Nick Piggin [Fri, 8 Feb 2008 12:19:49 +0000 (04:19 -0800)]
rewrite rd
This is a rewrite of the ramdisk block device driver.
The old one is really difficult because it effectively implements a block
device which serves data out of its own buffer cache. It relies on the dirty
bit being set, to pin its backing store in cache, however there are non
trivial paths which can clear the dirty bit (eg. try_to_free_buffers()),
which had recently lead to data corruption. And in general it is completely
wrong for a block device driver to do this.
The new one is more like a regular block device driver. It has no idea about
vm/vfs stuff. It's backing store is similar to the buffer cache (a simple
radix-tree of pages), but it doesn't know anything about page cache (the pages
in the radix tree are not pagecache pages).
There is one slight downside -- direct block device access and filesystem
metadata access goes through an extra copy and gets stored in RAM twice.
However, this downside is only slight, because the real buffercache of the
device is now reclaimable (because we're not playing crazy games with it), so
under memory intensive situations, footprint should effectively be the same --
maybe even a slight advantage to the new driver because it can also reclaim
buffer heads.
The fact that it now goes through all the regular vm/fs paths makes it
much more useful for testing, too.
text data bss dec hex filename
2837 849 384 4070 fe6 drivers/block/rd.o
3528 371 12 3911 f47 drivers/block/brd.o
Text is larger, but data and bss are smaller, making total size smaller.
A few other nice things about it:
- Similar structure and layout to the new loop device handlinag.
- Dynamic ramdisk creation.
- Runtime flexible buffer head size (because it is no longer part of the
ramdisk code).
- Boot / load time flexible ramdisk size, which could easily be extended
to a per-ramdisk runtime changeable size (eg. with an ioctl).
- Can use highmem for the backing store.
[akpm@linux-foundation.org: fix build]
[byron.bbradley@gmail.com: make rd_size non-static] Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Byron Bradley <byron.bbradley@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Howells [Fri, 8 Feb 2008 12:19:31 +0000 (04:19 -0800)]
mn10300: add the MN10300/AM33 architecture to the kernel
Add architecture support for the MN10300/AM33 CPUs produced by MEI to the
kernel.
This patch also adds board support for the ASB2303 with the ASB2308 daughter
board, and the ASB2305. The only processor supported is the MN103E010, which
is an AM33v2 core plus on-chip devices.
[akpm@linux-foundation.org: nuke cvs control strings] Signed-off-by: Masakazu Urade <urade.masakazu@jp.panasonic.com> Signed-off-by: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Howells [Fri, 8 Feb 2008 12:19:28 +0000 (04:19 -0800)]
aout: suppress A.OUT library support if !CONFIG_ARCH_SUPPORTS_AOUT
Suppress A.OUT library support if CONFIG_ARCH_SUPPORTS_AOUT is not set.
Not all architectures support the A.OUT binfmt, so the ELF binfmt should not
be permitted to go looking for A.OUT libraries to load in such a case. Not
only that, but under such conditions A.OUT core dumps are not produced either.
To make this work, this patch also does the following:
(1) Makes the existence of the contents of linux/a.out.h contingent on
CONFIG_ARCH_SUPPORTS_AOUT.
(2) Renames dump_thread() to aout_dump_thread() as it's only called by A.OUT
core dumping code.
(3) Moves aout_dump_thread() into asm/a.out-core.h and makes it inline. This
is then included only where needed. This means that this bit of arch
code will be stored in the appropriate A.OUT binfmt module rather than
the core kernel.
(4) Drops A.OUT support for Blackfin (according to Mike Frysinger it's not
needed) and FRV.
This patch depends on the previous patch to move STACK_TOP[_MAX] out of
asm/a.out.h and into asm/processor.h as they're required whether or not A.OUT
format is available.
