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2022-03-08serial: stm32: prevent TDR register overwrite when sending x_charValentin Caron1-0/+12
[ Upstream commit d3d079bde07e1b7deaeb57506dc0b86010121d17 ] When sending x_char in stm32_usart_transmit_chars(), driver can overwrite the value of TDR register by the value of x_char. If this happens, the previous value that was present in TDR register will not be sent through uart. This code checks if the previous value in TDR register is sent before writing the x_char value into register. Fixes: 48a6092fb41f ("serial: stm32-usart: Add STM32 USART Driver") Cc: stable <stable@vger.kernel.org> Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20220111164441.6178-2-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-02tty: n_gsm: fix deadlock in gsmtty_open()daniel.starke@siemens.com1-0/+3
commit a2ab75b8e76e455af7867e3835fd9cdf386b508f upstream. In the current implementation the user may open a virtual tty which then could fail to establish the underlying DLCI. The function gsmtty_open() gets stuck in tty_port_block_til_ready() while waiting for a carrier rise. This happens if the remote side fails to acknowledge the link establishment request in time or completely. At some point gsm_dlci_close() is called to abort the link establishment attempt. The function tries to inform the associated virtual tty by performing a hangup. But the blocking loop within tty_port_block_til_ready() is not informed about this event. The patch proposed here fixes this by resetting the initialization state of the virtual tty to ensure the loop exits and triggering it to make tty_port_block_til_ready() return. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220218073123.2121-7-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-02tty: n_gsm: fix wrong tty control line for flow controldaniel.starke@siemens.com1-4/+4
commit c19d93542a6081577e6da9bf5e887979c72e80c1 upstream. tty flow control is handled via gsmtty_throttle() and gsmtty_unthrottle(). Both functions propagate the outgoing hardware flow control state to the remote side via MSC (modem status command) frames. The local state is taken from the RTS (ready to send) flag of the tty. However, RTS gets mapped to DTR (data terminal ready), which is wrong. This patch corrects this by mapping RTS to RTS. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220218073123.2121-5-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-02tty: n_gsm: fix NULL pointer access due to DLCI releasedaniel.starke@siemens.com1-1/+6
commit 96b169f05cdcc844b400695184d77e42071d14f2 upstream. The here fixed commit made the tty hangup asynchronous to avoid a circular locking warning. I could not reproduce this warning. Furthermore, due to the asynchronous hangup the function call now gets queued up while the underlying tty is being freed. Depending on the timing this results in a NULL pointer access in the global work queue scheduler. To be precise in process_one_work(). Therefore, the previous commit made the issue worse which it tried to fix. This patch fixes this by falling back to the old behavior which uses a blocking tty hangup call before freeing up the associated tty. Fixes: 7030082a7415 ("tty: n_gsm: avoid recursive locking with async port hangup") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220218073123.2121-4-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-02tty: n_gsm: fix proper link termination after failed opendaniel.starke@siemens.com1-1/+1
commit e3b7468f082d106459e86e8dc6fb9bdd65553433 upstream. Trying to open a DLCI by sending a SABM frame may fail with a timeout. The link is closed on the initiator side without informing the responder about this event. The responder assumes the link is open after sending a UA frame to answer the SABM frame. The link gets stuck in a half open state. This patch fixes this by initiating the proper link termination procedure after link setup timeout instead of silently closing it down. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220218073123.2121-3-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-02tty: n_gsm: fix encoding of control signal octet bit DVdaniel.starke@siemens.com1-1/+1
commit 737b0ef3be6b319d6c1fd64193d1603311969326 upstream. n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010. See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516 The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to the newer 27.010 here. Chapter 5.4.6.3.7 describes the encoding of the control signal octet used by the MSC (modem status command). The same encoding is also used in convergence layer type 2 as described in chapter 5.5.2. Table 7 and 24 both require the DV (data valid) bit to be set 1 for outgoing control signal octets sent by the DTE (data terminal equipment), i.e. for the initiator side. Currently, the DV bit is only set if CD (carrier detect) is on, regardless of the side. This patch fixes this behavior by setting the DV bit on the initiator side unconditionally. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220218073123.2121-1-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-02sc16is7xx: Fix for incorrect data being transmittedPhil Elwell1-0/+3
