aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/tty/tty_buffer.c
Commit message (Collapse)AuthorAgeFilesLines
* tty: Don't include tty_buffer.h in tty.hIlpo Järvinen2024-02-181-0/+1
| | | | | | | | | There's no need to include linux/tty_buffer.h in linux/tty.h. Move the include into tty_buffer.c that is actually using it. Signed-off-by: Ilpo Järvinen <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: tty_buffer: use bool for 'restart' in tty_buffer_unlock_exclusive()Jiri Slaby (SUSE)2023-10-031-3/+2
| | | | | | | | It's a boolean value, so no need for 'int' there. Signed-off-by: "Jiri Slaby (SUSE)" <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: tty_buffer: invert conditions in __tty_buffer_request_room()Jiri Slaby (SUSE)2023-08-221-22/+22
| | | | | | | | | | | We are used to handle "bad" states in the 'if's in the kernel. Refactor (invert the two conditions in) __tty_buffer_request_room(), so that the code returns from the fast paths immediately instead of postponing to the heavy end of the function. Signed-off-by: "Jiri Slaby (SUSE)" <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: tty_buffer: initialize variables in initializers alreadyJiri Slaby (SUSE)2023-08-221-10/+3
| | | | | | | | It makes the code both more compact, and more understandable. Signed-off-by: "Jiri Slaby (SUSE)" <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: tty_buffer: better types in __tty_buffer_request_room()Jiri Slaby (SUSE)2023-08-221-1/+2
| | | | | | | | | | * use bool for 'change' as it holds a result of a boolean. * use size_t for 'left', so it is the same as 'size' which it is compared to. Both are supposed to contain an unsigned value. Signed-off-by: "Jiri Slaby (SUSE)" <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: tty_buffer: use __tty_insert_flip_string_flags() in tty_insert_flip_char()Jiri Slaby (SUSE)2023-08-221-26/+0
| | | | | | | | | | | | Use __tty_insert_flip_string_flags() for the slow path of tty_insert_flip_char(). The former is generic enough, so there is no reason to reimplement the injection once again. So now we have a single function stuffing into tty buffers. Signed-off-by: "Jiri Slaby (SUSE)" <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: tty_buffer: let tty_prepare_flip_string() return size_tJiri Slaby (SUSE)2023-08-221-2/+3
| | | | | | | | | | | | | | The same as in the previous patch, tty_prepare_flip_string() accepts size_t as an size argument. It returns the same size (or less). It is unexpected that it returns a signed value and can confuse users to check for negative values. Instead, return the same size_t as accepted to make clear we return values >= 0, where zero in fact means failure. Signed-off-by: "Jiri Slaby (SUSE)" <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: tty_buffer: switch insert functions to size_tJiri Slaby (SUSE)2023-08-221-6/+6
| | | | | | | | | | | | | All the functions accept size_t as a size argument. They finally return the same size (or less). It is quite unexpected that they return a signed value and can confuse users to check for negative values. Instead, return the same size_t as accepted to make clear we return values >= 0, where zero in fact means failure. Signed-off-by: "Jiri Slaby (SUSE)" <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: tty_buffer: warn if losing flags in __tty_insert_flip_string_flags()Jiri Slaby (SUSE)2023-08-221-0/+3
| | | | | | | | | And add a WARN_ON_ONCE(need_flags) to make sure we are not losing flags in __tty_insert_flip_string_flags(). Signed-off-by: "Jiri Slaby (SUSE)" <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: tty_buffer: unify tty_insert_flip_string_{fixed_flag,flags}()Jiri Slaby (SUSE)2023-08-221-55/+15
| | | | | | | | | | They both do the same except for flags. One mem-copies the flags from the caller, the other mem-sets to one flag given by the caller. This can be unified with a simple if in the unified function. Signed-off-by: "Jiri Slaby (SUSE)" <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: tty_buffer: use struct_size() in tty_buffer_alloc()Jiri Slaby (SUSE)2023-08-221-2/+1
