linux/drivers/tty/pty.c

883 lines
22 KiB

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 17:04:11 +09:00
pty: Fix input race when closing A read() from a pty master may mistakenly indicate EOF (errno == -EIO) after the pty slave has closed, even though input data remains to be read. For example, pty slave | input worker | pty master | | | | n_tty_read() pty_write() | | input avail? no add data | | sleep schedule worker --->| | . |---> flush_to_ldisc() | . pty_close() | fill read buffer | . wait for worker | wakeup reader --->| . | read buffer full? |---> input avail ? yes |<--- yes - exit worker | copy 4096 bytes to user TTY_OTHER_CLOSED <---| |<--- kick worker | | **** New read() before worker starts **** | | n_tty_read() | | input avail? no | | TTY_OTHER_CLOSED? yes | | return -EIO Several conditions are required to trigger this race: 1. the ldisc read buffer must become full so the input worker exits 2. the read() count parameter must be >= 4096 so the ldisc read buffer is empty 3. the subsequent read() occurs before the kicked worker has processed more input However, the underlying cause of the race is that data is pipelined, while tty state is not; ie., data already written by the pty slave end is not yet visible to the pty master end, but state changes by the pty slave end are visible to the pty master end immediately. Pipeline the TTY_OTHER_CLOSED state through input worker to the reader. 1. Introduce TTY_OTHER_DONE which is set by the input worker when TTY_OTHER_CLOSED is set and either the input buffers are flushed or input processing has completed. Readers/polls are woken when TTY_OTHER_DONE is set. 2. Reader/poll checks TTY_OTHER_DONE instead of TTY_OTHER_CLOSED. 3. A new input worker is started from pty_close() after setting TTY_OTHER_CLOSED, which ensures the TTY_OTHER_DONE state will be set if the last input worker is already finished (or just about to exit). Remove tty_flush_to_ldisc(); no in-tree callers. Fixes: 52bce7f8d4fc ("pty, n_tty: Simplify input processing on final close") Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=96311 BugLink: http://bugs.launchpad.net/bugs/1429756 Cc: <stable@vger.kernel.org> # 3.19+ Reported-by: Andy Whitcroft <apw@canonical.com> Reported-by: H.J. Lu <hjl.tools@gmail.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-13 13:24:34 -04:00
pty: Fix BUG()s when ptmx_open() errors out 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>
2013-01-30 12:43:49 -05:00
tty: Add EXTPROC support for LINEMODE This patch is against the 2.6.34 source. Paraphrased from the 1989 BSD patch by David Borman @ cray.com: These are the changes needed for the kernel to support LINEMODE in the server. There is a new bit in the termios local flag word, EXTPROC. When this bit is set, several aspects of the terminal driver are disabled. Input line editing, character echo, and mapping of signals are all disabled. This allows the telnetd to turn off these functions when in linemode, but still keep track of what state the user wants the terminal to be in. New ioctl: TIOCSIG Generate a signal to processes in the current process group of the pty. There is a new mode for packet driver, the TIOCPKT_IOCTL bit. When packet mode is turned on in the pty, and the EXTPROC bit is set, then whenever the state of the pty is changed, the next read on the master side of the pty will have the TIOCPKT_IOCTL bit set. This allows the process on the server side of the pty to know when the state of the terminal has changed; it can then issue the appropriate ioctl to retrieve the new state. Since the original BSD patches accompanied the source code for telnet I've left that reference here, but obviously the feature is useful for any remote terminal protocol, including ssh. The corresponding feature has existed in the BSD tty driver since 1989. For historical reference, a good copy of the relevant files can be found here: http://anonsvn.mit.edu/viewvc/krb5/trunk/src/appl/telnet/?pathrev=17741 Signed-off-by: Howard Chu <hyc@symas.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-06-22 10:14:49 -07:00