commit eebb0f4e894f1e9577a56b337693d1051dd6ebfd upstream. UART drivers are meant to use the port spinlock within certain methods, to protect against reentrancy. The sc16is7xx driver does very little locking, presumably because when added it triggers "scheduling while atomic" errors. This is due to the use of mutexes within the regmap abstraction layer, and the mutex implementation's habit of sleeping the current thread while waiting for access. Unfortunately this lack of interlocking can lead to corruption of outbound data, which occurs when the buffer used for I2C transmission is used simultaneously by two threads - a work queue thread running sc16is7xx_tx_proc, and an IRQ thread in sc16is7xx_port_irq, both of which can call sc16is7xx_handle_tx. An earlier patch added efr_lock, a mutex that controls access to the EFR register. This mutex is already claimed in the IRQ handler, and all that is required is to claim the same mutex in sc16is7xx_tx_proc. See: https://github.com/raspberrypi/linux/issues/4885 Fixes: 6393ff1c4435 ("sc16is7xx: Use threaded IRQ") Cc: stable <stable@vger.kernel.org> Signed-off-by: Phil Elwell <phil@raspberrypi.com> Link: https://lore.kernel.org/r/20220216160802.1026013-1-phil@raspberrypi.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-23tty: n_tty: do not look ahead for EOL character past the end of the bufferLinus Torvalds1-4/+2
commit 3593030761630e09200072a4bd06468892c27be3 upstream. Daniel Gibson reports that the n_tty code gets line termination wrong in very specific cases: "If you feed a line with exactly 64 chars + terminating newline, and directly afterwards (without reading) another line into a pseudo terminal, the the first read() on the other side will return the 64 char line *without* terminating newline, and the next read() will return the missing terminating newline AND the complete next line (if it fits in the buffer)" and bisected the behavior to commit 3b830a9c34d5 ("tty: convert tty_ldisc_ops 'read()' function to take a kernel pointer"). Now, digging deeper, it turns out that the behavior isn't exactly new: what changed in commit 3b830a9c34d5 was that the tty line discipline .read() function is now passed an intermediate kernel buffer rather than the final user space buffer. And that intermediate kernel buffer is 64 bytes in size - thus that special case with exactly 64 bytes plus terminating newline. The same problem did exist before, but historically the boundary was not the 64-byte chunk, but the user-supplied buffer size, which is obviously generally bigger (and potentially bigger than N_TTY_BUF_SIZE, which would hide the issue entirely). The reason is that the n_tty canon_copy_from_read_buf() code would look ahead for the EOL character one byte further than it would actually copy. It would then decide that it had found the terminator, and unmark it as an EOL character - which in turn explains why the next read wouldn't then be terminated by it. Now, the reason it did all this in the first place is related to some historical and pretty obscure EOF behavior, see commit ac8f3bf8832a ("n_tty: Fix poll() after buffer-limited eof push read") and commit 40d5e0905a03 ("n_tty: Fix EOF push handling"). And the reason for the EOL confusion is that we treat EOF as a special EOL condition, with the EOL character being NUL (aka "__DISABLED_CHAR" in the kernel sources). So that EOF look-ahead also affects the normal EOL handling. This patch just removes the look-ahead that causes problems, because EOL is much more critical than the historical "EOF in the middle of a line that coincides with the end of the buffer" handling ever was. Now, it is possible that we should indeed re-introduce the "look at next character to see if it's a EOF" behavior, but if so, that should be done not at the kernel buffer chunk boundary in canon_copy_from_read_buf(), but at a higher level, when we run out of the user buffer. In particular, the place to do that would be at the top of 'n_tty_read()', where we check if it's a continuation of a previously started read, and there is no more buffer space left, we could decide to just eat the __DISABLED_CHAR at that point. But that would be a separate patch, because I suspect nobody actually cares, and I'd like to get a report about it before bothering. Fixes: 3b830a9c34d5 ("tty: convert tty_ldisc_ops 'read()' function to take a kernel pointer") Fixes: ac8f3bf8832a ("n_tty: Fix poll() after buffer-limited eof push read") Fixes: 40d5e0905a03 ("n_tty: Fix EOF push handling") Link: https://bugzilla.kernel.org/show_bug.cgi?id=215611 Reported-and-tested-by: Daniel Gibson <metalcaedes@gmail.com> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-23serial: parisc: GSC: fix build when IOSAPIC is not setRandy Dunlap1-1/+1