[jdike@addtoit.com: uml: re-remove accidentally restored code] Signed-off-by: David Howells <dhowells@redhat.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Howells [Fri, 8 Feb 2008 12:19:27 +0000 (04:19 -0800)]
aout: mark arches that support A.OUT format
Mark arches that support A.OUT format by including the following in their
master Kconfig files:
config ARCH_SUPPORTS_AOUT
def_bool y
This should also be set if the arch provides compatibility A.OUT support for
an older arch, for instance x86_64 for i386 or sparc64 for sparc.
I've guessed at which arches don't, based on comments in the code, however I'm
sure that some of the ones I've marked as 'yes' actually should be 'no'.
Signed-off-by: David Howells <dhowells@redhat.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Li Zefan [Fri, 8 Feb 2008 12:19:24 +0000 (04:19 -0800)]
timekeeping: rename timekeeping_is_continuous to timekeeping_valid_for_hres
Function timekeeping_is_continuous() no longer checks flag
CLOCK_IS_CONTINUOUS, and it checks CLOCK_SOURCE_VALID_FOR_HRES now. So rename
the function accordingly.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pavel Emelyanov [Fri, 8 Feb 2008 12:19:22 +0000 (04:19 -0800)]
Clean up the kill_something_info
This is the first step (of two) in removing the kill_pgrp_info.
All the users of this function are in kernel/signal.c, but all they need is to
call __kill_pgrp_info() with the tasklist_lock read-locked.
Fortunately, one of its users is the kill_something_info(), which already
needs this lock in one of its branches, so clean these branches up and call
the __kill_pgrp_info() directly.
Based on Oleg's view of how this function should look.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> 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>
Pavel Emelyanov [Fri, 8 Feb 2008 12:19:21 +0000 (04:19 -0800)]
Pidns: fix badly converted mqueues pid handling
When sending the pid namespaces patches I wrongly converted the tsk->tgid into
task_pid_vnr(tsk) in mqueue-s (the git id of this patch is b488893a390edfe027bae7a46e9af8083e740668).
The proper behavior is to get the task_tgid_vnr(tsk).
This seem to be the only mistake of that kind.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pavel Emelyanov [Fri, 8 Feb 2008 12:19:20 +0000 (04:19 -0800)]
Pidns: make full use of xxx_vnr() calls
Some time ago the xxx_vnr() calls (e.g. pid_vnr or find_task_by_vpid) were
_all_ converted to operate on the current pid namespace. After this each call
like xxx_nr_ns(foo, current->nsproxy->pid_ns) is nothing but a xxx_vnr(foo)
one.
Switch all the xxx_nr_ns() callers to use the xxx_vnr() calls where
appropriate.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Reviewed-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Fri, 8 Feb 2008 12:19:19 +0000 (04:19 -0800)]
ITIMER_REAL: convert to use struct pid
signal_struct->tsk points to the ->group_leader and thus we have the nasty
code in de_thread() which has to change it and restart ->real_timer if the
leader is changed.
Use "struct pid *leader_pid" instead. This also allows us to kill now
unneeded send_group_sig_info().
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Davide Libenzi <davidel@xmailserver.org> Cc: Pavel Emelyanov <xemul@openvz.org> Acked-by: Roland McGrath <roland@redhat.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Fri, 8 Feb 2008 12:19:19 +0000 (04:19 -0800)]
uglify while_each_pid_task() to make sure we don't count the execing pricess twice
There is a window when de_thread() switches the leader and drops
tasklist_lock. In that window do_each_pid_task(PIDTYPE_PID) finds both new
and old leaders.
The problem is pretty much theoretical and probably can be ignored. Currently
the only users of do_each_pid_task(PIDTYPE_PID) are send_sigio/send_sigurg, so
they can send the signal to the same process twice.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Davide Libenzi <davidel@xmailserver.org> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Fri, 8 Feb 2008 12:19:18 +0000 (04:19 -0800)]
uglify kill_pid_info() to fix kill() vs exec() race
kill_pid_info()->pid_task() could be the old leader of the execing process.
