the protected data. So, re-add the locking. Reported-by: Dirk Behme <dirk.behme@de.bosch.com> Closes: https://lore.kernel.org/r/ee6c9e16-9f29-450e-81da-4a8dceaa8fc7@de.bosch.com Fixes: 2c4ee23530ff ("serial: sh-sci: Postpone DMA release when falling back to PIO") Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Link: https://lore.kernel.org/r/20240506114016.30498-7-wsa+renesas@sang-engineering.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit aae20f6e34cd0cbd67a1d0e5877561c40109a81b ]

The to-be-fixed commit removed locking when invalidating the DMA RX
descriptors on shutdown. It overlooked that there is still a rx_timer
running which may still access the protected data. So, re-add the
locking.

Reported-by: Dirk Behme <dirk.behme@de.bosch.com>
Closes: https://lore.kernel.org/r/ee6c9e16-9f29-450e-81da-4a8dceaa8fc7@de.bosch.com
Fixes: 2c4ee23530ff ("serial: sh-sci: Postpone DMA release when falling back to PIO")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20240506114016.30498-7-wsa+renesas@sang-engineering.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
serial: sc16is7xx: add proper sched.h include for sched_set_fifo() 2024-06-12T09:03:35+00:00 Hugo Villeneuve hvilleneuve@dimonoff.com 2024-04-09T15:42:49+00:00 3c080bd43b886cd70433a49e0502487d5ceef633 [ Upstream commit 2a8e4ab0c93fad30769479f86849e22d63cd0e12 ] Replace incorrect include with the proper one for sched_set_fifo() declaration. Fixes: 28d2f209cd16 ("sched,serial: Convert to sched_set_fifo()") Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20240409154253.3043822-2-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 2a8e4ab0c93fad30769479f86849e22d63cd0e12 ]

Replace incorrect include with the proper one for sched_set_fifo()
declaration.

Fixes: 28d2f209cd16 ("sched,serial: Convert to sched_set_fifo()")
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20240409154253.3043822-2-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>