- 31 Oct, 2011 1 commit
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Paul Gortmaker authored
These files were getting <linux/module.h> via an implicit include path, but we want to crush those out of existence since they cost time during compiles of processing thousands of lines of headers for no reason. Give them the lightweight header that just contains the EXPORT_SYMBOL infrastructure. Signed-off-by:Paul Gortmaker <paul.gortmaker@windriver.com>
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- 15 Nov, 2010 1 commit
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Greg Thelen authored
Using: - CONFIG_LOCKUP_DETECTOR=y - CONFIG_PREEMPT=y - CONFIG_LOCKDEP=y - CONFIG_PROVE_LOCKING=y - CONFIG_PROVE_RCU=y found a missing rcu lock during boot on a 512 MiB x86_64 ubuntu vm: =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- kernel/pid.c:419 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 1 lock held by ureadahead/1355: #0: (tasklist_lock){.+.+..}, at: [<ffffffff8115bc09>] sys_ioprio_set+0x7f/0x29e stack backtrace: Pid: 1355, comm: ureadahead Not tainted 2.6.37-dbg-DEV #1 Call Trace: [<ffffffff8109c10c>] lockdep_rcu_dereference+0xaa/0xb3 [<ffffffff81088cbf>] find_task_by_pid_ns+0x44/0x5d [<ffffffff81088cfa>] find_task_by_vpid+0x22/0x24 [<ffffffff8115bc3e>] sys_ioprio_set+0xb4/0x29e [<ffffffff8147cf21>] ? trace_hardirqs_off_thunk+0x3a/0x3c [<ffffffff8105c409>] sysenter_dispatch+0x7/0x2c [<ffffffff8147cee2>] ? trace_hardirqs_on_thunk+0x3a/0x3f The fix is to: a) grab rcu lock in sys_ioprio_{set,get}() and b) avoid grabbing tasklist_lock. Discussion in: http://marc.info/?l=linux-kernel&m=128951324702889 Signed-off-by:Greg Thelen <gthelen@google.com> Acked-by:
Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by:
Oleg Nesterov <oleg@redhat.com> Modified by Jens to remove the now redundant inner rcu lock and unlock since they are now protected by the outer lock. Signed-off-by:
Jens Axboe <jaxboe@fusionio.com>
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- 10 Nov, 2010 2 commits
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Sergey Senozhatsky authored
Commit 4221a991 "Add RCU check for find_task_by_vpid()" introduced rcu_lockdep_assert to find_task_by_pid_ns= Assertion failed in sys_ioprio_get. The patch is fixing assertion failure in ioprio_set as well. kernel/pid.c:419 invoked rcu_dereference_check() without protection! stack backtrace: Pid: 4254, comm: iotop Not tainted Call Trace: [<ffffffff810656f2>] lockdep_rcu_dereference+0xaa/0xb2 [<ffffffff81053c67>] find_task_by_pid_ns+0x4f/0x68 [<ffffffff81053c9d>] find_task_by_vpid+0x1d/0x1f [<ffffffff811104e2>] sys_ioprio_get+0x50/0x2da [<ffffffff81002182>] system_call_fastpath+0x16/0x1b V2: rcu critical section expanded according to comment by Paul E. McKenney Signed-off-by:
Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by:
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Daniel J Blueman authored
With 2.6.37-rc1, I observe sys_ioprio_set not taking the RCU lock [1] across access to the task credentials. Inspecting the code in fs/ioprio.c, the tasklist_lock is held for read across the __task_cred call, which is presumably sufficient to prevent the task credentials becoming stale. =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- kernel/pid.c:419 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 1 1 lock held by start-stop-daem/2246: #0: (tasklist_lock){.?.?..}, at: [<ffffffff811a2dfa>] sys_ioprio_set+0x8a/0x400 stack backtrace: Pid: 2246, comm: start-stop-daem Not tainted 2.6.37-rc1-330cd+ #2 Call Trace: [<ffffffff8109f5f4>] lockdep_rcu_dereference+0xa4/0xc0 [<ffffffff81085651>] find_task_by_pid_ns+0x81/0x90 [<ffffffff8108567d>] find_task_by_vpid+0x1d/0x20 [<ffffffff811a3160>] sys_ioprio_set+0x3f0/0x400 [<ffffffff816efa79>] ? trace_hardirqs_on_thunk+0x3a/0x3f [<ffffffff81003482>] system_call_fastpath+0x16/0x1b Take the RCU lock for read across acquiring the pointer to the task credentials and dereferencing it. Signed-off-by:Daniel J Blueman <daniel.blueman@gmail.com> Fixed up by Jens to fix missing rcu_read_unlock() on mismatches. Signed-off-by:
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- 30 Mar, 2010 1 commit
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Tejun Heo authored
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>
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- 14 Jan, 2009 1 commit
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Heiko Carstens authored
Signed-off-by:Heiko Carstens <heiko.carstens@de.ibm.com>
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- 06 Jan, 2009 1 commit
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Theodore Ts'o authored
Signed-off-by:"Theodore Ts'o" <tytso@mit.edu> Cc: Jens Axboe <jens.axboe@oracle.com>
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- 13 Nov, 2008 4 commits
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David Howells authored
Use RCU to access another task's creds and to release a task's own creds. This means that it will be possible for the credentials of a task to be replaced without another task (a) requiring a full lock to read them, and (b) seeing deallocated memory. Signed-off-by:
David Howells <dhowells@redhat.com> Acked-by:
James Morris <jmorris@namei.org> Acked-by:
Serge Hallyn <serue@us.ibm.com> Signed-off-by:
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David Howells authored
Wrap current->cred and a few other accessors to hide their actual implementation. Signed-off-by:
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David Howells authored