tty: Add EXTPROC support for LINEMODE This patch is against the 2.6.34 source. Paraphrased from the 1989 BSD patch by David Borman @ cray.com: These are the changes needed for the kernel to support LINEMODE in the server. There is a new bit in the termios local flag word, EXTPROC. When this bit is set, several aspects of the terminal driver are disabled. Input line editing, character echo, and mapping of signals are all disabled. This allows the telnetd to turn off these functions when in linemode, but still keep track of what state the user wants the terminal to be in. New ioctl: TIOCSIG Generate a signal to processes in the current process group of the pty. There is a new mode for packet driver, the TIOCPKT_IOCTL bit. When packet mode is turned on in the pty, and the EXTPROC bit is set, then whenever the state of the pty is changed, the next read on the master side of the pty will have the TIOCPKT_IOCTL bit set. This allows the process on the server side of the pty to know when the state of the terminal has changed; it can then issue the appropriate ioctl to retrieve the new state. Since the original BSD patches accompanied the source code for telnet I've left that reference here, but obviously the feature is useful for any remote terminal protocol, including ssh. The corresponding feature has existed in the BSD tty driver since 1989. For historical reference, a good copy of the relevant files can be found here: http://anonsvn.mit.edu/viewvc/krb5/trunk/src/appl/telnet/?pathrev=17741 Signed-off-by: Howard Chu <hyc@symas.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-06-22 10:14:49 -07:00
tty: Add EXTPROC support for LINEMODE This patch is against the 2.6.34 source. Paraphrased from the 1989 BSD patch by David Borman @ cray.com: These are the changes needed for the kernel to support LINEMODE in the server. There is a new bit in the termios local flag word, EXTPROC. When this bit is set, several aspects of the terminal driver are disabled. Input line editing, character echo, and mapping of signals are all disabled. This allows the telnetd to turn off these functions when in linemode, but still keep track of what state the user wants the terminal to be in. New ioctl: TIOCSIG Generate a signal to processes in the current process group of the pty. There is a new mode for packet driver, the TIOCPKT_IOCTL bit. When packet mode is turned on in the pty, and the EXTPROC bit is set, then whenever the state of the pty is changed, the next read on the master side of the pty will have the TIOCPKT_IOCTL bit set. This allows the process on the server side of the pty to know when the state of the terminal has changed; it can then issue the appropriate ioctl to retrieve the new state. Since the original BSD patches accompanied the source code for telnet I've left that reference here, but obviously the feature is useful for any remote terminal protocol, including ssh. The corresponding feature has existed in the BSD tty driver since 1989. For historical reference, a good copy of the relevant files can be found here: http://anonsvn.mit.edu/viewvc/krb5/trunk/src/appl/telnet/?pathrev=17741 Signed-off-by: Howard Chu <hyc@symas.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-06-22 10:14:49 -07:00
pty: Fix input race when closing A read() from a pty master may mistakenly indicate EOF (errno == -EIO) after the pty slave has closed, even though input data remains to be read. For example, pty slave | input worker | pty master | | | | n_tty_read() pty_write() | | input avail? no add data | | sleep schedule worker --->| | . |---> flush_to_ldisc() | . pty_close() | fill read buffer | . wait for worker | wakeup reader --->| . | read buffer full? |---> input avail ? yes |<--- yes - exit worker | copy 4096 bytes to user TTY_OTHER_CLOSED <---| |<--- kick worker | | **** New read() before worker starts **** | | n_tty_read() | | input avail? no | | TTY_OTHER_CLOSED? yes | | return -EIO Several conditions are required to trigger this race: 1. the ldisc read buffer must become full so the input worker exits 2. the read() count parameter must be >= 4096 so the ldisc read buffer is empty 3. the subsequent read() occurs before the kicked worker has processed more input However, the underlying cause of the race is that data is pipelined, while tty state is not; ie., data already written by the pty slave end is not yet visible to the pty master end, but state changes by the pty slave end are visible to the pty master end immediately. Pipeline the TTY_OTHER_CLOSED state through input worker to the reader. 