In that case it is possible that the leader will be released before we take
siglock. This means that kill_pid_info() (and thus sys_kill()) can return a
false -ESRCH.
Change the code to retry when lock_task_sighand() fails. The endless loop is
not possible, __exit_signal() both clears ->sighand and does detach_pid().
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Davide Libenzi <davidel@xmailserver.org> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
pid_vnr returns the user space pid with respect to the pid namespace the
struct pid was allocated in. What we want before we return a pid to user
space is the user space pid with respect to the pid namespace of current.
pid_vnr is a very nice optimization but because it isn't quite what we want
it is easy to use pid_vnr at times when we aren't certain the struct pid
was allocated in our pid namespace.
Currently this describes at least tiocgpgrp and tiocgsid in ttyio.c the
parent process reported in the core dumps and the parent process in
get_signal_to_deliver.
So unless the performance impact is huge having an interface that does what
we want instead of always what we want should be much more reliable and
much less error prone.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This modifies do_wait and eligible child to take a pair of enum pid_type
and struct pid *pid to precisely specify what set of processes are eligible
to be waited for, instead of the raw pid_t value from sys_wait4.
This fixes a bug in sys_waitid where you could not wait for children in
just process group 1.
This fixes a pid namespace crossing case in eligible_child. Allowing us to
wait for a processes in our current process group even if our current
process group == 0.
This allows the no child with this pid case to be optimized. This allows
us to optimize the pid membership test in eligible child to be optimized.
This even closes a theoretical pid wraparound race where in a threaded
parent if two threads are waiting for the same child and one thread picks
up the child and the pid numbers wrap around and generate another child
with that same pid before the other thread is scheduled (teribly insanely
unlikely) we could end up waiting on the second child with the same pid#
and not discover that the specific child we were waiting for has exited.
[akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Fri, 8 Feb 2008 12:19:13 +0000 (04:19 -0800)]
move the related code from exit_notify() to exit_signals()
The previous bugfix was not optimal, we shouldn't care about group stop
when we are the only thread or the group stop is in progress. In that case
nothing special is needed, just set PF_EXITING and return.
Also, take the related "TIF_SIGPENDING re-targeting" code from exit_notify().
So, from the performance POV the only difference is that we don't trust
!signal_pending() until we take ->siglock. But this in fact fixes another
___pure___ theoretical minor race. __group_complete_signal() finds the
task without PF_EXITING and chooses it as the target for signal_wake_up().
But nothing prevents this task from exiting in between without noticing the
pending signal and thus unpredictably delaying the actual delivery.
Oleg Nesterov [Fri, 8 Feb 2008 12:19:12 +0000 (04:19 -0800)]
fix group stop with exit race
do_signal_stop() counts all sub-thread and sets ->group_stop_count
accordingly. Every thread should decrement ->group_stop_count and stop,
the last one should notify the parent.
However a sub-thread can exit before it notices the signal_pending(), or it
may be somewhere in do_exit() already. In that case the group stop never
finishes properly.
Note: this is a minimal fix, we can add some optimizations later. Say we
can return quickly if thread_group_empty(). Also, we can move some signal
related code from exit_notify() to exit_signals().
Oleg Nesterov [Fri, 8 Feb 2008 12:19:11 +0000 (04:19 -0800)]
start the global /sbin/init with 0,0 special pids
As Eric pointed out, there is no problem with init starting with sid == pgid
== 0, and this was historical linux behavior changed in 2.6.18.
Remove kernel_init()->__set_special_pids(), this is unneeded and complicates
the rules for sys_setsid().
This change and the previous change in daemonize() mean that /sbin/init does
not need the special "session != 1" hack in sys_setsid() any longer. We can't
remove this check yet, we should cleanup copy_process(CLONE_NEWPID) first, so
update the comment only.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Fri, 8 Feb 2008 12:19:10 +0000 (04:19 -0800)]
move daemonized kernel threads into the swapper's session
Daemonized kernel threads run in the init's session. This doesn't match the
behaviour of kthread_create()'ed threads, and this is one of the 2 reasons
why we need a special hack in sys_setsid().
