02 Oct, 2006
6 commits
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This patch adds basic IPC namespace functionality to
IPC utils:
- init_ipc_ns
- copy/clone/unshare/free IPC ns
- /proc preparationsSigned-off-by: Pavel Emelianov
Signed-off-by: Kirill Korotaev
Cc: "Eric W. Biederman"
Cc: Cedric Le Goater
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch set allows to unshare IPCs and have a private set of IPC objects
(sem, shm, msg) inside namespace. Basically, it is another building block of
containers functionality.This patch implements core IPC namespace changes:
- ipc_namespace structure
- new config option CONFIG_IPC_NS
- adds CLONE_NEWIPC flag
- unshare support[clg@fr.ibm.com: small fix for unshare of ipc namespace]
[akpm@osdl.org: build fix]
Signed-off-by: Pavel Emelianov
Signed-off-by: Kirill Korotaev
Signed-off-by: Cedric Le Goater
Cc: "Eric W. Biederman"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The nsproxy was being copied in unshare() when anything was being unshared,
even if it was something not referenced from nsproxy. This should end up
in some cases with far more memory usage than necessary.Signed-off-by: Serge Hallyn
Cc: Kirill Korotaev
Cc: "Eric W. Biederman"
Cc: Herbert Poetzl
Cc: Andrey Savochkin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Implement a CLONE_NEWUTS flag, and use it at clone and sys_unshare.
[clg@fr.ibm.com: IPC unshare fix]
[bunk@stusta.de: cleanup]
Signed-off-by: Serge Hallyn
Cc: Kirill Korotaev
Cc: "Eric W. Biederman"
Cc: Herbert Poetzl
Cc: Andrey Savochkin
Signed-off-by: Adrian Bunk
Signed-off-by: Cedric Le Goater
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This moves the mount namespace into the nsproxy. The mount namespace count
now refers to the number of nsproxies point to it, rather than the number of
tasks. As a result, the unshare_namespace() function in kernel/fork.c no
longer checks whether it is being shared.Signed-off-by: Serge Hallyn
Cc: Kirill Korotaev
Cc: "Eric W. Biederman"
Cc: Herbert Poetzl
Cc: Andrey Savochkin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch adds a nsproxy structure to the task struct. Later patches will
move the fs namespace pointer into this structure, and introduce a new utsname
namespace into the nsproxy.The vserver and openvz functionality, then, would be implemented in large part
by virtualizing/isolating more and more resources into namespaces, each
contained in the nsproxy.[akpm@osdl.org: build fix]
Signed-off-by: Serge Hallyn
Cc: Kirill Korotaev
Cc: "Eric W. Biederman"
Cc: Herbert Poetzl
Cc: Andrey Savochkin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Oct, 2006
1 commit
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There were a few accounting data/macros that are used in CSA but are #ifdef'ed
inside CONFIG_BSD_PROCESS_ACCT. This patch is to change those ifdef's from
CONFIG_BSD_PROCESS_ACCT to CONFIG_TASK_XACCT. A few defines are moved from
kernel/acct.c and include/linux/acct.h to kernel/tsacct.c and
include/linux/tsacct_kern.h.Signed-off-by: Jay Lan
Cc: Shailabh Nagar
Cc: Balbir Singh
Cc: Jes Sorensen
Cc: Chris Sturtivant
Cc: Tony Ernst
Cc: Guillaume Thouvenin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
30 Sep, 2006
2 commits
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copy_process:
// holds tasklist_lock + ->siglock
/*
* inherit ioprio
*/
p->ioprio = current->ioprio;Why? ->ioprio was already copied in dup_task_struct(). I guess this is
needed to ensure that the child can't escape
sys_ioprio_set(IOPRIO_WHO_{PGRP,USER}), yes?In that case we don't need ->siglock held, and the comment should be
updated.Signed-off-by: Oleg Nesterov
Cc: Jens Axboe
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Alexey Dobriyan
Acked-by: Jens Axboe
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Sep, 2006
1 commit
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* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (130 commits)
[ARM] 3856/1: Add clocksource for Intel IXP4xx platforms
[ARM] 3855/1: Add generic time support
[ARM] 3873/1: S3C24XX: Add irq_chip names
[ARM] 3872/1: S3C24XX: Apply consistant tabbing to irq_chips
[ARM] 3871/1: S3C24XX: Fix ordering of EINT4..23
[ARM] nommu: confirms the CR_V bit in nommu mode
[ARM] nommu: abort handler fixup for !CPU_CP15_MMU cores.