Separate the task security context from task_struct. At this point, the security data is temporarily embedded in the task_struct with two pointers pointing to it. Note that the Alpha arch is altered as it refers to (E)UID and (E)GID in entry.S via asm-offsets. With comment fixes Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com> Signed-off-by:
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David Howells authored
Wrap access to task credentials so that they can be separated more easily from the task_struct during the introduction of COW creds. Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id(). Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more sense to use RCU directly rather than a convenient wrapper; these will be addressed by later patches. Signed-off-by:
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- 20 Aug, 2008 1 commit
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Ken Chen authored
When user calls sys_setpriority(PRIO_PGRP ...) on a NPTL style multi-LWP process, only the task leader of the process is affected, all other sibling LWP threads didn't receive the setting. The problem was that the iterator used in sys_setpriority() only iteartes over one task for each process, ignoring all other sibling thread. Introduce a new macro do_each_pid_thread / while_each_pid_thread to walk each thread of a process. Convert 4 call sites in {set/get}priority and ioprio_{set/get}. Signed-off-by:Ken Chen <kenchen@google.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Roland McGrath <roland@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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- 28 Jan, 2008 3 commits
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Jens Axboe authored
Currently you must be root to set idle io prio class on a process. This is due to the fact that the idle class is implemented as a true idle class, meaning that it will not make progress if someone else is requesting disk access. Unfortunately this means that it opens DOS opportunities by locking down file system resources, hence it is root only at the moment. This patch relaxes the idle class a little, by removing the truly idle part (which entals a grace period with associated timer). The modifications make the idle class as close to zero impact as can be done while still guarenteeing progress. This means we can relax the root only criteria as well. Signed-off-by:Jens Axboe <jens.axboe@oracle.com>
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Jens Axboe authored
Detach task state from ioc, instead keep track of how many processes are accessing the ioc. Signed-off-by: -
Jens Axboe authored
This is where it belongs and then it doesn't take up space for a process that doesn't do IO. Signed-off-by:
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- 07 Nov, 2007 1 commit
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Jens Axboe authored
Normally io priorities follow the CPU nice, unless a specific scheduling class has been set. Once that is set, there's no way to reset the behaviour to 'none' so that it follows CPU nice again. Currently passing in 0 as the ioprio class/value will return -1/EINVAL, change that to allow resetting of a set scheduling class. Signed-off-by:
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- 19 Oct, 2007 2 commits
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Pavel Emelyanov authored
The find_task_by_something is a set of macros are used to find task by pid depending on what kind of pid is proposed - global or virtual one. All of them are wrappers above the most generic one - find_task_by_pid_type_ns() - and just substitute some args for it. It turned out, that dereferencing the current->nsproxy->pid_ns construction and pushing one more argument on the stack inline cause kernel text size to grow. This patch moves all this stuff out-of-line into kernel/pid.c. Together with the next patch it saves a bit less than 400 bytes from the .text section. Signed-off-by:
Pavel Emelyanov <xemul@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> Acked-by:
Ingo Molnar <mingo@elte.hu> Signed-off-by:
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Pavel Emelyanov authored
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:
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:
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- 12 Feb, 2007 1 commit
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Eric W. Biederman authored
There isn't any real advantage to this change except that it allows the old functions to be removed. Which is easier on maintenance and puts the code in a more uniform style. 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:
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- 12 Oct, 2006 1 commit
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Vasily Tarasov authored
Currently ioprio_best function first checks wethere aioprio or bioprio equals IOPRIO_CLASS_NONE (ioprio_valid() macros does that) and if it is so it returns bioprio/aioprio appropriately. Thus the next four lines, that set aclass/bclass to IOPRIO_CLASS_BE, if aclass/bclass == IOPRIO_CLASS_NONE, are never executed. The second problem: if aioprio from class IOPRIO_CLASS_NONE and bioprio from class IOPRIO_CLASS_IDLE are passed to ioprio_best function, it will return IOPRIO_CLASS_IDLE. It means that during __make_request we can merge two requests and set the priority of merged request to IDLE, while one of the initial requests originates from a process with NONE (default) priority. So we can get a situation when a process with default ioprio will experience IO starvation, while there is no process from real-time class in the system. Just removing ioprio_valid check should correct situation. Signed-off-by:
