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* tty: introduce wait_event_interruptible_ttyArnd Bergmann2010-08-107-10/+59
| | | | | | | | | | | | Calling wait_event_interruptible implicitly releases the BKL when it sleeps, but we need to do this explcitly when we have converted it to a mutex. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* cdc-acm: remove dead codeArnd Bergmann2010-08-101-9/+3
| | | | | | | | | | | The wait_event_interruptible_timeout in acm_port_down is never reached. Remove it to avoid possible deadlocks with the big tty mutex if someone were to start using the blocking version of acm_port_down. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: fix console_sem lock orderArnd Bergmann2010-08-101-2/+0
| | | | | | | | | | | | | | vgacon_do_font_op releases and reacquires the BTM while holding console_sem. This violates the rule that BTM has to be the outer lock whenever we hold both. There does not seem to be any reason to give up the BTM here, so just stop doing that. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: never hold BTM while getting tty_mutexArnd Bergmann2010-08-102-19/+17
| | | | | | | | | | | | | | tty_mutex is never taken with the BTM held, except for two corner cases that are worked around here. We give up the BTM before calling tty_release() in the error path of tty_open(). Similarly, we reorder the locking in ptmx_open() to get tty_mutex before the BTM. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: replace BKL with a new tty_lockArnd Bergmann2010-08-1017-115/+161
| | | | | | | | | | | As a preparation for replacing the big kernel lock in the TTY layer, wrap all the callers in new macros tty_lock, tty_lock_nested and tty_unlock. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* serial: fix termios settings in openArnd Bergmann2010-08-101-10/+9
| | | | | | | | | | | | | | | | | | | | | | | Move termios initialization in open into uart_dtr_rts to make sure it always gets called when necessary. Based on a suggestion from Alan Cox. Alan writes: Ok this sort of makes sense. Something isn't getting initialised and both getty and minicom will do a termios set which is sorting it out. This is occurring because the generic block_til_ready sets ASYNCB_NORMAL_ACTIVE so the termios updating gets skipped. This patch should cure it and then we can think about doing it more elegantly by getting the serial layer to use tty_port_open, kfifo and the like and removing the tons of repeated crap in all the drivers. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reported-by: Tony Luck <tony.luck@intel.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* serial: Use block_til_ready helperAlan Cox2010-08-101-86/+1
| | | | | | | | | Our code now rather closely resembles the helper, so switch to it. Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* serial: trim locking on the helpersAlan Cox2010-08-101-4/+1
| | | | | | | | | | | | | The port mutex protects port->tty, but these paths never need to walk from port->tty. They do need the low level lock as the API expects that but they already also take it. Thus we can drop the extra mutex lock calls here. Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* serial: add port helpersAlan Cox2010-08-101-14/+37
| | | | | | | | | | | We can make this the same as the ones that will be needed by the tty_port helper logic that we want to move to but still call them from the existing code base. Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* serial: Change the wait for carrier lockingAlan Cox2010-08-101-9/+35
| | | | | | | | | | | | We want to push the lock/unlock into the helper functions so that we can prepare to move to using the tty_port helper. The expansion initially comes out a bit ugly but its worth the temporary expansion IMHO just so we can produce a nice testable series of changes. Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: Move the vt_tty field from the vc_data into the standard tty_portAlan Cox2010-08-104-12/+11
| | | | | | | | | | This takes all the tty references through the expected interface points so we can refcount them. Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: Make vt's have a tty_portAlan Cox2010-08-102-0/+4
| | | | | | | | | | | The vt layer isn't safely handling reference counts to tty object on the input side. Add a tty port structure to the vt layer in order to implement this using the standard helpers. Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* vc: Locking clean upAlan Cox2010-08-102-3/+8
| | | | | | | | | | The virtual console layer uses the BKL for various things that don't really need it. Clean them out. Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: serial - fix tty referencing in set_ldiscAlan Cox2010-08-103-7/+4
| | | | | | | | | | Pass down the ldisc number so that the drivers don't have to peek into the tty object themselves. This lets us get rid of another case of back referencing port to tty which we don't want (because of races versus hangup/close). Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: serial - fix tty back references in termiosAlan Cox2010-08-105-26/+19