1. Introduce TTY_OTHER_DONE which is set by the input worker when TTY_OTHER_CLOSED is set and either the input buffers are flushed or input processing has completed. Readers/polls are woken when TTY_OTHER_DONE is set. 2. Reader/poll checks TTY_OTHER_DONE instead of TTY_OTHER_CLOSED. 3. A new input worker is started from pty_close() after setting TTY_OTHER_CLOSED, which ensures the TTY_OTHER_DONE state will be set if the last input worker is already finished (or just about to exit). Remove tty_flush_to_ldisc(); no in-tree callers. Fixes: 52bce7f8d4fc ("pty, n_tty: Simplify input processing on final close") Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=96311 BugLink: http://bugs.launchpad.net/bugs/1429756 Cc: <stable@vger.kernel.org> # 3.19+ Reported-by: Andy Whitcroft <apw@canonical.com> Reported-by: H.J. Lu <hjl.tools@gmail.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-13 13:24:34 -04:00
pty: Fix input race when closing A read() from a pty master may mistakenly indicate EOF (errno == -EIO) after the pty slave has closed, even though input data remains to be read. For example, pty slave | input worker | pty master | | | | n_tty_read() pty_write() | | input avail? no add data | | sleep schedule worker --->| | . |---> flush_to_ldisc() | . pty_close() | fill read buffer | . wait for worker | wakeup reader --->| . | read buffer full? |---> input avail ? yes |<--- yes - exit worker | copy 4096 bytes to user TTY_OTHER_CLOSED <---| |<--- kick worker | | **** New read() before worker starts **** | | n_tty_read() | | input avail? no | | TTY_OTHER_CLOSED? yes | | return -EIO Several conditions are required to trigger this race: 1. the ldisc read buffer must become full so the input worker exits 2. the read() count parameter must be >= 4096 so the ldisc read buffer is empty 3. the subsequent read() occurs before the kicked worker has processed more input However, the underlying cause of the race is that data is pipelined, while tty state is not; ie., data already written by the pty slave end is not yet visible to the pty master end, but state changes by the pty slave end are visible to the pty master end immediately. Pipeline the TTY_OTHER_CLOSED state through input worker to the reader. 1. Introduce TTY_OTHER_DONE which is set by the input worker when TTY_OTHER_CLOSED is set and either the input buffers are flushed or input processing has completed. Readers/polls are woken when TTY_OTHER_DONE is set. 2. Reader/poll checks TTY_OTHER_DONE instead of TTY_OTHER_CLOSED. 3. A new input worker is started from pty_close() after setting TTY_OTHER_CLOSED, which ensures the TTY_OTHER_DONE state will be set if the last input worker is already finished (or just about to exit). Remove tty_flush_to_ldisc(); no in-tree callers. Fixes: 52bce7f8d4fc ("pty, n_tty: Simplify input processing on final close") Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=96311 BugLink: http://bugs.launchpad.net/bugs/1429756 Cc: <stable@vger.kernel.org> # 3.19+ Reported-by: Andy Whitcroft <apw@canonical.com> Reported-by: H.J. Lu <hjl.tools@gmail.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-13 13:24:34 -04:00
tty: Fix lock order in tty_do_resize() Commits 6a1c0680cf3ba94356ecd58833e1540c93472a57 and 9356b535fcb71db494fc434acceb79f56d15bda2, respectively 'tty: Convert termios_mutex to termios_rwsem' and 'n_tty: Access termios values safely' introduced a circular lock dependency with console_lock and termios_rwsem. The lockdep report [1] shows that n_tty_write() will attempt to claim console_lock while holding the termios_rwsem, whereas tty_do_resize() may already hold the console_lock while claiming the termios_rwsem. Since n_tty_write() and tty_do_resize() do not contend over the same data -- the tty->winsize structure -- correct the lock dependency by introducing a new lock which specifically serializes access to tty->winsize only. [1] Lockdep report ====================================================== [ INFO: possible circular locking dependency detected ] 3.10.0-0+tip-xeon+lockdep #0+tip Not tainted ------------------------------------------------------- modprobe/277 is trying to acquire lock: (&tty->termios_rwsem){++++..