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path: root/drivers/char/tty_io.c
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* [PATCH] split linux/file.hAl Viro2008-05-01
| | | | | | Initial splitoff of the low-level stuff; taken to fdtable.h Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* devpts: factor out PTY index allocationSukadev Bhattiprolu2008-04-30
| | | | | | | | | | | | | | Factor out the code used to allocate/free a pts index into new interfaces, devpts_new_index() and devpts_kill_index(). This localizes the external data structures used in managing the pts indices. [akpm@linux-foundation.org: undo accidental mutex2sem conversion] Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Matt Helsley <matthltc@us.ibm.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* devpts: propagate error code from devpts_pty_newSukadev Bhattiprolu2008-04-30
| | | | | | | | | | | Have ptmx_open() propagate any error code returned by devpts_pty_new() (which returns either 0 or -ENOMEM anyway). Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: fix routine name in ptmx_open()Hiroshi Shimamoto2008-04-30
| | | | | | | | | | At ptmx_open(), the 2nd parameter for check_tty_count() should be "ptmx_open". Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: The big operations reworkAlan Cox2008-04-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Operations are now a shared const function block as with most other Linux objects - Introduce wrappers for some optional functions to get consistent behaviour - Wrap put_char which used to be patched by the tty layer - Document which functions are needed/optional - Make put_char report success/fail - Cache the driver->ops pointer in the tty as tty->ops - Remove various surplus lock calls we no longer need - Remove proc_write method as noted by Alexey Dobriyan - Introduce some missing sanity checks where certain driver/ldisc combinations would oops as they didn't check needed methods were present [akpm@linux-foundation.org: fix fs/compat_ioctl.c build] [akpm@linux-foundation.org: fix isicom] [akpm@linux-foundation.org: fix arch/ia64/hp/sim/simserial.c build] [akpm@linux-foundation.org: fix kgdb] Signed-off-by: Alan Cox <alan@redhat.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Cc: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty/serial: lay the foundations for the next set of reworksAlan Cox2008-04-30
| | | | | | | | | | | | | | | | | | | | | | | | - Stop drivers calling their own flush method indirectly, it obfuscates code and it will change soon anyway - A few more lock_kernel paths temporarily needed in some driver internal waiting code - Remove private put_char method that does a write call for one char - we have that anyway - Most but not yet all of the termios copy under lock fixing (some has other dependencies to follow) - Note a few locking bugs in drivers found in the process - Kill remaining [ab]users of TIOCG/SSOFTCAR in the driver, these must go to fix the termios locking Signed-off-by: Alan Cox <alan@redhat.com> Cc: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: drop the BKL for driver/ldisc ioctl methodsAlan Cox2008-04-30
| | | | | | | | | Now we have pushed the lock down we can stop wrapping the call with a lock in the tty layer. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty_io: fix remaining pid struct lockingAlan Cox2008-04-30
| | | | | | | | | | This fixes the last couple of pid struct locking failures I know about. [oleg@tv-sign.ru: clean up do_task_stat()] Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* redo locking of tty->pgrpAlan Cox2008-04-30
| | | | | | | | | | | | Historically tty->pgrp and friends were pid_t and the code "knew" they were safe. The change to pid structs opened up a few races and the removal of the BKL in places made them quite hittable. We put tty->pgrp under the ctrl_lock for the tty. Signed-off-by: Alan Cox <alan@redhat.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: BKL pushdownAlan Cox2008-04-30
| | | | | | | | | | | | | | | | | - Push the BKL down into the line disciplines - Switch the tty layer to unlocked_ioctl - Introduce a new ctrl_lock spin lock for the control bits - Eliminate much of the lock_kernel use in n_tty - Prepare to (but don't yet) call the drivers with the lock dropped on the paths that historically held the lock BKL now primarily protects open/close/ldisc change in the tty layer [jirislaby@gmail.com: a couple of fixes] Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'audit.b50' of ↵Linus Torvalds2008-04-29