[ARM] 3870/1: AT91: Start removing static memory mappings
[ARM] 3869/1: AT91: NAND support for DK and KB9202 boards
[ARM] 3868/1: AT91 hardware header update
[ARM] 3867/1: AT91 GPIO update
[ARM] 3866/1: AT91 clock update
[ARM] 3865/1: AT91RM9200 header updates
[ARM] 3862/2: S3C2410 - add basic power management support for AML M5900 series
[ARM] kthread: switch arch/arm/kernel/apm.c
[ARM] Off-by-one in arch/arm/common/icst*
[ARM] 3864/1: Refactore sharpsl_pm
[ARM] 3863/1: Add Locomo SPI Device
[ARM] 3847/2: Convert LOMOMO to use struct device for GPIOs
[ARM] Use CPU_CACHE_* where possible in asm/cacheflush.h
...
26 Sep, 2006
1 commit
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This patch adds the per thread cookie field to the task struct and the PDA.
Also it makes sure that the PDA value gets the new cookie value at context
switch, and that a new task gets a new cookie at task creation time.Signed-off-by: Arjan van Ven
Signed-off-by: Ingo Molnar
Signed-off-by: Andi Kleen
CC: Andi Kleen
20 Sep, 2006
1 commit
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ARM has interrupts enabled over context switches (iow, has
__ARCH_WANT_INTERRUPTS_ON_CTXSW defined.) The lockdep code in fork.c
assumes that interrupts are always disabled. Fix this wrong
assumption by making the initialisation of 'p->hardirqs_enabled'
depend on __ARCH_WANT_INTERRUPTS_ON_CTXSW.Acked-by: Ingo Molnar
Signed-off-by: Russell King
02 Sep, 2006
1 commit
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Cleanup allocation and freeing of tsk->delays used by delay accounting.
This solves two problems reported for delay accounting:1. oops in __delayacct_blkio_ticks
http://www.uwsg.indiana.edu/hypermail/linux/kernel/0608.2/1844.htmlCurrently tsk->delays is getting freed too early in task exit which can
cause a NULL tsk->delays to get accessed via reading of /proc//stats.
The patch fixes this problem by freeing tsk->delays closer to when
task_struct itself is freed up. As a result, it also eliminates the use of
tsk->delays_lock which was only being used (inadequately) to safeguard
access to tsk->delays while a task was exiting.2. Possible memory leak in kernel/delayacct.c
http://www.uwsg.indiana.edu/hypermail/linux/kernel/0608.2/1389.htmlThe patch cleans up tsk->delays allocations after a bad fork which was
missing earlier.The patch has been tested to fix the problems listed above and stress
tested with rapid calls to delay accounting's taskstats command interface
(which is the other path that can access the same data, besides the /proc
interface causing the oops above).Signed-off-by: Shailabh Nagar
Cc: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
06 Aug, 2006
1 commit
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When delivering PTRACE_EVENT_VFORK_DONE, provide pid of the child process
when tracer calls ptrace(PTRACE_GETEVENTMSG). This is already
(accidentally) available when the tracer is tracing VFORK in addition to
VFORK_DONE.Signed-off-by: Chuck Ebbert
Cc: Daniel Jacobowitz
Cc: Albert Cahalan
Cc: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
15 Jul, 2006
2 commits
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Send per-tgid data only once during exit of a thread group instead of once
with each member thread exit.Currently, when a thread exits, besides its per-tid data, the per-tgid data
of its thread group is also sent out, if its thread group is non-empty.
