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2013-03-18driver: tty: serial: remove cast for kzalloc return valueZhang Yanfei1-2/+1
remove cast for kzalloc return value. Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18TTY: serial, stop accessing potential NULLsJiri Slaby2-2/+2
The following commits: * 6732c8bb8671acbdac6cdc93dd72ddd581dd5e25 (TTY: switch tty_schedule_flip) * 2e124b4a390ca85325fae75764bef92f0547fa25 (TTY: switch tty_flip_buffer_push) * 05c7cd39907184328f48d3e7899f9cdd653ad336 (TTY: switch tty_insert_flip_string) * 92a19f9cec9a80ad93c06e115822deb729e2c6ad (TTY: switch tty_insert_flip_char) * 227434f8986c3827a1faedd1feb437acd6285315 (TTY: switch tty_buffer_request_room to tty_port) introduced a potential NULL dereference to some drivers. In particular, when the device is used as a console, incoming bytes can kill the box. This is caused by removed checks for TTY against NULL. It happened because it was unclear to me why the checks were there. I assumed them superfluous because the interrupts were unbound or otherwise stopped. But this is not the case for consoles for these drivers, as was pointed out by David Miller. Now, this patch re-introduces the checks (at this point we check port->state, not the tty proper, as we do not care about tty pointers anymore). For both of the drivers, we place the check below the handling of break signal so that sysrq can actually work. (One needs to issue a break and then sysrq key within the following 5 seconds.) We do not change sc26xx, sunhv, and sunsu here because they behave the same as before. People having that hardware should fix the driver eventually, however. They always could unconditionally dereference tty in receive_chars, port->state in uart_handle_dcd_change, and up->port.state->port.tty. There is perhaps more to fix in all those drivers, but they are at least in a state they were before. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: "David S. Miller" <davem@davemloft.net> Cc: Grant Likely <grant.likely@secretlab.ca> Cc: Rob Herring <rob.herring@calxeda.com> Cc: sparclinux@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Fix recursive deadlock in tty_perform_flush()Peter Hurley3-11/+21
tty_perform_flush() can deadlock when called while holding a line discipline reference. By definition, all ldisc drivers hold a ldisc reference, so calls originating from ldisc drivers must not block for a ldisc reference. The deadlock can occur when: CPU 0 | CPU 1 | tty_ldisc_ref(tty) | .... | <line discipline halted> tty_ldisc_ref_wait(tty) | | CPU 0 cannot progess because it cannot obtain an ldisc reference with the line discipline has been halted (thus no new references are granted). CPU 1 cannot progress because an outstanding ldisc reference has not been released. An in-tree call-tree audit of tty_perform_flush() [1] shows 5 ldisc drivers calling tty_perform_flush() indirectly via n_tty_ioctl_helper() and 2 ldisc drivers calling directly. A single tty driver safely uses the function. [1] Recursive usage: /* These functions are line discipline ioctls and thus * recursive wrt line discipline references */ tty_perform_flush() - ./drivers/tty/tty_ioctl.c n_tty_ioctl_helper() hci_uart_tty_ioctl(default) - drivers/bluetooth/hci_ldisc.c (N_HCI) n_hdlc_tty_ioctl(default) - drivers/tty/n_hdlc.c (N_HDLC) gsmld_ioctl(default) - drivers/tty/n_gsm.c (N_GSM0710) n_tty_ioctl(default) - drivers/tty/n_tty.c (N_TTY) gigaset_tty_ioctl(default) - drivers/isdn/gigaset/ser-gigaset.c (N_GIGASET_M101) ppp_synctty_ioctl(TCFLSH) - drivers/net/ppp/pps_synctty.c ppp_asynctty_ioctl(TCFLSH) - drivers/net/ppp/ppp_async.c Non-recursive use: tty_perform_flush() - drivers/tty/tty_ioctl.c ipw_ioctl(TCFLSH) - drivers/tty/ipwireless/tty.c /* This function is a tty i/o ioctl method, which * is invoked by tty_ioctl() */ Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Remove redundant tty_wait_until_sent()Peter Hurley1-9/+0