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current * 'audit.b50' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current: [PATCH] new predicate - AUDIT_FILETYPE [patch 2/2] Use find_task_by_vpid in audit code [patch 1/2] audit: let userspace fully control TTY input auditing [PATCH 2/2] audit: fix sparse shadowed variable warnings [PATCH 1/2] audit: move extern declarations to audit.h Audit: MAINTAINERS update Audit: increase the maximum length of the key field Audit: standardize string audit interfaces Audit: stop deadlock from signals under load Audit: save audit_backlog_limit audit messages in case auditd comes back Audit: collect sessionid in netlink messages Audit: end printk with newline
| * [patch 1/2] audit: let userspace fully control TTY input auditingMiloslav Trmac2008-04-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the code that automatically disables TTY input auditing in processes that open TTYs when they have no other TTY open; this heuristic was intended to automatically handle daemons, but it has false positives (e.g. with sshd) that make it impossible to control TTY input auditing from a PAM module. With this patch, TTY input auditing is controlled from user-space only. On the other hand, not even for daemons does it make sense to audit "input" from PTY masters; this data was produced by a program writing to the PTY slave, and does not represent data entered by the user. Signed-off-by: Miloslav Trmac <mitr@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | drivers: atm, char fix integer as NULL pointer warningsHarvey Harrison2008-04-28
|/ | | | | | | | | drivers/atm/nicstar.c:418:25: warning: Using plain integer as NULL pointer drivers/char/drm/r128_cce.c:820:25: warning: Using plain integer as NULL pointer drivers/char/tty_io.c:1183:10: warning: Using plain integer as NULL pointer Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* consoles: polling support, kgdbocJason Wessel2008-04-17
| | | | | | | | | | | | | | | | polled console handling support, to access a console in an irq-less way while in debug or irq context. absolutely zero impact as long as CONFIG_CONSOLE_POLL is disabled. (which is the default) [ jan.kiszka@siemens.com: lots of cleanups ] [ mingo@elte.hu: redesign, splitups, cleanups. ] Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Jan Kiszka <jan.kiszka@web.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
* tty_io: drag screaming into coding style complianceAlan Cox2008-02-08
| | | | | | Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* unix98 allocated_ptys_lock semaphore to mutexDaniel Walker2008-02-06
| | | | | | | | | | Convert the unix98 allocated_ptys_lock to a mutex. Signed-off-by: Daniel Walker <dwalker@mvista.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/char/tty_io.c: remove pty_semDaniel Walker2008-02-06
| | | | | | | | | | I couldn't find any users, so removing it.. Signed-off-by: Daniel Walker <dwalker@mvista.com> Acked-by: Alan Cox <alan@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proper prototype for vty_init()Adrian Bunk2008-02-06
| | | | | | | | Add a proper prototype for vty_init() in include/linux/vt_kern.h Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Fix misspellings of "system", "controller", "interrupt" and "necessary".Robert P. J. Day2007-10-19
| | | | | | | | Fix the various misspellings of "system", controller", "interrupt" and "[un]necessary". Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Adrian Bunk <bunk@kernel.org>
* Use helpers to obtain task pid in printksPavel Emelyanov2007-10-19
| | | | | | | | | | | | | | | | The task_struct->pid member is going to be deprecated, so start using the helpers (task_pid_nr/task_pid_vnr/task_pid_nr_ns) in the kernel. The first thing to start with is the pid, printed to dmesg - in this case we may safely use task_pid_nr(). Besides, printks produce more (much more) than a half of all the explicit pid usage. [akpm@linux-foundation.org: git-drm went and changed lots of stuff] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Dave Airlie <airlied@linux.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pid namespaces: changes to show virtual ids to userPavel Emelyanov2007-10-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the largest patch in the set. Make all (I hope) the places where the pid is shown to or get from user operate on the virtual pids. The idea is: - all in-kernel data structures must store either struct pid itself or the pid's global nr, obtained with pid_nr() call; - when seeking the task from kernel code with the stored id one should use find_task_by_pid() call that works with global pids; - when showing pid's numerical value to the user the virtual one should be used, but however when one shows task's pid outside this task's namespace the global one is to be used; - when getting the pid from userspace one need to consider this as the virtual one and use appropriate task/pid-searching functions. [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: nuther build fix] [akpm@linux-foundation.org: yet nuther build fix] [akpm@linux-foundation.org: remove unneeded casts] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Paul Menage <menage@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pid namespaces: round up the APIPavel Emelianov2007-10-19