}, at: [<ffffffff81452656>] tty_do_resize+0x36/0xe0 but task is already holding lock: ((fb_notifier_list).rwsem){.+.+.+}, at: [<ffffffff8107aac6>] __blocking_notifier_call_chain+0x56/0xc0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 ((fb_notifier_list).rwsem){.+.+.+}: [<ffffffff810b6d62>] lock_acquire+0x92/0x1f0 [<ffffffff8175b797>] down_read+0x47/0x5c [<ffffffff8107aac6>] __blocking_notifier_call_chain+0x56/0xc0 [<ffffffff8107ab46>] blocking_notifier_call_chain+0x16/0x20 [<ffffffff813d7c0b>] fb_notifier_call_chain+0x1b/0x20 [<ffffffff813d95b2>] register_framebuffer+0x1e2/0x320 [<ffffffffa01043e1>] drm_fb_helper_initial_config+0x371/0x540 [drm_kms_helper] [<ffffffffa01bcb05>] nouveau_fbcon_init+0x105/0x140 [nouveau] [<ffffffffa01ad0af>] nouveau_drm_load+0x43f/0x610 [nouveau] [<ffffffffa008a79e>] drm_get_pci_dev+0x17e/0x2a0 [drm] [<ffffffffa01ad4da>] nouveau_drm_probe+0x25a/0x2a0 [nouveau] [<ffffffff813b13db>] local_pci_probe+0x4b/0x80 [<ffffffff813b1701>] pci_device_probe+0x111/0x120 [<ffffffff814977eb>] driver_probe_device+0x8b/0x3a0 [<ffffffff81497bab>] __driver_attach+0xab/0xb0 [<ffffffff814956ad>] bus_for_each_dev+0x5d/0xa0 [<ffffffff814971fe>] driver_attach+0x1e/0x20 [<ffffffff81496cc1>] bus_add_driver+0x111/0x290 [<ffffffff814982b7>] driver_register+0x77/0x170 [<ffffffff813b0454>] __pci_register_driver+0x64/0x70 [<ffffffffa008a9da>] drm_pci_init+0x11a/0x130 [drm] [<ffffffffa022a04d>] nouveau_drm_init+0x4d/0x1000 [nouveau] [<ffffffff810002ea>] do_one_initcall+0xea/0x1a0 [<ffffffff810c54cb>] load_module+0x123b/0x1bf0 [<ffffffff810c5f57>] SyS_init_module+0xd7/0x120 [<ffffffff817677c2>] system_call_fastpath+0x16/0x1b -> #1 (console_lock){+.+.+.}: [<ffffffff810b6d62>] lock_acquire+0x92/0x1f0 [<ffffffff810430a7>] console_lock+0x77/0x80 [<ffffffff8146b2a1>] con_flush_chars+0x31/0x50 [<ffffffff8145780c>] n_tty_write+0x1ec/0x4d0 [<ffffffff814541b9>] tty_write+0x159/0x2e0 [<ffffffff814543f5>] redirected_tty_write+0xb5/0xc0 [<ffffffff811ab9d5>] vfs_write+0xc5/0x1f0 [<ffffffff811abec5>] SyS_write+0x55/0xa0 [<ffffffff817677c2>] system_call_fastpath+0x16/0x1b -> #0 (&tty->termios_rwsem){++++..}: [<ffffffff810b65c3>] __lock_acquire+0x1c43/0x1d30 [<ffffffff810b6d62>] lock_acquire+0x92/0x1f0 [<ffffffff8175b724>] down_write+0x44/0x70 [<ffffffff81452656>] tty_do_resize+0x36/0xe0 [<ffffffff8146c841>] vc_do_resize+0x3e1/0x4c0 [<ffffffff8146c99f>] vc_resize+0x1f/0x30 [<ffffffff813e4535>] fbcon_init+0x385/0x5a0 [<ffffffff8146a4bc>] visual_init+0xbc/0x120 [<ffffffff8146cd13>] do_bind_con_driver+0x163/0x320 [<ffffffff8146cfa1>] do_take_over_console+0x61/0x70 [<ffffffff813e2b93>] do_fbcon_takeover+0x63/0xc0 [<ffffffff813e67a5>] fbcon_event_notify+0x715/0x820 [<ffffffff81762f9d>] notifier_call_chain+0x5d/0x110 [<ffffffff8107aadc>] __blocking_notifier_call_chain+0x6c/0xc0 [<ffffffff8107ab46>] blocking_notifier_call_chain+0x16/0x20 [<ffffffff813d7c0b>] fb_notifier_call_chain+0x1b/0x20 [<ffffffff813d95b2>] register_framebuffer+0x1e2/0x320 [<ffffffffa01043e1>] drm_fb_helper_initial_config+0x371/0x540 [drm_kms_helper] [<ffffffffa01bcb05>] nouveau_fbcon_init+0x105/0x140 [nouveau] [<ffffffffa01ad0af>] nouveau_drm_load+0x43f/0x610 [nouveau] [<ffffffffa008a79e>] drm_get_pci_dev+0x17e/0x2a0 [drm] [<ffffffffa01ad4da>] nouveau_drm_probe+0x25a/0x2a0 [nouveau] [<ffffffff813b13db>] local_pci_probe+0x4b/0x80 [<ffffffff813b1701>] pci_device_probe+0x111/0x120 [<ffffffff814977eb>] driver_probe_device+0x8b/0x3a0 [<ffffffff81497bab>] __driver_attach+0xab/0xb0 [<ffffffff814956ad>] bus_for_each_dev+0x5d/0xa0 [<ffffffff814971fe>] driver_attach+0x1e/0x20 [<ffffffff81496cc1>] bus_add_driver+0x111/0x290 [<ffffffff814982b7>] driver_register+0x77/0x170 [<ffffffff813b0454>] __pci_register_driver+0x64/0x70 [<ffffffffa008a9da>] drm_pci_init+0x11a/0x130 [drm] [<ffffffffa022a04d>] nouveau_drm_init+0x4d/0x1000 [nouveau] [<ffffffff810002ea>] do_one_initcall+0xea/0x1a0 [<ffffffff810c54cb>] load_module+0x123b/0x1bf0 [<ffffffff810c5f57>] SyS_init_module+0xd7/0x120 [<ffffffff817677c2>] system_call_fastpath+0x16/0x1b other info that might help us debug this: Chain exists of: &tty->termios_rwsem --> console_lock --> (fb_notifier_list).rwsem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((fb_notifier_list).rwsem); lock(console_lock); lock((fb_notifier_list).rwsem); lock(&tty->termios_rwsem); *** DEADLOCK *** 7 locks held by modprobe/277: #0: (&__lockdep_no_validate__){......