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* tty/vt: Fix the memory leak in visual_initDongxing Zhang2015-07-231-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If vc->vc_uni_pagedir_loc is not NULL, its refcount needs to be decreased before vc_uni_pagedir_loc is re-assigned. unreferenced object 0xffff88002cdd13b0 (size 512): comm "setfont", pid 503, jiffies 4294896503 (age 722.828s) hex dump (first 32 bytes): 40 92 61 2b 00 88 ff ff 00 00 00 00 00 00 00 00 @.a+............ 00 00 00 00 00 00 00 00 a0 ad 61 2b 00 88 ff ff ..........a+.... backtrace: [<ffffffff817b755e>] kmemleak_alloc+0x4e/0xb0 [<ffffffff811d4898>] kmem_cache_alloc_trace+0x1c8/0x240 [<ffffffff814ae7d3>] con_do_clear_unimap.isra.2+0x83/0xe0 [<ffffffff814ae9b2>] con_clear_unimap+0x22/0x40 [<ffffffff814a8db8>] vt_ioctl+0xeb8/0x1170 [<ffffffff8149b458>] tty_ioctl+0x208/0xca0 [<ffffffff81207858>] do_vfs_ioctl+0x2f8/0x510 [<ffffffff81207af1>] SyS_ioctl+0x81/0xa0 [<ffffffff817ca2b2>] system_call_fastpath+0x16/0x75 [<ffffffffffffffff>] 0xffffffffffffffff unreferenced object 0xffff88002b619240 (size 256): comm "setfont", pid 503, jiffies 4294896503 (age 722.828s) hex dump (first 32 bytes): 90 bc 84 d5 00 88 ff ff 58 85 84 d5 00 88 ff ff ........X....... 88 ac 84 d5 00 88 ff ff e0 b1 84 d5 00 88 ff ff ................ backtrace: [<ffffffff817b755e>] kmemleak_alloc+0x4e/0xb0 [<ffffffff811d4898>] kmem_cache_alloc_trace+0x1c8/0x240 [<ffffffff814ae286>] con_insert_unipair+0x86/0x170 [<ffffffff814af107>] con_set_unimap+0x1b7/0x280 [<ffffffff814a8d65>] vt_ioctl+0xe65/0x1170 [<ffffffff8149b458>] tty_ioctl+0x208/0xca0 [<ffffffff81207858>] do_vfs_ioctl+0x2f8/0x510 [<ffffffff81207af1>] SyS_ioctl+0x81/0xa0 [<ffffffff817ca2b2>] system_call_fastpath+0x16/0x75 [<ffffffffffffffff>] 0xffffffffffffffff Signed-off-by: Dongxing Zhang <dongxing.zhang@intel.com> Signed-off-by: Xiaoming Wang <xiaoming.wang@intel.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Tested-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vt: Don't check KD_GRAPHICS when binding/unbindingDaniel Vetter2015-05-101-20/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This was introduced in commit 6db4063c5b72b46e9793b0f141a7a3984ac6facf Author: Antonino A. Daplas <adaplas@gmail.com> Date: Mon Jun 26 00:27:12 2006 -0700 [PATCH] VT binding: Add sysfs control to the VT layer with the justification "In addition, if any of the consoles are in KD_GRAPHICS mode, binding and unbinding will not succeed. KD_GRAPHICS mode usually indicates that the underlying console hardware is used for other purposes other than displaying text (ie X). This feature should prevent binding/unbinding from interfering with a graphics application using the VT." I think we should lift this artificial restriction though: - KD_GRAPHICS doesn't get cleaned up automatically, which means it's easy to have terminals stuck in KD_GRAPHICS when hacking around on X. - X doesn't really care, especially with drm where kms already blocks fbdev (and hence fbcon) when there's an active compositor. - This is a root-only interface with a separate .config option and it's possible to hang your machine already anyway if you unload/reload drivers and don't know what you're doing. With this patch i915.ko module reloading works again reliably, something in the recent fedora upgrades broke things. Cc: Antonino A. Daplas <adaplas@gmail.com> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Imre Deak <imre.deak@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Acked-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vt: fix console lock vs. kernfs s_active lock orderImre Deak2015-05-101-10/+51
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently there is a lock order problem between the console lock and the kernfs s_active lock of the console driver's bind sysfs entry. When writing to the sysfs entry the lock order is first s_active then console lock, when unregistering the console driver via do_unregister_con_driver() the order is the opposite. See the below bugzilla reference for one instance of a lockdep backtrace. Fix this by unregistering the console driver from a deferred work, where we can safely drop the console lock while unregistering the device and corresponding sysfs entries (which in turn acquire s_active). Note that we have to keep the console driver slot in the registered_con_driver array reserved for the driver that's being unregistered until it's fully removed. Otherwise a concurrent call to do_register_con_driver could try to reuse the same slot and fail when registering the corresponding device with a minor index that's still in use. Note that the referenced bug report contains two dmesg logs with two distinct lockdep reports: [1] is about a locking scenario involving s_active, console_lock and the fb_notifier list lock, while [2] is about a locking scenario involving only s_active and console_lock. In [1] locking fb_notifier triggers the lockdep warning only because of its dependence on console_lock, otherwise case [1] is the same s_active<->console_lock dependency problem fixed by this patch. Before this change we have the following locking scenarios involving the 3 locks: a) via do_unregister_framebuffer()->...