Vasily Tarasov <vtaras@openvz.org> Signed-off-by:
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- 30 Sep, 2006 3 commits
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Jens Axboe authored
As people often look for the copyright in files to see who to mail, update the link to a neutral one. Signed-off-by:Jens Axboe <axboe@kernel.dk>
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Oleg Nesterov authored
Signed-off-by:
Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by:
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Jens Axboe authored
cfq_exit_lock is protecting two things now: - The per-ioc rbtree of cfq_io_contexts - The per-cfqd linked list of cfq_io_contexts The per-cfqd linked list can be protected by the queue lock, as it is (by definition) per cfqd as the queue lock is. The per-ioc rbtree is mainly used and updated by the process itself only. The only outside use is the io priority changing. If we move the priority changing to not browsing the rbtree, we can remove any locking from the rbtree updates and lookup completely. Let the sys_ioprio syscall just mark processes as having the iopriority changed and lazily update the private cfq io contexts the next time io is queued, and we can remove this locking as well. Signed-off-by:Jens Axboe <axboe@suse.de>
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- 21 Aug, 2006 3 commits
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Oleg Nesterov authored
Saves 376 bytes (5 callers) for me. Signed-off-by:
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Oleg Nesterov authored
I know nothing about io scheduler, but I suspect set_task_ioprio() is not safe. current_io_context() initializes "struct io_context", then sets ->io_context. set_task_ioprio() running on another cpu may see the changes out of order, so ->set_ioprio(ioc) may use io_context which was not initialized properly. Signed-off-by:
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Oleg Nesterov authored
From include/linux/sched.h: * Careful: do_each_thread/while_each_thread is a double loop so * 'break' will not work as expected - use goto instead. */ Signed-off-by:
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- 30 Jun, 2006 1 commit
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David Quigley authored
Add a new security hook definition for the sys_ioprio_get operation. At present, the SELinux hook function implementation for this hook is identical to the getscheduler implementation but a separate hook is introduced to allow this check to be specialized in the future if necessary. This patch also creates a helper function get_task_ioprio which handles the access check in addition to retrieving the ioprio value for the task. Signed-off-by:
David Quigley <dpquigl@tycho.nsa.gov> Acked-by:
Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by:
Andrew Morton <akpm@osdl.org> Signed-off-by:
Linus Torvalds <torvalds@osdl.org>
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- 23 Jun, 2006 1 commit
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James Morris authored
Implement an LSM hook for setting a task's IO priority, similar to the hook for setting a tasks's nice value. A previous version of this LSM hook was included in an older version of multiadm by Jan Engelhardt, although I don't recall it being submitted upstream. Also included is the corresponding SELinux hook, which re-uses the setsched permission in the proccess class. Signed-off-by:
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- 12 Jan, 2006 1 commit
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Randy Dunlap authored
fs: Use <linux/capability.h> where capable() is used. Signed-off-by:
Randy Dunlap <rdunlap@xenotime.net> Acked-by:
Tim Schmielau <tim@physik3.uni-rostock.de> Signed-off-by:
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- 08 Nov, 2005 1 commit
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Adrian Bunk authored
Every file should include the headers containing the prototypes for it's global functions. Signed-off-by:Adrian Bunk <bunk@stusta.de>
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- 21 Aug, 2005 1 commit
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Linus Torvalds authored
It has all the normal priority inversion problems. Signed-off-by:
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- 08 Jul, 2005 1 commit
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Anton Blanchard authored
- Make ioprio syscalls return long, like set/getpriority syscalls. - Move function prototypes into syscalls.h so we can pick them up in the 32/64bit compat code. Signed-off-by:
Anton Blanchard <anton@samba.org> Acked-by:
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- 27 Jun, 2005 1 commit
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Jens Axboe authored
This updates the CFQ io scheduler to the new time sliced design (cfq v3). It provides full process fairness, while giving excellent aggregate system throughput even for many competing processes. It supports io priorities, either inherited from the cpu nice value or set directly with the ioprio_get/set syscalls. The latter closely mimic set/getpriority. This import is based on my latest from -mm. Signed-off-by:
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