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path: root/drivers/tty/pty.c
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2013-06-17tty: Fix transient pty write() EIOPeter Hurley
Commit 699390354da6c258b65bf8fa79cfd5feaede50b6 ('pty: Ignore slave pty close() if never successfully opened') introduced a bug with ptys whereby a write() in parallel with an open() on an existing pty could mistakenly indicate an I/O error. Only indicate an I/O error if the condition on open() actually exists. Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Cc: stable <stable@vger.kernel.org> # 3.9 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-01tty: fix up atime/mtime mess, take threeLinus Torvalds
We first tried to avoid updating atime/mtime entirely (commit b0de59b5733d: "TTY: do not update atime/mtime on read/write"), and then limited it to only update it occasionally (commit 37b7f3c76595: "TTY: fix atime/mtime regression"), but it turns out that this was both insufficient and overkill. It was insufficient because we let people attach to the shared ptmx node to see activity without even reading atime/mtime, and it was overkill because the "only once a minute" means that you can't really tell an idle person from an active one with 'w'. So this tries to fix the problem properly. It marks the shared ptmx node as un-notifiable, and it lowers the "only once a minute" to a few seconds instead - still long enough that you can't time individual keystrokes, but short enough that you can tell whether somebody is active or not. Reported-by: Simon Kirby <sim@hostway.ca> Acked-by: Jiri Slaby <jslaby@suse.cz> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-15TTY: pty, fix compilation warningJiri Slaby
When CONFIG_UNIX98_PTYS is unset, we see this warning in pty: drivers/tty/pty.c:409:13: warning: ‘pty_unix98_shutdown’ defined but not used Fix that by moving the function to a section which depends on that config. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reported-by: Toralf Foerster <toralf.foerster@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-15pty: Remove redundant itty resetPeter Hurley
port->itty has already been reset by release_tty() before pty_cleanup() is called. Call stack: release_tty() tty_kref_put() queue_release_one_tty() release_one_tty() : workqueue tty->ops->cleanup() pty_cleanup() Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-04pty: Ignore slave open count for master pty openPeter Hurley
Multiple slave pty opens may be performed in parallel with the master open. Of course, all the slave opens will fail because the master pty is still locked but during this time the slave pty count will be artificially greater than 1. This is should not cause the master pty open to fail. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-04pty: Ignore slave pty close() if never successfully openedPeter Hurley
If the master and slave ptys are opened in parallel, the slave open fails because the pty is still locked. This is as designed. However, pty_close() is still called for the slave pty which sets TTY_OTHER_CLOSED in the master pty. This can cause the master open to fail as well. Use a common pattern in other tty drivers by setting TTY_IO_ERROR until the open is successful and only closing the pty if not set. Note: the master pty always closes regardless of whether the open was successful, so that proper cleanup can occur. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-04pty: Fix BUG()s when ptmx_open() errors outPeter Hurley
If pmtx_open() fails to get a slave inode or fails the pty_open(), the tty is released as part of the error cleanup. As evidenced by the first BUG stacktrace below, pty_close() assumes that the linked pty has a valid, initialized inode* stored in driver_data. Also, as evidenced by the second BUG stacktrace below, pty_unix98_shutdown() assumes that the master pty's driver_data has been initialized. 1) Fix the invalid assumption in pty_close(). 