->do_unregister_con_driver(): 1. console lock 2. fb_notifier lock 3. s_active lock b) for example via give_up_console()->do_unregister_con_driver(): 1. console lock 2. s_active lock c) via vt_bind()/vt_unbind(): 1. s_active lock 2. console lock Since c) is the console bind sysfs entry's write code path we can't change the locking order there. We can only fix this issue by removing s_active's dependence on the other two locks in a) and b). We can do this only in the vt code which owns the corresponding sysfs entry, so that after the change we have: a) 1. console lock 2. fb_notifier lock b) 1. console lock c) 1. s_active lock 2. console lock d) in the new con_driver_unregister_callback(): 1. s_active lock [1] https://bugs.freedesktop.org/attachment.cgi?id=87716 [2] https://bugs.freedesktop.org/attachment.cgi?id=107602 v2: - get console_lock earlier in con_driver_unregister_callback(), so we protect the following console driver field assignments there - add code coment explaining the reason for deferring the sysfs entry removal - add a third paragraph to the commit message explaining why there are two distinct lockdep reports and that this issue is independent of fb/fbcon. (Peter Hurley) v3: - clarify further the third paragraph v4: - rebased on v4 of patch 1/3 Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vt: add cursor blink interval escape sequenceScot Doyle2015-05-101-0/+9
| | | | | | | | | | | | | | | Add an escape sequence to specify the current console's cursor blink interval. The interval is specified as a number of milliseconds until the next cursor display state toggle, from 50 to 65535. /proc/loadavg did not show a difference with a one msec interval, but the lower bound is set to 50 msecs since slower hardware wasn't tested. Store the interval in the vc_data structure for later access by fbcon, initializing the value to fbcon's current hardcoded value of 200 msecs. Signed-off-by: Scot Doyle <lkml14@scotdoyle.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Use static attribute groups for sysfs entriesTakashi Iwai2015-03-261-39/+31
| | | | | | | | | Instead of manual calls of device_create_file() and device_remove_file(), pass the static attribute groups using device_create_with_groups(). Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vt: use msecs_to_jiffies for time conversionNicholas Mc Guire2015-03-071-1/+1
| | | | | | | | | | | Converting milliseconds to jiffies by "val * HZ / 1000" is technically OK but msecs_to_jiffies(val) is the cleaner solution and handles all corner cases correctly. This is a minor API consolidation only and should make things more readable. Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: vt/vt: fix sparse warningLad, Prabhakar2015-03-071-1/+1
| | | | | | | | this patch fixes following sparse warning: vt.c:1240:12: warning: symbol 'rgb_from_256' was not declared. Should it be static? Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vt: provide notifications on selection changesNicolas Pitre2015-02-021-1/+3
| | | | | | | | | | | | | The vcs device's poll/fasync support relies on the vt notifier to signal changes to the screen content. Notifier invocations were missing for changes that comes through the selection interface though. Fix that. Tested with BRLTTY 5.2. Signed-off-by: Nicolas Pitre <nico@linaro.org> Cc: Dave Mielke <dave@mielke.cc> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vt: fix locking around vt_bind/vt_unbindImre Deak2015-01-091-6/+5
| | | | | | | | | | | Currently vt_bind and vt_unbind access at least the con_driver object and registered_con_driver array without holding the console lock. Fix this by locking around the whole function in each case. Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vt: fix check for system/busy console drivers when unregistering themImre Deak2015-01-091-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The default console driver (conswitchp) and busy drivers bound to a console (as reported by con_is_bound()) shouldn't be unregistered. System console drivers (without the CON_DRIVER_FLAG_MODULE flag) can be unregistered, provided they are neither default nor busy. The current code checks for the CON_DRIVER_FLAG_INIT flag but this doesn't make sense: this flag is set for a driver whenever its associated console's con_startup() function is called, which first happens when the console driver is registered (so before the console gets bound) and gets cleared when the console gets unbound. The purpose of this flag is to show if we need to call con_startup() on a console before we use it. Based on the above, do_unregister_con_driver() in its current form will allow unregistering a console driver only if it was never bound, but will refuse to unregister one that was bound and later unbound. Fix this by dropping the CON_DRIVER_FLAG_INIT check, allowing unregistering of any console driver provided that it's not the default one and it's not busy. v2: - reword the third paragraph to clarify how the fix works (Peter Hurley) v3: - unchanged v4: - Allow unregistering a system console driver too, needed by i915 to unregister vgacon. Update commit description accordingly. (Daniel) Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: pr_warning->pr_warn and logging neateningJoe Perches2014-11-251-2/+2