Now that set_special_pids() was changed to use struct pid, not pid_t, we can
use init_struct_pid and set 0,0 special pids.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Fri, 8 Feb 2008 12:19:09 +0000 (04:19 -0800)]
teach set_special_pids() to use struct pid
Change set_special_pids() to work with struct pid, not pid_t from global name
space. This again speedups and imho cleanups the code, also a preparation for
the next patch.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Fri, 8 Feb 2008 12:19:09 +0000 (04:19 -0800)]
fix setsid() for sub-namespace /sbin/init
sys_setsid() still deals with pid_t's from the global namespace. This means
that the "session > 1" check can't help for sub-namespace init, setsid() can't
succeed because copy_process(CLONE_NEWPID) populates PIDTYPE_PGID/SID links.
Remove the usage of task_struct->pid and convert the code to use "struct pid".
This also simplifies and speedups the code, saves one find_pid().
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Fri, 8 Feb 2008 12:19:08 +0000 (04:19 -0800)]
sys_setpgid(): simplify pid/ns interaction
sys_setpgid() does unneeded conversions from pid_t to "struct pid" and vice
versa. Use "struct pid" more consistently. Saves one find_vpid() and
eliminates the explicit usage of ->nsproxy->pid_ns. Imho, cleanups the
code.
Also use the same_thread_group() helper.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Fri, 8 Feb 2008 12:19:07 +0000 (04:19 -0800)]
wait_task_zombie: remove ->exit_state/exit_signal checks for WNOWAIT
The first "p->exit_state != EXIT_ZOMBIE" check doesn't make too much sense.
The exit_state was EXIT_ZOMBIE when the function was called, and another
thread can change it to EXIT_DEAD right after the check.
The second condition is not possible, detached non-traced threads were already
filtered out by eligible_child(), we didn't drop tasklist since then.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Fri, 8 Feb 2008 12:19:07 +0000 (04:19 -0800)]
wait_task_continued/zombie: don't use task_pid_nr_ns() lockless
Surprise, the other two wait_task_*() functions also abuse the
task_pid_nr_ns() function, and may cause read-after-free or report nr == 0
in wait_task_continued(). wait_task_zombie() doesn't have this problem,
but it is still better to cache pid_t rather than call task_pid_nr_ns()
three times on the saved pid_namespace.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Fri, 8 Feb 2008 12:19:06 +0000 (04:19 -0800)]
do_wait: fix security checks
Imho, the current usage of security_task_wait() is not logical.
Suppose we have the single child p, and security_task_wait(p) return
-EANY. In that case waitpid(-1) returns this error. Why? Isn't it
better to return ECHLD? We don't really have reapable children.
Now suppose that child was stolen by gdb. In that case we find this
child on ->ptrace_children and set flag = 1, but we don't check that the
child was denied. So, do_wait(..., WNOHANG) returns 0, this doesn't
match the behaviour above. Without WNOHANG do_wait() blocks only to
return the error later, when the child will be untraced. Inho, really
strange.
I think eligible_child() should return the error only if the child's pid
was requested explicitly, otherwise we should silently ignore the tasks
which were nacked by security_task_wait().
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Roland McGrath <roland@redhat.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Eric Paris <eparis@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Fri, 8 Feb 2008 12:19:04 +0000 (04:19 -0800)]
do_wait: cleanup delay_group_leader() usage
eligible_child() == 2 means delay_group_leader(). With the previous patch
this only matters for EXIT_ZOMBIE task, we can move that special check to
the only place it is really needed.
Also, with this patch we don't skip security_task_wait() for the group
leaders in a non-empty thread group. I don't really understand the exact
semantics of security_task_wait(), but imho this change is a bugfix.