commit 6e8793674bb0d1135ca0e5c9f7e16fecbf815926 upstream. There is a build error when using a kernel .config file from 'kernel test robot' for a different build problem: hppa64-linux-ld: drivers/tty/serial/8250/8250_gsc.o: in function `.LC3': (.data.rel.ro+0x18): undefined reference to `iosapic_serial_irq' when: CONFIG_GSC=y CONFIG_SERIO_GSCPS2=y CONFIG_SERIAL_8250_GSC=y CONFIG_PCI is not set and hence PCI_LBA is not set. IOSAPIC depends on PCI_LBA, so IOSAPIC is not set/enabled. Make the use of iosapic_serial_irq() conditional to fix the build error. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: kernel test robot <lkp@intel.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: linux-parisc@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-serial@vger.kernel.org Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Johan Hovold <johan@kernel.org> Suggested-by: Helge Deller <deller@gmx.de> Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-16n_tty: wake up poll(POLLRDNORM) on receiving dataTATSUKAWA KOSUKE (立川 江介)1-2/+2
commit c816b2e65b0e86b95011418cad334f0524fc33b8 upstream. The poll man page says POLLRDNORM is equivalent to POLLIN when used as an event. $ man poll <snip> POLLRDNORM Equivalent to POLLIN. However, in n_tty driver, POLLRDNORM does not return until timeout even if there is terminal input, whereas POLLIN returns. The following test program works until kernel-3.17, but the test stops in poll() after commit 57087d515441 ("tty: Fix spurious poll() wakeups"). [Steps to run test program] $ cc -o test-pollrdnorm test-pollrdnorm.c $ ./test-pollrdnorm foo <-- Type in something from the terminal followed by [RET]. The string should be echoed back. ------------------------< test-pollrdnorm.c >------------------------ #include <stdio.h> #include <errno.h> #include <poll.h> #include <unistd.h> void main(void) { int n; unsigned char buf[8]; struct pollfd fds[1] = {{ 0, POLLRDNORM, 0 }}; n = poll(fds, 1, -1); if (n < 0) perror("poll"); n = read(0, buf, 8); if (n < 0) perror("read"); if (n > 0) write(1, buf, n); } ------------------------------------------------------------------------ The attached patch fixes this problem. Many calls to wake_up_interruptible_poll() in the kernel source code already specify "POLLIN | POLLRDNORM". Fixes: 57087d515441 ("tty: Fix spurious poll() wakeups") Cc: stable@vger.kernel.org Signed-off-by: Kosuke Tatsukawa <tatsu-ab1@nec.com> Link: https://lore.kernel.org/r/TYCPR01MB81901C0F932203D30E452B3EA5209@TYCPR01MB8190.jpnprd01.prod.outlook.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-16vt_ioctl: add array_index_nospec to VT_ACTIVATEJakob Koschel1-0/+1
commit 28cb138f559f8c1a1395f5564f86b8bbee83631b upstream. in vt_setactivate an almost identical code path has been patched with array_index_nospec. In the VT_ACTIVATE path the user input is from a system call argument instead of a usercopy. For consistency both code paths should have the same mitigations applied. Kasper Acknowledgements: Jakob Koschel, Brian Johannesmeyer, Kaveh Razavi, Herbert Bos, Cristiano Giuffrida from the VUSec group at VU Amsterdam. Co-developed-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com> Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com> Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com> Link: https://lore.kernel.org/r/20220127144406.3589293-2-jakobkoschel@gmail.com Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-16vt_ioctl: fix array_index_nospec in vt_setactivateJakob Koschel1-1/+1
commit 61cc70d9e8ef5b042d4ed87994d20100ec8896d9 upstream. array_index_nospec ensures that an out-of-bounds value is set to zero on the transient path. Decreasing the value by one afterwards causes a transient integer underflow. vsa.console should be decreased first and then sanitized with array_index_nospec. Kasper Acknowledgements: Jakob Koschel, Brian Johannesmeyer, Kaveh Razavi, Herbert Bos, Cristiano Giuffrida from the VUSec group at VU Amsterdam. Co-developed-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com> Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com> Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com> Link: https://lore.kernel.org/r/20220127144406.3589293-1-jakobkoschel@gmail.com Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-01tty: Add support for Brainboxes UC cards.Cameron Williams1-2/+98
commit 152d1afa834c84530828ee031cf07a00e0fc0b8c upstream. This commit adds support for the some of the Brainboxes PCI range of cards, including the UC-101, UC-235/246, UC-257, UC-268, UC-275/279, UC-302, UC-310, UC-313, UC-320/324, UC-346, UC-357, UC-368 and UC-420/431. Signed-off-by: Cameron Williams <cang1@live.co.uk> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/AM5PR0202MB2564688493F7DD9B9C610827C45E9@AM5PR0202MB2564.eurprd02.prod.outlook.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-01tty: n_gsm: fix SW flow control encoding/handlingdaniel.starke@siemens.com1-1/+3
commit 8838b2af23caf1ff0610caef2795d6668a013b2d upstream. n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010. See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516 The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to the newer 27.010 here. Chapter 5.2.7.3 states that DC1 (XON) and DC3 (XOFF) are the control characters defined in ISO/IEC 646. These shall be quoted if seen in the data stream to avoid interpretation as flow control characters. ISO/IEC 646 refers to the set of ISO standards described as the ISO 7-bit coded character set for information interchange. Its final version is also known as ITU T.50. See https://www.itu.int/rec/T-REC-T.50-199209-I/en To abide the standard it is needed to quote DC1 and DC3 correctly if these are seen as data bytes and not as control characters. The current implementation already tries to enforce this but fails to catch all defined cases. 