tty_ioctl() already waits until sent. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Locate get/put ldisc functions togetherPeter Hurley1-23/+23
Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Fold one-line assign function into callersPeter Hurley1-25/+6
Now that tty_ldisc_assign() is a one-line file-scoped function, remove it and perform the simple assignment at its call sites. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Document unsafe ldisc reference acquirePeter Hurley1-9/+5
Merge get_ldisc() into its only call site. Note how, after merging, the unsafe acquire of an ldisc reference is obvious. CPU 0 in tty_ldisc_try() | CPU 1 in tty_ldisc_halt() | test_bit(TTY_LDISC, &tty_flags) | if (true) | clear_bit(TTY_LDISC, &tty_flags) tty->ldisc != 0? | atomic_read(&tty->ldisc->users) if (true) | ret_val == 1? atomic_inc(&tty->ldisc->users) | if (false) | wait | <goes on assuming safe ldisc use> | <doesn't wait - proceeds w/ close> | The spin lock in tty_ldisc_try() does nothing wrt synchronizing the ldisc halt since it's not acquired as part of halting. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Separate release semantics of ldisc referencePeter Hurley1-34/+35
tty_ldisc_ref()/tty_ldisc_unref() have usage semantics equivalent to down_read_trylock()/up_read(). Only callers of tty_ldisc_put() are performing the additional operations necessary for proper ldisc teardown, and then only after ensuring no outstanding 'read lock' remains. Thus, tty_ldisc_unref() should never be the last reference; WARN if it is. Conversely, tty_ldisc_put() should never be destructing if the use count != 1. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Don't protect atomic operation with mutexPeter Hurley1-2/+0
test_bit() is already atomic; drop mutex lock/unlock. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Add ldisc hangup debug messagesPeter Hurley1-0/+19
Expected typical debug log: [ 582.721965] tty_open: opening pts3... [ 582.721970] tty_open: opening pts3... [ 582.721977] tty_release: pts3 (tty count=3)... [ 582.721980] tty_release: ptm3 (tty count=1)... [ 582.722015] pts3 vhangup... [ 582.722020] tty_ldisc_hangup: pts3: closing ldisc: ffff88007a920540 [ 582.724128] tty_release: pts3 (tty count=2)... [ 582.724217] tty_ldisc_hangup: pts3: re-opened ldisc: ffff88007a920580 [ 582.724221] tty_release: ptm3: final close [ 582.724234] tty_ldisc_release: ptm3: closing ldisc: ffff88007a920a80 [ 582.724238] tty_ldisc_release: ptm3: ldisc closed [ 582.724241] tty_release: ptm3: freeing structure... [ 582.724741] tty_open: opening pts3... Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Bracket ldisc release with TTY_DEBUG_HANGUP messagesPeter Hurley1-1/+4
Expected typical log output: [ 2.437211] tty_open: opening pts1... [ 2.443376] tty_open: opening pts5... [ 2.447830] tty_release: ptm0 (tty count=1)... [ 2.447849] pts0 vhangup... [ 2.447865] tty_release: ptm0: final close [ 2.447876] tty_release: ptm0: freeing structure... [ 2.451634] tty_release: tty1 (tty count=1)... [ 2.451638] tty_release: tty1: final close [ 2.451654] tty_release: tty1: freeing structure... [ 2.452505] tty_release: pts5 (tty count=2)... [ 2.453029] tty_open: opening pts0... Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Fix 'deferred reopen' ldisc commentPeter Hurley1-4/+5
This comment is a victim of code migration from "tty: Fix the ldisc hangup race"; re-parent it. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Make core responsible for synchronizing its workPeter Hurley2-20/+21