| | | | | | | | | | Now, that tty_buffer::data has the right type, use struct_size() for size calculation. struct_size() makes the code less error-prone and more readable. Signed-off-by: "Jiri Slaby (SUSE)" <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: use u8 for flagsJiri Slaby (SUSE)2023-08-111-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This makes all those 'char's an explicit 'u8'. This is part of the continuing unification of chars and flags to be consistent u8. This approaches tty_port_default_receive_buf(). Note that we do not change signedness as we compile with -funsigned-char. Signed-off-by: "Jiri Slaby (SUSE)" <[email protected]> Cc: William Hubbs <[email protected]> Cc: Chris Brannon <[email protected]> Cc: Kirk Reiser <[email protected]> Cc: Samuel Thibault <[email protected]> Cc: Marcel Holtmann <[email protected]> Cc: Johan Hedberg <[email protected]> Cc: Luiz Augusto von Dentz <[email protected]> Cc: Dmitry Torokhov <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Eric Dumazet <[email protected]> Cc: Jakub Kicinski <[email protected]> Cc: Paolo Abeni <[email protected]> Cc: Max Staudt <[email protected]> Cc: Wolfgang Grandegger <[email protected]> Cc: Marc Kleine-Budde <[email protected]> Cc: Dario Binacchi <[email protected]> Cc: Andreas Koensgen <[email protected]> Cc: Jeremy Kerr <[email protected]> Cc: Matt Johnston <[email protected]> Cc: Krzysztof Kozlowski <[email protected]> Cc: Liam Girdwood <[email protected]> Cc: Mark Brown <[email protected]> Cc: Jaroslav Kysela <[email protected]> Cc: Takashi Iwai <[email protected]> Acked-by: Mark Brown <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: use u8 for charsJiri Slaby (SUSE)2023-08-111-11/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This makes all those 'unsigned char's an explicit 'u8'. This is part of the continuing unification of chars and flags to be consistent u8. This approaches tty_port_default_receive_buf(). Flags to be next. Signed-off-by: "Jiri Slaby (SUSE)" <[email protected]> Cc: William Hubbs <[email protected]> Cc: Chris Brannon <[email protected]> Cc: Kirk Reiser <[email protected]> Cc: Samuel Thibault <[email protected]> Cc: Dmitry Torokhov <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Max Staudt <[email protected]> Cc: Wolfgang Grandegger <[email protected]> Cc: Marc Kleine-Budde <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Eric Dumazet <[email protected]> Cc: Jakub Kicinski <[email protected]> Cc: Paolo Abeni <[email protected]> Cc: Dario Binacchi <[email protected]> Cc: Andreas Koensgen <[email protected]> Cc: Jeremy Kerr <[email protected]> Cc: Matt Johnston <[email protected]> Cc: Liam Girdwood <[email protected]> Cc: Mark Brown <[email protected]> Cc: Jaroslav Kysela <[email protected]> Cc: Takashi Iwai <[email protected]> Cc: Peter Ujfalusi <[email protected]> Acked-by: Mark Brown <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: switch count in tty_ldisc_receive_buf() to size_tJiri Slaby (SUSE)2023-08-111-3/+3
| | | | | | | | | | | | | | | It comes from both paste_selection() and tty_port_default_receive_buf() as unsigned (int and size_t respectively). Switch to size_t to converge to that eventually. Return the count as size_t too (the two callers above expect that). Switch paste_selection()'s type of 'count' too, so that the returned and passed type match. Signed-off-by: "Jiri Slaby (SUSE)" <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: switch receive_buf() counts to size_tJiri Slaby (SUSE)2023-08-111-4/+4
| | | | | | | | | | | | 'size_t' is what receive_buf() expects and returns while handling count. So switch to 'size_t'. This renders both local 'count' and 'rcvd' in flush_to_ldisc() to be size_t too. Signed-off-by: "Jiri Slaby (SUSE)" <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: make tty_port_client_operations operate with u8Jiri Slaby (SUSE)2023-08-111-2/+2
| | | | | | | | | | The parameters are already unsigned chars. So make them explicitly u8s, as the rest is going to be unified to u8 eventually too. Signed-off-by: "Jiri Slaby (SUSE)" <[email protected]> Cc: Rob Herring <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: Convert tty_buffer flags to boolIlpo Järvinen2022-11-091-14/+14
| | | | | | | | | | | | | | | | | The struct tty_buffer has flags which is only used for storing TTYB_NORMAL. There is also a few quite confusing operations for checking the presense of TTYB_NORMAL. Simplify things by converting flags to bool. Despite the name remaining the same, the meaning of "flags" is altered slightly by this change. Previously it referred to flags of the buffer (only TTYB_NORMAL being used as a flag). After this change, flags tell whether the buffer contains/should be allocated with flags array along with character data array. It is much more suitable name that TTYB_NORMAL was for this purpose, thus the name remains. Signed-off-by: Ilpo Järvinen <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: Cleanup tty buffer align maskIlpo Järvinen2022-11-031-2/+2
| | | | | | | | Don't use decimal for mask. Don't use literal for aligning. Signed-off-by: Ilpo Järvinen <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: Fix lookahead_buf crash with serdevVincent Whitchurch2022-08-301-5/+9