Also rearrange the code a bit to kill an ugly "check_continued" backdoor.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Eric Paris <eparis@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Roland McGrath <roland@redhat.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
wait_task_stopped() doesn't need the "delay_group_leader" parameter. If
the child is not traced it must be a group leader. With or without
subthreads ->group_stop_count == 0 when the whole task is stopped.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Mika Penttila <mika.penttila@kolumbus.fi> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Fri, 8 Feb 2008 12:19:03 +0000 (04:19 -0800)]
ptrace_stop: fix racy nonstop_code setting
If the tracer is gone and we are not going to stop, ptrace_stop() sets
->exit_code = nostop_code. However, the tracer could actually clear the
exit code before detaching. In that case get_signal_to_deliver() "resends"
the signal which was cancelled by the debugger. For example, it is
possible that a quick PTRACE_ATTACH + PTRACE_DETACH can leave the tracee in
STOPPED state.
Change the behaviour of ptrace_stop(). If the caller is ptrace notify(),
we should always clear ->exit_code. If the caller is
get_signal_to_deliver(), we should not touch it at all. To do so, change
the nonstop_code parameter to "bool clear_code" and change the callers
accordingly.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Fri, 8 Feb 2008 12:19:01 +0000 (04:19 -0800)]
wait_task_stopped: simplify and fix races with SIGCONT/SIGKILL/untrace
wait_task_stopped() has multiple races with SIGCONT/SIGKILL. tasklist_lock
does not pin the child in TASK_TRACED/TASK_STOPPED stated, almost all info
reported (including exit_code) may be wrong.
In fact, the code under write_lock_irq(tasklist_lock) is not safe. The child
may be PTRACE_DETACH'ed at this time by another subthread, in that case it is
possible we are no longer its ->parent.
Change wait_task_stopped() to take ->siglock before inspecting the task. This
guarantees that the child can't resume and (for example) clear its
->exit_code, so we don't need to use xchg(&p->exit_code) and re-check. The
only exception is ptrace_stop() which changes ->state and ->exit_code without
->siglock held during abort. But this can only happen if both the tracer and
the tracee are dying (coredump is in progress), we don't care.
With this patch wait_task_stopped() doesn't move the child to the end of
the ->parent list on success. This optimization could be restored, but
in that case we have to take write_lock(tasklist) and do some nasty
checks.
Also change the do_wait() since we don't return EAGAIN any longer.
[akpm@linux-foundation.org: fix up after Willy renamed everything] Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Fri, 8 Feb 2008 12:19:00 +0000 (04:19 -0800)]
ptrace_stop: fix the race with ptrace detach+attach
If the tracer went away (may_ptrace_stop() failed), ptrace_stop() drops
tasklist and then changes the ->state from TASK_TRACED to TASK_RUNNING.
This can fool another tracer which attaches to us in between. Change the
->state under tasklist_lock to ensure that ptrace_check_attach() can't wrongly
succeed. Also, remove the unnecessary mb().
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is not possible to see the PT_PTRACED task without ->signal/sighand under
tasklist_lock, release_task() does ptrace_unlink() first. If the task was
already released before, ptrace_attach() can't succeed and set PT_PTRACED.
Remove this check.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Roland McGrath <roland@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg Nesterov [Fri, 8 Feb 2008 12:18:59 +0000 (04:18 -0800)]
kill my_ptrace_child()
Now that my_ptrace_child() is trivial we can use the "p->ptrace & PT_PTRACED"
inline and simplify the corresponding logic in do_wait: we can't find the
child in TASK_TRACED state without PT_PTRACED flag set, ptrace_untrace()
either sets TASK_STOPPED or wakes up the tracee.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Roland McGrath <roland@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
we set PT_ATTACHED and change child->parent "atomically" wrt task_list lock.