The tty core relies on the ldisc layer for synchronizing destruction of the tty. Instead, the final tty release must wait for any pending tty work to complete prior to tty destruction. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Complete ownership transfer of flip buffersPeter Hurley3-35/+14
Waiting for buffer work to complete is not required for safely performing changes to the line discipline, once the line discipline is halted. The buffer work routine, flush_to_ldisc(), will be unable to acquire an ldisc ref and all existing references were waited until released (so it can't already have one). Ensure running buffer work which may reference the soon-to-be-gone tty completes and any buffer work running after this point retrieves a NULL tty. Also, ensure all buffer work is cancelled on port destruction. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Don't reenable already enabled ldiscPeter Hurley3-4/+1
tty_ldisc_hangup() guarantees the ldisc is enabled (or that there is no ldisc). Since __tty_hangup() was the only user, re-define tty_ldisc_enable() in file-scope. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18n_tty: Fully initialize ldisc before restarting buffer workPeter Hurley1-9/+8
Buffer work may already be pending when the n_tty ldisc is re-opened, eg., when setting the ldisc (via TIOCSETD ioctl) and when hanging up the tty. Since n_tty_set_room() may restart buffer work, first ensure the ldisc is completely initialized. Factor n_tty_set_room() out of reset_buffer_flags() (only 2 callers) and reorganize n_tty_open() to set termios last; buffer work will be restarted there if necessary, after the char_map is properly initialized. Fixes this WARNING: [ 549.561769] ------------[ cut here ]------------ [ 549.598755] WARNING: at drivers/tty/n_tty.c:160 n_tty_set_room+0xff/0x130() [ 549.604058] scheduling buffer work for halted ldisc [ 549.607741] Pid: 9417, comm: trinity-child28 Tainted: G D W 3.7.0-next-20121217-sasha-00023-g8689ef9 #219 [ 549.652580] Call Trace: [ 549.662754] [<ffffffff81c432cf>] ? n_tty_set_room+0xff/0x130 [ 549.665458] [<ffffffff8110cae7>] warn_slowpath_common+0x87/0xb0 [ 549.668257] [<ffffffff8110cb71>] warn_slowpath_fmt+0x41/0x50 [ 549.671007] [<ffffffff81c432cf>] n_tty_set_room+0xff/0x130 [ 549.673268] [<ffffffff81c44597>] reset_buffer_flags+0x137/0x150 [ 549.675607] [<ffffffff81c45b71>] n_tty_open+0x131/0x1c0 [ 549.677699] [<ffffffff81c47824>] tty_ldisc_open.isra.5+0x54/0x70 [ 549.680147] [<ffffffff81c482bf>] tty_ldisc_hangup+0x11f/0x1e0 [ 549.682409] [<ffffffff81c3fa17>] __tty_hangup+0x137/0x440 [ 549.684634] [<ffffffff81c3fd49>] tty_vhangup+0x9/0x10 [ 549.686443] [<ffffffff81c4a42c>] pty_close+0x14c/0x160 [ 549.688446] [<ffffffff81c41225>] tty_release+0xd5/0x490 [ 549.690460] [<ffffffff8127d8a2>] __fput+0x122/0x250 [ 549.692577] [<ffffffff8127d9d9>] ____fput+0x9/0x10 [ 549.694534] [<ffffffff811348c2>] task_work_run+0xb2/0xf0 [ 549.696349] [<ffffffff81113c6d>] do_exit+0x36d/0x580 [ 549.698286] [<ffffffff8107d964>] ? syscall_trace_enter+0x24/0x2e0 [ 549.702729] [<ffffffff81113f4a>] do_group_exit+0x8a/0xc0 [ 549.706775] [<ffffffff81113f92>] sys_exit_group+0x12/0x20 [ 549.711088] [<ffffffff83cfab18>] tracesys+0xe1/0xe6 [ 549.728001] ---[ end trace 73eb41728f11f87e ]--- Reported-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18n_tty: Correct unthrottle-with-buffer-flush commentsPeter Hurley1-8/+5
The driver is no longer unthrottled on buffer reset, so remove comments that claim it is. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Wait for SAK work before waiting for hangup workPeter Hurley1-1/+1
SAK work may schedule hangup work (if TTY_SOFT_SAK is defined), thus SAK work must be flushed before hangup work. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Halt both ldiscs concurrentlyPeter Hurley1-13/+25
