Commit Graph

84652 Commits

Author SHA1 Message Date
Oleg Nesterov 20686a309a 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>
2008-02-08 09:22:26 -08:00
Oleg Nesterov 9cbab81005 do_wait: factor out "retval != 0" checks
Every branch if the main "if" statement does the same code at the end.  Move
it down.  Also, fix the indentation.

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>
2008-02-08 09:22:26 -08:00
Oleg Nesterov ee7c82da83 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>
2008-02-08 09:22:26 -08:00
Oleg Nesterov 6405f7f467 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>
2008-02-08 09:22:26 -08:00
Oleg Nesterov c0c0b649d6 ptrace_check_attach: remove unneeded ->signal != NULL check
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>
2008-02-08 09:22:26 -08:00
Oleg Nesterov 34a1738f7d 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>
2008-02-08 09:22:26 -08:00
Oleg Nesterov 6b39c7bfbd kill PT_ATTACHED
Since the patch

	"Fix ptrace_attach()/ptrace_traceme()/de_thread() race"
	commit f5b40e363a

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>
2008-02-08 09:22:26 -08:00
Pierre Peiffer 01b8b07a5d 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>
2008-02-08 09:22:26 -08:00
Pierre Peiffer ed2ddbf88c 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>
2008-02-08 09:22:26 -08:00
Pierre Peiffer 4b9fcb0ec6 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>
2008-02-08 09:22:26 -08:00
Pavel Emelyanov b2d75cddc8 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.

$ ./scripts/bloat-o-meter vmlinux-orig vmlinux
add/remove: 3/2 grow/shrink: 0/10 up/down: 490/-989 (-499)
function                                     old     new   delta
ipcget                                         -     392    +392
ipc_lock_check_down                            -      49     +49
ipc_lock_check                                 -      49     +49
sys_semget                                   119     105     -14
sys_shmget                                   108      86     -22
sys_msgget                                   100      78     -22
do_msgsnd                                    665     631     -34
do_msgrcv                                    680     644     -36
do_shmat                                     771     733     -38
sys_msgctl                                  1302    1229     -73
ipcget_new                                    80       -     -80
sys_semtimedop                              1534    1452     -82
sys_semctl                                  2034    1922    -112
sys_shmctl                                  1919    1765    -154
ipcget_public                                322       -    -322

The ipcget() growth is the result of gcc inlining of currently static
ipcget_new/_public.

Signed-off-by: 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>
2008-02-08 09:22:25 -08:00
Alan Cox a46c999424 serial_core: bring mostly into line with coding style
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:25 -08:00
Alan Cox b4c502a709 8250: enable rate reporting via termios
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:25 -08:00
Alan Cox 6f803cd08f serial8250: coding style
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:25 -08:00
Alan Cox 5756ee9996 8250_pci: coding style
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:25 -08:00
Alan Cox 3b0fd36ddc 8250_hub6: codding style
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:25 -08:00
Alan Cox 0fe1c13713 8250_hp300: coding style
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:25 -08:00
Alan Cox 8b4a483be5 8250_gsc: coding style
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:25 -08:00
Alan Cox ce2e204f0c 8250_early: coding style
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:25 -08:00
Alan Cox 355d95a1c8 tty_ioctl: drag screaming into compliance with the coding style
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:25 -08:00
Alan Cox 37bdfb074e tty_io: drag screaming into coding style compliance
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:25 -08:00
Alan Cox 66c6ceae39 tty_audit: fix checkpatch complaint
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:25 -08:00
Alan Cox 4129a6454d rocket: don't let random users reset the controller
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:25 -08:00
Alan Cox 6df3526b66 rocket: first pass at termios reporting
Also removes a cflag comparison that caused some mode changes to get wrongly
ignored

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:25 -08:00
Alan Cox 4edf1827ea n_tty: clean up old code to follow coding style and (mostly) checkpatch
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:25 -08:00
Alan Cox db1acaa632 moxa: first pass at termios reporting
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:24 -08:00
Andrew Morton 92dfc9dc7b fix "modules: make module_address_lookup() safe"
Get the constness right, avoid nasty cast.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:24 -08:00
Christoph Lameter 6d7623943c modules: include sections.h to avoid defining linker variables explicitly
module.c should not define linker variables on its own. We have an include
file for that.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:24 -08:00
Christoph Lameter 88173507e4 Modules: handle symbols that have a zero value
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>
2008-02-08 09:22:24 -08:00
Heiko Carstens 596f56018d tty: s390 support for termios2.
Backend for s390.

Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
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>
2008-02-08 09:22:24 -08:00
Heiko Carstens aa7738a5f5 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>
2008-02-08 09:22:24 -08:00
mark gross d94afc6ccf intel-iommu: fault_reason index cleanup
Fix an off by one bug in the fault reason string reporting function, and
clean up some of the code around this buglet.

[akpm@linux-foundation.org: cleanup]
Signed-off-by: mark gross <mgross@linux.intel.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>
2008-02-08 09:22:24 -08:00
mark gross f8bab73515 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>
2008-02-08 09:22:24 -08:00
Alexey Dobriyan 2d3a4e3666 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.