| | | | | | | | | | | | | | Convert the pr_warning to the more common pr_warn. Other miscellanea: o Convert unusual PR_FMT define and uses to pr_fmt o Remove unnecessary OOM message o Fix grammar in an error message o Convert a pr_warning with a KERN_ERR to pr_err Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vt: Fix build breakage when !CONFIG_VT_CONSOLEPeter Hurley2014-11-221-2/+2
| | | | | | | | | | | | | Commit 68952076e9226cc23ebce66d3fc2fdb8b6c04c30 ("vt: Remove vt_get_kmsg_redirect() from uapi header") fails to compile if !CONFIG_VT_CONSOLE. Move macro definition for vt_get_kmsg_redirect() up with file-scope function declarations. Reported-by: Jim Davis <jim.epost@gmail.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty:vt remove obsolete struct initializerPeng Fan2014-11-051-6/+10
| | | | | | | | This patch fixes sparse warning: "obsolete struct initializer, use C99 syntax" Signed-off-by: Peng Fan <van.freenix@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vt: Remove vt_get_kmsg_redirect() from uapi headerPeter Hurley2014-11-051-0/+2
| | | | | | | | | vt_get_kmsg_redirect() only has meaning to the console driver as an alias for calling vt_kmsg_redirect(). Move the macro definition to the only source file which uses it; remove from uapi/linux/vt.h Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'drm-intel-fixes-2014-06-17' of ↵Dave Airlie2014-06-191-10/+14
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://anongit.freedesktop.org/drm-intel into drm-next First round of fixes for 3.16-rc, mostly cc: stable, and the vt/vgacon fixes from Daniel [1] to avoid hangs and unclaimed register errors on module load/reload. * tag 'drm-intel-fixes-2014-06-17' of git://anongit.freedesktop.org/drm-intel: drm/i915/bdw: remove erroneous chv specific workarounds from bdw code drm/i915: fix possible refcount leak when resetting forcewake drm/i915: Reorder semaphore deadlock check drm/i95: Initialize active ring->pid to -1 drm/i915: set backlight duty cycle after backlight enable for gen4 drm/i915: Avoid div-by-zero when pixel_multiplier is zero drm/i915: Disable FBC by default also on Haswell and later drm/i915: Kick out vga console drm/i915: Fixup global gtt cleanup vt: Don't ignore unbind errors in vt_unbind vt: Fix up unregistration of vt drivers vt: Fix replacement console check when unbinding
| * vt: Don't ignore unbind errors in vt_unbindDaniel Vetter2014-06-061-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Otherwise the loop will never stop since we don't make any forward progress. Noticed while breaking this accidentally in a painful attempt to make vga_con unregistering work. With this patch we'll bail out on the first attempt, which at least leaves a useful enough system behind for debugging. Livelocks on console_lock just aren't fun. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.cz> Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
| * vt: Fix up unregistration of vt driversDaniel Vetter2014-06-061-7/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A bunch of issues: - We should not kick out the default console (which is tracked in conswitchp), so check for that. - Add better error codes so callers can differentiate between "something went wrong" and "your driver isn't registered already". i915 needs that so it doesn't fall over when reloading the driver and hence vga_con is already unregistered. - There's a mess with the driver flags: What we need to check for is that the driver isn't used any more, i.e. unbound completely (FLAG_INIT). And not whether it's the boot console or not (which is the only one which doesn't have FLAG_MODULE). Otherwise there's no way to kick out the boot console, which i915 wants to do to prevent havoc with vga_con interferring (which tends to hang machines). Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.cz> Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
| * vt: Fix replacement console check when unbindingDaniel Vetter2014-06-061-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I don't fully understand the magic of the vt register/unregister logic, but apparently everything but the inital console (as set in the conswitchp pointer) is marked with FLAG_MODULE. Which means if something unregistered the boot vt driver (e.g. i915.ko kicking out vga_con) there's nothing left when trying to unbind e.g. fbcon through sysfs. But in most cases have the dummy console hanging around besides the boot console, so this test is fairly dubious. What we actually want is simply a different console than the one we want to unbind. v2: Correct the commit message to clarify that the dummy console isn't always around, but only in most cases (David). Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.cz> Cc: David Herrmann <dh.herrmann@gmail.com> Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