| | | | | | | | | | | | | One or two drivers go poking back into the tty from the termios setting routine in unsafe ways. We don't need to pass the tty down because the [ab]users are just using it to get at things they can get at anyway. This leaves low_latency setting to sort out along with set_ldisc use. Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: serial - fix various misuses/mishandlings of port->ttyAlan Cox2010-08-101-49/+60
| | | | | | | | | | Make it robust against hang up events. In most cases we can do this simply by passing the right things in the first place. Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* synclink: reworking locking a bitAlan Cox2010-08-102-2/+19
| | | | | | | | | | | Use the port mutex and port lock to fix the various races. The locking still isn't totally consistent but its better than before. Wants switching to the port helpers. Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: Fix the digi acceleport driver NULL checksAlan Cox2010-08-101-5/+9
| | | | | | | | | This now refcounts but doesn't actually check the reference was obtained in all the places it should. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* specialix: Kill the BKLAlan Cox2010-08-101-6/+5
| | | | | | | | Use the port mutex instead Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* epca: Kill the big kernel lockAlan Cox2010-08-101-3/+1
| | | | | | | | | The lock is no longer needed for wait until sent paths so this can go Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* cyclades: Kill off BKL usageAlan Cox2010-08-101-11/+9
| | | | | | | | | | Use the port mutext for config setting, the rest is locked sufficiently anyway that the BKL makes no odds. Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* synclink: kill the big kernel lockAlan Cox2010-08-103-73/+56
| | | | | | | | | | | We don't need it while waiting and we can lock the ioctls using the port mutex. While at it eliminate use of the hangup mutex and switch to the port mutex. Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* rocket: kill BKLAlan Cox2010-08-101-9/+19
| | | | | | | | | | | | | | We can use the port mutex for this and also for the hangup path so removing the problematic use of the hangup mutex in this driver. Fix up the locking on the various port flags while we are at it. Ultimately this driver needs to be using tty_port_ helpers which would sort this out far better. Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* isicom: kill off the BKLAlan Cox2010-08-101-8/+5
| | | | | | | | | | As with the others we can use the port mutex to get the needed locking properties and fix the race with open. Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* riscom8: kill use of lock_kernelAlan Cox2010-08-101-6/+8
| | | | | | | | | | | | The riscom8 board uses lock_kernel to protect bits of the port setting ioctl logic. We can use the port mutex for this as the logic is internal and will also lock set versus open (a locking property that has been lost somewhere along the way) Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* istallion: use bit ops for the board flagsAlan Cox2010-08-102-19/+19
| | | | | | | | | This lets us avoid problems with races on the flag changes Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* stallion: prune lock_kernel callsAlan Cox2010-08-102-17/+25
| | | | | | | | | | | Remove unneeded tty layer lock kernel bits. Relock the needed bits using the port mutex. The istallion still has brd state races but those are not new or introduced by the removal of the lock_kernel logic. Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* vt/console: try harder to print output when panicingJesse Barnes2010-08-108-9/+27
| | | | | | | | | | | | | | | | | | | | | | | | Jesse's initial patch commit said: "At panic time (i.e. when oops_in_progress is set) we should try a bit harder to update the screen and make sure output gets to the VT, since some drivers are capable of flipping back to it. So make sure we try to unblank and update the display if called from a panic context." I've enhanced this to add a flag to the vc that console layer can set to indicate they want this behaviour to occur. This also adds support to fbcon for that flag and adds an fb flag for drivers to indicate they want to use the support. It enables this for KMS drivers. Signed-off-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> Acked-by: James Simmons <jsimmons@infradead.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: Add EXTPROC support for LINEMODEhyc@symas.com2010-08-1039-10/+101
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* tty: remove remaining Hayes ESP ioctlsGreg Kroah-Hartman2010-08-108-16/+0