| | | | | | | | | | | | | | | | | | | | | | | | | | The set of functions process_session, task_session, process_group and task_pgrp is confusing, as the names can be mixed with each other when looking at the code for a long time. The proposals are to * equip the functions that return the integer with _nr suffix to represent that fact, * and to make all functions work with task (not process) by making the common prefix of the same name. For monotony the routines signal_session() and set_signal_session() are replaced with task_session_nr() and set_task_session(), especially since they are only used with the explicit task->signal dereference. Signed-off-by: Pavel Emelianov <xemul@openvz.org> Acked-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: dont needlessly cast kmalloc() return valueJesper Juhl2007-08-24
| | | | | | | kmalloc() hands us a void pointer, we don't need to cast it. Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fix serial buffer memory leakAlan Cox2007-08-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch c5c34d4862e18ef07c1276d233507f540fb5a532 (tty: flush flip buffer on ldisc input queue flush) introduces a race condition which can lead to memory leaks. The problem can be triggered when tcflush() is called when data are being pushed to the line discipline driver by flush_to_ldisc(). flush_to_ldisc() releases tty->buf.lock when calling the line discipline receive_buf function. At that poing tty_buffer_flush() kicks in and sets both tty->buf.head and tty->buf.tail to NULL. When flush_to_ldisc() finishes, it restores tty->buf.head but doesn't touch tty->buf.tail. This corrups the buffer queue, and the next call to tty_buffer_request_room() will allocate a new buffer and overwrite tty->buf.head. The previous buffer is then lost forever without being released. (Thanks to Laurent for the above text, for finding, disgnosing and reporting the bug) - Use tty->flags bits for the flush status. - Wait for the flag to clear again before returning - Fix the doc error noted - Fix flush of empty queue leaving stale flushpending [akpm@linux-foundation.org: cleanup] Signed-off-by: Alan Cox <alan@redhat.com> Acked-by: Paul Fulghum <paulkf@microgate.com> Cc: Laurent Pinchart <laurentp@cse-semaphore.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Audit: add TTY input auditingMiloslav Trmac2007-07-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add TTY input auditing, used to audit system administrator's actions. This is required by various security standards such as DCID 6/3 and PCI to provide non-repudiation of administrator's actions and to allow a review of past actions if the administrator seems to overstep their duties or if the system becomes misconfigured for unknown reasons. These requirements do not make it necessary to audit TTY output as well. Compared to an user-space keylogger, this approach records TTY input using the audit subsystem, correlated with other audit events, and it is completely transparent to the user-space application (e.g. the console ioctls still work). TTY input auditing works on a higher level than auditing all system calls within the session, which would produce an overwhelming amount of mostly useless audit events. Add an "audit_tty" attribute, inherited across fork (). Data read from TTYs by process with the attribute is sent to the audit subsystem by the kernel. The audit netlink interface is extended to allow modifying the audit_tty attribute, and to allow sending explanatory audit events from user-space (for example, a shell might send an event containing the final command, after the interactive command-line editing and history expansion is performed, which might be difficult to decipher from the TTY input alone). Because the "audit_tty" attribute is inherited across fork (), it would be set e.g. for sshd restarted within an audited session. To prevent this, the audit_tty attribute is cleared when a process with no open TTY file descriptors (e.g. after daemon startup) opens a TTY. See https://www.redhat.com/archives/linux-audit/2007-June/msg00000.html for a more detailed rationale document for an older version of this patch. [akpm@linux-foundation.org: build fix] Signed-off-by: Miloslav Trmac <mitr@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Paul Fulghum <paulkf@microgate.com> Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: Steve Grubb <sgrubb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty_io: Use kzallocJean Delvare2007-07-16