The per-tgid data sent consists of the sum of per-tid stats for all
*remaining* threads of the thread group.This patch modifies this sending in two ways:
- the per-tgid data is sent only when the last thread of a thread group
exits. This cuts down heavily on the overhead of sending/receiving
per-tgid data, especially when other exploiters of the taskstats
interface aren't interested in per-tgid stats- the semantics of the per-tgid data sent are changed. Instead of being
the sum of per-tid data for remaining threads, the value now sent is the
true total accumalated statistics for all threads that are/were part of
the thread group.The patch also addresses a minor issue where failure of one accounting
subsystem to fill in the taskstats structure was causing the send of
taskstats to not be sent at all.The patch has been tested for stability and run cerberus for over 4 hours
on an SMP.[akpm@osdl.org: bugfixes]
Signed-off-by: Shailabh Nagar
Signed-off-by: Balbir Singh
Cc: Jay Lan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Initialization code related to collection of per-task "delay" statistics which
measure how long it had to wait for cpu, sync block io, swapping etc. The
collection of statistics and the interface are in other patches. This patch
sets up the data structures and allows the statistics collection to be
disabled through a kernel boot parameter.Signed-off-by: Shailabh Nagar
Signed-off-by: Balbir Singh
Cc: Jes Sorensen
Cc: Peter Chubb
Cc: Erich Focht
Cc: Levent Serinol
Cc: Jay Lan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Jul, 2006
1 commit
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As announced half a year ago this patch will remove the tasklist_lock
export. The previous two patches got rid of the remaining modular users.Signed-off-by: Christoph Hellwig
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 Jul, 2006
5 commits
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cleanup: remove task_t and convert all the uses to struct task_struct. I
introduced it for the scheduler anno and it was a mistake.Conversion was mostly scripted, the result was reviewed and all
secondary whitespace and style impact (if any) was fixed up by hand.Signed-off-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Teach special (recursive) locking code to the lock validator. Has no effect
on non-lockdep kernels.Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Do 'make oldconfig' and accept all the defaults for new config options -
reboot into the kernel and if everything goes well it should boot up fine and
you should have /proc/lockdep and /proc/lockdep_stats files.Typically if the lock validator finds some problem it will print out
voluminous debug output that begins with "BUG: ..." and which syslog output
can be used by kernel developers to figure out the precise locking scenario.What does the lock validator do? It "observes" and maps all locking rules as
they occur dynamically (as triggered by the kernel's natural use of spinlocks,
rwlocks, mutexes and rwsems). Whenever the lock validator subsystem detects a
new locking scenario, it validates this new rule against the existing set of
rules. If this new rule is consistent with the existing set of rules then the
new rule is added transparently and the kernel continues as normal. If the
new rule could create a deadlock scenario then this condition is printed out.When determining validity of locking, all possible "deadlock scenarios" are
considered: assuming arbitrary number of CPUs, arbitrary irq context and task
context constellations, running arbitrary combinations of all the existing
locking scenarios. In a typical system this means millions of separate
scenarios. This is why we call it a "locking correctness" validator - for all
rules that are observed the lock validator proves it with mathematical
certainty that a deadlock could not occur (assuming that the lock validator
implementation itself is correct and its internal data structures are not
corrupted by some other kernel subsystem). [see more details and conditionals
of this statement in include/linux/lockdep.h and
Documentation/lockdep-design.txt]Furthermore, this "all possible scenarios" property of the validator also
enables the finding of complex, highly unlikely multi-CPU multi-context races
via single single-context rules, increasing the likelyhood of finding bugs
drastically. In practical terms: the lock validator already found a bug in
the upstream kernel that could only occur on systems with 3 or more CPUs, and
which needed 3 very unlikely code sequences to occur at once on the 3 CPUs.
That bug was found and reported on a single-CPU system (!). So in essence a
race will be found "piecemail-wise", triggering all the necessary components
for the race, without having to reproduce the race scenario itself! In its
short existence the lock validator found and reported many bugs before they
actually caused a real deadlock.To further increase the efficiency of the validator, the mapping is not per
"lock instance", but per "lock-class". For example, all struct inode objects
in the kernel have inode->inotify_mutex. If there are 10,000 inodes cached,
then there are 10,000 lock objects. But ->inotify_mutex is a single "lock
type", and all locking activities that occur against ->inotify_mutex are
"unified" into this single lock-class. The advantage of the lock-class
approach is that all historical ->inotify_mutex uses are mapped into a single
(and as narrow as possible) set of locking rules - regardless of how many
different tasks or inode structures it took to build this set of rules. The
set of rules persist during the lifetime of the kernel.To see the rough magnitude of checking that the lock validator does, here's a
portion of /proc/lockdep_stats, fresh after bootup:lock-classes: 694 [max: 2048]
direct dependencies: 1598 [max: 8192]
indirect dependencies: 17896
all direct dependencies: 16206
dependency chains: 1910 [max: 8192]
in-hardirq chains: 17
in-softirq chains: 105
in-process chains: 1065
stack-trace entries: 38761 [max: 131072]
combined max dependencies: 2033928
hardirq-safe locks: 24
hardirq-unsafe locks: 176
softirq-safe locks: 53
softirq-unsafe locks: 137
irq-safe locks: 59
irq-unsafe locks: 176The lock validator has observed 1598 actual single-thread locking patterns,
and has validated all possible 2033928 distinct locking scenarios.More details about the design of the lock validator can be found in
Documentation/lockdep-design.txt, which can also found at:http://redhat.com/~mingo/lockdep-patches/lockdep-design.txt
[bunk@stusta.de: cleanups]
Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Adrian Bunk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Accurate hard-IRQ-flags and softirq-flags state tracing.