}, at: [<ffffffff81497b5b>] __driver_attach+0x5b/0xb0 #1: (&__lockdep_no_validate__){......}, at: [<ffffffff81497b69>] __driver_attach+0x69/0xb0 #2: (drm_global_mutex){+.+.+.}, at: [<ffffffffa008a6dd>] drm_get_pci_dev+0xbd/0x2a0 [drm] #3: (registration_lock){+.+.+.}, at: [<ffffffff813d93f5>] register_framebuffer+0x25/0x320 #4: (&fb_info->lock){+.+.+.}, at: [<ffffffff813d8116>] lock_fb_info+0x26/0x60 #5: (console_lock){+.+.+.}, at: [<ffffffff813d95a4>] register_framebuffer+0x1d4/0x320 #6: ((fb_notifier_list).rwsem){.+.+.+}, at: [<ffffffff8107aac6>] __blocking_notifier_call_chain+0x56/0xc0 stack backtrace: CPU: 0 PID: 277 Comm: modprobe Not tainted 3.10.0-0+tip-xeon+lockdep #0+tip Hardware name: Dell Inc. Precision WorkStation T5400 /0RW203, BIOS A11 04/30/2012 ffffffff8213e5e0 ffff8802aa2fb298 ffffffff81755f19 ffff8802aa2fb2e8 ffffffff8174f506 ffff8802aa2fa000 ffff8802aa2fb378 ffff8802aa2ea8e8 ffff8802aa2ea910 ffff8802aa2ea8e8 0000000000000006 0000000000000007 Call Trace: [<ffffffff81755f19>] dump_stack+0x19/0x1b [<ffffffff8174f506>] print_circular_bug+0x1fb/0x20c [<ffffffff810b65c3>] __lock_acquire+0x1c43/0x1d30 [<ffffffff810b775e>] ? mark_held_locks+0xae/0x120 [<ffffffff810b78d5>] ? trace_hardirqs_on_caller+0x105/0x1d0 [<ffffffff810b6d62>] lock_acquire+0x92/0x1f0 [<ffffffff81452656>] ? tty_do_resize+0x36/0xe0 [<ffffffff8175b724>] down_write+0x44/0x70 [<ffffffff81452656>] ? tty_do_resize+0x36/0xe0 [<ffffffff81452656>] tty_do_resize+0x36/0xe0 [<ffffffff8146c841>] vc_do_resize+0x3e1/0x4c0 [<ffffffff8146c99f>] vc_resize+0x1f/0x30 [<ffffffff813e4535>] fbcon_init+0x385/0x5a0 [<ffffffff8146a4bc>] visual_init+0xbc/0x120 [<ffffffff8146cd13>] do_bind_con_driver+0x163/0x320 [<ffffffff8146cfa1>] do_take_over_console+0x61/0x70 [<ffffffff813e2b93>] do_fbcon_takeover+0x63/0xc0 [<ffffffff813e67a5>] fbcon_event_notify+0x715/0x820 [<ffffffff81762f9d>] notifier_call_chain+0x5d/0x110 [<ffffffff8107aadc>] __blocking_notifier_call_chain+0x6c/0xc0 [<ffffffff8107ab46>] blocking_notifier_call_chain+0x16/0x20 [<ffffffff813d7c0b>] fb_notifier_call_chain+0x1b/0x20 [<ffffffff813d95b2>] register_framebuffer+0x1e2/0x320 [<ffffffffa01043e1>] drm_fb_helper_initial_config+0x371/0x540 [drm_kms_helper] [<ffffffff8173cbcb>] ? kmemleak_alloc+0x5b/0xc0 [<ffffffff81198874>] ? kmem_cache_alloc_trace+0x104/0x290 [<ffffffffa01035e1>] ? drm_fb_helper_single_add_all_connectors+0x81/0xf0 [drm_kms_helper] [<ffffffffa01bcb05>] nouveau_fbcon_init+0x105/0x140 [nouveau] [<ffffffffa01ad0af>] nouveau_drm_load+0x43f/0x610 [nouveau] [<ffffffffa008a79e>] drm_get_pci_dev+0x17e/0x2a0 [drm] [<ffffffffa01ad4da>] nouveau_drm_probe+0x25a/0x2a0 [nouveau] [<ffffffff8175f162>] ? _raw_spin_unlock_irqrestore+0x42/0x80 [<ffffffff813b13db>] local_pci_probe+0x4b/0x80 [<ffffffff813b1701>] pci_device_probe+0x111/0x120 [<ffffffff814977eb>] driver_probe_device+0x8b/0x3a0 [<ffffffff81497bab>] __driver_attach+0xab/0xb0 [<ffffffff81497b00>] ? driver_probe_device+0x3a0/0x3a0 [<ffffffff814956ad>] bus_for_each_dev+0x5d/0xa0 [<ffffffff814971fe>] driver_attach+0x1e/0x20 [<ffffffff81496cc1>] bus_add_driver+0x111/0x290 [<ffffffffa022a000>] ? 0xffffffffa0229fff [<ffffffff814982b7>] driver_register+0x77/0x170 [<ffffffffa022a000>] ? 0xffffffffa0229fff [<ffffffff813b0454>] __pci_register_driver+0x64/0x70 [<ffffffffa008a9da>] drm_pci_init+0x11a/0x130 [drm] [<ffffffffa022a000>] ? 0xffffffffa0229fff [<ffffffffa022a000>] ? 0xffffffffa0229fff [<ffffffffa022a04d>] nouveau_drm_init+0x4d/0x1000 [nouveau] [<ffffffff810002ea>] do_one_initcall+0xea/0x1a0 [<ffffffff810c54cb>] load_module+0x123b/0x1bf0 [<ffffffff81399a50>] ? ddebug_proc_open+0xb0/0xb0 [<ffffffff813855ae>] ? trace_hardirqs_on_thunk+0x3a/0x3f [<ffffffff810c5f57>] SyS_init_module+0xd7/0x120 [<ffffffff817677c2>] system_call_fastpath+0x16/0x1b Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-24 16:43:51 -04:00