2) Initialize driver_data immediately so proper devpts fs cleanup occurs. Fixes this BUG: [ 815.868844] BUG: unable to handle kernel NULL pointer dereference at 0000000000000028 [ 815.869018] IP: [<ffffffff81207bcc>] devpts_pty_kill+0x1c/0xa0 [ 815.869190] PGD 7c775067 PUD 79deb067 PMD 0 [ 815.869315] Oops: 0000 [#1] PREEMPT SMP [ 815.869443] Modules linked in: kvm_intel kvm snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_seq_midi microcode snd_rawmidi psmouse serio_raw snd_seq_midi_event snd_seq snd_timer$ [ 815.870025] CPU 0 [ 815.870143] Pid: 27819, comm: stress_test_tty Tainted: G W 3.8.0-next-20130125+ttypatch-2-xeon #2 Bochs Bochs [ 815.870386] RIP: 0010:[<ffffffff81207bcc>] [<ffffffff81207bcc>] devpts_pty_kill+0x1c/0xa0 [ 815.870540] RSP: 0018:ffff88007d3e1ac8 EFLAGS: 00010282 [ 815.870661] RAX: ffff880079c20800 RBX: 0000000000000000 RCX: 0000000000000000 [ 815.870804] RDX: ffff880079c209a8 RSI: 0000000000000286 RDI: 0000000000000000 [ 815.870933] RBP: ffff88007d3e1ae8 R08: 0000000000000000 R09: 0000000000000000 [ 815.871078] R10: 0000000000000000 R11: 0000000000000001 R12: ffff88007bfb7e00 [ 815.871209] R13: 0000000000000005 R14: ffff880079c20c00 R15: ffff880079c20c00 [ 815.871343] FS: 00007f2e86206700(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000 [ 815.871495] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 815.871617] CR2: 0000000000000028 CR3: 000000007ae56000 CR4: 00000000000006f0 [ 815.871752] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 815.871902] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 815.872012] Process stress_test_tty (pid: 27819, threadinfo ffff88007d3e0000, task ffff88007c874530) [ 815.872012] Stack: [ 815.872012] ffff88007bfb7e00 ffff880079c20c00 ffff88007bfb7e00 0000000000000005 [ 815.872012] ffff88007d3e1b08 ffffffff81417be7 ffff88007caa9bd8 ffff880079c20800 [ 815.872012] ffff88007d3e1bc8 ffffffff8140e5f8 0000000000000000 0000000000000000 [ 815.872012] Call Trace: [ 815.872012] [<ffffffff81417be7>] pty_close+0x157/0x170 [ 815.872012] [<ffffffff8140e5f8>] tty_release+0x138/0x580 [ 815.872012] [<ffffffff816d29f3>] ? _raw_spin_lock+0x23/0x30 [ 815.872012] [<ffffffff816d267a>] ? _raw_spin_unlock+0x1a/0x40 [ 815.872012] [<ffffffff816d0178>] ? __mutex_unlock_slowpath+0x48/0x60 [ 815.872012] [<ffffffff81417dff>] ptmx_open+0x11f/0x180 [ 815.872012] [<ffffffff8119394b>] chrdev_open+0x9b/0x1c0 [ 815.872012] [<ffffffff8118d643>] do_dentry_open+0x203/0x290 [ 815.872012] [<ffffffff811938b0>] ? cdev_put+0x30/0x30 [ 815.872012] [<ffffffff8118d705>] finish_open+0x35/0x50 [ 815.872012] [<ffffffff8119dcce>] do_last+0x6fe/0xe90 [ 815.872012] [<ffffffff8119a7af>] ? link_path_walk+0x7f/0x880 [ 815.872012] [<ffffffff810909d5>] ? cpuacct_charge+0x75/0x80 [ 815.872012] [<ffffffff8119e51c>] path_openat+0xbc/0x4e0 [ 815.872012] [<ffffffff816d0fd0>] ? __schedule+0x400/0x7f0 [ 815.872012] [<ffffffff8140e956>] ? tty_release+0x496/0x580 [ 815.872012] [<ffffffff8119ec11>] do_filp_open+0x41/0xa0 [ 815.872012] [<ffffffff816d267a>] ? _raw_spin_unlock+0x1a/0x40 [ 815.872012] [<ffffffff811abe39>] ? __alloc_fd+0xe9/0x140 [ 815.872012] [<ffffffff8118ea44>] do_sys_open+0xf4/0x1e0 [ 815.872012] [<ffffffff8118eb51>] sys_open+0x21/0x30 [ 815.872012] [<ffffffff816da499>] system_call_fastpath+0x16/0x1b [ 815.872012] Code: 0f 1f 80 00 00 00 00 45 31 e4 eb d7 0f 0b 90 0f 1f 44 00 00 55 48 89 e5 48 83 ec 20 48 89 5d e8 48 89 fb 4c 89 65 f0 4c 89 6d f8 <48> 8b 47 28 48 81 78 58 d1 1c 0$ [ 815.872012] RIP [<ffffffff81207bcc>] devpts_pty_kill+0x1c/0xa0 [ 815.872012] RSP <ffff88007d3e1ac8> [ 815.872012] CR2: 0000000000000028 [ 815.897036] ---[ end trace eadf50b7f34e47d5 ]--- Fixes this BUG also: [ 608.366836] BUG: unable to handle kernel NULL pointer dereference at 0000000000000028 [ 608.366948] IP: [<ffffffff812078d8>] devpts_kill_index+0x18/0x70 [ 608.367050] PGD 7c75b067 PUD 7b919067 PMD 0 [ 608.367135] Oops: 0000 [#1] PREEMPT SMP [ 608.367201] Modules linked in: kvm_intel kvm snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_seq_midi snd_rawmidi snd_seq_midi_event microcode snd_seq psmouse snd_timer snd_seq_device serio_raw snd mac_hid soundcore snd_page_alloc rfcomm virtio_balloon parport_pc bnep bluetooth ppdev i2c_piix4 lp parport floppy [ 608.367617] CPU 2 [ 608.367669] Pid: 1918, comm: stress_test_tty Tainted: G W 3.8.0-next-20130125+ttypatch-2-xeon #2 Bochs Bochs [ 608.367796] RIP: 0010:[<ffffffff812078d8>] [<ffffffff812078d8>] devpts_kill_index+0x18/0x70 [ 608.367885] RSP: 0018:ffff88007ae41a88 EFLAGS: 00010286 [ 608.367951] RAX: ffffffff81417e80 RBX: ffff880036472400 RCX: 0000000180400028 [ 608.368010] RDX: ffff880036470004 RSI: 0000000000000004 RDI: 0000000000000000 [ 608.368010] RBP: ffff88007ae41a98 R08: 0000000000000000 R09: 0000000000000001 [ 608.368010] R10: ffffea0001f22e40 