| | | | | | | | | Also remove needless casts. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Prevent an O_NDELAY writer from blocking when a tty write is blocked by the ↵Alan Cox2007-07-16
| | | | | | | | | | | | | tty atomic writer mutex Without this a tty write could block if a previous blocking tty write was in progress on the same tty and blocked by a line discipline or hardware event. Originally found and reported by Dave Johnson. Signed-off-by: Alan Cox <alan@redhat.com> Acked-by: Dave Johnson <djohnson+linux-kernel@sw.starentnetworks.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: restore locked ioctl file opPaul Fulghum2007-06-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Restore tty locked ioctl handler which was replaced with an unlocked ioctl handler in hung_up_tty_fops by the patch: commit e10cc1df1d2014f68a4bdcf73f6dd122c4561f94 Author: Paul Fulghum <paulkf@microgate.com> Date: Thu May 10 22:22:50 2007 -0700 tty: add compat_ioctl This was reported in: [Bug 8473] New: Oops: 0010 [1] SMP The bug is caused by switching to hung_up_tty_fops in do_tty_hangup. An ioctl call can be waiting on BLK after testing for existence of the locked ioctl handler in the normal tty fops, but before calling the locked ioctl handler. If a hangup occurs at that point, the locked ioctl fop is NULL and an oops occurs. (akpm: we can remove my debugging code from do_ioctl() now, but it'll be OK to do that for 2.6.23) Signed-off-by: Paul Fulghum <paulkf@microgate.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: fix leakage of -ERESTARTSYS to userlandOleg Nesterov2007-06-01
| | | | | | | | | | | | | | | | | Spotted by Satoru Takeuchi. kill_pgrp(task_pgrp(current)) sends the signal to the current's thread group, but can choose any sub-thread as a target for signal_wake_up(). This means that job_control() and tty_check_change() may return -ERESTARTSYS without signal_pending(). Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> Cc: Roland McGrath <roland@redhat.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: flush flip buffer on ldisc input queue flushPaul Fulghum2007-05-12
| | | | | | | | | | | | | Flush the tty flip buffer when the line discipline input queue is flushed, including the user call tcflush(TCIFLUSH/TCIOFLUSH). This prevents unexpected stale data after a user application calls tcflush(). Signed-off-by: Alan Cox <alan@redhat.com> Cc: Antonino Ingargiola <tritemio@gmail.com> Signed-off-by: Paul Fulghum <paulkf@microgate.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [TTY]: Export proc_clear_tty() to modulea.David S. Miller2007-05-12
| | | | | | | A use was added to the solaris syscall module which can be built modular. Signed-off-by: David S. Miller <davem@davemloft.net>
* tty: add compat_ioctlPaul Fulghum2007-05-11
| | | | | | | | | | | | | | | Add compat_ioctl method for tty code to allow processing of 32 bit ioctl calls on 64 bit systems by tty core, tty drivers, and line disciplines. Based on patch by Arnd Bergmann: http://www.uwsg.iu.edu/hypermail/linux/kernel/0511.0/1732.html [akpm@linux-foundation.org: make things static] Signed-off-by: Paul Fulghum <paulkf@microgate.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivialLinus Torvalds2007-05-09
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial: (25 commits) sound: convert "sound" subdirectory to UTF-8 MAINTAINERS: Add cxacru website/mailing list include files: convert "include" subdirectory to UTF-8 general: convert "kernel" subdirectory to UTF-8 documentation: convert the Documentation directory to UTF-8 Convert the toplevel files CREDITS and MAINTAINERS to UTF-8. remove broken URLs from net drivers' output Magic number prefix consistency change to Documentation/magic-number.txt trivial: s/i_sem /i_mutex/ fix file specification in comments drivers/base/platform.c: fix small typo in doc misc doc and kconfig typos Remove obsolete fat_cvf help text Fix occurrences of "the the " Fix minor typoes in kernel/module.c Kconfig: Remove reference to external mqueue library Kconfig: A couple of grammatical fixes in arch/i386/Kconfig Correct comments in genrtc.c to refer to correct /proc file. Fix more "deprecated" spellos. Fix "deprecated" typoes. ... Fix trivial comment conflict in kernel/relay.c.