This allows us to attach extra functionality to IRQ flags on/off
events (such as trace-on/off).Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Generic lock debugging:
- generalized lock debugging framework. For example, a bug in one lock
subsystem turns off debugging in all lock subsystems.- got rid of the caller address passing (__IP__/__IP_DECL__/etc.) from
the mutex/rtmutex debugging code: it caused way too much prototype
hackery, and lockdep will give the same information anyway.- ability to do silent tests
- check lock freeing in vfree too.
- more finegrained debugging options, to allow distributions to
turn off more expensive debugging features.There's no separate 'held mutexes' list anymore - but there's a 'held locks'
stack within lockdep, which unifies deadlock detection across all lock
classes. (this is independent of the lockdep validation stuff - lockdep first
checks whether we are holding a lock already)Here are the current debugging options:
CONFIG_DEBUG_MUTEXES=y
CONFIG_DEBUG_LOCK_ALLOC=ywhich do:
config DEBUG_MUTEXES
bool "Mutex debugging, basic checks"config DEBUG_LOCK_ALLOC
bool "Detect incorrect freeing of live mutexes"Signed-off-by: Ingo Molnar
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Jul, 2006
1 commit
-
Signed-off-by: Jörn Engel
Signed-off-by: Adrian Bunk
28 Jun, 2006
2 commits
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This adds the actual pi-futex implementation, based on rt-mutexes.
[dino@in.ibm.com: fix an oops-causing race]
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner
Signed-off-by: Arjan van de Ven
Signed-off-by: Dinakar Guniguntala
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Core functions for the rt-mutex subsystem.
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Jun, 2006
2 commits
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After the previous patch SIGNAL_GROUP_EXIT implies a pending SIGKILL, we
can remove this check from copy_process() because we already checked
!signal_pending().Signed-off-by: Oleg Nesterov
Cc: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
To keep the dcache from filling up with dead /proc entries we flush them on
process exit. However over the years that code has gotten hairy with a
dentry_pointer and a lock in task_struct and misdocumented as a correctness
feature.I have rewritten this code to look and see if we have a corresponding entry in
the dcache and if so flush it on process exit. This removes the extra fields
in the task_struct and allows me to trivially handle the case of a
/proc//task/ entry as well as the current /proc/ entries.Signed-off-by: Eric W. Biederman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
26 Jun, 2006
1 commit
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The pacct facility need an i/o operation when an accounting record is
generated. There is a possibility to wake OOM killer up. If OOM killer is
activated, it kills some processes to make them release process memory
regions.But acct_process() is called in the killed processes context before calling
exit_mm(), so those processes cannot release own memory. In the results, any
processes stop in this point and it finally cause a system stall.
23 Jun, 2006
2 commits
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Set errorp in dup_fd, it will be used in sys_unshare also.
Signed-off-by: Prasanna Meda
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
exit_aio() and exit_mmap() can sleep. But it's easy to accidentally call
mmput() from inside locks.Cc: Dave Peterson
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 May, 2006
1 commit
-
Signed-off-by: Al Viro
20 Apr, 2006
2 commits
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It's really task private, so clear that field on fork after copying
task structure.Signed-off-by: Jens Axboe
-
While we can currently walk through thread groups, process groups, and
sessions with just the rcu_read_lock, this opens the door to walking the
entire task list.We already have all of the other RCU guarantees so there is no cost in
doing this, this should be enough so that proc can stop taking the
tasklist lock during readdir.prev_task was killed because it has no users, and using it will miss new
tasks when doing an rcu traversal.Signed-off-by: Eric W. Biederman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
15 Apr, 2006
1 commit
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Somehow in the midst of dotting i's and crossing t's during
the merge up to rc1 we wound up keeping __put_task_struct_cb
when it should have been killed as it no longer has any users.
Sorry I probably should have caught this while it was
still in the -mm tree.Having the old code there gets confusing when reading
through the code and trying to understand what is
happening.Signed-off-by: Eric W. Biederman
Signed-off-by: Linus Torvalds
01 Apr, 2006
3 commits
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Wrong error path in dup_fd() - it should return NULL on error,
not an address of already freed memory :/Triggered by OpenVZ stress test suite.