3GPP 27.010 chapter 5.2.7.3 clearly states that the most significant bit shall be ignored for DC1 and DC3 handling. The current implementation handles only the case with the most significant bit set 0. Cases in which DC1 and DC3 have the most significant bit set 1 are left unhandled. This patch fixes this by masking the data bytes with ISO_IEC_646_MASK (only the 7 least significant bits set 1) before comparing them with XON (a.k.a. DC1) and XOFF (a.k.a. DC3) when testing which byte values need quotation via byte stuffing. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220120101857.2509-1-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-01serial: stm32: fix software flow control transferValentin Caron1-1/+1
commit 037b91ec7729524107982e36ec4b40f9b174f7a2 upstream. x_char is ignored by stm32_usart_start_tx() when xmit buffer is empty. Fix start_tx condition to allow x_char to be sent. Fixes: 48a6092fb41f ("serial: stm32-usart: Add STM32 USART Driver") Cc: stable <stable@vger.kernel.org> Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com> Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Link: https://lore.kernel.org/r/20220111164441.6178-3-valentin.caron@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-01serial: 8250: of: Fix mapped region size when using reg-offset propertyRobert Hancock1-1/+10
commit d06b1cf28297e27127d3da54753a3a01a2fa2f28 upstream. 8250_of supports a reg-offset property which is intended to handle cases where the device registers start at an offset inside the region of memory allocated to the device. The Xilinx 16550 UART, for which this support was initially added, requires this. However, the code did not adjust the overall size of the mapped region accordingly, causing the driver to request an area of memory past the end of the device's allocation. For example, if the UART was allocated an address of 0xb0130000, size of 0x10000 and reg-offset of 0x1000 in the device tree, the region of memory reserved was b0131000-b0140fff, which caused the driver for the region starting at b0140000 to fail to probe. Fix this by subtracting reg-offset from the mapped region size. Fixes: b912b5e2cfb3 ([POWERPC] Xilinx: of_serial support for Xilinx uart 16550.) Cc: stable <stable@vger.kernel.org> Signed-off-by: Robert Hancock <robert.hancock@calian.com> Link: https://lore.kernel.org/r/20220112194214.881844-1-robert.hancock@calian.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27serial: Fix incorrect rs485 polarity on uart openLukas Wunner1-2/+2
commit d3b3404df318504ec084213ab1065b73f49b0f1d upstream. Commit a6845e1e1b78 ("serial: core: Consider rs485 settings to drive RTS") sought to deassert RTS when opening an rs485-enabled uart port. That way, the transceiver does not occupy the bus until it transmits data. Unfortunately, the commit mixed up the logic and *asserted* RTS instead of *deasserting* it: The commit amended uart_port_dtr_rts(), which raises DTR and RTS when opening an rs232 port. "Raising" actually means lowering the signal that's coming out of the uart, because an rs232 transceiver not only changes a signal's voltage level, it also *inverts* the signal. See the simplified schematic in the MAX232 datasheet for an example: https://www.ti.com/lit/ds/symlink/max232.pdf So, to raise RTS on an rs232 port, TIOCM_RTS is *set* in port->mctrl and that results in the signal being driven low. In contrast to rs232, the signal level for rs485 Transmit Enable is the identity, not the inversion: If the transceiver expects a "high" RTS signal for Transmit Enable, the signal coming out of the uart must also be high, so TIOCM_RTS must be *cleared* in port->mctrl. The commit did the exact opposite, but it's easy to see why given the confusing semantics of rs232 and rs485. Fix it. Fixes: a6845e1e1b78 ("serial: core: Consider rs485 settings to drive RTS") Cc: stable@vger.kernel.org # v4.14+ Cc: Rafael Gago Castano <rgc@hms.se> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Su Bao Cheng <baocheng.su@siemens.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/9395767847833f2f3193c49cde38501eeb3b5669.1639821059.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27serial: core: Keep mctrl register state and cached copy in syncLukas Wunner1-1/+2
[ Upstream commit 93a770b7e16772530196674ffc79bb13fa927dc6 ] struct uart_port contains a cached copy of the Modem Control signals. It is used to skip register writes in uart_update_mctrl() if the new signal state equals the old signal state. It also avoids a register read to obtain the current state of output signals. When a uart_port is registered, uart_configure_port() changes signal state but neglects to keep the cached copy in sync. That may cause a subsequent register write to be incorrectly skipped. Fix it before it trips somebody up. This behavior has been present ever since the serial core was introduced in 2002: https://git.kernel.org/history/history/c/33c0d1b0c3eb So far it was never an issue because the cached copy is initialized to 0 by kzalloc() and when uart_configure_port() is executed, at most DTR has been set by uart_set_options() or sunsu_console_setup(). Therefore, a stable designation seems unnecessary. Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/bceeaba030b028ed810272d55d5fc6f3656ddddb.1641129752.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27serial: pl010: Drop CR register reset on set_termiosLukas Wunner1-3/+0