| * Fix misspellings collected by members of KJ list.Robert P. J. Day2007-05-09
| | | | | | | | | | | | | | | | Fix the misspellings of "propogate", "writting" and (oh, the shame :-) "kenrel" in the source tree. Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* | tty_set_ldisc() receive_room fixPaul Fulghum2007-05-09
|/ | | | | | | | | | | | | | | | | | | | | | | | | | Fix tty_set_ldisc in tty_io.c so that tty->receive_room is only cleared if actually changing line disciplines. Without this fix a problem occurs when requesting the line discipline to change to the same line discipline. In this case tty->receive_room is cleared but ldisc->open() is not called to set tty->receive_room back to a sane value. The result is that tty->receive_room is stuck at 0 preventing the tty flip buffer from passing receive data to the line discipline. For example: a switch from N_TTY to N_TTY followed by a select() call for read input results in data never being received because tty->receive_room is stuck at zero. A switch from N_TTY to N_TTY followed by a read() call works because the read() call itself sets tty->receive_room correctly (but select does not). Previously (< 2.6.18) this was not a problem because the tty flip buffer pushed data to the line discipline without regard for tty->receive room. Signed-off-by: Paul Fulghum <paulkf@microgate.com> Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Protect tty drivers list with tty_mutexAlexey Dobriyan2007-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Additions and removal from tty_drivers list were just done as well as iterating on it for /proc/tty/drivers generation. testing: modprobe/rmmod loop of simple module which does nothing but tty_register_driver() vs cat /proc/tty/drivers loop BUG: unable to handle kernel paging request at virtual address 6b6b6b6b printing eip: c01cefa7 *pde = 00000000 Oops: 0000 [#1] PREEMPT last sysfs file: devices/pci0000:00/0000:00:1d.7/usb5/5-0:1.0/bInterfaceProtocol Modules linked in: ohci_hcd af_packet e1000 ehci_hcd uhci_hcd usbcore xfs CPU: 0 EIP: 0060:[<c01cefa7>] Not tainted VLI EFLAGS: 00010297 (2.6.21-rc4-mm1 #4) EIP is at vsnprintf+0x3a4/0x5fc eax: 6b6b6b6b ebx: f6cb50f2 ecx: 6b6b6b6b edx: fffffffe esi: c0354700 edi: f6cb6000 ebp: 6b6b6b6b esp: f31f5e68 ds: 007b es: 007b fs: 00d8 gs: 0033 ss: 0068 Process cat (pid: 31864, ti=f31f4000 task=c1998030 task.ti=f31f4000) Stack: 00000000 c0103f20 c013003a c0103f20 00000000 f6cb50da 0000000a 00000f0e f6cb50f2 00000010 00000014 ffffffff ffffffff 00000007 c0354753 f6cb50f2 f73e39dc f73e39dc 00000001 c0175416 f31f5ed8 f31f5ed4 0ee00000 f32090bc Call Trace: [<c0103f20>] restore_nocheck+0x12/0x15 [<c013003a>] mark_held_locks+0x6d/0x86 [<c0103f20>] restore_nocheck+0x12/0x15 [<c0175416>] seq_printf+0x2e/0x52 [<c0192895>] show_tty_range+0x35/0x1f3 [<c0175416>] seq_printf+0x2e/0x52 [<c0192add>] show_tty_driver+0x8a/0x1d9 [<c01758f6>] seq_read+0x70/0x2ba [<c0175886>] seq_read+0x0/0x2ba [<c018d8e6>] proc_reg_read+0x63/0x9f [<c015e764>] vfs_read+0x7d/0xb5 [<c018d883>] proc_reg_read+0x0/0x9f [<c015eab1>] sys_read+0x41/0x6a [<c0103e4e>] sysenter_past_esp+0x5f/0x99 ======================= Code: 00 8b 4d 04 e9 44 ff ff ff 8d 4d 04 89 4c 24 50 8b 6d 00 81 fd ff 0f 00 00 b8 a4 c1 35 c0 0f 46 e8 8b 54 24 2c 89 e9 89 c8 eb 06 <80> 38 00 74 07 40 4a 83 fa ff 75 f4 29 c8 89 c6 8b 44 24 28 89 EIP: [<c01cefa7>] vsnprintf+0x3a4/0x5fc SS:ESP 0068:f31f5e68 Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: introduce no_tty and use it in selinuxEric W. Biederman2007-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | While researching the tty layer pid leaks I found a weird case in selinux when we drop a controlling tty because of inadequate permissions we don't do the normal hangup processing. Which is a problem if it happens the session leader has exec'd something that can no longer access the tty. We already have code in the kernel to handle this case in the form of the TIOCNOTTY ioctl. So this patch factors out a helper function that is the essence of that ioctl and calls it from the selinux code. This removes the inconsistency in handling dropping of a controlling tty and who knows it might even make some part of user space happy because it received a SIGHUP it was expecting. In addition since this removes the last user of proc_set_tty outside of tty_io.c proc_set_tty is made static and removed from tty.h Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: James Morris <jmorris@namei.org> Cc: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: simplify calling of put_pid.Eric W. Biederman2007-05-08
