LatencyTOP kernel infrastructure; it measures latencies in the
scheduler and tracks it system wide and per process.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Commit 84427eaef1 (remove task_ppid_nr_ns)
moved the task_tgid_nr_ns(task->real_parent) outside of lock_task_sighand().
This is wrong, ->real_parent could be freed/reused.
Both ->parent/real_parent point to nothing after __exit_signal() because
we remove the child from ->children list, and thus the child can't be
reparented when its parent exits.
rcu_read_lock() protects ->parent/real_parent, but _only_ if we know it was
valid before we take rcu lock.
Revert this part of the patch.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
task_ppid_nr_ns is called in three places. One of these should never
have called it. In the other two, using it broke the existing
semantics. This was presumably accidental. If the function had not
been there, it would have been much more obvious to the eye that those
patches were changing the behavior. We don't need this function.
In task_state, the pid of the ptracer is not the ppid of the ptracer.
In do_task_stat, ppid is the tgid of the real_parent, not its pid.
I also moved the call outside of lock_task_sighand, since it doesn't
need it.
In sys_getppid, ppid is the tgid of the real_parent, not its pid.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Contents of /proc/*/maps is sensitive and may become sensitive after
open() (e.g. if target originally shares our ->mm and later does exec
on suid-root binary).
Check at read() (actually, ->start() of iterator) time that mm_struct
we'd grabbed and locked is
- still the ->mm of target
- equal to reader's ->mm or the target is ptracable by reader.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Both SLUB and SLAB really did almost exactly the same thing for
/proc/slabinfo setup, using duplicate code and per-allocator #ifdef's.
This just creates a common CONFIG_SLABINFO that is enabled by both SLUB
and SLAB, and shares all the setup code. Maybe SLOB will want this some
day too.
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We need to register slabinfo to procfs when CONFIG_SLUB is enabled to
make the file actually visible to user-space.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ultimately to implement /proc perfectly we need an implementation of
d_revalidate because files and directories can be removed behind the back
of the VFS, and d_revalidate is the only way we can let the VFS know that
this has happened.
Unfortunately the linux VFS can not cope with anything in the path to a
mount point going away. So a proper d_revalidate method that calls d_drop
also needs to call have_submounts which is moderately expensive, so you
really don't want a d_revalidate method that unconditionally calls it, but
instead only calls it when the backing object has really gone away.
proc generic entries only disappear on module_unload (when not counting the
fledgling network namespace) so it is quite rare that we actually encounter
that case and has not actually caused us real world trouble yet.
So until we get a proper test for keeping dentries in the dcache fix the
current d_revalidate method by completely removing it. This returns us to
the current status quo.
So with CONFIG_NETNS=n things should look as they have always looked.
For CONFIG_NETNS=y things work most of the time but there are a few rare
corner cases that don't behave properly. As the network namespace is
barely present in 2.6.24 this should not be a problem.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "Denis V. Lunev" <den@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/net-2.6: (27 commits)
[INET]: Fix inet_diag dead-lock regression
[NETNS]: Fix /proc/net breakage
[TEXTSEARCH]: Do not allow zero length patterns in the textsearch infrastructure
[NETFILTER]: fix forgotten module release in xt_CONNMARK and xt_CONNSECMARK
[NETFILTER]: xt_TCPMSS: remove network triggerable WARN_ON
[DECNET]: dn_nl_deladdr() almost always returns no error
[IPV6]: Restore IPv6 when MTU is big enough
[RXRPC]: Add missing select on CRYPTO
mac80211: rate limit wep decrypt failed messages
rfkill: fix double-mutex-locking
mac80211: drop unencrypted frames if encryption is expected
mac80211: Fix behavior of ieee80211_open and ieee80211_close
ieee80211: fix unaligned access in ieee80211_copy_snap
mac80211: free ifsta->extra_ie and clear IEEE80211_STA_PRIVACY_INVOKED
SCTP: Fix build issues with SCTP AUTH.
SCTP: Fix chunk acceptance when no authenticated chunks were listed.
SCTP: Fix the supported extensions paramter
SCTP: Fix SCTP-AUTH to correctly add HMACS paramter.
SCTP: Fix the number of HB transmissions.
[TCP] illinois: Incorrect beta usage
...
Well I clearly goofed when I added the initial network namespace support
for /proc/net. Currently things work but there are odd details visible to
user space, even when we have a single network namespace.
Since we do not cache proc_dir_entry dentries at the moment we can just
modify ->lookup to return a different directory inode depending on the
network namespace of the process looking at /proc/net, replacing the
current technique of using a magic and fragile follow_link method.
To accomplish that this patch:
- introduces a shadow_proc method to allow different dentries to
be returned from proc_lookup.
- Removes the old /proc/net follow_link magic
- Fixes a weakness in our not caching of proc generic dentries.
As shadow_proc uses a task struct to decided which dentry to return we can
go back later and fix the proc generic caching without modifying any code
that uses the shadow_proc method.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Oleg noticed that the call of task_pid_nr_ns() in proc_pid_readdir
is racy with respect to tasks exiting.
After a bit of examination it also appears that the call itself
is completely unnecessary.
So to fix the problem this patch modifies next_tgid() to return
both a tgid and the task struct in question.