The pty driver does not obtain an ldisc reference to the linked tty when writing. When the ldiscs are sequentially halted, it is possible for one ldisc to be halted, and before the second ldisc can be halted, a concurrent write schedules buffer work on the first ldisc. This can lead to an access-after-free error when the scheduled buffer work starts on the closed ldisc. Prevent subsequent use after halt by performing each stage of the halt on both ttys. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Strengthen no-subsequent-use guarantee of tty_ldisc_halt()Peter Hurley1-18/+24
In preparation for destructing and freeing the tty, the line discipline must first be brought to an inactive state before it can be destructed. This line discipline shutdown must: - disallow new users of the ldisc - wait for existing ldisc users to finish - only then, cancel/flush their pending/running work Factor tty_ldisc_wait_idle() from tty_set_ldisc() and tty_ldisc_kill() to ensure this shutdown order. Failure to provide this guarantee can result in scheduled work running after the tty has already been freed, as indicated in the following log message: [ 88.331234] WARNING: at drivers/tty/tty_buffer.c:435 flush_to_ldisc+0x194/0x1d0() [ 88.334505] Hardware name: Bochs [ 88.335618] tty is bad=-1 [ 88.335703] Modules linked in: netconsole configfs bnep rfcomm bluetooth ...... [ 88.345272] Pid: 39, comm: kworker/1:1 Tainted: G W 3.7.0-next-20121129+ttydebug-xeon #20121129+ttydebug [ 88.347736] Call Trace: [ 88.349024] [<ffffffff81058aff>] warn_slowpath_common+0x7f/0xc0 [ 88.350383] [<ffffffff81058bf6>] warn_slowpath_fmt+0x46/0x50 [ 88.351745] [<ffffffff81432bd4>] flush_to_ldisc+0x194/0x1d0 [ 88.353047] [<ffffffff816f7fe1>] ? _raw_spin_unlock_irq+0x21/0x50 [ 88.354190] [<ffffffff8108a809>] ? finish_task_switch+0x49/0xe0 [ 88.355436] [<ffffffff81077ad1>] process_one_work+0x121/0x490 [ 88.357674] [<ffffffff81432a40>] ? __tty_buffer_flush+0x90/0x90 [ 88.358954] [<ffffffff81078c84>] worker_thread+0x164/0x3e0 [ 88.360247] [<ffffffff81078b20>] ? manage_workers+0x120/0x120 [ 88.361282] [<ffffffff8107e230>] kthread+0xc0/0xd0 [ 88.362284] [<ffffffff816f0000>] ? cmos_do_probe+0x2eb/0x3bf [ 88.363391] [<ffffffff8107e170>] ? flush_kthread_worker+0xb0/0xb0 [ 88.364797] [<ffffffff816fff6c>] ret_from_fork+0x7c/0xb0 [ 88.366087] [<ffffffff8107e170>] ? flush_kthread_worker+0xb0/0xb0 [ 88.367266] ---[ end trace 453a7c9f38fbfec0 ]--- Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Relocate tty_ldisc_halt() to avoid forward declarationPeter Hurley1-23/+23
tty_ldisc_halt() will use the file-scoped function, tty_ldisc_wait_idle(), in the following patch. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Fix ldisc halt sequence on hangupPeter Hurley1-20/+19
Flip buffer work cannot be cancelled until all outstanding ldisc references have been released. Convert the ldisc ref wait into a full ldisc halt with buffer work cancellation. Note that the legacy mutex is not held while cancelling. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Remove unnecessary re-test of ldisc ref countPeter Hurley1-19/+19
Since the tty->ldisc is prevented from being changed by tty_set_ldisc() when a tty is being hung up, re-testing the ldisc user count is unnecessary -- ie, it cannot be a different ldisc and the user count cannot have increased (assuming the caller meets the precondition that TTY_LDISC flag is cleared) Removal of the 'early-out' locking optimization is necessary for the subsequent patch 'tty: Fix ldisc halt sequence on hangup'. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Refactor wait for ldisc refs out of tty_ldisc_hangup()Peter Hurley1-18/+36
Refactor tty_ldisc_hangup() to extract standalone function, tty_ldisc_hangup_wait_idle(), to wait for ldisc references to be released. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18n_tty: Don't flush buffer when closing ldiscPeter Hurley1-1/+3