BUG: unable to handle kernel NULL pointer dereference at virtual address 00000024
printing eip: c1188c1b *pdpt = 000000002929e001 *pde = 0000000000000000
Oops: 0002 [#1] PREEMPT SMP DEBUG_PAGEALLOC
last sysfs file: /sys/block/sda/sda1/dev
Modules linked in: foo af_packet ipv6 cpufreq_ondemand loop serio_raw psmouse k8temp hwmon sr_mod cdrom

Pid: 24679, comm: cat Not tainted (2.6.24-rc3-mm1 #2)
EIP: 0060:[<c1188c1b>] EFLAGS: 00210002 CPU: 0
EIP is at mutex_lock_nested+0x75/0x25d
EAX: 000006fe EBX: fffffffb ECX: 00001000 EDX: e9340570
ESI: 00000020 EDI: 00200246 EBP: e9340570 ESP: e8ea1ef8
 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process cat (pid: 24679, ti=E8EA1000 task=E9340570 task.ti=E8EA1000)
Stack: 00000000 c106f7ce e8ee05b4 00000000 00000001 458003d0 f6fb6f20 fffffffb
       00000000 c106f7aa 00001000 c106f7ce 08ae9000 f6db53f0 00000020 00200246
       00000000 00000002 00000000 00200246 00200246 e8ee05a0 fffffffb e8ee0550
Call Trace:
 [<c106f7ce>] seq_read+0x24/0x28a
 [<c106f7aa>] seq_read+0x0/0x28a
 [<c106f7ce>] seq_read+0x24/0x28a
 [<c106f7aa>] seq_read+0x0/0x28a
 [<c10818b8>] proc_reg_read+0x60/0x73
 [<c1081858>] proc_reg_read+0x0/0x73
 [<c105a34f>] vfs_read+0x6c/0x8b
 [<c105a6f3>] sys_read+0x3c/0x63
 [<c10025f2>] sysenter_past_esp+0x5f/0xa5
 [<c10697a7>] destroy_inode+0x24/0x33
 =======================
INFO: lockdep is turned off.
Code: 75 21 68 e1 1a 19 c1 68 87 00 00 00 68 b8 e8 1f c1 68 25 73 1f c1 e8 84 06 e9 ff e8 52 b8 e7 ff 83 c4 10 9c 5f fa e8 28 89 ea ff <f0> fe 4e 04 79 0a f3 90 80 7e 04 00 7e f8 eb f0 39 76 34 74 33
EIP: [<c1188c1b>] mutex_lock_nested+0x75/0x25d SS:ESP 0068:e8ea1ef8

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.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>
2008-02-08 09:22:24 -08:00
Eric W. Biederman c6caeb7c45 proc: fix the threaded /proc/self
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>
2008-02-08 09:22:24 -08:00
Eric W. Biederman 488e5bc456 proc: proper pidns handling for /proc/self
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>
2008-02-08 09:22:24 -08:00
Eric W. Biederman df5f8314ca 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>
2008-02-08 09:22:24 -08:00
Eric W. Biederman a56d3fc74c seqfile convert proc_pid_statm
This conversion is just for code cleanliness, uniformity, and general safety.

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>
2008-02-08 09:22:24 -08:00
Eric W. Biederman ee992744ea 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>
2008-02-08 09:22:23 -08:00
Eric W. Biederman be614086a4 proc: implement proc_single_file_operations
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>
2008-02-08 09:22:23 -08:00
Zhang Rui 94413d8807 proc: detect duplicate names on registration
Print a warning if PDE is registered with a name which already exists in
target directory.

Bug report and a simple fix can be found here:
http://bugzilla.kernel.org/show_bug.cgi?id=8798

[\n fixlet and no undescriptive variable usage --adobriyan]
[akpm@linux-foundation.org: make printk comprehensible]
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:23 -08:00
Alexey Dobriyan fd2cbe4888 proc: remove useless check on symlink removal
proc symlinks always have valid ->data containing destination of symlink.  No
need to check it on removal -- proc_symlink() already done it.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:23 -08:00
Alexey Dobriyan 76df0c25d0 proc: simplify function prototypes
Move code around so as to reduce the number of forward-declarations.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:23 -08:00
Alexey Dobriyan 4237e0d3de proc: less LOCK operations during lookup
Pseudo-code for lookup effectively is:

	LOCK kernel
	LOCK proc_subdir_lock
		find PDE
		UNLOCK proc_subdir_lock

		get inode

		LOCK proc_subdir_lock
		goto unlock
	UNLOCK proc_subdir_lock
	UNLOCK kernel

We can get rid of LOCK/UNLOCK pair after getting inode simply by jumping
to unlock_kernel() directly.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:23 -08:00
Alexey Dobriyan 5b3fe63b19 proc: remove MODULE_LICENSE
proc is not modular, so MODULE_LICENSE just expands to empty space.  proc
without doubts remains GPLed.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:23 -08:00
Pavel Emelyanov cbdc738732 namespaces: mark NET_NS with "depends on NAMESPACES"
There's already an option controlling the net namespaces cloning code, so make
it work the same way as all the other namespaces' options.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: "David S. Miller" <davem@davemloft.net>
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>
2008-02-08 09:22:23 -08:00
Pavel Emelyanov 74bd59bb39 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>
2008-02-08 09:22:23 -08:00
Pavel Emelyanov aee16ce73c 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>
2008-02-08 09:22:23 -08:00
Pavel Emelyanov ae5e1b22f1 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>
2008-02-08 09:22:23 -08:00
Pavel Emelyanov 58bfdd6dee namespaces: move the UTS namespace under UTS_NS option
Currently all the namespace management code is in the kernel/utsname.c file,
so just compile it out and make stubs in the appropriate header.

The init namespace itself is in init/version.c and is in the kernel all the
time.

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>
2008-02-08 09:22:23 -08:00