| | | | | | | | | | | | | Do not follow a NULL pointer if the tty_port_client_operations does not implement the ->lookahead_buf() callback, which is the case with serdev's ttyport. Reported-by: Hans de Goede <[email protected]> Fixes: 6bb6fa6908ebd3 ("tty: Implement lookahead to process XON/XOFF timely") Reviewed-by: Ilpo Järvinen <[email protected]> Signed-off-by: Vincent Whitchurch <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* Merge tag 'tty-6.0-rc1' of ↵Linus Torvalds2022-08-081-9/+50
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty / serial driver updates from Greg KH: "Here is the big set of tty and serial driver changes for 6.0-rc1. It was delayed from last week as I wanted to make sure the last commit here got some good testing in linux-next and elsewhere as it seemed to show up only late in testing for some reason. Nothing major here, just lots of cleanups from Jiri and Ilpo to make the tty core cleaner (Jiri) and the rs485 code simpler to use (Ilpo). Also included in here is the obligatory n_gsm updates from Daniel Starke and lots of tiny driver updates and minor fixes and tweaks for other smaller serial drivers. All of these have been in linux-next for a while with no reported problems" * tag 'tty-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (186 commits) tty: serial: qcom-geni-serial: Fix %lu -> %u in print statements tty: amiserial: Fix comment typo tty: serial: document uart_get_console() tty: serial: serial_core, reformat kernel-doc for functions Documentation: serial: link uart_ops properly Documentation: serial: move GPIO kernel-doc to the functions Documentation: serial: dedup kernel-doc for uart functions Documentation: serial: move uart_ops documentation to the struct dt-bindings: serial: snps-dw-apb-uart: Document Rockchip RV1126 serial: mvebu-uart: uart2 error bits clearing tty: serial: fsl_lpuart: correct the count of break characters serial: stm32: make info structs static to avoid sparse warnings serial: fsl_lpuart: zero out parity bit in CS7 mode tty: serial: qcom-geni-serial: Fix get_clk_div_rate() which otherwise could return a sub-optimal clock rate. serial: 8250_bcm2835aux: Add missing clk_disable_unprepare() tty: vt: initialize unicode screen buffer serial: remove VR41XX serial driver serial: 8250: lpc18xx: Remove redundant sanity check for RS485 flags serial: 8250_dwlib: remove redundant sanity check for RS485 flags dt_bindings: rs485: Correct delay values ...
| * tty: Implement lookahead to process XON/XOFF timelyIlpo Järvinen2022-06-101-9/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When tty is not read from, XON/XOFF may get stuck into an intermediate buffer. As those characters are there to do software flow-control, it is not very useful. In the case where neither end reads from ttys, the receiving ends might not be able receive the XOFF characters and just keep sending more data to the opposite direction. This problem is almost guaranteed to occur with DMA which sends data in large chunks. If TTY is slow to process characters, that is, eats less than given amount in receive_buf, invoke lookahead for the rest of the chars to process potential XON/XOFF characters. We need to keep track of how many characters have been processed by the lookahead to avoid processing the flow control char again on the normal path. Bookkeeping occurs parallel on two layers (tty_buffer and n_tty) to avoid passing the lookahead_count through the whole call chain. When a flow-control char is processed, two things must occur: a) it must not be treated as normal char b) if not yet processed, flow-control actions need to be taken The return value of n_tty_receive_char_flow_ctrl() tells caller a), and b) is kept internal to n_tty_receive_char_flow_ctrl(). If characters were previous looked ahead, __receive_buf() makes two calls to the appropriate n_tty_receive_buf_* function. First call is made with lookahead_done=true for the characters that were subject to lookahead earlier and then with lookahead=false for the new characters. Either of the calls might be skipped when it has no characters to handle. Reported-by: Gilles Buloz <[email protected]> Reviewed-by: Andy Shevchenko <[email protected]> Signed-off-by: Ilpo Järvinen <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* | tty: use new tty_insert_flip_string_and_push_buffer() in pty_write()Jiri Slaby2022-07-081-0/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a race in pty_write(). pty_write() can be called in parallel with e.g. ioctl(TIOCSTI) or ioctl(TCXONC) which also inserts chars to the buffer. Provided, tty_flip_buffer_push() in pty_write() is called outside the lock, it can commit inconsistent tail. This can lead to out of bounds writes and other issues. See the Link below. To fix this, we have to introduce a new helper called tty_insert_flip_string_and_push_buffer(). It does both tty_insert_flip_string() and tty_flip_buffer_commit() under the port lock. It also calls queue_work(), but outside the lock. See 71a174b39f10 (pty: do tty_flip_buffer_push without port->lock in pty_write) for the reasons. Keep the helper internal-only (in drivers' tty.h). It is not intended to be used widely. Link: https://seclists.org/oss-sec/2022/q2/155 Fixes: 71a174b39f10 (pty: do tty_flip_buffer_push without port->lock in pty_write) Cc: 一只狗 <[email protected]> Cc: Dan Carpenter <[email protected]> Suggested-by: Hillf Danton <[email protected]> Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* | tty: extract tty_flip_buffer_commit() from tty_flip_buffer_push()Jiri Slaby2022-07-081-5/+10