A buffer flush is both undesirable and unnecessary when the ldisc is closing. A buffer flush performs the following: 1. resets ldisc data fields to their initial state 2. resets tty->receive_room to indicate more data can be sent 3. schedules buffer work to receive more data 4. signals a buffer flush has happened to linked pty in packet mode Since the ldisc has been halted and the tty may soon be destructed, buffer work must not be scheduled as that work might access an invalid tty and ldisc state. Also, the ldisc read buffer is about to be freed, so that's pointless. Resetting the ldisc data fields is pointless as well since that structure is about to be freed. Resetting tty->receive_room is unnecessary, as it will be properly reset if a new ldisc is reopened. Besides, resetting the original receive_room value would be wrong since the read buffer will be gone. Since the packet mode flush is observable from userspace, this behavior has been preserved. The test jig originally authored by Ilya Zykov <ilya@ilyx.ru> and signed off by him is included below. The test jig prompts the following warnings which this patch fixes. [ 38.051111] ------------[ cut here ]------------ [ 38.052113] WARNING: at drivers/tty/n_tty.c:160 n_tty_set_room.part.6+0x8b/0xa0() [ 38.053916] Hardware name: Bochs [ 38.054819] Modules linked in: netconsole configfs bnep rfcomm bluetooth parport_pc ppdev snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq psmouse snd_timer serio_raw mac_hid snd_seq_device snd microcode lp parport virtio_balloon soundcore i2c_piix4 snd_page_alloc floppy 8139too 8139cp [ 38.059704] Pid: 1564, comm: pty_kill Tainted: G W 3.7.0-next-20121130+ttydebug-xeon #20121130+ttydebug [ 38.061578] Call Trace: [ 38.062491] [<ffffffff81058b4f>] warn_slowpath_common+0x7f/0xc0 [ 38.063448] [<ffffffff81058baa>] warn_slowpath_null+0x1a/0x20 [ 38.064439] [<ffffffff8142dc2b>] n_tty_set_room.part.6+0x8b/0xa0 [ 38.065381] [<ffffffff8142dc82>] n_tty_set_room+0x42/0x80 [ 38.066323] [<ffffffff8142e6f2>] reset_buffer_flags+0x102/0x160 [ 38.077508] [<ffffffff8142e76d>] n_tty_flush_buffer+0x1d/0x90 [ 38.078782] [<ffffffff81046569>] ? default_spin_lock_flags+0x9/0x10 [ 38.079734] [<ffffffff8142e804>] n_tty_close+0x24/0x60 [ 38.080730] [<ffffffff81431b61>] tty_ldisc_close.isra.2+0x41/0x60 [ 38.081680] [<ffffffff81431bbb>] tty_ldisc_kill+0x3b/0x80 [ 38.082618] [<ffffffff81432a07>] tty_ldisc_release+0x77/0xe0 [ 38.083549] [<ffffffff8142b781>] tty_release+0x451/0x4d0 [ 38.084525] [<ffffffff811950be>] __fput+0xae/0x230 [ 38.085472] [<ffffffff8119524e>] ____fput+0xe/0x10 [ 38.086401] [<ffffffff8107aa88>] task_work_run+0xc8/0xf0 [ 38.087334] [<ffffffff8105ea56>] do_exit+0x196/0x4b0 [ 38.088304] [<ffffffff8106c77b>] ? __dequeue_signal+0x6b/0xb0 [ 38.089240] [<ffffffff8105ef34>] do_group_exit+0x44/0xa0 [ 38.090182] [<ffffffff8106f43d>] get_signal_to_deliver+0x20d/0x4e0 [ 38.091125] [<ffffffff81016979>] do_signal+0x29/0x130 [ 38.092096] [<ffffffff81431a9e>] ? tty_ldisc_deref+0xe/0x10 [ 38.093030] [<ffffffff8142a317>] ? tty_write+0xb7/0xf0 [ 38.093976] [<ffffffff81193f53>] ? vfs_write+0xb3/0x180 [ 38.094904] [<ffffffff81016b20>] do_notify_resume+0x80/0xc0 [ 38.095830] [<ffffffff81700492>] int_signal+0x12/0x17 [ 38.096788] ---[ end trace 5f6f7a9651cd999b ]--- [ 2730.570602] ------------[ cut here ]------------ [ 2730.572130] WARNING: at drivers/tty/n_tty.c:160 n_tty_set_room+0x107/0x140() [ 2730.574904] scheduling buffer work for halted ldisc [ 2730.578303] Pid: 9691, comm: trinity-child15 Tainted: G W 3.7.0-rc8-next-20121205-sasha-00023-g59f0d85 #207 [ 2730.588694] Call Trace: [ 2730.590486] [<ffffffff81c41d77>] ? n_tty_set_room+0x107/0x140 [ 