19 Jun, 2009
40 commits
-
create_uts_ns() will be used by C/R to create fresh uts_ns.
Signed-off-by: Alexey Dobriyan
Acked-by: Serge Hallyn
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
copy_pid_ns() is a perfect example of a case where unwinding leads to more
code and makes it less clear. Watch the diffstat.Signed-off-by: Alexey Dobriyan
Cc: Pavel Emelyanov
Cc: "Eric W. Biederman"
Reviewed-by: Serge Hallyn
Acked-by: Sukadev Bhattiprolu
Reviewed-by: WANG Cong
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
create_pid_namespace() creates everything, but caller has to assign parent
pidns by hand, which is unnatural. At the moment of call new ->level has
to be taken from somewhere and parent pidns is already available.Signed-off-by: Alexey Dobriyan
Cc: Pavel Emelyanov
Cc: "Eric W. Biederman"
Acked-by: Serge Hallyn
Acked-by: Sukadev Bhattiprolu
Reviewed-by: WANG Cong
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
find_task_by_pid_type_ns is only used to implement find_task_by_vpid and
find_task_by_pid_ns, but both of them pass PIDTYPE_PID as first argument.
So just fold find_task_by_pid_type_ns into find_task_by_pid_ns and use
find_task_by_pid_ns to implement find_task_by_vpid.While we're at it also remove the exports for find_task_by_pid_ns and
find_task_by_vpid - we don't have any modular callers left as the only
modular caller of he old pre pid namespace find_task_by_pid (gfs2) was
switched to pid_task which operates on a struct pid pointer instead of a
pid_t. Given the confusion about pid_t values vs namespace that's
generally the better option anyway and I think we're better of restricting
modules to do it that way.Signed-off-by: Christoph Hellwig
Cc: Pavel Emelyanov
Cc: "Eric W. Biederman"
Cc: Ingo Molnar
Cc: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Remoce the unused variable 'val' from __do_proc_dointvec()
The integer has been declared and used as 'val = -val' and there is no
reference to it anywhere.Signed-off-by: Sukanto Ghosh
Cc: Jaswinder Singh Rajput
Cc: Sukanto Ghosh
Cc: Jiri Kosina
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
One of my programs frequently grabs the parport, does something with it
and then drops it again. This results in spamming of the kernel log with"... registered pardevice"
"... unregistered pardevice"These messages are completely useless, except for debugging ppdev,
probably. So put them under DEBUG (or dynamic debug).Signed-off-by: Michael Buesch
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fix this:
isicom.c: In function `isicom_probe':
isicom.c:1587: warning: `signature' may be used uninitialized in this function
by uninitialized_var(), because if the signature is not initialized in
reset_card(), we won't use it.Signed-off-by: Jiri Slaby
Cc: Alan Cox
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
memory_open() ignores devlist and does a switch for each item, duplicating
code and conditional definitions.Clean it up by adding backing_dev_info to devlist and use it to lookup for
the minor device.[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Adriano dos Santos Fernandes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The definition of ipc_parse_version depends on
__ARCH_WANT_IPC_PARSE_VERSION, but the header file declares it
conditionally based on the architecture.Use the macro consistently to make it easier to add new architectures.
Signed-off-by: Arnd Bergmann
Acked-by: Serge Hallyn
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Now that kthread_stop() can be used even if the task has already exited,
we can kill the "wait_to_die:" loop in migration_thread(). But we must
pin rq->migration_thread after creation.Actually, I don't think CPU_UP_CANCELED or CPU_DEAD should wait for
->migration_thread exit. Perhaps we can simplify this code a bit more.
migration_call() can set ->should_stop and forget about this thread. But
we need a new helper in kthred.c for that.Signed-off-by: Oleg Nesterov
Cc: Christoph Hellwig
Cc: "Eric W. Biederman"
Cc: Ingo Molnar
Cc: Pavel Emelyanov
Cc: Rusty Russell
Cc: Vitaliy Gusev
Signed-off-by: Linus Torvalds -
Based on Eric's patch which in turn was based on my patch.
kthread_stop() has the nasty problems:
- it runs unpredictably long with the global semaphore held.