| | | | | | | | | | | | | | | As Jeff Dike pointed out, the Hayes ESP driver was removed in commit f53a2ade0bb9f2a81f473e6469155172a96b7c38, so these ioctl definitions should also be removed. This cleans up the remaining arch-specific locations of this ioctl value. Thanks to Arnd for pointing these out. Cc: Jeff Dike <jdike@addtoit.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: Remove Hayes ESP ioctlsJeff Dike2010-08-101-4/+2
| | | | | | | | | | | | | | Remove Hayes ESP ioctls The Hayes ESP driver has been removed from the tree: commit f53a2ade0bb9f2a81f473e6469155172a96b7c38 ("tty: esp: remove broken driver") so its ioctls aren't needed any more. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* serial: fix wakup races in the mrst_max3110 driverArjan van de Ven2010-08-101-28/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | The mrst_max3110 driver had a set of unsafe wakeup sequences along the following line: if (!atomic_read(&foo)) { atomic_set(&foo, 1); wake_up(worker_thread); } and the worker thread would do if (atomic_read(&foo)) { do_work(); atomic_set(&foo, 0); } which can result in various missed wakups due to test-then-set races, as well as due to clear-after-work instead of clear-before-work. This patch fixes these races by using the proper bit test-and-set operations, and by doing clear-before-work. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* serial: replace open coded mutex with a real mutex in mrst_max3110.cArjan van de Ven2010-08-101-7/+8
| | | | | | | | | | | | | | | | | | The mrst_max3110.c driver uses an open coded, non atomic variable to create exclusion between two of its worker threads. More than that, while the main thread does a proper set-work-clear sequence, the other thread only does a test, with the result that no actual exclusion is happening. this patch replaces this open coded variable with a proper mutex in addition, the 'lock' spinlock is removed from the per adapter structure, the lock was only ever initialized but never used Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* max3110 sanity check a registerjianwei.yang2010-08-101-2/+11
| | | | | | | | | | | | | | MAX3111 is the SPI/UART IC installed on the MRST SPI Port Card as a serial debug goal, and the SPI Port Card will be frequently mounted and unmounted from the main board by developers depending whether debug serial is required or not. As the MAX3111 has no subvendor or product id registers available, the patch will try to access one register to decide if this IC is present or not. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* mrst_max3110: add UART driver for Max3110 on MoorestownFeng Tang2010-08-104-0/+921
| | | | | | | | | | | | | This driver enable the max3110 device, it can be used as a system console. the IRQ needs be enabled if user want a better performance. MRST max3110 works in 3.684MHz clock, which supports 230400 as its maximum rate. Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* serial: add UART_CAP_EFR and UART_CAP_SLEEP flags to 16C950 UARTs definitionYegor Yefremov2010-08-101-1/+1
| | | | | | | | | | | | Adding UART_CAP_EFR and UART_CAP_SLEEP flags will enable sleep mode and automatic CTS flow control for 16C950 UARTs. It will also avoid capabilities detection warning like this: "ttyS0: detected caps 00000700 should be 00000100" Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* vt: clean up the code - use kernel libraryAndy Shevchenko2010-08-101-2/+3
| | | | | | | | Signed-off-by: Andy Shevchenko <ext-andriy.shevchenko@nokia.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* serial: There's no config CONSOLEChristoph Egger2010-08-101-8/+0
| | | | | | | | | | | as there's no config CONSOLE (never has been as far as I can tell) and noone has ever missed that piece of code, it should be safe to remove it making the kernel a tiny bit less complex. Signed-off-by: Christoph Egger <siccegge@cs.fau.de> Acked-by: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* n_gsm.c: removed duplicated #includesAndrea Gelmini2010-08-101-1/+0
| | | | | | | | drivers/char/n_gsm.c: linux/timer.h is included more than once. Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Merge branch 'writable_limits' of git://decibel.fi.muni.cz/~xslaby/linuxLinus Torvalds2010-08-1015-75/+207
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'writable_limits' of git://decibel.fi.muni.cz/~xslaby/linux: unistd: add __NR_prlimit64 syscall numbers rlimits: implement prlimit64 syscall rlimits: switch more rlimit syscalls to do_prlimit rlimits: redo do_setrlimit to more generic do_prlimit rlimits: add rlimit64 structure rlimits: do security check under task_lock rlimits: allow setrlimit to non-current tasks rlimits: split sys_setrlimit rlimits: selinux, do rlimits changes under task_lock rlimits: make sure ->rlim_max never grows in sys_setrlimit rlimits: add task_struct to update_rlimit_cpu rlimits: security, add task_struct to setrlimit Fix up various system call number conflicts. We not only added fanotify system calls in the meantime, but asm-generic/unistd.h added a wait4 along with a range of reserved per-architecture system calls.