|/ | | | | | | | | | | We will need this new helper in the next patch. Cc: Hillf Danton <[email protected]> Cc: 一只狗 <[email protected]> Cc: Dan Carpenter <[email protected]> Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: fix deadlock caused by calling printk() under tty_port->lockQi Zheng2022-05-131-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pty_write() invokes kmalloc() which may invoke a normal printk() to print failure message. This can cause a deadlock in the scenario reported by syz-bot below: CPU0 CPU1 CPU2 ---- ---- ---- lock(console_owner); lock(&port_lock_key); lock(&port->lock); lock(&port_lock_key); lock(&port->lock); lock(console_owner); As commit dbdda842fe96 ("printk: Add console owner and waiter logic to load balance console writes") said, such deadlock can be prevented by using printk_deferred() in kmalloc() (which is invoked in the section guarded by the port->lock). But there are too many printk() on the kmalloc() path, and kmalloc() can be called from anywhere, so changing printk() to printk_deferred() is too complicated and inelegant. Therefore, this patch chooses to specify __GFP_NOWARN to kmalloc(), so that printk() will not be called, and this deadlock problem can be avoided. Syzbot reported the following lockdep error: ====================================================== WARNING: possible circular locking dependency detected 5.4.143-00237-g08ccc19a-dirty #10 Not tainted ------------------------------------------------------ syz-executor.4/29420 is trying to acquire lock: ffffffff8aedb2a0 (console_owner){....}-{0:0}, at: console_trylock_spinning kernel/printk/printk.c:1752 [inline] ffffffff8aedb2a0 (console_owner){....}-{0:0}, at: vprintk_emit+0x2ca/0x470 kernel/printk/printk.c:2023 but task is already holding lock: ffff8880119c9158 (&port->lock){-.-.}-{2:2}, at: pty_write+0xf4/0x1f0 drivers/tty/pty.c:120 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&port->lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x35/0x50 kernel/locking/spinlock.c:159 tty_port_tty_get drivers/tty/tty_port.c:288 [inline] <-- lock(&port->lock); tty_port_default_wakeup+0x1d/0xb0 drivers/tty/tty_port.c:47 serial8250_tx_chars+0x530/0xa80 drivers/tty/serial/8250/8250_port.c:1767 serial8250_handle_irq.part.0+0x31f/0x3d0 drivers/tty/serial/8250/8250_port.c:1854 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1827 [inline] <-- lock(&port_lock_key); serial8250_default_handle_irq+0xb2/0x220 drivers/tty/serial/8250/8250_port.c:1870 serial8250_interrupt+0xfd/0x200 drivers/tty/serial/8250/8250_core.c:126 __handle_irq_event_percpu+0x109/0xa50 kernel/irq/handle.c:156 [...] -> #1 (&port_lock_key){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x35/0x50 kernel/locking/spinlock.c:159 serial8250_console_write+0x184/0xa40 drivers/tty/serial/8250/8250_port.c:3198 <-- lock(&port_lock_key); call_console_drivers kernel/printk/printk.c:1819 [inline] console_unlock+0x8cb/0xd00 kernel/printk/printk.c:2504 vprintk_emit+0x1b5/0x470 kernel/printk/printk.c:2024 <-- lock(console_owner); vprintk_func+0x8d/0x250 kernel/printk/printk_safe.c:394 printk+0xba/0xed kernel/printk/printk.c:2084 register_console+0x8b3/0xc10 kernel/printk/printk.c:2829 univ8250_console_init+0x3a/0x46 drivers/tty/serial/8250/8250_core.c:681 console_init+0x49d/0x6d3 kernel/printk/printk.c:2915 start_kernel+0x5e9/0x879 init/main.c:713 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241 -> #0 (console_owner){....}-{0:0}: [...] lock_acquire+0x127/0x340 kernel/locking/lockdep.c:4734 console_trylock_spinning kernel/printk/printk.c:1773 [inline] <-- lock(console_owner); vprintk_emit+0x307/0x470 kernel/printk/printk.c:2023 vprintk_func+0x8d/0x250 kernel/printk/printk_safe.c:394 printk+0xba/0xed kernel/printk/printk.c:2084 fail_dump lib/fault-inject.c:45 [inline] should_fail+0x67b/0x7c0 lib/fault-inject.c:144 __should_failslab+0x152/0x1c0 mm/failslab.c:33 should_failslab+0x5/0x10 mm/slab_common.c:1224 slab_pre_alloc_hook mm/slab.h:468 [inline] slab_alloc_node mm/slub.c:2723 [inline] slab_alloc mm/slub.c:2807 [inline] __kmalloc+0x72/0x300 mm/slub.c:3871 kmalloc include/linux/slab.h:582 [inline] tty_buffer_alloc+0x23f/0x2a0 drivers/tty/tty_buffer.c:175 __tty_buffer_request_room+0x156/0x2a0 drivers/tty/tty_buffer.c:273 