[ Upstream commit 08a0c6dff91c965e39905cf200d22db989203ccb ] pl010_set_termios() briefly resets the CR register to zero. Where does this register write come from? The PL010 driver's IRQ handler ambauart_int() originally modified the CR register without holding the port spinlock. ambauart_set_termios() also modified that register. To prevent concurrent read-modify-writes by the IRQ handler and to prevent transmission while changing baudrate, ambauart_set_termios() had to disable interrupts. That is achieved by writing zero to the CR register. However in 2004 the PL010 driver was amended to acquire the port spinlock in the IRQ handler, obviating the need to disable interrupts in ->set_termios(): https://git.kernel.org/history/history/c/157c0342e591 That rendered the CR register write obsolete. Drop it. Cc: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/fcaff16e5b1abb4cc3da5a2879ac13f278b99ed0.1641128728.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27tty: serial: imx: disable UCR4_OREN in .stop_rx() instead of .shutdown()Fugang Duan1-2/+5
[ Upstream commit 028e083832b06fdeeb290e1e57dc1f6702c4c215 ] The UCR4_OREN should be disabled before disabling the uart receiver in .stop_rx() instead of in the .shutdown(). Otherwise, if we have the overrun error during the receiver disable process, the overrun interrupt will keep trigging until we disable the OREN interrupt in the .shutdown(), because the ORE status can only be cleared when read the rx FIFO or reset the controller. Although the called time between the receiver disable and OREN disable in .shutdown() is very short, there is still the risk of endless interrupt during this short period of time. So here change to disable OREN before the receiver been disabled in .stop_rx(). Signed-off-by: Fugang Duan <fugang.duan@nxp.com> Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20211125020349.4980-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27serial: amba-pl011: do not request memory region twiceLino Sanfilippo1-24/+3
[ Upstream commit d1180405c7b5c7a1c6bde79d5fc24fe931430737 ] With commit 3873e2d7f63a ("drivers: PL011: refactor pl011_probe()") the function devm_ioremap() called from pl011_setup_port() was replaced with devm_ioremap_resource(). Since this function not only remaps but also requests the ports io memory region it now collides with the .config_port() callback which requests the same region at uart port registration. Since devm_ioremap_resource() already claims the memory successfully, the request in .config_port() fails. Later at uart port deregistration the attempt to release the unclaimed memory also fails. The failure results in a “Trying to free nonexistent resource" warning. Fix these issues by removing the callbacks that implement the redundant memory allocation/release. Also make sure that changing the drivers io memory base address via TIOCSSERIAL is not allowed any more. Fixes: 3873e2d7f63a ("drivers: PL011: refactor pl011_probe()") Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Link: https://lore.kernel.org/r/20211129174238.8333-1-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27tty: serial: uartlite: allow 64 bit addressLizhi Hou1-1/+1
[ Upstream commit 3672fb65155530b5eea6225685c75329b6debec3 ] The base address of uartlite registers could be 64 bit address which is from device resource. When ulite_probe() calls ulite_assign(), this 64 bit address is casted to 32-bit. The fix is to replace "u32" type with "phys_addr_t" type for the base address in ulite_assign() argument list. Fixes: 8fa7b6100693 ("[POWERPC] Uartlite: Separate the bus binding from the driver proper") Signed-off-by: Lizhi Hou <lizhi.hou@xilinx.com> Link: https://lore.kernel.org/r/20211129202302.1319033-1-lizhi.hou@xilinx.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27tty: serial: atmel: Call dma_async_issue_pending()Tudor Ambarus1-0/+4
[ Upstream commit 4f4b9b5895614eb2e2b5f4cab7858f44bd113e1b ] The driver wrongly assummed that tx_submit() will start the transfer, which is not the case, now that the at_xdmac driver is fixed. tx_submit is supposed to push the current transaction descriptor to a pending queue, waiting for issue_pending to be called. issue_pending must start the transfer, not tx_submit. Fixes: 34df42f59a60 ("serial: at91: add rx dma support") Fixes: 08f738be88bb ("serial: at91: add tx dma support") Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com> Link: https://lore.kernel.org/r/20211125090028.786832-4-tudor.ambarus@microchip.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27tty: serial: atmel: Check return code of dmaengine_submit()Tudor Ambarus1-0/+10