2730.592559] [<ffffffff8110c827>] warn_slowpath_common+0x87/0xb0 [ 2730.595317] [<ffffffff8110c8b1>] warn_slowpath_fmt+0x41/0x50 [ 2730.599186] [<ffffffff81c41d77>] n_tty_set_room+0x107/0x140 [ 2730.603141] [<ffffffff81c42fe7>] reset_buffer_flags+0x137/0x150 [ 2730.607166] [<ffffffff81c43018>] n_tty_flush_buffer+0x18/0x90 [ 2730.610123] [<ffffffff81c430af>] n_tty_close+0x1f/0x60 [ 2730.612068] [<ffffffff81c461f2>] tty_ldisc_close.isra.4+0x52/0x60 [ 2730.614078] [<ffffffff81c462ab>] tty_ldisc_reinit+0x3b/0x70 [ 2730.615891] [<ffffffff81c46db2>] tty_ldisc_hangup+0x102/0x1e0 [ 2730.617780] [<ffffffff81c3e537>] __tty_hangup+0x137/0x440 [ 2730.619547] [<ffffffff81c3e869>] tty_vhangup+0x9/0x10 [ 2730.621266] [<ffffffff81c48f1c>] pty_close+0x14c/0x160 [ 2730.622952] [<ffffffff81c3fd45>] tty_release+0xd5/0x490 [ 2730.624674] [<ffffffff8127fbe2>] __fput+0x122/0x250 [ 2730.626195] [<ffffffff8127fd19>] ____fput+0x9/0x10 [ 2730.627758] [<ffffffff81134602>] task_work_run+0xb2/0xf0 [ 2730.629491] [<ffffffff811139ad>] do_exit+0x36d/0x580 [ 2730.631159] [<ffffffff81113c8a>] do_group_exit+0x8a/0xc0 [ 2730.632819] [<ffffffff81127351>] get_signal_to_deliver+0x501/0x5b0 [ 2730.634758] [<ffffffff8106de34>] do_signal+0x24/0x100 [ 2730.636412] [<ffffffff81204865>] ? user_exit+0xa5/0xd0 [ 2730.638078] [<ffffffff81183cd8>] ? trace_hardirqs_on_caller+0x118/0x140 [ 2730.640279] [<ffffffff81183d0d>] ? trace_hardirqs_on+0xd/0x10 [ 2730.642164] [<ffffffff8106df78>] do_notify_resume+0x48/0xa0 [ 2730.643966] [<ffffffff83cdff6a>] int_signal+0x12/0x17 [ 2730.645672] ---[ end trace a40d53149c07fce0 ]--- /* * pty_thrash.c * * Based on original test jig by Ilya Zykov <ilya@ilyx.ru> * * Signed-off-by: Peter Hurley <peter@hurleysoftware.com> * Signed-off-by: Ilya Zykov <ilya@ilyx.ru> */ static int fd; static void error_exit(char *f, ...) { va_list va; va_start(va, f); vprintf(f, va); printf(": %s\n", strerror(errno)); va_end(va); if (fd >= 0) close(fd); exit(EXIT_FAILURE); } int main(int argc, char *argv[]) { int parent; char pts_name[24]; int ptn, unlock; while (1) { fd = open("/dev/ptmx", O_RDWR); if (fd < 0) error_exit("opening pty master"); unlock = 0; if (ioctl(fd, TIOCSPTLCK, &unlock) < 0) error_exit("unlocking pty pair"); if (ioctl(fd, TIOCGPTN, &ptn) < 0) error_exit("getting pty #"); snprintf(pts_name, sizeof(pts_name), "/dev/pts/%d", ptn); child_id = fork(); if (child_id == -1) error_exit("forking child"); if (parent) { int err, id, status; char buf[128]; int n; n = read(fd, buf, sizeof(buf)); if (n < 0) error_exit("master reading"); printf("%.*s\n", n-1, buf); close(fd); err = kill(child_id, SIGKILL); if (err < 0) error_exit("killing child"); id = waitpid(child_id, &status, 0); if (id < 0 || id != child_id) error_exit("waiting for child"); } else { /* Child */ close(fd); printf("Test cycle on slave pty %s\n", pts_name); fd = open(pts_name, O_RDWR); if (fd < 0) error_exit("opening pty slave"); while (1) { char pattern[] = "test\n"; if (write(fd, pattern, strlen(pattern)) < 0) error_exit("slave writing"); } } } /* never gets here */ return 0; } Reported-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18n_tty: Factor packet mode status change for reusePeter Hurley1-10/+14
Factor the packet mode status change from n_tty_flush_buffer for use by follow-on patch. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Add diagnostic for halted line disciplinePeter Hurley3-1/+15
Flip buffer work must not be scheduled by the line discipline after the line discipline has been halted; issue warning. Note: drivers can still schedule flip buffer work. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: ifx6x60: Remove unused suspend/resume callbacksLars-Peter Clausen1-26/+0