tty: Fix lock order in tty_do_resize() Commits 6a1c0680cf3ba94356ecd58833e1540c93472a57 and 9356b535fcb71db494fc434acceb79f56d15bda2, respectively 'tty: Convert termios_mutex to termios_rwsem' and 'n_tty: Access termios values safely' introduced a circular lock dependency with console_lock and termios_rwsem. The lockdep report [1] shows that n_tty_write() will attempt to claim console_lock while holding the termios_rwsem, whereas tty_do_resize() may already hold the console_lock while claiming the termios_rwsem. Since n_tty_write() and tty_do_resize() do not contend over the same data -- the tty->winsize structure -- correct the lock dependency by introducing a new lock which specifically serializes access to tty->winsize only. [1] Lockdep report ====================================================== [ INFO: possible circular locking dependency detected ] 3.10.0-0+tip-xeon+lockdep #0+tip Not tainted ------------------------------------------------------- modprobe/277 is trying to acquire lock: (&tty->termios_rwsem){++++..}, at: [<ffffffff81452656>] tty_do_resize+0x36/0xe0 but task is already holding lock: ((fb_notifier_list).rwsem){.+.+.+}, at: [<ffffffff8107aac6>] __blocking_notifier_call_chain+0x56/0xc0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 ((fb_notifier_list).rwsem){.+.+.+}: [<ffffffff810b6d62>] lock_acquire+0x92/0x1f0 [<ffffffff8175b797>] down_read+0x47/0x5c [<ffffffff8107aac6>] __blocking_notifier_call_chain+0x56/0xc0 [<ffffffff8107ab46>] blocking_notifier_call_chain+0x16/0x20 [<ffffffff813d7c0b>] fb_notifier_call_chain+0x1b/0x20 [<ffffffff813d95b2>] register_framebuffer+0x1e2/0x320 [<ffffffffa01043e1>] drm_fb_helper_initial_config+0x371/0x540 [drm_kms_helper] [<ffffffffa01bcb05>] nouveau_fbcon_init+0x105/0x140 [nouveau] [<ffffffffa01ad0af>] nouveau_drm_load+0x43f/0x610 [nouveau] [<ffffffffa008a79e>] drm_get_pci_dev+0x17e/0x2a0 [drm] [<ffffffffa01ad4da>] nouveau_drm_probe+0x25a/0x2a0 [nouveau] [<ffffffff813b13db>] local_pci_probe+0x4b/0x80 [<ffffffff813b1701>] pci_device_probe+0x111/0x120 [<ffffffff814977eb>] driver_probe_device+0x8b/0x3a0 [<ffffffff81497bab>] __driver_attach+0xab/0xb0 [<ffffffff814956ad>] bus_for_each_dev+0x5d/0xa0 [<ffffffff814971fe>] driver_attach+0x1e/0x20 [<ffffffff81496cc1>] bus_add_driver+0x111/0x290 [<ffffffff814982b7>] driver_register+0x77/0x170 [<ffffffff813b0454>] __pci_register_driver+0x64/0x70 [<ffffffffa008a9da>] drm_pci_init+0x11a/0x130 [drm] [<ffffffffa022a04d>] nouveau_drm_init+0x4d/0x1000 [nouveau] [<ffffffff810002ea>] do_one_initcall+0xea/0x1a0 [<ffffffff810c54cb>] load_module+0x123b/0x1bf0 [<ffffffff810c5f57>] SyS_init_module+0xd7/0x120 [<ffffffff817677c2>] system_call_fastpath+0x16/0x1b -> #1 (console_lock){+.+.+.}: [<ffffffff810b6d62>] lock_acquire+0x92/0x1f0 [<ffffffff810430a7>] console_lock+0x77/0x80 [<ffffffff8146b2a1>] con_flush_chars+0x31/0x50 [<ffffffff8145780c>] n_tty_write+0x1ec/0x4d0 [<ffffffff814541b9>] tty_write+0x159/0x2e0 [<ffffffff814543f5>] redirected_tty_write+0xb5/0xc0 [<ffffffff811ab9d5>] vfs_write+0xc5/0x1f0 [<ffffffff811abec5>] SyS_write+0x55/0xa0 [<ffffffff817677c2>] system_call_fastpath+0x16/0x1b -> #0 (&tty->termios_rwsem){++++..}: [<ffffffff810b65c3>] __lock_acquire+0x1c43/0x1d30 [<ffffffff810b6d62>] lock_acquire+0x92/0x1f0 [<ffffffff8175b724>] down_write+0x44/0x70 [<ffffffff81452656>] tty_do_resize+0x36/0xe0 [<ffffffff8146c841>] vc_do_resize+0x3e1/0x4c0 [<ffffffff8146c99f>] vc_resize+0x1f/0x30 [<ffffffff813e4535>] fbcon_init+0x385/0x5a0 [<ffffffff8146a4bc>] visual_init+0xbc/0x120 [<ffffffff8146cd13>] do_bind_con_driver+0x163/0x320 [<ffffffff8146cfa1>] do_take_over_console+0x61/0x70 [<ffffffff813e2b93>] do_fbcon_takeover+0x63/0xc0 [<ffffffff813e67a5>] fbcon_event_notify+0x715/0x820 [<ffffffff81762f9d>] notifier_call_chain+0x5d/0x110 [<ffffffff8107aadc>] __blocking_notifier_call_chain+0x6c/0xc0 [<ffffffff8107ab46>] blocking_notifier_call_chain+0x16/0x20 [<ffffffff813d7c0b>] fb_notifier_call_chain+0x1b/0x20 [<ffffffff813d95b2>] register_framebuffer+0x1e2/0x320 [<ffffffffa01043e1>] drm_fb_helper_initial_config+0x371/0x540 [drm_kms_helper] [<ffffffffa01bcb05>] nouveau_fbcon_init+0x105/0x140 [nouveau] [<ffffffffa01ad0af>] nouveau_drm_load+0x43f/0x610 [nouveau] [<ffffffffa008a79e>] drm_get_pci_dev+0x17e/0x2a0 [drm] [<ffffffffa01ad4da>] nouveau_drm_probe+0x25a/0x2a0 [nouveau] [<ffffffff813b13db>] local_pci_probe+0x4b/0x80 [<ffffffff813b1701>] pci_device_probe+0x111/0x120 [<ffffffff814977eb>] driver_probe_device+0x8b/0x3a0 [<ffffffff81497bab>] __driver_attach+0xab/0xb0 [<ffffffff814956ad>] bus_for_each_dev+0x5d/0xa0 [<ffffffff814971fe>] driver_attach+0x1e/0x20 [<ffffffff81496cc1>] bus_add_driver+0x111/0x290 [<ffffffff814982b7>] driver_register+0x77/0x170 [<ffffffff813b0454>] __pci_register_driver+0x64/0x70 [<ffffffffa008a9da>] drm_pci_init+0x11a/0x130 [drm] [<ffffffffa022a04d>] nouveau_drm_init+0x4d/0x1000 [nouveau] [<ffffffff810002ea>] do_one_initcall+0xea/0x1a0 [<ffffffff810c54cb>] load_module+0x123b/0x1bf0 [<ffffffff810c5f57>] SyS_init_module+0xd7/0x120 [<ffffffff817677c2>] system_call_fastpath+0x16/0x1b other info that might help us debug this: Chain exists of: &tty->termios_rwsem --> console_lock --> (fb_notifier_list).rwsem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((fb_notifier_list).rwsem); lock(console_lock); lock((fb_notifier_list).rwsem); lock(&tty->termios_rwsem); *** DEADLOCK *** 7 locks held by modprobe/277: #0: (&__lockdep_no_validate__){......}, at: [<ffffffff81497b5b>] __driver_attach+0x5b/0xb0 #1: (&__lockdep_no_validate__){......}, at: [<ffffffff81497b69>] __driver_attach+0x69/0xb0 #2: (drm_global_mutex){+.+.+.}, at: [<ffffffffa008a6dd>] drm_get_pci_dev+0xbd/0x2a0 [drm] #3: (registration_lock){+.+.+.}, at: [<ffffffff813d93f5>] register_framebuffer+0x25/0x320 #4: (&fb_info->lock){+.+.+.}, at: [<ffffffff813d8116>] lock_fb_info+0x26/0x60 #5: (console_lock){+.+.+.}, at: [<ffffffff813d95a4>] register_framebuffer+0x1d4/0x320 #6: ((fb_notifier_list).rwsem){.+.+.+}, at: [<ffffffff8107aac6>] __blocking_notifier_call_chain+0x56/0xc0 stack backtrace: CPU: 0 PID: 277 Comm: modprobe Not tainted 3.10.0-0+tip-xeon+lockdep #0+tip Hardware name: Dell Inc. Precision WorkStation T5400 /0RW203, BIOS A11 04/30/2012 ffffffff8213e5e0 ffff8802aa2fb298 ffffffff81755f19 ffff8802aa2fb2e8 ffffffff8174f506 ffff8802aa2fa000 ffff8802aa2fb378 ffff8802aa2ea8e8 ffff8802aa2ea910 ffff8802aa2ea8e8 0000000000000006 0000000000000007 Call Trace: [<ffffffff81755f19>] dump_stack+0x19/0x1b [<ffffffff8174f506>] print_circular_bug+0x1fb/0x20c [<ffffffff810b65c3>] __lock_acquire+0x1c43/0x1d30 [<ffffffff810b775e>] ? mark_held_locks+0xae/0x120 [<ffffffff810b78d5>] ? trace_hardirqs_on_caller+0x105/0x1d0 [<ffffffff810b6d62>] lock_acquire+0x92/0x1f0 [<ffffffff81452656>] ? tty_do_resize+0x36/0xe0 [<ffffffff8175b724>] down_write+0x44/0x70 [<ffffffff81452656>] ? tty_do_resize+0x36/0xe0 [<ffffffff81452656>] tty_do_resize+0x36/0xe0 [<ffffffff8146c841>] vc_do_resize+0x3e1/0x4c0 [<ffffffff8146c99f>] vc_resize+0x1f/0x30 [<ffffffff813e4535>] fbcon_init+0x385/0x5a0 [<ffffffff8146a4bc>] visual_init+0xbc/0x120 [<ffffffff8146cd13>] do_bind_con_driver+0x163/0x320 [<ffffffff8146cfa1>] do_take_over_console+0x61/0x70 [<ffffffff813e2b93>] do_fbcon_takeover+0x63/0xc0 [<ffffffff813e67a5>] fbcon_event_notify+0x715/0x820 [<ffffffff81762f9d>] notifier_call_chain+0x5d/0x110 [<ffffffff8107aadc>] __blocking_notifier_call_chain+0x6c/0xc0 [<ffffffff8107ab46>] blocking_notifier_call_chain+0x16/0x20 [<ffffffff813d7c0b>] fb_notifier_call_chain+0x1b/0x20 [<ffffffff813d95b2>] register_framebuffer+0x1e2/0x320 [<ffffffffa01043e1>] drm_fb_helper_initial_config+0x371/0x540 [drm_kms_helper] [<ffffffff8173cbcb>] ? kmemleak_alloc+0x5b/0xc0 [<ffffffff81198874>] ? kmem_cache_alloc_trace+0x104/0x290 [<ffffffffa01035e1>] ? drm_fb_helper_single_add_all_connectors+0x81/0xf0 [drm_kms_helper] [<ffffffffa01bcb05>] nouveau_fbcon_init+0x105/0x140 [nouveau] [<ffffffffa01ad0af>] nouveau_drm_load+0x43f/0x610 [nouveau] [<ffffffffa008a79e>] drm_get_pci_dev+0x17e/0x2a0 [drm] [<ffffffffa01ad4da>] nouveau_drm_probe+0x25a/0x2a0 [nouveau] [<ffffffff8175f162>] ? _raw_spin_unlock_irqrestore+0x42/0x80 [<ffffffff813b13db>] local_pci_probe+0x4b/0x80 [<ffffffff813b1701>] pci_device_probe+0x111/0x120 [<ffffffff814977eb>] driver_probe_device+0x8b/0x3a0 [<ffffffff81497bab>] __driver_attach+0xab/0xb0 [<ffffffff81497b00>] ? driver_probe_device+0x3a0/0x3a0 [<ffffffff814956ad>] bus_for_each_dev+0x5d/0xa0 [<ffffffff814971fe>] driver_attach+0x1e/0x20 [<ffffffff81496cc1>] bus_add_driver+0x111/0x290 [<ffffffffa022a000>] ? 