[ Upstream commit 1e67bd2b8cb90b66e89562598e9c2046246832d3 ] The tx_submit() method of struct dma_async_tx_descriptor is entitled to do sanity checks and return errors if encountered. It's not the case for the DMA controller drivers that this client is using (at_h/xdmac), because they currently don't do sanity checks and always return a positive cookie at tx_submit() method. In case the controller drivers will implement sanity checks and return errors, print a message so that the client will be informed that something went wrong at tx_submit() level. Fixes: 08f738be88bb ("serial: at91: add tx dma support") Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com> Acked-by: Richard Genoud <richard.genoud@gmail.com> Link: https://lore.kernel.org/r/20211125090028.786832-3-tudor.ambarus@microchip.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-22xen/console: harden hvc_xen against event channel stormsJuergen Gross1-3/+27
commit fe415186b43df0db1f17fa3a46275fd92107fe71 upstream. The Xen console driver is still vulnerable for an attack via excessive number of events sent by the backend. Fix that by using a lateeoi event channel. For the normal domU initial console this requires the introduction of bind_evtchn_to_irq_lateeoi() as there is no xenbus device available at the time the event channel is bound to the irq. As the decision whether an interrupt was spurious or not requires to test for bytes having been read from the backend, move sending the event into the if statement, as sending an event without having found any bytes to be read is making no sense at all. This is part of XSA-391 Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-22serial: 8250_fintek: Fix garbled text for consoleJi-Ze Hong (Peter Hong)1-20/+0
commit 6c33ff728812aa18792afffaf2c9873b898e7512 upstream. Commit fab8a02b73eb ("serial: 8250_fintek: Enable high speed mode on Fintek F81866") introduced support to use high baudrate with Fintek SuperIO UARTs. It'll change clocksources when the UART probed. But when user add kernel parameter "console=ttyS0,115200 console=tty0" to make the UART as console output, the console will output garbled text after the following kernel message. [ 3.681188] Serial: 8250/16550 driver, 32 ports, IRQ sharing enabled The issue is occurs in following step: probe_setup_port() -> fintek_8250_goto_highspeed() It change clocksource from 115200 to 921600 with wrong time, it should change clocksource in set_termios() not in probed. The following 3 patches are implemented change clocksource in fintek_8250_set_termios(). Commit 58178914ae5b ("serial: 8250_fintek: UART dynamic clocksource on Fintek F81216H") Commit 195638b6d44f ("serial: 8250_fintek: UART dynamic clocksource on Fintek F81866") Commit 423d9118c624 ("serial: 8250_fintek: Add F81966 Support") Due to the high baud rate had implemented above 3 patches and the patch Commit fab8a02b73eb ("serial: 8250_fintek: Enable high speed mode on Fintek F81866") is bugged, So this patch will remove it. Fixes: fab8a02b73eb ("serial: 8250_fintek: Enable high speed mode on Fintek F81866") Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com> Link: https://lore.kernel.org/r/20211215075835.2072-1-hpeter+linux_kernel@gmail.com Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-22tty: n_hdlc: make n_hdlc_tty_wakeup() asynchronousTetsuo Handa1-1/+22
commit 1ee33b1ca2b8dabfcc17198ffd049a6b55674a86 upstream. syzbot is reporting that an unprivileged user who logged in from tty console can crash the system using a reproducer shown below [1], for n_hdlc_tty_wakeup() is synchronously calling n_hdlc_send_frames(). ---------- #include <sys/ioctl.h> #include <unistd.h> int main(int argc, char *argv[]) { const int disc = 0xd; ioctl(1, TIOCSETD, &disc); while (1) { ioctl(1, TCXONC, 0); write(1, "", 1); ioctl(1, TCXONC, 1); /* Kernel panic - not syncing: scheduling while atomic */ } } ---------- Linus suspected that "struct tty_ldisc"->ops->write_wakeup() must not sleep, and Jiri confirmed it from include/linux/tty_ldisc.h. Thus, defer n_hdlc_send_frames() from n_hdlc_tty_wakeup() to a WQ context like net/nfc/nci/uart.c does. Link: https://syzkaller.appspot.com/bug?extid=5f47a8cea6a12b77a876 [1] Reported-by: syzbot <syzbot+5f47a8cea6a12b77a876@syzkaller.appspotmail.com> Cc: stable <stable@vger.kernel.org> Analyzed-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Confirmed-by: Jiri Slaby <jirislaby@kernel.org> Reviewed-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Link: https://lore.kernel.org/r/40de8b7e-a3be-4486-4e33-1b1d1da452f8@i-love.sakura.ne.jp Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-17Revert "tty: serial: fsl_lpuart: drop earlycon entry for i.MX8QXP"Alexander Stein1-0/+1
[ Upstream commit 4e9679738a918d8a482ac6a2cb2bb871f094bb84 ] Revert commit b4b844930f27 ("tty: serial: fsl_lpuart: drop earlycon entry for i.MX8QXP"), because this breaks earlycon support on imx8qm/imx8qxp. While it is true that for earlycon there is no difference between i.MX8QXP and i.MX7ULP (for now at least), there are differences regarding clocks and fixups for wakeup support. For that reason it was deemed unacceptable to add the imx7ulp compatible to device tree in order to get earlycon working again. Reviewed-by: Peng Fan <peng.fan@nxp.com> Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com> Link: https://lore.kernel.org/r/20211124073109.805088-1-alexander.stein@ew.tq-group.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-08serial: 8250: Fix RTS modem control while in rs485 modeLukas Wunner2-7/+5