| * unistd: add __NR_prlimit64 syscall numbersJiri Slaby2010-07-165-2/+9
| | | | | | | | | | | | | | | | | | | | Add __NR_prlimit64 syscall numbers to asm-generic. Add them also to asm-x86, both 32 and 64-bit. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com>
| * rlimits: implement prlimit64 syscallJiri Slaby2010-07-162-0/+98
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the code to support the sys_prlimit64 syscall which modifies-and-returns the rlim values of a selected process atomically. The first parameter, pid, being 0 means current process. Unlike the current implementation, it is a generic interface, architecture indepentent so that we needn't handle compat stuff anymore. In the future, after glibc start to use this we can deprecate sys_setrlimit and sys_getrlimit in favor to clean up the code finally. It also adds a possibility of changing limits of other processes. We check the user's permissions to do that and if it succeeds, the new limits are propagated online. This is good for large scale applications such as SAP or databases where administrators need to change limits time by time (e.g. on crashes increase core size). And it is unacceptable to restart the service. For safety, all rlim users now either use accessors or doesn't need them due to - locking - the fact a process was just forked and nobody else knows about it yet (and nobody can't thus read/write limits) hence it is safe to modify limits now. The limitation is that we currently stay at ulong internal representation. So the rlim64_is_infinity check is used where value is compared against ULONG_MAX on 32-bit which is the maximum value there. And since internally the limits are held in struct rlimit, converters which are used before and after do_prlimit call in sys_prlimit64 are introduced. Signed-off-by: Jiri Slaby <jslaby@suse.cz>
| * rlimits: switch more rlimit syscalls to do_prlimitJiri Slaby2010-07-162-23/+11
| | | | | | | | | | | | | | | | After we added more generic do_prlimit, switch sys_getrlimit to that. Also switch compat handling, so we can get rid of ugly __user casts and avoid setting process' address limit to kernel data and back. Signed-off-by: Jiri Slaby <jslaby@suse.cz>
| * rlimits: redo do_setrlimit to more generic do_prlimitJiri Slaby2010-07-162-36/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | It now allows also reading of limits. I.e. all read and writes will later use this function. It takes two parameters, new and old limits which can be both NULL. If new is non-NULL, the value in it is set to rlimits. If old is non-NULL, current rlimits are stored there. If both are non-NULL, old are stored prior to setting the new ones, atomically. (Similar to sigaction.) Signed-off-by: Jiri Slaby <jslaby@suse.cz>
| * rlimits: add rlimit64 structureJiri Slaby2010-07-161-0/+7
| | | | | | | | | | | | | | | | | | | | Add a platform independent structure for resource limits to use with a new prlimit64 syscall. This structure is the same which uses glibc for 64-bit limits. Also add corresponding infinity which is a 64-bit full of bit-ones. Signed-off-by: Jiri Slaby <jslaby@suse.cz>
| * rlimits: do security check under task_lockJiri Slaby2010-07-161-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Do security_task_setrlimit under task_lock. Other tasks may change limits under our hands while we are checking limits inside the function. From now on, they can't. Note that all the security work is done under a spinlock here now. Security hooks count with that, they are called from interrupt context (like security_task_kill) and with spinlocks already held (e.g. capable->security_capable). Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: James Morris <jmorris@namei.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
| * rlimits: allow setrlimit to non-current tasksJiri Slaby2010-07-161-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add locking to allow setrlimit accept task parameter other than current. Namely, lock tasklist_lock for read and check whether the task structure has sighand non-null. Do all the signal processing under that lock still held. There are some points: 1) security_task_setrlimit is now called with that lock held. This is not new, many security_* functions are called with this lock held already so it doesn't harm (all this security_* stuff does almost the same). 2) task->sighand->siglock (in update_rlimit_cpu) is nested in tasklist_lock. This dependence is already existing. 3) tsk->alloc_lock is nested in tasklist_lock. This is OK too, already existing dependence. Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com>
| * rlimits: split sys_setrlimitJiri Slaby2010-07-162-16/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Create do_setrlimit from sys_setrlimit and declare do_setrlimit in the resource header. This is the first phase to have generic do_prlimit which allows to be called from read, write and compat rlimits code. The new do_setrlimit also accepts a task pointer to change the limits of. Currently, it cannot be other than current, but this will change with locking later. Also pass tsk->group_leader to security_task_setrlimit to check whether current is allowed to change rlimits of the process and not its arbitrary thread because it makes more sense given that rlimit are per process and not per-thread. Signed-off-by: Jiri Slaby <jslaby@suse.cz>
| * rlimits: selinux, do rlimits changes under task_lockOleg Nesterov2010-07-161-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | When doing an exec, selinux updates rlimits in its code of current process depending on current max. Make sure max or cur doesn't change in the meantime by grabbing task_lock which do_prlimit needs for changing limits too. While at it, use rlimit helper for accessing CPU rlimit a line below. To have a volatile access too. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Oleg Nesterov <oleg@redhat.com>
| * rlimits: make sure ->rlim_max never grows in sys_setrlimitOleg Nesterov2010-07-161-7/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mostly preparation for Jiri's changes, but probably makes sense anyway. sys_setrlimit() checks new_rlim.rlim_max <= old_rlim->rlim_max, but when it takes task_lock() old_rlim->rlim_max can be already lowered. Move this check under task_lock(). Currently this is not important, we can only race with our sub-thread, this means the application is stupid. But when we change the code to allow the update of !current task's limits, it becomes important to make sure ->rlim_max can be lowered "reliably" even if we race with the application doing sys_setrlimit(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
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