tty_insert_flip_string_fixed_flag+0x93/0x250 drivers/tty/tty_buffer.c:318 tty_insert_flip_string include/linux/tty_flip.h:37 [inline] pty_write+0x126/0x1f0 drivers/tty/pty.c:122 <-- lock(&port->lock); n_tty_write+0xa7a/0xfc0 drivers/tty/n_tty.c:2356 do_tty_write drivers/tty/tty_io.c:961 [inline] tty_write+0x512/0x930 drivers/tty/tty_io.c:1045 __vfs_write+0x76/0x100 fs/read_write.c:494 [...] other info that might help us debug this: Chain exists of: console_owner --> &port_lock_key --> &port->lock Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: b6da31b2c07c ("tty: Fix data race in tty_insert_flip_string_fixed_flag") Signed-off-by: Qi Zheng <[email protected]> Acked-by: Jiri Slaby <[email protected]> Acked-by: Greg Kroah-Hartman <[email protected]> Cc: Akinobu Mita <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Steven Rostedt (Google) <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
* tty: reformat kernel-doc in tty_buffer.cJiri Slaby2021-11-261-123/+120
| | | | | | | | | | | | | | | | | | | | Kernel-doc is a bit strict about some formatting. So fix these: 1) When there is a tab in comments, it thinks the line is a continuation one. So the description of the functions end up as descriptions of the last parameter described. Remove the tabs. 2) Remove newlines before parameters description and after the comments. This was not wrong per se, only inconsistent with the rest of the file. 3) Add periods to the end of sentences where appropriate. 4) Add "()" to function names and "%" to constants, so that they are properly highlighted. Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: drop tty_schedule_flip()Jiri Slaby2021-11-251-22/+8
| | | | | | | | | | | | | | | Since commit a9c3f68f3cd8d (tty: Fix low_latency BUG) in 2014, tty_flip_buffer_push() is only a wrapper to tty_schedule_flip(). All users were converted in the previous patches, so remove tty_schedule_flip() completely while inlining its body into tty_flip_buffer_push(). One less exported function. Reviewed-by: Johan Hovold <[email protected]> Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: tty_buffer: Fix the softlockup issue in flush_to_ldiscGuanghui Feng2021-10-181-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: tty_buffer: Fix incorrectly documented function __tty_buffer_request_room()Lee Jones2021-05-201-1/+1
| | | | | | | | | | | | Fixes the following W=1 kernel build warning(s): drivers/tty/tty_buffer.c:259: warning: expecting prototype for tty_buffer_request_room(). Prototype was for __tty_buffer_request_room() instead Cc: Greg Kroah-Hartman <[email protected]> Cc: Jiri Slaby <[email protected]> Signed-off-by: Lee Jones <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: tty_buffer: Fix coding style issues of block commentsXiaofei Tan2021-05-131-3/+6
| | | | | | | | | 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 <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: tty_buffer: Remove the repeated word 'the'Xiaofei Tan2021-05-131-2/+2
| | | | | | | | | Remove the repeated word 'the' following advice of checkpatch.pl Besides, add a period at the end of comment sentence. Signed-off-by: Xiaofei Tan <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: tty_buffer: Add a blank line after declarationsXiaofei Tan2021-05-131-0/+7
| | | | | | | | Add a blank line after declarations, reported by checkpatch.pl. Signed-off-by: Xiaofei Tan <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: make tty_buffer_space_avail return uintJiri Slaby2021-05-131-1/+1
| | | | | | | | | | tty_buffer_space_avail returns values >= 0, so make it clear by the return type. Signed-off-by: Jiri Slaby <[email protected]> Cc: Joel Stanley <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: make fp of tty_ldisc_ops::receive_buf{,2} constJiri Slaby2021-05-131-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Char pointer (cp) passed to tty_ldisc_ops::receive_buf{,2} is const. There is no reason for flag pointer (fp) not to be too. So switch it in the definition and all uses. Signed-off-by: Jiri Slaby <[email protected]> Cc: William Hubbs <[email protected]> Cc: Chris Brannon <[email protected]> Cc: Kirk Reiser <[email protected]> Cc: Samuel Thibault <[email protected]> Cc: Marcel Holtmann <[email protected]> Cc: Johan Hedberg <[email protected]> Cc: Luiz Augusto von Dentz <[email protected]> Cc: Dmitry Torokhov <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Jakub Kicinski <[email protected]> Cc: Wolfgang Grandegger <[email protected]> Cc: Marc Kleine-Budde <[email protected]> Cc: Andreas Koensgen <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Liam Girdwood <[email protected]> Cc: Mark Brown <[email protected]> Cc: Jaroslav Kysela <[email protected]> Cc: Takashi Iwai <[email protected]> Cc: Peter Ujfalusi <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: move some internal tty lock enums and functions out of tty.hGreg Kroah-Hartman2021-04-151-1/+1