| | | | | | | | | | | | | | | | This patch should contain no functional changes. At some point I got confused and thought put_pid could not be called while a spin lock was held. While it may be nice to avoid that to reduce lock hold times put_pid can be safely called while we hold a spin lock. This patch removes all of the complications from the code introduced by my misunderstanding, making the code a little more readable. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: remove unnecessary export of proc_clear_ttyEric W. Biederman2007-05-08
| | | | | | | | | | All of the users of proc_clear_tty are compiled into the kernel so exporting this symbol appears gratuitous. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Fixes and cleanups for earlyprintk aka boot consoleGerd Hoffmann2007-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The console subsystem already has an idea of a boot console, using the CON_BOOT flag. The implementation has some flaws though. The major problem is that presence of a boot console makes register_console() ignore any other console devices (unless explicitly specified on the kernel command line). This patch fixes the console selection code to *not* consider a boot console a full-featured one, so the first non-boot console registering will become the default console instead. This way the unregister call for the boot console in the register_console() function actually triggers and the handover from the boot console to the real console device works smoothly. Added a printk for the handover, so you know which console device the output goes to when the boot console stops printing messages. The disable_early_printk() call is obsolete with that patch, explicitly disabling the early console isn't needed any more as it works automagically with that patch. I've walked through the tree, dropped all disable_early_printk() instances found below arch/ and tagged the consoles with CON_BOOT if needed. The code is tested on x86, sh (thanks to Paul) and mips (thanks to Ralf). Changes to last version: Rediffed against -rc3, adapted to mips cleanups by Ralf, fixed "udbg-immortal" cmd line arg on powerpc. Signed-off-by: Gerd Hoffmann <kraxel@exsuse.de> Acked-by: Paul Mundt <lethal@linux-sh.org> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: Andi Kleen <ak@suse.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty_register_driver: only allocate tty instances when definedAndy Whitcroft2007-05-07
| | | | | | | | | | | | If device->num is zero we attempt to kmalloc() zero bytes. When SLUB is enabled this returns a null pointer and take that as an allocation failure and fail the device register. Check for no devices and avoid the allocation. [akpm: opportunistic kzalloc() conversion] Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] tty: Fix two reported pid leaksEric W. Biederman2007-03-18
| | | | | | | | | | | | | | | | | | | | | | These leaks were reported by: Catalin Marinas <catalin.marians@gmail.com> and I have been able to very by inspection they are possible. When converting tty_io.c to store pids as struct pid pointers instead of pid_t values it appears I overlooked two places where we stop using the pid value. The very obvious one is in do_tty_hangup, and the one the less obvious one in __proc_set_tty. When looking into the code __proc_set_tty only has pids that need to be put because of failures of other parts of the code to properly perform hangup processing. Fixing the leak here in __proc_set_tty is easy and obviously correct so I am doing that first. Fixing the places that should be performing hangup processing is much less obviously correct. So those I'm aiming those patches at -mm. for now, so the can age a while before they are merged. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] tty_io: fix race in master pty close/slave pty close pathAristeu Sergio Rozanski Filho2007-03-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes a possible race that leads to double freeing an idr index. When the master begin to close, release_dev() is called and then pty_close() is called: if (tty->driver->close) tty->driver->close(tty, filp); This is done without helding any locks other than BKL. Inside pty_close(), being a master close, the devpts entry will be removed: #ifdef CONFIG_UNIX98_PTYS if (tty->driver == ptm_driver) devpts_pty_kill(tty->index); #endif But devpts_pty_kill() will call get_node() that may sleep while waiting for &devpts_root->d_inode->i_sem. When this happens and the slave is being opened, tty_open() just found the driver and index: driver = get_tty_driver(device, &index); if (!driver) { mutex_unlock(&tty_mutex); return -ENODEV; } This part of the code is already protected under tty_mute. The problem is that the slave close already got an index. Then init_dev() is called and blocks waiting for the same &devpts_root->d_inode->i_sem. When the master close resumes, it removes the devpts entry, and the relation between idr index and the tty is gone. The master then sleeps waiting for the tty_mutex on release_dev(). Slave open resumes and found no tty for that index. As result, a NULL tty is returned and init_dev() doesn't flow to fast_track: /* check whether we're reopening an existing tty */ if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { tty = devpts_get_tty(idx); if (tty && driver->subtype == PTY_TYPE_MASTER) tty = tty->link; } else { tty = driver->ttys[idx]; } if (tty) goto fast_track; The result of this, is that a new tty will be created and init_dev() returns sucessfull. After returning, tty_mutex is dropped and master close may resume. Master close finds it's the only use and both sides are closing, then releases the tty and the index. At this point, the idr index is free, but slave still has it. Slave open then calls pty_open() and finds that tty->link->count is 0, because there's no master and returns error. Then tty_open() calls release_dev() which executes without any warning, as it was a case of last slave close when the master is already closed (master->count == 0, slave->count == 1). The tty is then released with the already released idr index. This normally would only issue a warning on idr_remove() but in case of a customer's critical application, it's never too simple: thread1: opens master, gets index X thread1: begin closing master thread2: begin opening slave with index X thread1: finishes closing master, index X released thread3: opens master, gets index X, just released thread2: fails opening slave, releases index X <---- thread4: opens master, gets index X, init_dev() then find an already in use and healthy tty and fails If no more indexes are released, ptmx_open() will keep failing, as the first free index available is X, and it will make init_dev() fail because you're trying to "reopen a master" which isn't valid. The patch notices when this race happens and make init_dev() fail imediately. The init_dev() function is called with tty_mutex held, so it's safe to continue with tty till the end of function because release_dev() won't make any further changes without grabbing the tty_mutex. Without the patch, on some machines it's possible get easily idr warnings like this one: idr_remove called for id=15 which is not allocated. [<c02555b9>] idr_remove+0x139/0x170 [<c02a1b62>] release_mem+0x182/0x230 [<c02a28e7>] release_dev+0x4b7/0x700 [<c02a0ea7>] tty_ldisc_enable+0x27/0x30 [<c02a1e64>] init_dev+0x254/0x580 [<c02a0d64>] check_tty_count+0x14/0xb0 [<c02a4f05>] tty_open+0x1c5/0x340 [<c02a4d40>] tty_open+0x0/0x340 [<c017388f>] chrdev_open+0xaf/0x180 [<c017c2ac>] open_namei+0x8c/0x760 [<c01737e0>] chrdev_open+0x0/0x180 [<c0167bc9>] __dentry_open+0xc9/0x210 [<c0167e2c>] do_filp_open+0x5c/0x70 [<c0167a91>] get_unused_fd+0x61/0xd0 [<c0167e93>] do_sys_open+0x53/0x100 [<c0167f97>] sys_open+0x27/0x30 [<c010303b>] syscall_call+0x7/0xb using this test application available on: http://www.ruivo.org/~aris/pty_sodomizer.c Signed-off-by: Aristeu Sergio Rozanski Filho <aris@ruivo.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Chuck Ebbert <cebbert@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] tty: use NULL for ptrsRandy Dunlap2007-02-20