* | console: Use explicit pointer type for vc_uni_pagedir* fieldsTakashi Iwai2014-05-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The vc_data.vc_uni_pagedir filed is currently long int, supposedly to be served generically. This, however, leads to lots of cast to pointer, and rather it worsens the readability significantly. Actually, we have now only a single uni_pagedir map implementation, and this won't change likely. So, it'd be much more simple and error-prone to just use the exact pointer for struct uni_pagedir instead of long. Ditto for vc_uni_pagedir_loc. It's a pointer to the uni_pagedir, thus it can be changed similarly to the exact type. Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | vt: emulate 8- and 24-bit colour codes.Adam Borowski2014-05-281-8/+79
|/ | | | | | | | | | | | | Most other mainstream terminals support "xterm256" colours, which means people sometimes use these blindly without checking capabilities. Because of hardware limitations of VGA consoles, colours are downgraded to 16 foregrounds and 8 backgrounds. On fbdev consoles it would be possible to support them without quality loss, but adding that would require quite a large amount of code. Signed-off-by: Adam Borowski <kilobyte@angband.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vt: detect and ignore OSC codes.Adam Borowski2014-02-281-3/+11
| | | | | | | | | | | | | | | | | | | | | | These can be used to send commands consisting of an arbitrary string to the terminal, most often used to set a terminal's window title or to redefine the colour palette. Our console doesn't use OSC, unlike everything else, which can lead to junk being displayed if a process sends such a code unconditionally. The rules for termination follow established practice rather than Ecma-48. Ecma-48 requires the string to use only byte values 0x08..0x0D and 0x20..0x7E, terminated with either ESC \ or 0x9C. This would disallow using 8-bit characters, which are reasonable for example in window titles. A widespread idiom is to terminate with 0x07. The behaviour for other control characters differs between terminal emulators, I followed libvte and xterm: * 0x07 and ESC anything terminate * nothing else terminates, all 8-bit values including 0x9C are considered a part of the string Signed-off-by: Adam Borowski <kilobyte@angband.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vt: drop an useless enum and assignment.Adam Borowski2014-02-281-4/+2
| | | | | Signed-off-by: Adam Borowski <kilobyte@angband.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vt: Fix secure clear screenPetr Písař2014-02-131-0/+2
| | | | | | | | | | | | | | | | | \E[3J console code (secure clear screen) needs to update_screen(vc) in order to write-through blanks into off-screen video memory. This has been removed accidentally in 3.6 by: commit 81732c3b2fede049a692e58a7ceabb6d18ffb18c Author: Jean-François Moine <moinejf@free.fr> Date: Thu Sep 6 19:24:13 2012 +0200 tty vt: Fix line garbage in virtual console on command line edition Signed-off-by: Petr Písař <petr.pisar@atlas.cz> Cc: stable <stable@vger.kernel.org> # 3.6 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vt: properly ignore xterm-256 colour codesAdam Borowski2013-09-261-0/+22
| | | | | | | | | | | | | | | This is not a bug on our side, but a misdesign in ITU T.416, yet with all popular terminals supporting these codes, people consider this to be a bug in Linux. By breaking the design principles behind SGR codes (gracefully ignoring unsupported ones should not require knowing about them), 256 colour ones tend to turn blinking on before invoking an arbitrary unrelated command. This commit doesn't add such support, merely skips such codes without ill effects. Signed-off-by: Adam Borowski <kilobyte@angband.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vt: break a couple of obsolete SCOish codes.Adam Borowski2013-09-261-14/+1
| | | | | | | | | No modern terminal supports them, and SGR 38 conflicts with detecting xterm-256 colours. This also makes SGR 39 consistent with other popular terminals. Neither are used by ncurses' terminfo. Signed-off-by: Adam Borowski <kilobyte@angband.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vt: make the default color configurableClemens Ladisch2013-08-051-1/+3
| | | | | | | | | | | | | | | The virtual console has (undocumented) module parameters to set the colors for italic and underlined text, but the default text color was hardcoded for some reason. This made it impossible to change the color for startup messages, or to set the default for new virtual consoles. Add a module parameter for that, and document the entire bunch. Any hacker who thinks that a command prompt on a "black screen with white font" is not supicious enough can now use the kernel parameter vt.color=10 to get a nice, evil green. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Convert termios_mutex to termios_rwsemPeter Hurley2013-07-231-2/+2