What is interesting is that it was causing different oopses in RCU like
below:
Call Trace:
[] rcu_do_batch+0x2c/0x80
[] rcu_process_callbacks+0x3d/0x70
[] tasklet_action+0x73/0xe0
[] __do_softirq+0x10a/0x130
[] do_softirq+0x4f/0x60
=======================
[] smp_apic_timer_interrupt+0x77/0x110
[] apic_timer_interrupt+0x1c/0x24
Code: Bad EIP value.
Kernel panic - not syncing: Fatal exception in interruptSigned-Off-By: Pavel Emelianov
Signed-Off-By: Dmitry Mishin
Signed-Off-By: Kirill Korotaev
Signed-Off-By: Linus Torvalds -
Simplifies the code, reduces the need for 4 pid hash tables, and makes the
code more capable.In the discussions I had with Oleg it was felt that to a large extent the
cleanup itself justified the work. With struct pid being dynamically
allocated meant we could create the hash table entry when the pid was
allocated and free the hash table entry when the pid was freed. Instead of
playing with the hash lists when ever a process would attach or detach to a
process.For myself the fact that it gave what my previous task_ref patch gave for free
with simpler code was a big win. The problem is that if you hold a reference
to struct task_struct you lock in 10K of low memory. If you do that in a user
controllable way like /proc does, with an unprivileged but hostile user space
application with typical resource limits of 1000 fds and 100 processes I can
trigger the OOM killer by consuming all of low memory with task structs, on a
machine wight 1GB of low memory.If I instead hold a reference to struct pid which holds a pointer to my
task_struct, I don't suffer from that problem because struct pid is 2 orders
of magnitude smaller. In fact struct pid is small enough that most other
kernel data structures dwarf it, so simply limiting the number of referring
data structures is enough to prevent exhaustion of low memory.This splits the current struct pid into two structures, struct pid and struct
pid_link, and reduces our number of hash tables from PIDTYPE_MAX to just one.
struct pid_link is the per process linkage into the hash tables and lives in
struct task_struct. struct pid is given an indepedent lifetime, and holds
pointers to each of the pid types.The independent life of struct pid simplifies attach_pid, and detach_pid,
because we are always manipulating the list of pids and not the hash table.
In addition in giving struct pid an indpendent life it makes the concept much
more powerful.Kernel data structures can now embed a struct pid * instead of a pid_t and
not suffer from pid wrap around problems or from keeping unnecessarily
large amounts of memory allocated.Signed-off-by: Eric W. Biederman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This just got nuked in mainline. Bring it back because Eric's patches use it.
Cc: "Eric W. Biederman"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Mar, 2006
3 commits
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Move 'tsk->sighand = NULL' from cleanup_sighand() to __exit_signal(). This
makes the exit path more understandable and allows us to do
cleanup_sighand() outside of ->siglock protected section.Signed-off-by: Oleg Nesterov
Cc: "Eric W. Biederman"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Eric W. Biederman wrote:
>
> Ok. SUSV3/Posix is clear, fork is atomic with respect
> to signals. Either a signal comes before or after a
> fork but not during. (See the rationale section).
> http://www.opengroup.org/onlinepubs/000095399/functions/fork.html
>
> The tasklist_lock does not stop forks from adding to a process
> group. The forks stall while the tasklist_lock is held, but a fork
> that began before we grabbed the tasklist_lock simply completes
> afterwards, and the child does not receive the signal.This also means that SIGSTOP or sig_kernel_coredump() signal can't
be delivered to pgrp/session reliably.With this patch copy_process() returns -ERESTARTNOINTR when it
detects a pending signal, fork() will be restarted transparently
after handling the signals.This patch also deletes now unneeded "group_stop_count > 0" check,
copy_process() can no longer succeed while group stop in progress.Signed-off-by: Oleg Nesterov
Acked-By: Eric Biederman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch kills PIDTYPE_TGID pid_type thus saving one hash table in
kernel/pid.c and speeding up subthreads create/destroy a bit. It is also a
preparation for the further tref/pids rework.This patch adds 'struct list_head thread_group' to 'struct task_struct'
instead.We don't detach group leader from PIDTYPE_PID namespace until another
thread inherits it's ->pid == ->tgid, so we are safe wrt premature
free_pidmap(->tgid) call.Currently there are no users of find_task_by_pid_type(PIDTYPE_TGID).
Should the need arise, we can use find_task_by_pid()->group_leader.Signed-off-by: Oleg Nesterov
Acked-By: Eric Biederman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds