- 28 Oct, 2010 40 commits
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KOSAKI Motohiro authored
Oleg Nesterov pointed out we have to prevent multiple-threads-inside-exec itself and we can reuse ->cred_guard_mutex for it. Yes, concurrent execve() has no worth. Let's move ->cred_guard_mutex from task_struct to signal_struct. It naturally prevent multiple-threads-inside-exec. Signed-off-by:
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by:
Oleg Nesterov <oleg@redhat.com> Acked-by:
Roland McGrath <roland@redhat.com> Acked-by:
David Howells <dhowells@redhat.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Namhyung Kim authored
ptrace_stop() releases and regrabs current->sighand->siglock but was missing proper annotation. Add it. Signed-off-by:
Namhyung Kim <namhyung@gmail.com> Acked-by:
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Namhyung Kim authored
lock_task_sighand() grabs sighand->siglock in case of returning non-NULL but unlock_task_sighand() releases it unconditionally. This leads sparse to complain about the lock context imbalance. Rename and wrap lock_task_sighand() using __cond_lock() macro to make sparse happy. Suggested-by:
Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by:
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Namhyung Kim authored
Use new 'datap' variable in order to remove unnecessary castings. Signed-off-by:
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Namhyung Kim authored
Remove unnecessary castings using void pointer and fix copy_to_user() return value. Also add missing __user markup on the argument of arch_ptrctl(). Signed-off-by:
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Namhyung Kim authored
Remove checking @addr less than 0 because @addr is now unsigned. Signed-off-by:
Chris Metcalf <cmetcalf@tilera.com> Signed-off-by:
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Namhyung Kim authored
Factor out struct fps and remove redundant castings. Signed-off-by:
David S. Miller <davem@davemloft.net> Signed-off-by:
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Namhyung Kim authored
Remove unnecessary castings and get rid of dummy pointer in favor of offsetof() macro in ptrace_32.c. Also use temporary variables and break long lines in order to improve readability. Signed-off-by:
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Namhyung Kim authored
Remove unnecessary castings. Signed-off-by:
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Namhyung Kim authored
Use new 'datavp' and 'datalp' variables in order to remove unnecessary castings. Signed-off-by:
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Namhyung Kim authored
Add missing __user markup on the argument of put_user(). Signed-off-by:
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Namhyung Kim authored
Use new 'datap' variable in order to remove unnecessary castings. Also remove checking @addr less than 0 because @addr is now unsigned. Signed-off-by:
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Namhyung Kim authored
Use new 'addrp', 'datavp' and 'datalp' variables in order to remove unnecessary castings. Signed-off-by:
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Namhyung Kim authored
Remove checking @addr greater than 0 because @addr is now unsigned. Signed-off-by:
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Namhyung Kim authored
Use new 'regno', 'datap' variables in order to remove duplicated expressions and unnecessary castings. Alse remove checking @addr less than 0 because addr is now unsigned. Signed-off-by:
Greg Ungerer <gerg@uclinux.org> Signed-off-by:
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Namhyung Kim authored
Use new 'regno', 'datap' variables in order to remove duplicated expressions and unnecessary castings. Signed-off-by:
Geert Uytterhoeven <geert@linux-m68k.org> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by:
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Namhyung Kim authored
Use new 'datap' variable in order to remove duplicated castings. Signed-off-by:
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Namhyung Kim authored
Use new 'regno', 'datap' variables in order to remove duplicated expressions and unnecessary castings. Alse remove checking @addr less than 0 because addr is now unsigned. Signed-off-by:
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Namhyung Kim authored
Use new 'regno', 'datap' variables in order to remove duplicated expressions and unnecessary castings. Alse remove checking @addr less than 0 because addr is now unsigned. Signed-off-by:
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Namhyung Kim authored
Use new 'regno' variable in order to remove redandunt expression and remove checking @addr less than 0 because @addr is now unsigned. Also update 'datap' on PTRACE_GET/SETREGS to fix a bug on arch-v10. Signed-off-by:
Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Signed-off-by:
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Namhyung Kim authored
Change signature of get/put_reg() according to the change of arch_ptrace() and remove unnecessary castings. Signed-off-by:
Mike Frysinger <vapier@gentoo.org> Signed-off-by:
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Namhyung Kim authored
use new 'datap' variable type of void pointer in order to remove unnecessary castings. Signed-off-by:
Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com> Signed-off-by:
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Namhyung Kim authored
use new 'datap' variable in order to remove unnecessary castings. Signed-off-by:
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Namhyung Kim authored
Remove checking @addr less than 0 because @addr is now unsigned and use new udescp variable in order to remove unnecessary castings. [akpm@linux-foundation.org: fix unused variable 'udescp'] Signed-off-by:
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Namhyung Kim authored
Fix up the arguments to arch_ptrace() to take account of the fact that @addr and @data are now unsigned long rather than long as of a preceding patch in this series. Signed-off-by:
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Namhyung Kim authored
Use new 'datavp' and 'datalp' variables to remove unnecesary castings. Signed-off-by:
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Namhyung Kim authored
Since userspace API of ptrace syscall defines @addr and @data as void pointers, it would be more appropriate to define them as unsigned long in kernel. Therefore related functions are changed also. 'unsigned long' is typically used in other places in kernel as an opaque data type and that using this helps cleaning up a lot of warnings from sparse. Suggested-by:
Arnd Bergmann <arnd@arndb.de> Signed-off-by:
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Namhyung Kim authored
exit_ptrace() releases and regrabs tasklist_lock but was missing proper annotation. Add it. Signed-off-by:
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KAMEZAWA Hiroyuki authored
This patch extracts the core logic from mem_cgroup_update_file_mapped() as mem_cgroup_update_file_stat() and adds a wrapper. As a planned future update, memory cgroup has to count dirty pages to implement dirty_ratio/limit. And more, the number of dirty pages is required to kick flusher thread to start writeback. (Now, no kick.) This patch is preparation for it and makes other statistics implementation clearer. Just a clean up. Signed-off-by:
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by:
Balbir Singh <balbir@linux.vnet.ibm.com> Reviewed-by:
Greg Thelen <gthelen@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by:
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KAMEZAWA Hiroyuki authored
An event counter MEM_CGROUP_ON_MOVE is used for quick check whether file stat update can be done in async manner or not. Now, it use percpu counter and for_each_possible_cpu to update. This patch replaces for_each_possible_cpu to for_each_online_cpu and adds necessary synchronization logic at CPU HOTPLUG. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:
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KAMEZAWA Hiroyuki authored
Now, memcgroup's per cpu coutner uses for_each_possible_cpu() to get the value. It's better to use for_each_online_cpu() and a cpu hotplug handler. This patch only handles statistics counter. MEM_CGROUP_ON_MOVE will be handled in another patch. Signed-off-by:
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KAMEZAWA Hiroyuki authored
In memory cgroup management, we sometimes have to walk through subhierarchy of cgroup to gather informaiton, or lock something, etc. Now, to do that, mem_cgroup_walk_tree() function is provided. It calls given callback function per cgroup found. But the bad thing is that it has to pass a fixed style function and argument, "void*" and it adds much type casting to memcontrol.c. To make the code clean, this patch replaces walk_tree() with for_each_mem_cgroup_tree(iter, root) An iterator style call. The good point is that iterator call doesn't have to assume what kind of function is called under it. A bad point is that it may cause reference-count leak if a caller use "break" from the loop by mistake. I think the benefit is larger. The modified code seems straigtforward and easy to read because we don't have misterious callbacks and pointer cast. Signed-off-by:
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KAMEZAWA Hiroyuki authored
At accounting file events per memory cgroup, we need to find memory cgroup via page_cgroup->mem_cgroup. Now, we use lock_page_cgroup() for guarantee pc->mem_cgroup is not overwritten while we make use of it. But, considering the context which page-cgroup for files are accessed, we can use alternative light-weight mutual execusion in the most case. At handling file-caches, the only race we have to take care of is "moving" account, IOW, overwriting page_cgroup->mem_cgroup. (See comment in the patch) Unlike charge/uncharge, "move" happens not so frequently. It happens only when rmdir() and task-moving (with a special settings.) This patch adds a race-checker for file-cache-status accounting v.s. account moving. The new per-cpu-per-memcg counter MEM_CGROUP_ON_MOVE is added. The routine for account move 1. Increment it before start moving 2. Call synchronize_rcu() 3. Decrement it after the end of moving. By this, file-status-counting routine can check it needs to call lock_page_cgroup(). In most case, I doesn't need to call it. Following is a perf data of a process which mmap()/munmap 32MB of file cache in a minute. Before patch: 28.25% mmap mmap [.] main 22.64% mmap [kernel.kallsyms] [k] page_fault 9.96% mmap [kernel.kallsyms] [k] mem_cgroup_update_file_mapped 3.67% mmap [kernel.kallsyms] [k] filemap_fault 3.50% mmap [kernel.kallsyms] [k] unmap_vmas 2.99% mmap [kernel.kallsyms] [k] __do_fault 2.76% mmap [kernel.kallsyms] [k] find_get_page After patch: 30.00% mmap mmap [.] main 23.78% mmap [kernel.kallsyms] [k] page_fault 5.52% mmap [kernel.kallsyms] [k] mem_cgroup_update_file_mapped 3.81% mmap [kernel.kallsyms] [k] unmap_vmas 3.26% mmap [kernel.kallsyms] [k] find_get_page 3.18% mmap [kernel.kallsyms] [k] __do_fault 3.03% mmap [kernel.kallsyms] [k] filemap_fault 2.40% mmap [kernel.kallsyms] [k] handle_mm_fault 2.40% mmap [kernel.kallsyms] [k] do_page_fault This patch reduces memcg's cost to some extent. (mem_cgroup_update_file_mapped is called by both of map/unmap) Note: It seems some more improvements are required..but no idea. maybe removing set/unset flag is required. Signed-off-by:Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Greg Thelen <gthelen@google.com> Signed-off-by:
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KAMEZAWA Hiroyuki authored
Presently memory cgroup accounts file-mapped by counter and flag. counter is working in the same way with zone_stat but FileMapped flag only exists in memcg (for helping move_account). This flag can be updated wrongly in a case. Assume CPU0 and CPU1 and a thread mapping a page on CPU0, another thread unmapping it on CPU1. CPU0 CPU1 rmv rmap (mapcount 1->0) add rmap (mapcount 0->1) lock_page_cgroup() memcg counter+1 (some delay) set MAPPED FLAG. unlock_page_cgroup() lock_page_cgroup() memcg counter-1 clear MAPPED flag In the above sequence counter is properly updated but FLAG is not. This means that representing a state by a flag which is maintained by counter needs some special care. To handle this, when clearing a flag, this patch check mapcount directly and clear the flag only when mapcount == 0. (if mapcount >0, someone will make it to zero later and flag will be cleared.) Reverse case, dec-after-inc cannot be a problem because page_table_lock() works well for it. (IOW, to make above sequence, 2 processes should touch the same page at once with map/unmap.) Signed-off-by: -
Daniel Lezcano authored
The ns_cgroup will be removed very soon. Let's warn, for this version, ns_cgroup is deprecated. Make ns_cgroup and clone_children exclusive. If the clone_children is set and the ns_cgroup is mounted, let's fail with EINVAL when the ns_cgroup subsys is created (a printk will help the user to understand why the creation fails). Update the feature remove schedule file with the deprecated ns_cgroup. Signed-off-by:
Daniel Lezcano <daniel.lezcano@free.fr> Acked-by:
Paul Menage <menage@google.com> Signed-off-by:
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Evgeny Kuznetsov authored
Function "strcpy" is used without check for maximum allowed source string length and could cause destination string overflow. Check for string length is added before using "strcpy". Function now is return error if source string length is more than a maximum. akpm: presently considered NotABug, but add the check for general future-safeness and robustness. Signed-off-by:
Evgeny Kuznetsov <EXT-Eugeny.Kuznetsov@nokia.com> Acked-by:
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Daniel Lezcano authored
Current behavior: ================= (1) When we mount a cgroup, we can specify the 'all' option which means to enable all the cgroup subsystems. This is the default option when no option is specified. (2) If we want to mount a cgroup with a subset of the supported cgroup subsystems, we have to specify a subsystems name list for the mount option. (3) If we specify another option like 'noprefix' or 'release_agent', the actual code wants the 'all' or a subsystem name option specified also. Not critical but a bit not friendly as we should assume (1) in this case. (4) Logically, the 'all' option is mutually exclusive with a subsystem name, but this is not detected. In other words: succeed : mount -t cgroup -o all,freezer cgroup /cgroup => is it 'all' or 'freezer' ? fails : mount -t cgroup -o noprefix cgroup /cgroup => succeed if we do '-o noprefix,all' The following patches consolidate a bit the mount options check. New behavior: ============= (1) untouched (2) untouched (3) the 'all' option will be by default when specifying other than a subsystem name option (4) raises an error In other words: fails : mount -t cgroup -o all,freezer cgroup /cgroup succeed : mount -t cgroup -o noprefix cgroup /cgroup For the sake of lisibility, the if ... then ... else ... if ... indentation when parsing the options has been changed to: if ... then ... continue fi Signed-off-by:Serge E. Hallyn <serge.hallyn@canonical.com> Reviewed-by:
Li Zefan <lizf@cn.fujitsu.com> Reviewed-by:
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Daniel Lezcano authored
The ns_cgroup is a control group interacting with the namespaces. When a new namespace is created, a corresponding cgroup is automatically created too. The cgroup name is the pid of the process who did 'unshare' or the child of 'clone'. This cgroup is tied with the namespace because it prevents a process to escape the control group and use the post_clone callback, so the child cgroup inherits the values of the parent cgroup. Unfortunately, the more we use this cgroup and the more we are facing problems with it: (1) when a process unshares, the cgroup name may conflict with a previous cgroup with the same pid, so unshare or clone return -EEXIST (2) the cgroup creation is out of control because there may have an application creating several namespaces where the system will automatically create several cgroups in his back and let them on the cgroupfs (eg. a vrf based on the network namespace). (3) the mix of (1) and (2) force an administrator to regularly check and clean these cgroups. This patchset removes the ns_cgroup by adding a new flag to the cgroup and the cgroupfs mount option. It enables the copy of the parent cgroup when a child cgroup is created. We can then safely remove the ns_cgroup as this flag brings a compatibility. We have now to manually create and add the task to a cgroup, which is consistent with the cgroup framework. This patch: Sent as an answer to a previous thread around the ns_cgroup. https://lists.linux-foundation.org/pipermail/containers/2009-June/018627.html It adds a control file 'clone_children' for a cgroup. This control file is a boolean specifying if the child cgroup should be a clone of the parent cgroup or not. The default value is 'false'. This flag makes the child cgroup to call the post_clone callback of all the subsystem, if it is available. At present, the cpuset is the only one which had implemented the post_clone callback. The option can be set at mount time by specifying the 'clone_children' mount option. Signed-off-by: -
Tomasz Buchert authored
There are 4 state transitions possible for a freezer. Only FREEZING -> FROZEN transaction is done lazily. This patch allows update_freezer_state only to perform this transaction and renames the function to update_if_frozen. Moreover is_task_frozen_enough function is removed and its every occurence is replaced with frozen(). Therefore for a group to become FROZEN every task must be frozen. The previous version could trigger a following bug: When cgroup is in the process of freezing (but none of its tasks are frozen yet), update_freezer_state() (called from freezer_read or freezer_write) would incorrectly report that a group is 'THAWED' (because nfrozen = 0), allowing the transaction FREEZING -> THAWED without writing anything to 'freezer.state'. This is incorrect according to the documentation. This could result in a 'THAWED' cgroup with frozen tasks inside. A code to reproduce this bug is available here: http://pentium.hopto.org/~thinred/repos/linux-misc/freezer_bug2.c [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:
Tomasz Buchert <tomasz.buchert@inria.fr> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by:
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Tomasz Buchert authored
It is possible to move a task from its cgroup even if this group is 'FREEZING'. This results in a nasty bug - the moved task will become frozen OUTSIDE its original cgroup and will remain in a permanent 'D' state. This patch allows to migrate the task only between THAWED cgroups. This behavior was observed and easily reproduced on a single core laptop. Notice that reproducibility depends highly on the machine used. Program and instructions how to reproduce the bug can be fetched from: http://pentium.hopto.org/~thinred/repos/linux-misc/freezer_bug.cSigned-off-by:
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