- it deadlocks if kthread itself does kthread_stop() before it obeys
the kthread_should_stop() request.- it is not useable if kthread exits on its own, see for example the
ugly "wait_to_die:" hack in migration_thread()- it is not possible to just tell kthread it should stop, we must always
wait for its exit.With this patch kthread() allocates all neccesary data (struct kthread) on
its own stack, globals kthread_stop_xxx are deleted. ->vfork_done is used
as a pointer into "struct kthread", this means kthread_stop() can easily
wait for kthread's exit.Signed-off-by: Oleg Nesterov
Cc: Christoph Hellwig
Cc: "Eric W. Biederman"
Cc: Ingo Molnar
Cc: Pavel Emelyanov
Cc: Rusty Russell
Cc: Vitaliy Gusev
Signed-off-by: Linus Torvalds -
We use two completions two create the kernel thread, this is a bit ugly.
kthread() wakes up create_kthread() via ->started, then create_kthread()
wakes up the caller kthread_create() via ->done. But kthread() does not
need to wait for kthread(), it can just return. Instead kthread() itself
can wake up the caller of kthread_create().Kill kthread_create_info->started, ->done is enough. This improves the
scalability a bit and sijmplifies the code.The only problem if kernel_thread() fails, in that case create_kthread()
must do complete(&create->done).Signed-off-by: Oleg Nesterov
Cc: Christoph Hellwig
Cc: "Eric W. Biederman"
Cc: Ingo Molnar
Cc: Pavel Emelyanov
Cc: Rusty Russell
Cc: Vitaliy Gusev
Signed-off-by: Linus Torvalds -
Reorder struct wait_opts to remove 8 bytes of alignment padding on 64 bit
builds.Signed-off-by: Richard Kennedy
Cc: Oleg Nesterov
Cc: Ingo Molnar
Cc: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
do_wait:
current->state = TASK_INTERRUPTIBLE;
read_lock(&tasklist_lock);
... search for the task to reap ...In theory, the ->state changing can leak into the critical section. Since
the child can change its status under read_lock(tasklist) in parallel
(finish_stop/ptrace_stop), we can miss the wakeup if __wake_up_parent()
sees us in TASK_RUNNING state. Add the barrier.Also, use __set_current_state() to set TASK_RUNNING.
Signed-off-by: Oleg Nesterov
Cc: Ingo Molnar
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
do_wait() does BUG_ON(tsk->signal != current->signal), this looks like a
raher obsolete check. At least, I don't think do_wait() is the best place
to verify that all threads have the same ->signal. Remove it.Also, change the code to use while_each_thread().
Signed-off-by: Oleg Nesterov
Cc: Ingo Molnar
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Now that we don't pass &retval down to other helpers we can simplify
the code more.- kill tsk_result, just use retval
- add the "notask" label right after the main loop, and
s/got end/goto notask/ after the fastpath pid check.This way we don't need to initialize retval before this
check and the code becomes a bit more clean, if this pid
has no attached tasks we should just skip the list search.Signed-off-by: Oleg Nesterov
Cc: Ingo Molnar
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Introduce "struct wait_opts" which holds the parameters for misc helpers
in do_wait() pathes.This adds 13 lines to kernel/exit.c, but saves 256 bytes from .o and imho
makes the code much more readable.This patch temporary uglifies rusage/siginfo code a little bit, will be
addressed by further cleanups.Signed-off-by: Oleg Nesterov
Reviewed-by: Ingo Molnar
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
No functional changes, preparation for the next patch.