R11: ffffffff814151d5 R12: 0000000000000004 [ 608.368010] R13: ffff880036470000 R14: 0000000000000004 R15: ffff880036472400 [ 608.368010] FS: 00007ff7a5268700(0000) GS:ffff88007fd00000(0000) knlGS:0000000000000000 [ 608.368010] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 608.368010] CR2: 0000000000000028 CR3: 000000007a0fd000 CR4: 00000000000006e0 [ 608.368010] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 608.368010] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 608.368010] Process stress_test_tty (pid: 1918, threadinfo ffff88007ae40000, task ffff88003688dc40) [ 608.368010] Stack: [ 608.368010] ffff880036472400 0000000000000001 ffff88007ae41aa8 ffffffff81417e98 [ 608.368010] ffff88007ae41ac8 ffffffff8140c42b ffff88007ac73100 ffff88007ac73100 [ 608.368010] ffff88007ae41b98 ffffffff8140ead5 ffff88007ae41b38 ffff88007ca40e40 [ 608.368010] Call Trace: [ 608.368010] [<ffffffff81417e98>] pty_unix98_shutdown+0x18/0x20 [ 608.368010] [<ffffffff8140c42b>] release_tty+0x3b/0xe0 [ 608.368010] [<ffffffff8140ead5>] __tty_release+0x575/0x5d0 [ 608.368010] [<ffffffff816d2c63>] ? _raw_spin_lock+0x23/0x30 [ 608.368010] [<ffffffff816d28ea>] ? _raw_spin_unlock+0x1a/0x40 [ 608.368010] [<ffffffff816d03e8>] ? __mutex_unlock_slowpath+0x48/0x60 [ 608.368010] [<ffffffff8140ef79>] tty_open+0x449/0x5f0 [ 608.368010] [<ffffffff8119394b>] chrdev_open+0x9b/0x1c0 [ 608.368010] [<ffffffff8118d643>] do_dentry_open+0x203/0x290 [ 608.368010] [<ffffffff811938b0>] ? cdev_put+0x30/0x30 [ 608.368010] [<ffffffff8118d705>] finish_open+0x35/0x50 [ 608.368010] [<ffffffff8119dcce>] do_last+0x6fe/0xe90 [ 608.368010] [<ffffffff8119a7af>] ? link_path_walk+0x7f/0x880 [ 608.368010] [<ffffffff8119e51c>] path_openat+0xbc/0x4e0 [ 608.368010] [<ffffffff8119ec11>] do_filp_open+0x41/0xa0 [ 608.368010] [<ffffffff816d28ea>] ? _raw_spin_unlock+0x1a/0x40 [ 608.368010] [<ffffffff811abe39>] ? __alloc_fd+0xe9/0x140 [ 608.368010] [<ffffffff8118ea44>] do_sys_open+0xf4/0x1e0 [ 608.368010] [<ffffffff816d2c63>] ? _raw_spin_lock+0x23/0x30 [ 608.368010] [<ffffffff8118eb51>] sys_open+0x21/0x30 [ 608.368010] [<ffffffff816da719>] system_call_fastpath+0x16/0x1b [ 608.368010] Code: ec 48 83 c4 10 5b 41 5c 5d c3 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 48 83 ec 10 4c 89 65 f8 41 89 f4 48 89 5d f0 <48> 8b 47 28 48 81 78 58 d1 1c 00 00 74 0b 48 8b 05 4b 66 cf 00 [ 608.368010] RIP [<ffffffff812078d8>] devpts_kill_index+0x18/0x70 [ 608.368010] RSP <ffff88007ae41a88> [ 608.368010] CR2: 0000000000000028 [ 608.394153] ---[ end trace afe83b0fb5fbda93 ]--- Reported-by: Ilya Zykov <ilya@ilyx.ru> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-25Merge 3.8-rc5 into tty-nextGreg Kroah-Hartman
This resolves a number of tty driver merge issues found in linux-next Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-17pty: return EINVAL for TIOCGPTN for BSD ptysJiri Slaby
Commit bbb63c514a3464342967237a51a21ea8f61ab951 (drivers:tty:fix up ENOIOCTLCMD error handling) changed the default return value from tty ioctl to be ENOTTY and not EINVAL. This is appropriate. But in case of TIOCGPTN for the old BSD ptys glibc started failing because it expects EINVAL to be returned. Only then it continues to obtain the pts name the other way around. So fix this case by explicit return of EINVAL in this case. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reported-by: Florian Westphal <fw@strlen.de> Cc: Alan Cox <alan@linux.intel.com> Cc: stable <stable@vger.kernel.org> # 3.7+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15TTY: do not reset master's packet modeJiri Slaby
Now that login from util-linux is forced to drop all references to a TTY which it wants to hangup (to reach reference count 1) we are seeing issues with telnet. When login closes its last reference to the slave PTY, it also resets packet mode on the *master* side. And we have a race here. What telnet does is fork+exec of `login'. Then there are two scenarios: * `login' closes the slave TTY and resets thus master's packet mode, but even now telnet properly sets the mode, or * `telnetd' sets packet mode on the master, `login' closes the slave TTY and resets master's packet mode. The former case is OK. However the latter happens in much more cases, by the order of magnitude to be precise. So when one tries to login to such a messed telnet setup, they see the following: inux login: ogin incorrect Note the missing first letters -- telnet thinks it is still in the packet mode, so when it receives "linux login" from `login', it considers "l" as the type of the packet and strips it. SuS does not mention how the implementation should behave. Both BSDs I checked (Free and Net) do not reset the flag upon the last close. By this I am resurrecting an old bug, see References. We are hitting it regularly now, i.e. with updated util-linux, ergo login. Here, I am changing a behavior introduced back in 2.1 times. It would better have a long time testing before goes upstream. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Mauro Carvalho Chehab <mchehab@redhat.com> Cc: Bryan Mason <bmason@redhat.com> References: https://lkml.org/lkml/2009/11/11/223 References: https://bugzilla.redhat.com/show_bug.cgi?id=504703 References: https://bugzilla.novell.com/show_bug.cgi?id=797042 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15tty: cleanup checkpatch warning in pty.cCong Ding
spaces are used for indent in 3 places of tty/pty.c, we change it to tab. Signed-off-by: Cong Ding <dinggnu@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15tty: cleanup the panic messageCong Ding
the "\n" in panic message is excess, so we remove it in tty/pty.c as what it is used in other places. Signed-off-by: Cong Ding <dinggnu@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15TTY: switch tty_flip_buffer_pushJiri Slaby
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. Now, the one where most of tty_port_tty_get gets removed: tty_flip_buffer_push. IOW we also closed all the races in drivers not using tty_port_tty_get at all yet. Also we move tty_flip_buffer_push declaration from include/linux/tty.h to include/linux/tty_flip.h to all others while we are changing it anyway. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15TTY: switch tty_insert_flip_stringJiri Slaby
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_string this time. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-21pty: Mark pty_resize staticJosh Triplett
Nothing outside of drivers/tty/pty.c references pty_resize. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-15TTY: pty, fix tty buffers leakJiri Slaby
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. PTY is one of those, here we just need to use tty_port_put instead of kfree. (Assuming tty_port_destructor does not need port->ops to be set which we change here too.) Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-25tty: Add get- ioctls to fetch tty status v3Cyrill Gorcunov
For checkpoint/restore we need to know if tty has exclusive or packet mode set, as well as if pty is currently locked. Just to be able to restore this characteristics. For this sake the following ioctl codes are introduced - TIOCGPKT to get packet mode state - TIOCGPTLCK to get Pty locked state - TIOCGEXCL to get Exclusive mode state Note this ioctls are a bit unsafe in terms of data obtained consistency. The tty characteristics might be changed right after ioctl complete. Keep it in mind and use this ioctl carefully. v2: - Use TIOC prefix for ioctl codes (by jslaby@) Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> CC: Alan Cox <alan@lxorguk.ukuu.org.uk> CC: "H. Peter Anvin" <hpa@zytor.com> CC: Pavel Emelyanov <xemul@parallels.com> CC: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-25tty: pty - Move TIOCPKT handling into pty.cCyrill Gorcunov
Since this ioctl is for pty devices only move it to pty.c. v2: - drop PTY_TYPE_MASTER test since it's master peer ioctl anyway (by jslaby@) Suggested-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> CC: "H. Peter Anvin" <hpa@zytor.com> CC: Pavel Emelyanov <xemul@parallels.com> CC: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: move tty buffers to tty_portJiri Slaby
So this is it. The big step why we did all the work over the past kernel releases. Now everything is prepared, so nothing protects us from doing that big step. | | \ \ nnnn/^l | | | | \ / / | | | '-,.__ => \/ ,-` => | '-,.__ | O __.´´) ( .` | O __.´´) ~~~ ~~ `` ~~~ ~~ The buffers are now in the tty_port structure and we can start teaching the buffer helpers (insert char/string, flip etc.) to use tty_port instead of tty_struct all around. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: add port -> tty linkJiri Slaby