| | | | | | | | | Move the TTY_LOCK_* enums and tty_ldisc lock functions out of the global tty.h into the local header file to clean things up. Cc: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: tty_buffer: Add missing description for 'limit'Lee Jones2020-11-061-0/+1
| | | | | | | | | | | | Fixes the following W=1 kernel build warning(s): drivers/tty/tty_buffer.c:592: warning: Function parameter or member 'limit' not described in 'tty_buffer_set_limit' Cc: Greg Kroah-Hartman <[email protected]> Cc: Jiri Slaby <[email protected]> Signed-off-by: Lee Jones <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: fix kernel-docJiri Slaby2020-08-181-7/+7
| | | | | | | | | | | | | | | With W=1, the kernel-doc checker complains quite a lot in the tty layer. Over the time, many documented parameters were renamed, removed or switched from tty to tty_port and similar. Some were mistyped in the doc too. So fix all these in the tty core. (But do not add the missing ones which the checker complains about too. Not now.) The rest in the tty layer will follow in the next patches. Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: increase the default flip buffer limit to 2*640KManfred Schlaegl2019-01-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | We increase the default limit for buffer memory allocation by a factor of 10 to 640K to prevent data loss when using fast serial interfaces. For example when using RS485 without flow-control at speeds of 1Mbit/s an upwards we've run into problems such as applications being too slow to read out this buffer (on embedded devices based on imx53 or imx6). If you want to write transmitted data to a slow SD card and thus have realtime requirements, this limit can become a problem. That shouldn't be the case and 640K buffers fix such problems for us. This value is a maximum limit for allocation only. It has no effect on systems that currently run fine. When transmission is slow enough applications and hardware can keep up and increasing this limit doesn't change anything. It only _allows_ to allocate more than 2*64K in cases we currently fail to allocate memory despite having some. Signed-off-by: Manfred Schlaegl <[email protected]> Signed-off-by: Martin Kepplinger <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: wipe buffer.Linus Torvalds2018-10-111-1/+5
| | | | | | | | | | | After we are done with the tty buffer, zero it out. Reported-by: aszlig <[email protected]> Tested-by: Milan Broz <[email protected]> Tested-by: Daniel Zatovic <[email protected]> Tested-by: aszlig <[email protected]> Cc: Willy Tarreau <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
* TTY: tty_buffer, warn on leaksJiri Slaby2018-09-181-1/+6
| | | | | | | | | | | | | | | When we leak some tty buffer, warn about that. For that we need to account the memory used also in the tty_buffer_free_all function. On other locations, the accounting is handled correctly. Note that we do not account the free list, as that was accounted in tty_buffer_free before put on the free list. I have been using this patch for ages, so let's see if anybody else encounters any issues. Signed-off-by: Jiri Slaby <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: add SPDX identifiers to all remaining files in drivers/tty/Greg Kroah-Hartman2017-11-081-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the drivers/tty files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Jiri Slaby <[email protected]> Cc: Benjamin Herrenschmidt <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Chris Metcalf <[email protected]> Cc: Jiri Kosina <[email protected]> Cc: David Sterba <[email protected]> Cc: James Hogan <[email protected]> Cc: Rob Herring <[email protected]> Cc: Eric Anholt <[email protected]> Cc: Stefan Wahren <[email protected]> Cc: Florian Fainelli <[email protected]> Cc: Ray Jui <[email protected]> Cc: Scott Branden <[email protected]> Cc: [email protected] Cc: "James E.J. Bottomley" <[email protected]> Cc: Helge Deller <[email protected]> Cc: Joachim Eastwood <[email protected]> Cc: Matthias Brugger <[email protected]> Cc: Masahiro Yamada <[email protected]> Cc: Tobias Klauser <[email protected]> Cc: Russell King <[email protected]> Cc: Vineet Gupta <[email protected]> Cc: Richard Genoud <[email protected]> Cc: Alexander Shiyan <[email protected]> Cc: Baruch Siach <[email protected]> Cc: "Maciej W. Rozycki" <[email protected]> Cc: "Uwe Kleine-König" <[email protected]> Cc: Pat Gefre <[email protected]> Cc: "Guilherme G. Piccoli" <[email protected]> Cc: Jason Wessel <[email protected]> Cc: Vladimir Zapolskiy <[email protected]> Cc: Sylvain Lemieux <[email protected]> Cc: Carlo