ptrace_do_wait() adds WUNTRACED to options for wait_task_stopped() which
should always accept the stopped tracee, even if do_wait() was called
without WUNTRACED.Change wait_task_stopped() to check "ptrace || WUNTRACED" instead. This
makes the code more explicit, and "int options" argument becomes const in
do_wait() pathes.Signed-off-by: Oleg Nesterov
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
In theory it is not safe to dereference ->parent/real_parent without
tasklist or rcu lock, we can race with re-parenting.Signed-off-by: Oleg Nesterov
Acked-by: Roland McGrath
Cc: David Howells
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The forked child can have TIF_SIGPENDING if it was copied from parent's
ti->flags. But this is harmless and actually almost never happens,
because copy_process() can't succeed if signal_pending() == T.Signed-off-by: Oleg Nesterov
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
There is no reason for thread_group_cputime() in wait_task_zombie(), there
must be no other threads.This call was previously needed to collect the per-cpu data which we do
not have any longer.Signed-off-by: Oleg Nesterov
Cc: Peter Zijlstra
Acked-by: Roland McGrath
Cc: Stanislaw Gruszka
Cc: Vitaly Mayatskikh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Change ptrace_getsiginfo/ptrace_setsiginfo to use lock_task_sighand()
without tasklist_lock. Perhaps it makes sense to make a single helper
with "bool rw" argument.Signed-off-by: Oleg Nesterov
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
If the non-traced sub-thread calls do_notify_parent_cldstop(), we send the
notification to group_leader->real_parent and we report group_leader's
pid.But, if group_leader is traced we use the wrong ->parent->nsproxy->pid_ns,
the tracer and parent can live in different namespaces. Change the code
to use "parent" instead of tsk->parent.Signed-off-by: Oleg Nesterov
Acked-by: Roland McGrath
Acked-by: Sukadev Bhattiprolu
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Change wait_task_zombie() to use ->real_parent instead of ->parent. We
could even use current afaics, but ->real_parent is more clean.We know that the child is not ptrace_reparented() and thus they are equal.
But we should avoid using task_struct->parent, we are going to remove it.Signed-off-by: Oleg Nesterov
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
- Use rcu_read_lock() instead of tasklist_lock to find/get the task
in ptrace_get_task_struct().- Make it static, it has no callers outside of ptrace.c.
- The comment doesn't match the reality, this helper does not do
any checks. Beacuse it is really trivial and static I removed the
whole comment.Signed-off-by: Oleg Nesterov
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Remove the "Nasty, nasty" lock dance in ptrace_attach()/ptrace_traceme() -
from now task_lock() has nothing to do with ptrace at all.With the recent changes nobody uses task_lock() to serialize with ptrace,
but in fact it was never needed and it was never used consistently.However ptrace_attach() calls __ptrace_may_access() and needs task_lock()
to pin task->mm for get_dumpable(). But we can call __ptrace_may_access()
before we take tasklist_lock, ->cred_exec_mutex protects us against
do_execve() path which can change creds and MMF_DUMP* flags.(ugly, but we can't use ptrace_may_access() because it hides the error
code, so we have to take task_lock() and use __ptrace_may_access()).NOTE: this change assumes that LSM hooks, security_ptrace_may_access() and
security_ptrace_traceme(), can be called without task_lock() held.Signed-off-by: Oleg Nesterov
Cc: Chris Wright
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
ptrace_attach() and ptrace_traceme() are the last functions which look as
if the untraced task can have task->ptrace != 0, this must not be
possible. Change the code to just check ->ptrace != 0 and s/|=/=/ to set
PT_PTRACED.Also, a couple of trivial whitespace cleanups in ptrace_attach().
And move ptrace_traceme() up near ptrace_attach() to keep them close to
each other.Signed-off-by: Oleg Nesterov
Cc: Chris Wright
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
- Add PF_KTHREAD check to prevent attaching to the kernel thread
with a borrowed ->mm.With or without this change we can race with daemonize() which
can set PF_KTHREAD or clear ->mm after ptrace_attach() does the
check, but this doesn't matter because reparent_to_kthreadd()
does ptrace_unlink().- Kill "!task->mm" check. We don't really care about ->mm != NULL,
and the task can call exit_mm() right after we drop task_lock().
What we need is to make sure we can't attach after exit_notify(),
check task->exit_state != 0 instead.Also, move the "already traced" check down for cosmetic reasons.
Signed-off-by: Oleg Nesterov
Cc: Chris Wright
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
No functional changes.
- Nobody except ptrace.c & co should use ptrace flags directly, we have
task_ptrace() for that.- No need to specially check PT_PTRACED, we must not have other PT_ bits
set without PT_PTRACED. And no need to know this flag exists.Signed-off-by: Oleg Nesterov
Cc: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
tracehook_unsafe_exec() doesn't need task_lock(), remove the old comment.