The ifx6x60 driver implements both legacy suspend/resume callbacks and dev_pm_ops. The SPI core is going to ignore legacy suspend/resume callbacks if a driver implements dev_pm_ops. Since the legacy suspend/resume callbacks are empty in this case it is safe to just remove them. Cc: Bi Chao <chao.bi@intel.com> Cc: Chen Jun <jun.d.chen@intel.com> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: mrst_max3110: Use dev_pm_opsLars-Peter Clausen1-7/+12
Use dev_pm_ops instead of the deprecated legacy suspend/resume for the mrst_max3110 driver. Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: max310x: Use dev_pm_opsLars-Peter Clausen1-8/+16
Use dev_pm_ops instead of the deprecated legacy suspend/resume for the max310x driver. Cc: Alexander Shiyan <shc_work@mail.ru> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: max3100: Use dev_pm_opsLars-Peter Clausen1-10/+10
Use dev_pm_ops instead of the deprecated legacy suspend/resume for the max3100 driver. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18TTY: fix close of uninitialised portsJohan Hovold1-8/+10
Make sure we do not make tty-driver callbacks or wait for port to drain on uninitialised ports (e.g. when open failed) in tty_port_close_start(). No callback, such as flush_buffer or wait_until_sent, needs to be made on a port that has never been opened. Neither does it make much sense to add drain delay for an uninitialised port. Currently a drain delay of up to two seconds could be added when a tty fails to open. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18TTY: clean up port drain-delay handlingJohan Hovold1-11/+16
Move port drain-delay handling to a separate function. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18TTY: fix DTR not being dropped on hang upJohan Hovold3-12/+23
Move HUPCL handling to port shutdown so that DTR is dropped also on hang up (tty_port_close is a noop for hung-up ports). Also do not try to drop DTR for uninitialised ports where it has never been raised (e.g. after a failed open). Note that this is also the current behaviour of serial-core. Nine drivers currently call tty_port_close_start directly (rather than through tty_port_close) and seven of them lower DTR as part of their close (if the port has been initialised). Fixup the remaining two drivers so that it continues to be lowered also on normal (non-HUP) close. [ Note that most of those other seven drivers did not expect DTR to have been dropped by tty_port_close_start in the first place. ] Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18TTY: fix DTR being raised on hang upJohan Hovold1-1/+1
Make sure to check ASYNC_INITIALISED before raising DTR when waking up from blocked open in tty_port_block_til_ready. Currently DTR could get raised at hang up as a blocked process would raise DTR unconditionally before checking for hang up and returning. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18TTY: wake up processes last at hangupJohan Hovold1-1/+1
Move wake up of processes on blocked-open and modem-status wait queues to after port shutdown at hangup. This way the woken up processes can use the ASYNC_INITIALIZED flag to detect port shutdown. Note that this is the order currently used by serial-core. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18TTY: clean up port shutdownJohan Hovold1-2/+7
Untangle port-shutdown logic and make sure the initialised flag is always cleared for non-console ports. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18crisv10: use counts from tty_portJiri Slaby2-27/+23
The same as flags, convert to using open/close counts from tty_port. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18crisv10: use *_wait from tty_portJiri Slaby2-11/+7
The same as flags, convert to using *_wait queues from tty_port. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18crisv10: use close delays from tty_portJiri Slaby2-13/+9