This means we can remove the checks like "PT_ATTACHED && ->parent != ptracer"
which were needed to catch the "ptrace attach is in progress" case. We can
also remove the flag itself since nobody else uses it.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Roland McGrath <roland@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pierre Peiffer [Fri, 8 Feb 2008 12:18:57 +0000 (04:18 -0800)]
IPC: consolidate sem_exit_ns(), msg_exit_ns() and shm_exit_ns()
sem_exit_ns(), msg_exit_ns() and shm_exit_ns() are all called when an
ipc_namespace is released to free all ipcs of each type. But in fact, they
do the same thing: they loop around all ipcs to free them individually by
calling a specific routine.
This patch proposes to consolidate this by introducing a common function,
free_ipcs(), that do the job. The specific routine to call on each
individual ipcs is passed as parameter. For this, these ipc-specific
'free' routines are reworked to take a generic 'struct ipc_perm' as
parameter.
Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pierre Peiffer [Fri, 8 Feb 2008 12:18:57 +0000 (04:18 -0800)]
IPC: make struct ipc_ids static in ipc_namespace
Each ipc_namespace contains a table of 3 pointers to struct ipc_ids (3 for
msg, sem and shm, structure used to store all ipcs) These 'struct ipc_ids'
are dynamically allocated for each icp_namespace as the ipc_namespace
itself (for the init namespace, they are initialized with pointers to
static variables instead)
It is so for historical reason: in fact, before the use of idr to store the
ipcs, the ipcs were stored in tables of variable length, depending of the
maximum number of ipc allowed. Now, these 'struct ipc_ids' have a fixed
size. As they are allocated in any cases for each new ipc_namespace, there
is no gain of memory in having them allocated separately of the struct
ipc_namespace.
This patch proposes to make this table static in the struct ipc_namespace.
Thus, we can allocate all in once and get rid of all the code needed to
allocate and free these ipc_ids separately.
Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net> Acked-by: Cedric Le Goater <clg@fr.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pierre Peiffer [Fri, 8 Feb 2008 12:18:56 +0000 (04:18 -0800)]
IPC/semaphores: consolidate SEM_STAT and IPC_STAT commands
These commands (SEM_STAT and IPC_STAT) are rather doing the same things
(only the meaning of the id given as input and the return value differ).
However, for the semaphores, they are handled in two different places (two
different functions).
This patch consolidates this for clarification by handling these both
commands in the same place in semctl_nolock(). It also removes one unused
parameter for this function.
Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pavel Emelyanov [Fri, 8 Feb 2008 12:18:54 +0000 (04:18 -0800)]
ipc: uninline some code from util.h
ipc_lock_check_down(), ipc_lock_check() and ipcget() seem too large to be
inline. Besides, they give no optimization being inline as they perform
calls inside in any case.
Moving them into ipc/util.c saves 500 bytes of vmlinux and shortens IPC
internal API.
The module subsystem cannot handle symbols that are zero. If symbols are
present that have a zero value then the module resolver prints out a
message that these symbols are unresolved.
[akinobu.mita@gmail.com: fix __find_symbl() error checks] Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Kay Sievers <kay.sievers@vrfy.org Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Heiko Carstens [Fri, 8 Feb 2008 12:18:39 +0000 (04:18 -0800)]
tty: let architectures override the user/kernel macros.
Give architectures that support the new termios2 the possibilty to overide the
user_termios_to_kernel_termios and kernel_termios_to_user_termios macros. As
soon as all architectures that use the generic variant have been converted the
ifdefs can go away again. Architectures in question are avr32, frv, powerpc
and s390.
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Paul Mackerras <paulus@samba.org> Cc: David Howells <dhowells@redhat.com> Cc: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mark gross [Fri, 8 Feb 2008 12:18:38 +0000 (04:18 -0800)]
intel-iommu: PMEN support
Add support for protected memory enable bits by clearing them if they are
set at startup time. Some future boot loaders or firmware could have this
bit set after it loads the kernel, and it needs to be cleared if DMA's are
going to happen effectively.