commit f85e04503f369b3f2be28c83fc48b74e19936ebc upstream. Commit f45709df7731 ("serial: 8250: Don't touch RTS modem control while in rs485 mode") sought to prevent user space from interfering with rs485 communication by ignoring a TIOCMSET ioctl() which changes RTS polarity. It did so in serial8250_do_set_mctrl(), which turns out to be too deep in the call stack: When a uart_port is opened, RTS polarity is set by the rs485-aware function uart_port_dtr_rts(). It calls down to serial8250_do_set_mctrl() and that particular RTS polarity change should *not* be ignored. The user-visible result is that on 8250_omap ports which use rs485 with inverse polarity (RTS bit in MCR register is 1 to receive, 0 to send), a newly opened port initially sets up RTS for sending instead of receiving. That's because omap_8250_startup() sets the cached value up->mcr to 0 and omap_8250_restore_regs() subsequently writes it to the MCR register. Due to the commit, serial8250_do_set_mctrl() preserves that incorrect register value: do_sys_openat2 do_filp_open path_openat vfs_open do_dentry_open chrdev_open tty_open uart_open tty_port_open uart_port_activate uart_startup uart_port_startup serial8250_startup omap_8250_startup # up->mcr = 0 uart_change_speed serial8250_set_termios omap_8250_set_termios omap_8250_restore_regs serial8250_out_MCR # up->mcr written tty_port_block_til_ready uart_dtr_rts uart_port_dtr_rts serial8250_set_mctrl omap8250_set_mctrl serial8250_do_set_mctrl # mcr[1] = 1 ignored Fix by intercepting RTS changes from user space in uart_tiocmset() instead. Link: https://lore.kernel.org/linux-serial/20211027111644.1996921-1-baocheng.su@siemens.com/ Fixes: f45709df7731 ("serial: 8250: Don't touch RTS modem control while in rs485 mode") Cc: Chao Zeng <chao.zeng@siemens.com> Cc: stable@vger.kernel.org # v5.7+ Reported-by: Su Bao Cheng <baocheng.su@siemens.com> Reported-by: Jan Kiszka <jan.kiszka@siemens.com> Tested-by: Su Bao Cheng <baocheng.su@siemens.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/21170e622a1aaf842a50b32146008b5374b3dd1d.1637596432.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08serial: 8250_pci: rewrite pericom_do_set_divisor()Jay Dolan1-13/+17
commit bb1201d4b38ec67bd9a871cf86b0cc10f28b15b5 upstream. Have pericom_do_set_divisor() use the uartclk instead of a hard coded value to work with different speed crystals. Tested with 14.7456 and 24 MHz crystals. Have pericom_do_set_divisor() always calculate the divisor rather than call serial8250_do_set_divisor() for rates below baud_base. Do not write registers or call serial8250_do_set_divisor() if valid divisors could not be found. Fixes: 6bf4e42f1d19 ("serial: 8250: Add support for higher baud rates to Pericom chips") Cc: stable <stable@vger.kernel.org> Signed-off-by: Jay Dolan <jay.dolan@accesio.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20211122120604.3909-3-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08serial: 8250_pci: Fix ACCES entries in pci_serial_quirks arrayJay Dolan1-1/+8
commit c525c5d2437f93520388920baac6d9340c65d239 upstream. Fix error in table for PCI_DEVICE_ID_ACCESIO_PCIE_ICM_4S that caused it and PCI_DEVICE_ID_ACCESIO_PCIE_ICM232_4 to be missing their fourth port. Fixes: 78d3820b9bd3 ("serial: 8250_pci: Have ACCES cards that use the four port Pericom PI7C9X7954 chip use the pci_pericom_setup()") Cc: stable <stable@vger.kernel.org> Signed-off-by: Jay Dolan <jay.dolan@accesio.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20211122120604.3909-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08serial: core: fix transmit-buffer reset and memleakJohan Hovold1-1/+12
commit 00de977f9e0aa9760d9a79d1e41ff780f74e3424 upstream. Commit 761ed4a94582 ("tty: serial_core: convert uart_close to use tty_port_close") converted serial core to use tty_port_close() but failed to notice that the transmit buffer still needs to be freed on final close. Not freeing the transmit buffer means that the buffer is no longer cleared on next open so that any ioctl() waiting for the buffer to drain might wait indefinitely (e.g. on termios changes) or that stale data can end up being transmitted in case tx is restarted. Furthermore, the buffer of any port that has been opened would leak on driver unbind. Note that the port lock is held when clearing the buffer pointer due to the ldisc race worked around by commit a5ba1d95e46e ("uart: fix race between uart_put_char() and uart_shutdown()"). Also note that the tty-port shutdown() callback is not called for console ports so it is not strictly necessary to free the buffer page after releasing the lock (cf. d72402145ace ("tty/serial: do not free trasnmit buffer page under port lock")). Link: https://lore.kernel.org/r/319321886d97c456203d5c6a576a5480d07c3478.1635781688.git.baruch@tkos.co.il Fixes: 761ed4a94582 ("tty: serial_core: convert uart_close to use tty_port_close") Cc: stable@vger.kernel.org # 4.9 Cc: Rob Herring <robh@kernel.org> Reported-by: Baruch Siach <baruch@tkos.co.il> Tested-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20211108085431.12637-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08serial: tegra: Change lower tolerance baud rate limit for tegra20 and tegra30Patrik John1-2/+2