The same as flags, convert to using close delays from tty_port. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18crisv10: remove unused membersJiri Slaby1-6/+0
Well, all those are unused. They were perhaps copied from generic serial structure ages ago. Remove them for good. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18crisv10: stop returning info from handle_ser_rx_interruptJiri Slaby1-6/+4
The return value is not used anywhere, so no need to return anything. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18crisv10: use flags from tty_portJiri Slaby2-37/+29
First, remove STD_FLAGS as the value, or its subvalues (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST) is not tested anywhere -- there is no point to initialize flags to that. Second, use flags member from tty_port when we have it now. So that we do not waste space. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18TTY: cleanup tty->hw_stopped usesJiri Slaby7-45/+17
tty->hw_stopped is set only by drivers to remember HW state. If it is never set to 1 in a particular driver, there is no need to check it in the driver at all. Remove such checks. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18TTY: serial/msm_serial_hs, remove unused ttyJiri Slaby1-2/+0
Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18TTY: serial/bfin_uart, unbreak build with KGDB enabledJiri Slaby1-23/+0
There are no (and never were any) kgdb fields in uart_ops. Setting them produces a build error: drivers/tty/serial/bfin_uart.c:1054:2: error: unknown field 'kgdboc_port_startup' specified in initializer drivers/tty/serial/bfin_uart.c:1054:2: warning: initialization from incompatible pointer type [enabled by default] drivers/tty/serial/bfin_uart.c:1054:2: warning: (near initialization for 'bfin_serial_pops.ioctl') [enabled by default] drivers/tty/serial/bfin_uart.c:1055:2: error: unknown field 'kgdboc_port_shutdown' specified in initializer drivers/tty/serial/bfin_uart.c:1055:2: warning: initialization from incompatible pointer type [enabled by default] drivers/tty/serial/bfin_uart.c:1055:2: warning: (near initialization for 'bfin_serial_pops.poll_init') [enabled by default] Remove them. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Sonic Zhang <sonic.zhang@analog.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18TTY: add tty_port_tty_hangup helperJiri Slaby16-148/+58
It allows for cleaning up on a considerable amount of places. They did port_get, hangup, kref_put. Now the only thing needed is to call tty_port_tty_hangup which does exactly that. And they can also decide whether to consider CLOCAL or completely ignore that. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18TTY: quatech2, remove unneeded is_openJiri Slaby1-10/+0
tty->ops->break_ctl cannot be called outside the gap between open and close. So there is no need to check whether the port is open in break_ctl in quatech2. Remove the check and also that member completely. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Bill Pemberton <wfp5p@virginia.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18TTY: add tty_port_tty_wakeup helperJiri Slaby22-176/+51
It allows for cleaning up on a considerable amount of places. They did port_get, wakeup, kref_put. Now the only thing needed is to call tty_port_tty_wakeup which does exactly that. One exception is ifx6x60 where tty_wakeup was open-coded. We now call tty_wakeup properly there. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18TTY: msm_smd_tty, clean up activate/shutdownJiri Slaby1-9/+5
Do not dig struct smd_tty_info out of tty_struct using tty_port_tty_get. It is unnecessarily too complicated, use simple container_of instead. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-25 22:08:14 +0000