For that purpose we have to temporarily introduce a second tty back pointer into tty_port. It is because serial layer, and maybe others, still do not use tty_port_tty_set/get. So that we cannot set the tty_port->tty to NULL at will now. Yes, the fix would be to convert whole serial layer and all its users to tty_port_tty_set/get. However we are in the process of removing the need of tty in most of the call sites, so this would lead to a duplicated work. Instead we have now tty_port->itty (internal tty) which will be used only in flush_to_ldisc. For that one it is ensured that itty is valid wherever the work is run. IOW, the work is synchronously cancelled before we set itty to NULL and also before hangup is processed. After we need only tty_port and not tty_struct in most code, this shall be changed to tty_port_tty_set/get and itty removed completely. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: move devpts kill to ptyJiri Slaby
Now that we have control over tty->driver_data in pty, we can just kill the /dev/pts/ in pty code too. Namely, in ->shutdown hook of tty. For pty, this is called only once, for whichever end is closed last. But we don't care, both driver_data are the inode as it used to be till now. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: devpts, do not set driver_dataJiri Slaby
The goal is to stop setting and using tty->driver_data in devpts code. It should be used solely by the driver's code, pty in this case. Now driver_data are managed only in the pty driver. devpts_pty_new is switched to accept what we used to dig out of tty_struct, i.e. device node number and index. This also removes a note about driver_data being set outside of the driver. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: devpts, return created inode from devpts_pty_newJiri Slaby
The goal is to stop setting and using tty->driver_data in devpts code. It should be used solely by the driver's code, pty in this case. For the cleanup of layering, we will need the inode created in devpts_pty_new to be stored into slave's driver_data. So we convert devpts_pty_new to return the inode or an ERR_PTR-encoded error in case of failure. The move of 'inode = new_inode(sb);' from declarators to the code is only cosmetical, but it makes the code easier to read. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: devpts, don't care about TTY in devpts_get_ttyJiri Slaby
The goal is to stop setting and using tty->driver_data in devpts code. It should be used solely by the driver's code, pty in this case. First, here we remove TTY from devpts_get_tty and rename it to devpts_get_priv. Note we do not remove type safety, we just shift the [implicit] (void *) cast one layer up. index was unused in devpts_get_tty, so remove that from the prototype too. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-21pty: Fix locking bug on error pathAlan Cox
We end up dropping the mutex twice on some errors. We don't want to do that. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-16TTY: tty_alloc_driver() returns error pointersDan Carpenter
We changed these from alloc_tty_driver() to tty_alloc_driver() so the error handling needs to modified to check for IS_ERR() instead of NULL. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-13TTY: pty, switch to tty_alloc_driverJiri Slaby
Switch to the new driver allocation interface, as this is one of the special call-sites. Here, we need TTY_DRIVER_DYNAMIC_ALLOC to not allocate tty_driver->ports, cdevs and potentially other structures because we reserve too many lines in pty. Instead, it provides the tty_port<->tty_struct link in tty->ops->install already. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-10TTY: pty, stop passing NULL to free_tty_structJiri Slaby
In case alloc_tty_struct fails in pty_common_install, we pass NULL to free_tty_struct. This is invalid as the function is not ready to cope with that. And even if it was, it is not nice to do that anyway. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-10tty: localise the lockAlan Cox
The termios and other changes mean the other protections needed on the driver tty arrays should be adequate. Turn it all back on. This contains pieces folded in from the fixes made to the original patches | From: Geert Uytterhoeven <geert@linux-m68k.org> (fix m68k) | From: Paul Gortmaker <paul.gortmaker@windriver.com> (fix cris) | From: Jiri Kosina <jkosina@suze.cz> (lockdep) | From: Eric Dumazet <eric.dumazet@gmail.com> (lockdep) Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-27tty: Fix race in tty releaseAlan Cox