| | | | | | | | | termios is commonly accessed unsafely (especially by N_TTY) because the existing mutex forces exclusive access. Convert existing usage. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge 3.10-rc3 into tty-nextGreg Kroah-Hartman2013-05-271-8/+6
|\ | | | | | | | | | | We want these fixes. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * tty/vt: Fix vc_deallocate() lock orderPeter Hurley2013-05-201-8/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that the tty port owns the flip buffers and i/o is allowed from the driver even when no tty is attached, the destruction of the tty port (and the flip buffers) must ensure that no outstanding work is pending. Unfortunately, this creates a lock order problem with the console_lock (see attached lockdep report [1] below). For single console deallocation, drop the console_lock prior to port destruction. When multiple console deallocation, defer port destruction until the consoles have been deallocated. tty_port_destroy() is not required if the port has not been used; remove from vc_allocate() failure path. [1] lockdep report from Dave Jones <davej@redhat.com> ====================================================== [ INFO: possible circular locking dependency detected ] 3.9.0+ #16 Not tainted ------------------------------------------------------- (agetty)/26163 is trying to acquire lock: blocked: ((&buf->work)){+.+...}, instance: ffff88011c8b0020, at: [<ffffffff81062065>] flush_work+0x5/0x2e0 but task is already holding lock: blocked: (console_lock){+.+.+.}, instance: ffffffff81c2fde0, at: [<ffffffff813bc201>] vt_ioctl+0xb61/0x1230 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (console_lock){+.+.+.}: [<ffffffff810b3f74>] lock_acquire+0xa4/0x210 [<ffffffff810416c7>] console_lock+0x77/0x80 [<ffffffff813c3dcd>] con_flush_chars+0x2d/0x50 [<ffffffff813b32b2>] n_tty_receive_buf+0x122/0x14d0 [<ffffffff813b7709>] flush_to_ldisc+0x119/0x170 [<ffffffff81064381>] process_one_work+0x211/0x700 [<ffffffff8106498b>] worker_thread+0x11b/0x3a0 [<ffffffff8106ce5d>] kthread+0xed/0x100 [<ffffffff81601cac>] ret_from_fork+0x7c/0xb0 -> #0 ((&buf->work)){+.+...}: [<ffffffff810b349a>] __lock_acquire+0x193a/0x1c00 [<ffffffff810b3f74>] lock_acquire+0xa4/0x210 [<ffffffff810620ae>] flush_work+0x4e/0x2e0 [<ffffffff81065305>] __cancel_work_timer+0x95/0x130 [<ffffffff810653b0>] cancel_work_sync+0x10/0x20 [<ffffffff813b8212>] tty_port_destroy+0x12/0x20 [<ffffffff813c65e8>] vc_deallocate+0xf8/0x110 [<ffffffff813bc20c>] vt_ioctl+0xb6c/0x1230 [<ffffffff813b01a5>] tty_ioctl+0x285/0xd50 [<ffffffff811ba825>] do_vfs_ioctl+0x305/0x530 [<ffffffff811baad1>] sys_ioctl+0x81/0xa0 [<ffffffff81601d59>] system_call_fastpath+0x16/0x1b other info that might help us debug this: [ 6760.076175] Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(console_lock); lock((&buf->work)); lock(console_lock); lock((&buf->work)); *** DEADLOCK *** 1 lock on stack by (agetty)/26163: #0: blocked: (console_lock){+.+.+.}, instance: ffffffff81c2fde0, at: [<ffffffff813bc201>] vt_ioctl+0xb61/0x1230 stack backtrace: Pid: 26163, comm: (agetty) Not tainted 3.9.0+ #16 Call Trace: [<ffffffff815edb14>] print_circular_bug+0x200/0x20e [<ffffffff810b349a>] __lock_acquire+0x193a/0x1c00 [<ffffffff8100a269>] ? sched_clock+0x9/0x10 [<ffffffff8100a269>] ? sched_clock+0x9/0x10 [<ffffffff8100a200>] ? native_sched_clock+0x20/0x80 [<ffffffff810b3f74>] lock_acquire+0xa4/0x210 [<ffffffff81062065>] ? flush_work+0x5/0x2e0 [<ffffffff810620ae>] flush_work+0x4e/0x2e0 [<ffffffff81062065>] ? flush_work+0x5/0x2e0 [<ffffffff810b15db>] ? mark_held_locks+0xbb/0x140 [<ffffffff8113c8a3>] ? __free_pages_ok.part.57+0x93/0xc0 [<ffffffff810b15db>] ? mark_held_locks+0xbb/0x140 [<ffffffff810652f2>] ? __cancel_work_timer+0x82/0x130 [<ffffffff81065305>] __cancel_work_timer+0x95/0x130 [<ffffffff810653b0>] cancel_work_sync+0x10/0x20 [<ffffffff813b8212>] tty_port_destroy+0x12/0x20 [<ffffffff813c65e8>] vc_deallocate+0xf8/0x110 [<ffffffff813bc20c>] vt_ioctl+0xb6c/0x1230 [<ffffffff810aec41>] ? lock_release_holdtime.part.30+0xa1/0x170 [<ffffffff813b01a5>] tty_ioctl+0x285/0xd50 [<ffffffff812b00f6>] ? inode_has_perm.isra.46.constprop.61+0x56/0x80 [<ffffffff811ba825>] do_vfs_ioctl+0x305/0x530 [<ffffffff812b04db>] ? selinux_file_ioctl+0x5b/0x110 [<ffffffff811baad1>] sys_ioctl+0x81/0xa0 [<ffffffff81601d59>] system_call_fastpath+0x16/0x1b Cc: Dave Jones <davej@redhat.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | TTY:vt: convert remain take_over_console's users to do_take_over_consoleWang YanQing2013-05-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: 1:convert all remain take_over_console to do_take_over_console 2:update take_over_console to do_take_over_console in comment Commit dc9641895abb ("vt: delete unneeded functions register_con_driver|take_over_console") delete take_over_console, but forget to convert remain take_over_console's users to new API do_take_over_console, this patch fix it. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Wang YanQing <udknight@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | vt: delete unneeded function unregister_con_driverWang YanQing2013-05-201-12/+1