A structure is introduced to return these values because it is
slightly cleaner and easier to optimize, and the resulting code
is a little shorter.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
proc_kill_inodes() can clear ->i_fop in the middle of vfs_readdir resulting in
NULL dereference during "file->f_op->readdir(file, buf, filler)".
The solution is to remove proc_kill_inodes() completely:
a) we don't have tricky modules implementing their tricky readdir hooks which
could keeping this revoke from hell.
b) In a situation when module is gone but PDE still alive, standard
readdir will return only "." and "..", because pde->next was cleared by
remove_proc_entry().
c) the race proc_kill_inode() destined to prevent is not completely
fixed, just race window made smaller, because vfs_readdir() is run
without sb_lock held and without file_list_lock held. Effectively,
->i_fop is cleared at random moment, which can't fix properly anything.
BUG: unable to handle kernel NULL pointer dereference at virtual address 00000018
printing eip: c1061205 *pdpt = 0000000005b22001 *pde = 0000000000000000
Oops: 0000 [#1] PREEMPT SMP
Modules linked in: foo af_packet ipv6 cpufreq_ondemand loop serio_raw sr_mod k8temp cdrom hwmon amd_rng
Pid: 2033, comm: find Not tainted (2.6.24-rc1-b1d08ac064268d0ae2281e98bf5e82627e0f0c56 #2)
EIP: 0060:[<c1061205>] EFLAGS: 00010246 CPU: 0
EIP is at vfs_readdir+0x47/0x74
EAX: c6b6a780 EBX: 00000000 ECX: c1061040 EDX: c5decf94
ESI: c6b6a780 EDI: fffffffe EBP: c9797c54 ESP: c5decf78
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process find (pid: 2033, ti=c5dec000 task=c64bba90 task.ti=c5dec000)
Stack: c5decf94 c1061040 fffffff7 0805ffbc 00000000 c6b6a780 c1061295 0805ffbc
00000000 00000400 00000000 00000004 0805ffbc 4588eff4 c5dec000 c10026ba
00000004 0805ffbc 00000400 0805ffbc 4588eff4 bfdc6c70 000000dc 0000007b
Call Trace:
[<c1061040>] filldir64+0x0/0xc5
[<c1061295>] sys_getdents64+0x63/0xa5
[<c10026ba>] sysenter_past_esp+0x5f/0x85
=======================
Code: 49 83 78 18 00 74 43 8d 6b 74 bf fe ff ff ff 89 e8 e8 b8 c0 12 00 f6 83 2c 01 00 00 10 75 22 8b 5e 10 8b 4c 24 04 89 f0 8b 14 24 <ff> 53 18 f6 46 1a 04 89 c7 75 0b 8b 56 0c 8b 46 08 e8 c8 66 00
EIP: [<c1061205>] vfs_readdir+0x47/0x74 SS:ESP 0068:c5decf78
hch: "Nice, getting rid of this is a very good step formwards.
Unfortunately we have another copy of this junk in
security/selinux/selinuxfs.c:sel_remove_entries() which would need the
same treatment."
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Acked-by: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
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>
Srivatsa Vaddagiri noticed occasionally incorrect CPU usage
values in top and tracked it down to stime going below 0 in
task_stime(). Negative values are possible there due to the
sampled nature of stime/utime.
Fix suggested by Balbir Singh.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Tested-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Reviewed-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Currently we special case when we have only the initial pid namespace.
Unfortunately in doing so the copied case for the other namespaces was
broken so we don't properly flush the thread directories :(
So this patch removes the unnecessary special case (removing a usage of
proc_mnt) and corrects the flushing of the thread directories.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: Kirill Korotaev <dev@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It appears we overlooked support for removing generic proc files
when we added support for multiple proc super blocks. Handle
that now.
[akpm@linux-foundation.org: coding-style cleanups]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Acked-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch reverts Eric's commit 2b008b0a8e
It diets .text & .data section of the kernel if CONFIG_NET_NS is not set.
This is safe after list operations cleanup.
Signed-of-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
keep utime/stime monotonic.
cpustats use utime/stime as a ratio against sum_exec_runtime, as a
consequence it can happen - when the ratio changes faster than time
accumulates - that either can be appear to go backwards.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
It is not safe to to place struct pernet_operations in a special section.
We need struct pernet_operations to last until we call unregister_pernet_subsys.
Which doesn't happen until module unload.
So marking struct pernet_operations is a disaster for modules in two ways.
- We discard it before we call the exit method it points to.
- Because I keep struct pernet_operations on a linked list discarding
it for compiled in code removes elements in the middle of a linked
list and does horrible things for linked insert.
So this looks safe assuming __exit_refok is not discarded
for modules.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix pointer mismatches in proc_sysctl.c. The proc_handler() method returns a
size_t through an arg pointer, but is given a pointer to a ssize_t to return
into.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix mnt_flush_task() misplaced kernel-doc.
Fix typos in some of the doc text.
Warning(linux-2.6.23-git17//fs/proc/base.c:2280): No description found for parameter 'mnt'
Warning(linux-2.6.23-git17//fs/proc/base.c:2280): No description found for parameter 'pid'
Warning(linux-2.6.23-git17//fs/proc/base.c:2280): No description found for parameter 'tgid'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When removing the explicit task_struct->pid usage I found that
proc_readfd_common() and proc_pident_readdir() get this field, but do not
use it at all. So this cleanup is a cheap help with the task_struct->pid
isolation.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