| | | | | | | | | Fix sparse warning in tty_io: drivers/char/tty_io.c:1536:34: warning: Using plain integer as NULL pointer Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] tty_register_driver: Remove incorrect and superfluous castGeert Uytterhoeven2007-02-20
| | | | | | | | | tty_register_driver: Remove incorrect and superfluous cast (expected and passed types are both const char *) Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] Fix SAK_work workqueue initialization.Eric W. Biederman2007-02-13
| | | | | | | | | | | | | | | | | | | | | | | Somewhere in the rewrite of the work queues my cleanup of SAK handling got broken. Maybe I didn't retest it properly or possibly the API was changing so fast I missed something. Regardless currently triggering a SAK now generates an ugly BUG_ON and kills the kernel. Thanks to Alexey Dobriyan <adobriyan@openvz.org> for spotting this. This modifies the use of SAK_work to initialize it when the data structure it resides in is initialized, and to simply call schedule_work when we need to generate a SAK. I update both data structures that have a SAK_work member for consistency. All of the old PREPARE_WORK calls that are now gone. If we call schedule_work again before it has processed it has generated the first SAK it will simply ignore the duplicate schedule_work request. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] tty: update the tty layer to work with struct pidEric W. Biederman2007-02-12
| | | | | | | | | | | | | | | | | Of kernel subsystems that work with pids the tty layer is probably the largest consumer. But it has the nice virtue that the assiation with a session only lasts until the session leader exits. Which means that no reference counting is required. So using struct pid winds up being a simple optimization to avoid hash table lookups. In the long term the use of pid_nr also ensures that when we have multiple pid spaces mixed everything will work correctly. Signed-off-by: Eric W. Biederman <eric@maxwell.lnxi.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] pid: replace is_orphaned_pgrp with is_current_pgrp_orphanedEric W. Biederman2007-02-12
| | | | | | | | | | | | | | | | | | | Every call to is_orphaned_pgrp passed in process_group(current) which is racy with respect to another thread changing our process group. It didn't bite us because we were dealing with integers and the worse we would get would be a stale answer. In switching the checks to use struct pid to be a little more efficient and prepare the way for pid namespaces this race became apparent. So I simplified the calls to the more specialized is_current_pgrp_orphaned so I didn't have to worry about making logic changes to avoid the race. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] pid: make session_of_pgrp use struct pid instead of pid_tEric W. Biederman2007-02-12
| | | | | | | | | | | | | | | | | | | | | | | | | To properly implement a pid namespace I need to deal exclusively in terms of struct pid, because pid_t values become ambiguous. To this end session_of_pgrp is transformed to take and return a struct pid pointer. To avoid the need to worry about reference counting I now require my caller to hold the appropriate locks. Leaving callers repsonsible for increasing the reference count if they need access to the result outside of the locks. Since session_of_pgrp currently only has one caller and that caller simply uses only test the result for equality with another process group, the locking change means I don't actually have to acquire the tasklist_lock at all. tiocspgrp is also modified to take and release the lock. The logic there is a little more complicated but nothing I won't need when I convert pgrp of a tty to a struct pid pointer. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] tty: fix the locking for signal->session in disassociate_cttyEric W. Biederman2007-02-12
| | | | | | | | | | | | commit 24ec839c431eb79bb8f6abc00c4e1eb3b8c4d517 while fixing the locking for signal->tty got the locking wrong for signal->session. This places our accesses of signal->session back under the tasklist_lock where they belong. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-29 08:48:32 -0500