Caione <[email protected]> Cc: Kevin Hilman <[email protected]> Cc: Liviu Dudau <[email protected]> Cc: Sudeep Holla <[email protected]> Cc: Lorenzo Pieralisi <[email protected]> Cc: Andy Gross <[email protected]> Cc: David Brown <[email protected]> Cc: "Andreas Färber" <[email protected]> Cc: Kevin Cernekee <[email protected]> Cc: Laxman Dewangan <[email protected]> Cc: Thierry Reding <[email protected]> Cc: Jonathan Hunter <[email protected]> Cc: Barry Song <[email protected]> Cc: Patrice Chotard <[email protected]> Cc: Maxime Coquelin <[email protected]> Cc: Alexandre Torgue <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Peter Korsgaard <[email protected]> Cc: Timur Tabi <[email protected]> Cc: Tony Prisk <[email protected]> Cc: Michal Simek <[email protected]> Cc: "Sören Brinkmann" <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Kate Stewart <[email protected]> Cc: Philippe Ombredanne <[email protected]> Cc: Jiri Slaby <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: fix tty_ldisc_receive_buf() documentationJohan Hovold2017-11-041-1/+1
| | | | | | | | | The tty_ldisc_receive_buf() helper returns the number of bytes processed so drop the bogus "not" from the kernel doc comment. Fixes: 8d082cd300ab ("tty: Unify receive_buf() code paths") Signed-off-by: Johan Hovold <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: fix __tty_insert_flip_char regressionArnd Bergmann2017-08-021-1/+2
| | | | | | | | | | | | | | | | | Sergey noticed a small but fatal mistake in __tty_insert_flip_char, leading to an oops in an interrupt handler when using any serial port. The problem is that I accidentally took the tty_buffer pointer before calling __tty_buffer_request_room(), which replaces the buffer. This moves the pointer lookup to the right place after allocating the new buffer space. Fixes: 979990c62848 ("tty: improve tty_insert_flip_char() fast path") Reported-by: Sergey Senozhatsky <[email protected]> Tested-by: Sergey Senozhatsky <[email protected]> Signed-off-by: Arnd Bergmann <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: improve tty_insert_flip_char() slow pathArnd Bergmann2017-07-301-2/+3
| | | | | | | | | | | | | | | | | | While working on improving the fast path of tty_insert_flip_char(), I noticed that by calling tty_buffer_request_room(), we needlessly move to the separate flag buffer mode for the tty, even when all characters use TTY_NORMAL as the flag. This changes the code to call __tty_buffer_request_room() with the correct flag, which will then allocate a regular buffer when it rounds out of space but no special flags have been used. I'm guessing that this is the behavior that Peter Hurley intended when he introduced the compacted flip buffers. Fixes: acc0f67f307f ("tty: Halve flip buffer GFP_ATOMIC memory consumption") Cc: Peter Hurley <[email protected]> Signed-off-by: Arnd Bergmann <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: improve tty_insert_flip_char() fast pathArnd Bergmann2017-07-301-0/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kernelci.org reports a crazy stack usage for the VT code when CONFIG_KASAN is enabled: drivers/tty/vt/keyboard.c: In function 'kbd_keycode': drivers/tty/vt/keyboard.c:1452:1: error: the frame size of 2240 bytes is larger than 2048 bytes [-Werror=frame-larger-than=] The problem is that tty_insert_flip_char() gets inlined many times into kbd_keycode(), and also into other functions, and each copy requires 128 bytes for stack redzone to check for a possible out-of-bounds access on the 'ch' and 'flags' arguments that are passed into tty_insert_flip_string_flags as a variable-length string. This introduces a new __tty_insert_flip_char() function for the slow path, which receives the two arguments by value. This completely avoids the problem and the stack usage goes back down to around 100 bytes. Without KASAN, this is also slightly better, as we don't have to spill the arguments to the stack but can simply pass 'ch' and 'flag' in registers, saving a few bytes in .text for each call site. This should be backported to linux-4.0 or later, which first introduced the stack sanitizer in the kernel. Cc: [email protected] Fixes: c420f167db8c ("kasan: enable stack instrumentation") Signed-off-by: Arnd Bergmann <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty_port: Add port client functionsRob Herring2017-02-031-14/+3
| | | | | | | | | | | | | | Introduce a client (upward direction) operations struct for tty_port clients. Initially supported operations are for receiving data and write wake-up. This will allow for having clients other than an ldisc. Convert the calls to the ldisc to use the client ops as the default operations. Signed-off-by: Rob Herring <[email protected]> Reviewed-By: Sebastian Reichel <[email protected]> Tested-By: Sebastian Reichel <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: constify tty_ldisc_receive_buf buffer pointerRob Herring2017-01-191-1/+1