| | | | | | | | | | | | | | | | | | | | Now there is no place use unregister_con_driver, and we can achieve unregister_con_driver's function with unregister_con_driver easily, so just delete it to reduce code size and duplication. Signed-off-by: Wang YanQing <udknight@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | fbcon: convert last two unregister_con_driver call to do_unregister_con_driverWang YanQing2013-05-201-1/+3
| | | | | | | | | | | | | | | | | | | | There are only two place use unregister_con_driver now, this patch convert them to do_unregister_con_driver too, then we can delete unregister_con_driver whos function can be achieved with do_unregister_con_driver easily to reduce code size and duplication. Signed-off-by: Wang YanQing <udknight@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | vt: delete unneeded function bind_con_driverWang YanQing2013-05-201-11/+0
| | | | | | | | | | | | | | | | | | | | Now there is no place use bind_con_driver, and do_bind_con_driver can achieve bind_con_driver's function easily, so just delete it to reduce code size and duplication. Signed-off-by: Wang YanQing <udknight@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | vt: convert last bind_con_driver call to do_bind_con_driverWang YanQing2013-05-201-2/+5
| | | | | | | | | | | | | | | | | | | | There is only one place use bind_con_driver now, this patch convert it to do_bind_con_driver too, then we can delete bind_con_driver whos function can be replaced by do_bind_con_driver easily to reduce code size and duplication. Signed-off-by: Wang YanQing <udknight@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | vt: delete unneeded function unbind_con_driverWang YanQing2013-05-201-28/+0
| | | | | | | | | | | | | | | | | | | | Now there is no place use unbind_con_driver, and we can achieve unbind_con_driver's function with do_unbind_con_driver easily, so just delete it to reduce code size and duplication. Signed-off-by: Wang YanQing <udknight@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | vt: convert last unbind_con_driver call to do_unbind_con_driverWang YanQing2013-05-201-2/+5
| | | | | | | | | | | | | | | | | | There is only one place use unbind_con_driver, this patch convert it to do_unbind_con_driver too, then we can delete unbind_con_driver to reduce code size and duplication. Signed-off-by: Wang YanQing <udknight@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | vt: delete unneeded functions register_con_driver|take_over_consoleWang YanQing2013-05-201-45/+0
|/ | | | | | | | | Now there is no place use register_con_driver|take_over_console, and we can achieve their function with do_register_con_driver| do_take_over_console easily, so just delete them to reduce code duplication. Signed-off-by: Wang YanQing <udknight@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linuxLinus Torvalds2013-02-251-38/+98
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull drm merge from Dave Airlie: "Highlights: - TI LCD controller KMS driver - TI OMAP KMS driver merged from staging - drop gma500 stub driver - the fbcon locking fixes - the vgacon dirty like zebra fix. - open firmware videomode and hdmi common code helpers - major locking rework for kms object handling - pageflip/cursor won't block on polling anymore! - fbcon helper and prime helper cleanups - i915: all over the map, haswell power well enhancements, valleyview macro horrors cleaned up, killing lots of legacy GTT code, - radeon: CS ioctl unification, deprecated UMS support, gpu reset rework, VM fixes - nouveau: reworked thermal code, external dp/tmds encoder support (anx9805), fences sleep instead of polling, - exynos: all over the driver fixes." Lovely conflict in radeon/evergreen_cs.c between commit de0babd60d8d ("drm/radeon: enforce use of radeon_get_ib_value when reading user cmd") and the new changes that modified that evergreen_dma_cs_parse() function. * 'drm-next' of git://people.freedesktop.org/~airlied/linux: (508 commits) drm/tilcdc: only build on arm drm/i915: Revert hdmi HDP pin checks drm/tegra: Add list of framebuffers to debugfs drm/tegra: Fix color expansion drm/tegra: Split DC_CMD_STATE_CONTROL register write drm/tegra: Implement page-flipping support drm/tegra: Implement VBLANK support drm/tegra: Implement .mode_set_base() drm/tegra: Add plane support drm/tegra: Remove bogus tegra_framebuffer structure drm: Add consistency check for page-flipping drm/radeon: Use generic HDMI infoframe helpers drm/tegra: Use generic HDMI infoframe helpers drm: Add EDID helper documentation drm: Add HDMI infoframe helpers video: Add generic HDMI infoframe helpers drm: Add some missing forward declarations drm: Move mode tables to drm_edid.c drm: Remove duplicate drm_mode_cea_vic() gma500: Fix n, m1 and m2 clock limits for sdvo and lvds ...
| * Merge branch 'console-fixes' into drm-nextDave Airlie2013-02-081-1/+1
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | (not the fbcon maintainer pull 2) fix bug in vgacon on bootup and fbcon losing fonts on startup. * console-fixes: (50 commits) fbcon: don't lose the console font across generic->chip driver switch vgacon/vt: clear buffer attributes when we load a 512 character font (v2)
| | * vgacon/vt: clear buffer attributes when we load a 512 character font (v2)Dave Airlie2013-02-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we switch from 256->512 byte font rendering mode, it means the current contents of the screen is being reinterpreted. The bit that holds the high bit of the 9-bit font, may have been previously set, and thus the new font misrenders. The problem case we see is grub2 writes spaces with the bit set, so it ends up with data like 0x820, which gets reinterpreted into 0x120 char which the font translates into G with a circumflex. This flashes up on screen at boot and is quite ugly. A current side effect of this patch though is that any rendering on the screen changes color to a slightly darker color, but at least the screen no longer corrupts. v2: as suggested by hpa, always clear the attribute space, whether we are are going to or from 512 chars. Cc: stable@vger.kernel.org Signed-off-by: Dave Airlie <airlied@redhat.com>
| * | fb: Yet another band-aid for fixing lockdep messTakashi Iwai2013-02-081-15/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I've still got lockdep warnings even after Alan's patch, and it seems that yet more band aids are required to paper over similar paths for unbind_con_driver() and unregister_con_driver(). After this hack, lockdep warnings are finally gone. Signed-off-by: Takashi Iwai <tiwai@suse.de> Cc: Alan Cox <alan@linux.intel.com> Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: stable <stable@vger.kernel.org> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Airlie <airlied@redhat.com>
| * | fb: rework locking to fix lock ordering on takeoverAlan Cox2013-02-081-23/+70
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adjust the console layer to allow a take over call where the caller already holds the locks. Make the fb layer lock in order. This is partly a band aid, the fb layer is terminally confused about the locking rules it uses for its notifiers it seems. [akpm@linux-foundation.org: remove stray non-ascii char, tidy comment] [akpm@linux-foundation.org: export do_take_over_console()] [airlied: cleanup another non-ascii char] Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Jiri Kosina <jkosina@suse.cz> Cc: stable <stable@vger.kernel.org> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Airlie <airlied@redhat.com>
* | tty vt: fix character insertion overflowNicolas Pitre2013-02-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 81732c3b2fed ("tty vt: Fix line garbage in virtual console on command line edition") broke insert_char() in multiple ways. Then commit b1a925f44a3a ("tty vt: Fix a regression in command line edition") partially fixed it. However, the buffer being moved is still too large and overflowing beyond the end of the current line, corrupting existing characters on the next line. Example test case: echo -e "abc\nde\x1b[A\x1b[4h \x1b[4l\x1b[B" Expected result: ab c de Current result: ab c e Needless to say that this is very annoying when inserting words in the middle of paragraphs with certain text editors. Signed-off-by: Nicolas Pitre <nico@linaro.org> Cc: Jean-François Moine <moinejf@free.fr> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: <stable@vger.kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | TTY: switch tty_schedule_flipJiri Slaby2013-01-151-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | Now, we start converting tty buffer functions to actually use tty_port. This will allow us to get rid of the need of tty in many call sites. Only tty_port will needed and hence no more tty_port_tty_get in those paths. This is the last one: tty_schedule_flip Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | TTY: switch tty_insert_flip_charJiri Slaby2013-01-151-1/+1
|/ | | | | | | | | | | | | Now, we start converting tty buffer functions to actually use tty_port. This will allow us to get rid of the need of tty in many call sites. Only tty_port will needed and hence no more tty_port_tty_get in those paths. tty_insert_flip_char is the next one to proceed. This one is used all over the code, so the patch is huge. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'tty-3.8-rc1' of ↵Linus Torvalds2012-12-111-1/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull TTY/Serial merge from Greg Kroah-Hartman: "Here's the big tty/serial tree set of changes for 3.8-rc1. Contained in here is a bunch more reworks of the tty port layer from Jiri and bugfixes from Alan, along with a number of other tty and serial driver updates by the various driver authors. Also, Jiri has been coerced^Wconvinced to be the co-maintainer of the TTY layer, which is much appreciated by me. All of these have been in the linux-next tree for a while. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>" Fixed up some trivial conflicts in the staging tree, due to the fwserial driver having come in both ways (but fixed up a bit in the serial tree), and the ioctl handling in the dgrp driver having been done slightly differently (staging tree got that one right, and removed both TIOCGSOFTCAR and TIOCSSOFTCAR). * tag 'tty-3.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (146 commits) staging: sb105x: fix potential NULL pointer dereference in mp_chars_in_buffer() staging/fwserial: Remove superfluous free staging/fwserial: Use WARN_ONCE when port table is corrupted staging/fwserial: Destruct embedded tty_port on teardown staging/fwserial: Fix build breakage when !CONFIG_BUG staging: fwserial: Add TTY-over-Firewire serial driver drivers/tty/serial/serial_core.c: clean up HIGH_BITS_OFFSET usage staging: dgrp: dgrp_tty.c: Audit the return values of get/put_user() staging: dgrp: dgrp_tty.c: Remove the TIOCSSOFTCAR ioctl handler from dgrp driver serial: ifx6x60: Add modem power off function in the platform reboot process serial: mxs-auart: unmap the scatter list before we copy the data serial: mxs-auart: disable the Receive Timeout Interrupt when DMA is enabled serial: max310x: Setup missing "can_sleep" field for GPIO tty/serial: fix ifx6x60.c declaration warning serial: samsung: add devicetree properties for non-Exynos SoCs serial: samsung: fix potential soft lockup during uart write tty: vt: Remove redundant null check before kfree. tty/8250 Add check for pci_ioremap_bar failure tty/8250 Add support for Commtech's Fastcom Async-335 and Fastcom Async-PCIe cards tty/8250 Add XR17D15x devices to the exar_handle_irq override ...
| * TTY: call tty_port_destroy in the rest of driversJiri Slaby2012-11-151-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After commit "TTY: move tty buffers to tty_port", the tty buffers are not freed in some drivers. This is because tty_port_destructor is not called whenever a tty_port is freed. This was an assumption I counted with but was unfortunately untrue. So fix the drivers to fulfil this assumption. To be sure, the TTY buffers (and later some stuff) are gone along with the tty_port, we have to call tty_port_destroy at tear-down places. This is mostly where the structure containing a tty_port is freed. This patch does exactly that -- put tty_port_destroy at those places. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | tty vt: Fix a regression in command line editionJean-François Moine2012-11-211-4/+4
|/ | | | | | | | | | | | | | The commit 81732c3b2fede049a692e58a7ceabb6d18ffb18c ("Fix line garbage in virtual console on command line edition") made a regression with some machines: some characters were not erased after line edition. This patch adjusts the number of moved characters and the size of the region to be updated. Signed-off-by: Jean-François Moine <moinejf@free.fr> Tested-by: Krzysztof Mazur <krzysiek@podlesie.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'for_linus-3.7' of ↵Linus Torvalds2012-10-131-0/+13
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb Pull KGDB/KDB fixes and cleanups from Jason Wessel: "Cleanups - Clean up compile warnings in kgdboc.c and x86/kernel/kgdb.c - Add module event hooks for simplified debugging with gdb Fixes - Fix kdb to stop paging with 'q' on bta and dmesg - Fix for data that scrolls off the vga console due to line wrapping when using the kdb pager New - The debug core registers for kernel module events which allows a kernel aware gdb to automatically load symbols and break on entry to a kernel module - Allow kgdboc=kdb to setup kdb on the vga console" * tag 'for_linus-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb: tty/console: fix warnings in drivers/tty/serial/kgdboc.c kdb,vt_console: Fix missed data due to pager overruns kdb: Fix dmesg/bta scroll to quit with 'q' kgdboc: Accept either kbd or kdb to activate the vga + keyboard kdb shell kgdb,x86: fix warning about unused variable mips,kgdb: fix recursive page fault with CONFIG_KPROBES kgdb: Add module event hooks
| * kdb,vt_console: Fix missed data due to pager overrunsJason Wessel2012-10-121-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is possible to miss data when using the kdb pager. The kdb pager does not pay attention to the maximum column constraint of the screen or serial terminal. This result is not incrementing the shown lines correctly and the pager will print more lines that fit on the screen. Obviously that is less than useful when using a VGA console where you cannot scroll back. The pager will now look at the kdb_buffer string to see how many characters are printed. It might not be perfect considering you can output ASCII that might move the cursor position, but it is a substantially better approximation for viewing dmesg and trace logs. This also means that the vt screen needs to set the kdb COLUMNS variable. Cc: <stable@vger.kernel.org> Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
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