commit b40de7469ef135161c80af0e8c462298cc5dac00 upstream. The current implementation uses 0 as lower limit for the baud rate tolerance for tegra20 and tegra30 chips which causes isses on UART initialization as soon as baud rate clock is lower than required even when within the standard UART tolerance of +/- 4%. This fix aligns the implementation with the initial commit description of +/- 4% tolerance for tegra chips other than tegra186 and tegra194. Fixes: d781ec21bae6 ("serial: tegra: report clk rate errors") Cc: stable <stable@vger.kernel.org> Signed-off-by: Patrik John <patrik.john@u-blox.com> Link: https://lore.kernel.org/r/sig.19614244f8.20211123132737.88341-1-patrik.john@u-blox.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08serial: pl011: Add ACPI SBSA UART match idPierre Gondois1-0/+1
commit ac442a077acf9a6bf1db4320ec0c3f303be092b3 upstream. The document 'ACPI for Arm Components 1.0' defines the following _HID mappings: -'Prime cell UART (PL011)': ARMH0011 -'SBSA UART': ARMHB000 Use the sbsa-uart driver when a device is described with the 'ARMHB000' _HID. Note: PL011 devices currently use the sbsa-uart driver instead of the uart-pl011 driver. Indeed, PL011 devices are not bound to a clock in ACPI. It is not possible to change their baudrate. Cc: <stable@vger.kernel.org> Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com> Link: https://lore.kernel.org/r/20211109172248.19061-1-Pierre.Gondois@arm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08tty: serial: msm_serial: Deactivate RX DMA for polling supportSven Eckelmann1-0/+3
commit 7492ffc90fa126afb67d4392d56cb4134780194a upstream. The CONSOLE_POLLING mode is used for tools like k(g)db. In this kind of setup, it is often sharing a serial device with the normal system console. This is usually no problem because the polling helpers can consume input values directly (when in kgdb context) and the normal Linux handlers can only consume new input values after kgdb switched back. This is not true anymore when RX DMA is enabled for UARTDM controllers. Single input values can no longer be received correctly. Instead following seems to happen: * on 1. input, some old input is read (continuously) * on 2. input, two old inputs are read (continuously) * on 3. input, three old input values are read (continuously) * on 4. input, 4 previous inputs are received This repeats then for each group of 4 input values. This behavior changes slightly depending on what state the controller was when the first input was received. But this makes working with kgdb basically impossible because control messages are always corrupted when kgdboc tries to parse them. RX DMA should therefore be off when CONSOLE_POLLING is enabled to avoid these kind of problems. No such problem was noticed for TX DMA. Fixes: 99693945013a ("tty: serial: msm: Add RX DMA support") Cc: stable@vger.kernel.org Signed-off-by: Sven Eckelmann <sven@narfation.org> Link: https://lore.kernel.org/r/20211113121050.7266-1-sven@narfation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-01tty: hvc: replace BUG_ON() with negative return valueJuergen Gross1-3/+14
commit e679004dec37566f658a255157d3aed9d762a2b7 upstream. Xen frontends shouldn't BUG() in case of illegal data received from their backends. So replace the BUG_ON()s when reading illegal data from the ring page with negative return values. Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20210707091045.460-1-jgross@suse.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-26tty: tty_buffer: Fix the softlockup issue in flush_to_ldiscGuanghui Feng1-0/+3
[ Upstream commit 3968ddcf05fb4b9409cd1859feb06a5b0550a1c1 ] When running ltp testcase(ltp/testcases/kernel/pty/pty04.c) with arm64, there is a soft lockup, which look like this one: Workqueue: events_unbound flush_to_ldisc Call trace: dump_backtrace+0x0/0x1ec show_stack+0x24/0x30 dump_stack+0xd0/0x128 panic+0x15c/0x374 watchdog_timer_fn+0x2b8/0x304 __run_hrtimer+0x88/0x2c0 __hrtimer_run_queues+0xa4/0x120 hrtimer_interrupt+0xfc/0x270 arch_timer_handler_phys+0x40/0x50 handle_percpu_devid_irq+0x94/0x220 __handle_domain_irq+0x88/0xf0 gic_handle_irq+0x84/0xfc el1_irq+0xc8/0x180 slip_unesc+0x80/0x214 [slip] tty_ldisc_receive_buf+0x64/0x80 tty_port_default_receive_buf+0x50/0x90 flush_to_ldisc+0xbc/0x110 process_one_work+0x1d4/0x4b0 worker_thread+0x180/0x430 kthread+0x11c/0x120 In the testcase pty04, The first process call the write syscall to send data to the pty master. At the same time, the workqueue will do the flush_to_ldisc to pop data in a loop until there is no more data left. When the sender and workqueue running in different core, the sender sends data fastly in full time which will result in workqueue doing work in loop for a long time and occuring softlockup in flush_to_ldisc with kernel configured without preempt. So I add need_resched check and cond_resched in the flush_to_ldisc loop to avoid it. Signed-off-by: Guanghui Feng <guanghuifeng@linux.alibaba.com> Link: https://lore.kernel.org/r/1633961304-24759-1-git-send-email-guanghuifeng@linux.alibaba.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18serial: xilinx_uartps: Fix race condition causing stuck TXAnssi Hannula1-1/+2