Signed-off-by: mark gross <mgross@intel.com> Acked-by: Muli Ben-Yehuda <muli@il.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Alexey Dobriyan [Fri, 8 Feb 2008 12:18:37 +0000 (04:18 -0800)]
proc: fix ->open'less usage due to ->proc_fops flip
Typical PDE creation code looks like:
pde = create_proc_entry("foo", 0, NULL);
if (pde)
pde->proc_fops = &foo_proc_fops;
Notice that PDE is first created, only then ->proc_fops is set up to
final value. This is a problem because right after creation
a) PDE is fully visible in /proc , and
b) ->proc_fops are proc_file_operations which do not have ->open callback. So, it's
possible to ->read without ->open (see one class of oopses below).
The fix is new API called proc_create() which makes sure ->proc_fops are
set up before gluing PDE to main tree. Typical new code looks like:
pde = proc_create("foo", 0, NULL, &foo_proc_fops);
if (!pde)
return -ENOMEM;
Fix most networking users for a start.
In the long run, create_proc_entry() for regular files will go.
Long ago when the CLONE_THREAD support first went it someone thought it
would be wise to point /proc/self at /proc/<tgid> instead of /proc/<pid>.
Given that /proc/<tgid> can return information about a very different task
(if enough things have been unshared) then our current process /proc/<tgid>
seems blatantly wrong. So far I have yet to think up an example where the
current behavior would be advantageous, and I can see several places where
it is seriously non-intuitive.
We may be stuck with the current broken behavior for backwards
compatibility reasons but lets try fixing our ancient bug for the 2.6.25
time frame and see if anyone screams.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: "Guillaume Chazarain" <guichaz@yahoo.fr> Cc: "Pavel Emelyanov" <xemul@openvz.org> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently if you access a /proc that is not mounted with your processes
current pid namespace /proc/self will point at a completely random task.
This patch fixes /proc/self to point to the current process if it is
available in the particular mount of /proc or to return -ENOENT if the
current process is not visible.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
proc: seqfile convert proc_pid_status to properly handle pid namespaces
Currently we possibly lookup the pid in the wrong pid namespace. So
seq_file convert proc_pid_status which ensures the proper pid namespaces is
passed in.
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: another build fix]
[akpm@linux-foundation.org: s390 build fix]
[akpm@linux-foundation.org: fix task_name() output]
[akpm@linux-foundation.org: fix nommu build] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Andrew Morgan <morgan@kernel.org> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Paul Jackson <pj@sgi.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
proc: rewrite do_task_stat to correctly handle pid namespaces.
Currently (as pointed out by Oleg) do_task_stat has a race when calling
task_pid_nr_ns with the task exiting. In addition do_task_stat is not
currently displaying information in the context of the pid namespace that
mounted the /proc filesystem. So "cut -d' ' -f 1 /proc/<pid>/stat" may not
equal <pid>.
This patch fixes the problem by converting to a single_open seq_file show
method. Getting the pid namespace from the filesystem superblock instead of
current, and simply using the the struct pid from the inode instead of
attempting to get that same pid from the task.
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>
Currently many /proc/pid files use a crufty precursor to the current seq_file
api, and they don't have direct access to the pid_namespace or the pid of for
which they are displaying data.
So implement proc_single_file_operations to make the seq_file routines easy to
use, and to give access to the full state of the pid of we are displaying data
for.
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>
Pavel Emelyanov [Fri, 8 Feb 2008 12:18:24 +0000 (04:18 -0800)]
namespaces: cleanup the code managed with PID_NS option
Just like with the user namespaces, move the namespace management code into
the separate .c file and mark the (already existing) PID_NS option as "depend
on NAMESPACES"
[akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pavel Emelyanov [Fri, 8 Feb 2008 12:18:23 +0000 (04:18 -0800)]
namespaces: cleanup the code managed with the USER_NS option
Make the user_namespace.o compilation depend on this option and move the
init_user_ns into user.c file to make the kernel compile and work without the
namespaces support. This make the user namespace code be organized similar to
other namespaces'.