Ian Abbott found that the tty layer would explode with the right set of parallel open and close operations. This is because we race in the handling of tty->drivers->termios[]. Correct this by Making tty_ldisc_release behave like nromal code (takes the lock, does stuff, drops the lock) Drop the tty lock earlier in tty_ldisc_release Taking the tty mutex around the driver->termios update in all cases Adding a WARN_ON to catch future screwups. I also forgot to clean up the pty resources properly. With a pty pair we need to pull both halves out of the tables. Signed-off-by: Alan Cox <alan@linux.intel.com> Tested-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17tty: Move the handling of the tty release logicAlan Cox
Now that we don't have tty->termios tied to drivers->tty we can untangle the logic here. In addition we can push the removal logic out of the destructor path. At that point we can think about sorting out tty_port and console and all the other ugly hangovers. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-16tty: move the termios object into the ttyAlan Cox
This will let us sort out a whole pile of tty related races. The alternative would be to keep points and refcount the termios objects. However 1. They are tiny anyway 2. Many devices don't use the stored copies 3. We can remove a pty special case Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-16tty: revert incorrectly applied lock patchAlan Cox
I sent GregKH this after the pre-requisites. He dropped the pre-requesites for good reason and unfortunately then applied this patch. Without this reverted you get random kernel memory corruption which will make bisecting anything between it and the properly applied patches a complete sod. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-12tty: double unlock on error in ptmx_open()Dan Carpenter
The problem here is that we called mutex_unlock(&devpts_mutex) on the error path when we weren't holding the lock. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-06tty: localise the lockAlan Cox
The termios and other changes mean the other protections needed on the driver tty arrays should be adequate. Turn it all back on. This contains pieces folded in from the fixes made to the original patches | From: Geert Uytterhoeven <geert@linux-m68k.org> (fix m68k) | From: Paul Gortmaker <paul.gortmaker@windriver.com> (fix cris) | From: Jiri Kosina <jkosina@suze.cz> (lockdep) | From: Eric Dumazet <eric.dumazet@gmail.com> (lockdep) Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13PTY: add tty_portJiri Slaby
This has *no* function in the PTY driver yet. However as the tty buffers will move to the tty_port structure, we will need tty_port for all TTYs in the system, PTY inclusive. For PTYs this is ensured by allocating 2 tty_port's in pty_install, i.e. where the tty->link is allocated. Both tty_port's are properly assigned to each end of the tty. Freeing is done at the same place where tty is freed, i.e. in tty->ops->cleanup. This means BTW that tty_port does not outlive TTY in PTY. This might be a subject to change in the future if we see some problems. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13PTY: merge pty_install implementationsJiri Slaby
There are currently two instances of code which handles PTY install. One for the legacy BSD PTY's, one for unix98's PTY's. Both of them are very similar and differ only in termios allocation and handling. Since we will need to allocate a tty_port at that place, this would require editing two places with the same pattern. Instead, let us move the implementation to one common place and call it from both places. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13PTY: remove one empty ops->removeJiri Slaby
Currently, there are two as a left-over from previous patches. Although we really need to provide an empty handler, we do not need two. So remove one of them. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-02tty: Revert the tty locking series, it needs more workLinus Torvalds