| | | | | | | | | | | | This is needed to work with the client operations which uses const ptrs. Really, the flags pointer could be const, too, but this would be a tree wide fix. Signed-off-by: Rob Herring <[email protected]> Reviewed-by: Andy Shevchenko <[email protected]> Reviewed-By: Sebastian Reichel <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
* Fix OpenSSH pty regression on closeBrian Bloniarz2016-05-011-28/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | OpenSSH expects the (non-blocking) read() of pty master to return EAGAIN only if it has received all of the slave-side output after it has received SIGCHLD. This used to work on pre-3.12 kernels. This fix effectively forces non-blocking read() and poll() to block for parallel i/o to complete for all ttys. It also unwinds these changes: 1) f8747d4a466ab2cafe56112c51b3379f9fdb7a12 tty: Fix pty master read() after slave closes 2) 52bce7f8d4fc633c9a9d0646eef58ba6ae9a3b73 pty, n_tty: Simplify input processing on final close 3) 1a48632ffed61352a7810ce089dc5a8bcd505a60 pty: Fix input race when closing Inspired by analysis and patch from Marc Aurele La France <[email protected]> Reported-by: Volth <[email protected]> Reported-by: Marc Aurele La France <[email protected]> BugLink: https://bugzilla.mindrot.org/show_bug.cgi?id=52 BugLink: https://bugzilla.mindrot.org/show_bug.cgi?id=2492 Signed-off-by: Brian Bloniarz <[email protected]> Reviewed-by: Peter Hurley <[email protected]> Cc: stable <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: Unify receive_buf() code pathsPeter Hurley2016-01-281-11/+28
| | | | | | | | Instead of two distinct code branches for receive_buf() handling, use tty_ldisc_receive_buf() as the single code path. Signed-off-by: Peter Hurley <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: Fix GPF in flush_to_ldisc()Peter Hurley2015-12-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A line discipline which does not define a receive_buf() method can can cause a GPF if data is ever received [1]. Oddly, this was known to the author of n_tracesink in 2011, but never fixed. [1] GPF report BUG: unable to handle kernel NULL pointer dereference at (null) IP: [< (null)>] (null) PGD 3752d067 PUD 37a7b067 PMD 0 Oops: 0010 [#1] SMP KASAN Modules linked in: CPU: 2 PID: 148 Comm: kworker/u10:2 Not tainted 4.4.0-rc2+ #51 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Workqueue: events_unbound flush_to_ldisc task: ffff88006da94440 ti: ffff88006db60000 task.ti: ffff88006db60000 RIP: 0010:[<0000000000000000>] [< (null)>] (null) RSP: 0018:ffff88006db67b50 EFLAGS: 00010246 RAX: 0000000000000102 RBX: ffff88003ab32f88 RCX: 0000000000000102 RDX: 0000000000000000 RSI: ffff88003ab330a6 RDI: ffff88003aabd388 RBP: ffff88006db67c48 R08: ffff88003ab32f9c R09: ffff88003ab31fb0 R10: ffff88003ab32fa8 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff88006db67c20 R14: ffffffff863df820 R15: ffff88003ab31fb8 FS: 0000000000000000(0000) GS:ffff88006dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000000 CR3: 0000000037938000 CR4: 00000000000006e0 Stack: ffffffff829f46f1 ffff88006da94bf8 ffff88006da94bf8 0000000000000000 ffff88003ab31fb0 ffff88003aabd438 ffff88003ab31ff8 ffff88006430fd90 ffff88003ab32f9c ffffed0007557a87 1ffff1000db6cf78 ffff88003ab32078 Call Trace: [<ffffffff8127cf91>] process_one_work+0x8f1/0x17a0 kernel/workqueue.c:2030 [<ffffffff8127df14>] worker_thread+0xd4/0x1180 kernel/workqueue.c:2162 [<ffffffff8128faaf>] kthread+0x1cf/0x270 drivers/block/aoe/aoecmd.c:1302 [<ffffffff852a7c2f>] ret_from_fork+0x3f/0x70 arch/x86/entry/entry_64.S:468 Code: Bad RIP value. RIP [< (null)>] (null) RSP <ffff88006db67b50> CR2: 0000000000000000 ---[ end trace a587f8947e54d6ea ]--- Reported-by: Dmitry Vyukov <[email protected]> Cc: <[email protected]> Signed-off-by: Peter Hurley <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
* tty: Use unbound workqueue for all input workersPeter Hurley2015-10-181-1/+1
| | | | | | | | | | | | | | | | | The commonly accepted wisdom that scheduling work on the same cpu that handled interrupt i/o benefits from cache-locality is only true if the cpu is idle (since bound kworkers are often the highest vruntime and thus the lowest priority). Measurements of scheduling via the unbound queue show lowered worst-case latency responses of up to 5x over bound workqueue, without increase in average latency or throughput. pty i/o test measurements show >3x (!) reduced total running time; tests previously taking ~8s now complete in <2.5s. Signed-off-by: Peter Hurley <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
generated by cgit (git 2.51.2) at 2025-12-02 19:17:50 +0000