Also mask the USER_NS option as "depend on NAMESPACES".
[akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pavel Emelyanov [Fri, 8 Feb 2008 12:18:22 +0000 (04:18 -0800)]
namespaces: move the IPC namespace under IPC_NS option
Currently the IPC namespace management code is spread over the ipc/*.c files.
I moved this code into ipc/namespace.c file which is compiled out when needed.
The linux/ipc_namespace.h file is used to store the prototypes of the
functions in namespace.c and the stubs for NAMESPACES=n case. This is done
so, because the stub for copy_ipc_namespace requires the knowledge of the
CLONE_NEWIPC flag, which is in sched.h. But the linux/ipc.h file itself in
included into many many .c files via the sys.h->sem.h sequence so adding the
sched.h into it will make all these .c depend on sched.h which is not that
good. On the other hand the knowledge about the namespaces stuff is required
in 4 .c files only.
Besides, this patch compiles out some auxiliary functions from ipc/sem.c,
msg.c and shm.c files. It turned out that moving these functions into
namespaces.c is not that easy because they use many other calls and macros
from the original file. Moving them would make this patch complicated. On
the other hand all these functions can be consolidated, so I will send a
separate patch doing this a bit later.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When I replaced hugetlb_dynamic_pool with nr_overcommit_hugepages I used
proc_doulongvec_minmax() directly. However, hugetlb.c's locking rules
require that all counter modifications occur under the hugetlb_lock. Add a
callback into the hugetlb code similar to the one for nr_hugepages. Grab
the lock around the manipulation of nr_overcommit_hugepages in
proc_doulongvec_minmax().
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Acked-by: Adam Litke <agl@us.ibm.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: William Lee Irwin III <wli@holomorphy.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Fri, 8 Feb 2008 03:12:12 +0000 (19:12 -0800)]
Merge branch 'for-linus' of git://oss.sgi.com:8090/xfs/xfs-2.6
* 'for-linus' of git://oss.sgi.com:8090/xfs/xfs-2.6: (62 commits)
[XFS] add __init/__exit mark to specific init/cleanup functions
[XFS] Fix oops in xfs_file_readdir()
[XFS] kill xfs_root
[XFS] keep i_nlink updated and use proper accessors
[XFS] stop updating inode->i_blocks
[XFS] Make xfs_ail_check check less by default
[XFS] Move AIL pushing into it's own thread
[XFS] use generic_permission
[XFS] stop re-checking permissions in xfs_swapext
[XFS] clean up xfs_swapext
[XFS] remove permission check from xfs_change_file_space
[XFS] prevent panic during log recovery due to bogus op_hdr length
[XFS] Cleanup various fid related bits:
[XFS] Fix xfs_lowbit64
[XFS] Remove CFORK macros and use code directly in IFORK and DFORK macros.
[XFS] kill superflous buffer locking (2nd attempt)
[XFS] Use kernel-supplied "roundup_pow_of_two" for simplicity
[XFS] Remove the BPCSHIFT and NB* based macros from XFS.
[XFS] Remove bogus assert
[XFS] optimize XFS_IS_REALTIME_INODE w/o realtime config
...
Nick Piggin [Fri, 8 Feb 2008 02:46:06 +0000 (18:46 -0800)]
Convert SG from nopage to fault.
Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Douglas Gilbert <dougg@torque.net> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Fri, 8 Feb 2008 02:22:29 +0000 (18:22 -0800)]
Merge branch 'slub-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/christoph/vm
* 'slub-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/christoph/vm:
SLUB: fix checkpatch warnings
Use non atomic unlock
SLUB: Support for performance statistics
SLUB: Alternate fast paths using cmpxchg_local
SLUB: Use unique end pointer for each slab page.
SLUB: Deal with annoying gcc warning on kfree()
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