Signed-off-by: Oleg Nesterov
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
"Search in the siblings" should use ->real_parent, not ->parent. If the
task is traced then ->parent == tracer, while the task's parent is always
->real_parent.Signed-off-by: Oleg Nesterov
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
m32r: PTRACE_SINGLESTEP sets PT_DTRACE, it is never used except cleared
after do_execve().Signed-off-by: Oleg Nesterov
Acked-by: Hirokazu Takata
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
m68k sets PT_DTRACE in trap_c() but never uses it.
Signed-off-by: Oleg Nesterov
Acked-by: Geert Uytterhoeven
Acked-by: Greg Ungerer
Cc: Roman Zippel
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
avr32, mn10300, parisc, s390, sh, xtensa:
They never set PT_DTRACE, but clear it after do_execve().
Signed-off-by: Oleg Nesterov
Cc: David Howells
Acked-by: Kyle McMartin
Cc: Grant Grundler
Cc: Matthew Wilcox
Acked-by: Martin Schwidefsky
Cc: Heiko Carstens
Acked-by: Paul Mundt
Acked-by: Chris Zankel
Acked-by: Roland McGrath
Acked-by: Haavard Skinnemoen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
h8300 defines PT_DTRACE for asm but never uses it.
DEFINE(PT_PTRACED, PT_PTRACED) seems to be unused too.
Signed-off-by: Oleg Nesterov
Acked-by: Yoshinori Sato
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
allow_signal() checks ->mm == NULL. Not sure why. Perhaps to make sure
current is the kernel thread. But this helper must not be used unless we
are the kernel thread, kill this check.Also, document the fact that the CLONE_SIGHAND kthread must not use
allow_signal(), unless the caller really wants to change the parent's
->sighand->action as well.Signed-off-by: Oleg Nesterov
Acked-by: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Try to fix memcg's lru rotation sanity: make memcg use the same logic as
the global LRU does.Now, at __isolate_lru_page() retruns -EBUSY, the page is rotated to the
tail of LRU in global LRU's isolate LRU pages. But in memcg, it's not
handled. This makes memcg do the same behavior as global LRU and rotate
LRU in the page is busy.Signed-off-by: KAMEZAWA Hiroyuki
Cc: KOSAKI Motohiro
Acked-by: Daisuke Nishimura
Cc: Balbir Singh
Cc: Mel Gorman
Cc: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
We don't have an interface to reset mem.limit or memsw.limit now.
This patch allows to reset mem.limit or memsw.limit when they are being
set to -1.Signed-off-by: Daisuke Nishimura
Cc: KAMEZAWA Hiroyuki
Cc: Balbir Singh
Cc: Li Zefan
Cc: Dhaval Giani
Cc: YAMAMOTO Takashi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
A user can set memcg.limit_in_bytes == memcg.memsw.limit_in_bytes when the
user just want to limit the total size of applications, in other words,
not very interested in memory usage itself. In this case, swap-out will
be done only by global-LRU.But, under current implementation, memory.limit_in_bytes is checked at
first and try_to_free_page() may do swap-out. But, that swap-out is
useless for memsw.limit_in_bytes and the thread may hit limit again.This patch tries to fix the current behavior at memory.limit ==
memsw.limit case. And documentation is updated to explain the behavior of
this special case.Signed-off-by: KAMEZAWA Hiroyuki
Cc: Daisuke Nishimura
Cc: Balbir Singh
Cc: Li Zefan
Cc: Dhaval Giani
Cc: YAMAMOTO Takashi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch fixes mis-accounting of swap usage in memcg.
In the current implementation, memcg's swap account is uncharged only when
swap is completely freed. But there are several cases where swap cannot
be freed cleanly. For handling that, this patch changes that memcg
uncharges swap account when swap has no references other than cache.By this, memcg's swap entry accounting can be fully synchronous with the
application's behavior.This patch also changes memcg's hooks for swap-out.
Signed-off-by: KAMEZAWA Hiroyuki
Cc: Daisuke Nishimura
Acked-by: Balbir Singh
Cc: Hugh Dickins
Cc: Johannes Weiner
Cc: Li Zefan
Cc: Dhaval Giani
Cc: YAMAMOTO Takashi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