0xffffffffa0229fff [<ffffffff814982b7>] driver_register+0x77/0x170 [<ffffffffa022a000>] ? 0xffffffffa0229fff [<ffffffff813b0454>] __pci_register_driver+0x64/0x70 [<ffffffffa008a9da>] drm_pci_init+0x11a/0x130 [drm] [<ffffffffa022a000>] ? 0xffffffffa0229fff [<ffffffffa022a000>] ? 0xffffffffa0229fff [<ffffffffa022a04d>] nouveau_drm_init+0x4d/0x1000 [nouveau] [<ffffffff810002ea>] do_one_initcall+0xea/0x1a0 [<ffffffff810c54cb>] load_module+0x123b/0x1bf0 [<ffffffff81399a50>] ? ddebug_proc_open+0xb0/0xb0 [<ffffffff813855ae>] ? trace_hardirqs_on_thunk+0x3a/0x3f [<ffffffff810c5f57>] SyS_init_module+0xd7/0x120 [<ffffffff817677c2>] system_call_fastpath+0x16/0x1b Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-24 16:43:51 -04:00
tty: Add EXTPROC support for LINEMODE This patch is against the 2.6.34 source. Paraphrased from the 1989 BSD patch by David Borman @ cray.com: These are the changes needed for the kernel to support LINEMODE in the server. There is a new bit in the termios local flag word, EXTPROC. When this bit is set, several aspects of the terminal driver are disabled. Input line editing, character echo, and mapping of signals are all disabled. This allows the telnetd to turn off these functions when in linemode, but still keep track of what state the user wants the terminal to be in. New ioctl: TIOCSIG Generate a signal to processes in the current process group of the pty. There is a new mode for packet driver, the TIOCPKT_IOCTL bit. When packet mode is turned on in the pty, and the EXTPROC bit is set, then whenever the state of the pty is changed, the next read on the master side of the pty will have the TIOCPKT_IOCTL bit set. This allows the process on the server side of the pty to know when the state of the terminal has changed; it can then issue the appropriate ioctl to retrieve the new state. Since the original BSD patches accompanied the source code for telnet I've left that reference here, but obviously the feature is useful for any remote terminal protocol, including ssh. The corresponding feature has existed in the BSD tty driver since 1989. For historical reference, a good copy of the relevant files can be found here: http://anonsvn.mit.edu/viewvc/krb5/trunk/src/appl/telnet/?pathrev=17741 Signed-off-by: Howard Chu <hyc@symas.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-06-22 10:14:49 -07:00
tty: Add EXTPROC support for LINEMODE This patch is against the 2.6.34 source. Paraphrased from the 1989 BSD patch by David Borman @ cray.com: These are the changes needed for the kernel to support LINEMODE in the server. There is a new bit in the termios local flag word, EXTPROC. When this bit is set, several aspects of the terminal driver are disabled. Input line editing, character echo, and mapping of signals are all disabled. This allows the telnetd to turn off these functions when in linemode, but still keep track of what state the user wants the terminal to be in. New ioctl: TIOCSIG Generate a signal to processes in the current process group of the pty. There is a new mode for packet driver, the TIOCPKT_IOCTL bit. When packet mode is turned on in the pty, and the EXTPROC bit is set, then whenever the state of the pty is changed, the next read on the master side of the pty will have the TIOCPKT_IOCTL bit set. This allows the process on the server side of the pty to know when the state of the terminal has changed; it can then issue the appropriate ioctl to retrieve the new state. Since the original BSD patches accompanied the source code for telnet I've left that reference here, but obviously the feature is useful for any remote terminal protocol, including ssh. The corresponding feature has existed in the BSD tty driver since 1989. For historical reference, a good copy of the relevant files can be found here: http://anonsvn.mit.edu/viewvc/krb5/trunk/src/appl/telnet/?pathrev=17741 Signed-off-by: Howard Chu <hyc@symas.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-06-22 10:14:49 -07:00
pty: Fix BUG()s when ptmx_open() errors out 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>
2013-01-30 12:43:49 -05:00
pty: Fix BUG()s when ptmx_open() errors out 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>
2013-01-30 12:43:49 -05:00