This reverts the tty layer change to use per-tty locking, because it's not correct yet, and fixing it will require some more deep surgery. The main revert is d29f3ef39be4 ("tty_lock: Localise the lock"), but there are several smaller commits that built upon it, they also get reverted here. The list of reverted commits is: fde86d310886 - tty: add lockdep annotations 8f6576ad476b - tty: fix ldisc lock inversion trace d3ca8b64b97e - pty: Fix lock inversion b1d679afd766 - tty: drop the pty lock during hangup abcefe5fc357 - tty/amiserial: Add missing argument for tty_unlock() fd11b42e3598 - cris: fix missing tty arg in wait_event_interruptible_tty call d29f3ef39be4 - tty_lock: Localise the lock The revert had a trivial conflict in the 68360serial.c staging driver that got removed in the meantime. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29pty: Fix lock inversionAlan Cox
The ptmx_open path takes the tty and devpts locks in the wrong order because tty_init_dev locks and returns a locked tty. As far as I can tell this is actually safe anyway because the tty being returned is new so nobody can get a reference to lock it at this point. However we don't even need the devpts lock at this point, it's only held as a byproduct of the way the locks were pushe down. Signed-off-by: Alan Cox <alan@linux.intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-09tty: drop the pty lock during hangupAlan Cox
In theory we don't need it, in practice we are hitting some ill understood deadlock when we don't drop it. The old code dropped it here so we are not undoing anything problematic for pty. If pty could be unloaded it would be a problem but it can't. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-04tty_lock: Localise the lockAlan Cox
In each remaining case the tty_lock is associated with a specific tty. This means we can now lock on a per tty basis. We do need tty_lock_pair() for the pty case. Uglier but still a step in the right direction. [fixed up calls in 3 missing drivers - gregkh] Signed-off-by: Alan Cox <alan@linux.intel.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-04pty: Lock the devpts bits privatelyAlan Cox
This is a private pty affair, we don't want to tangle it with the tty_lock any more as we know all the other non tty locking is now handled by the vfs so we too can move. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-28Remove all #inclusions of asm/system.hDavid Howells
Remove all #inclusions of asm/system.h preparatory to splitting and killing it. Performed with the following command: perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *` Signed-off-by: David Howells <dhowells@redhat.com>
2012-03-08TTY: remove re-assignments to tty_driver membersJiri Slaby
All num, magic and owner are set by alloc_tty_driver. No need to re-set them on each allocation site. pti driver sets something different to what it passes to alloc_tty_driver. It is not a bug, since we don't use the lines parameter in any way. Anyway this is fixed, and now we do the right thing. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Tilman Schmidt <tilman@imap.cc> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-02-24Revert "TTY: pty, remove superfluous ptm test"Greg Kroah-Hartman
This reverts commit a50f724a432997321cabb6c9e665c28e34850f78. Sasha reported that this causes problems, so revert it. Cc: Alan Cox <alan@linux.intel.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-02-24Revert "TTY: get rid of BTM around devpts_*"Greg Kroah-Hartman
This reverts commit d3bda5298aad98c7a27678bdd0dd9d008ab9e685. Sasha reported that this causes problems, so revert it. Cc: Sasha Levin <levinsasha928@gmail.com> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-02-02TTY: get rid of BTM around devpts_*Jiri Slaby
devpts operations are protected by inode mutexes and dentry refcounting. There is no need to hold BTM. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-02-02TTY: pty, remove superfluous ptm testJiri Slaby
The code looks like: if (tty->driver->subtype == PTY_TYPE_MASTER) { ... if (tty->driver == ptm_driver) But the second if is superfluous because only the ptm_driver is of PTY_TYPE_MASTER subtype. Also we can remove the #if now because devpts_pty_kill is defined as an empty function for non-CONFIG_UNIX98_PTYS configs. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-01-24tty: move pty count limiting into devptsKonstantin Khlebnikov
Let's move this stuff to the better place, where we can account pty right in tty-indexes managing code. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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