Commit Graph

1377 Commits

Author SHA1 Message Date
Al Viro
5f2c4179e1 switch ->put_link() from dentry to inode
only one instance looks at that argument at all; that sole
exception wants inode rather than dentry.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11 08:13:12 -04:00
Al Viro
6e77137b36 don't pass nameidata to ->follow_link()
its only use is getting passed to nd_jump_link(), which can obtain
it from current->nameidata

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-10 22:20:15 -04:00
Al Viro
680baacbca new ->follow_link() and ->put_link() calling conventions
a) instead of storing the symlink body (via nd_set_link()) and returning
an opaque pointer later passed to ->put_link(), ->follow_link() _stores_
that opaque pointer (into void * passed by address by caller) and returns
the symlink body.  Returning ERR_PTR() on error, NULL on jump (procfs magic
symlinks) and pointer to symlink body for normal symlinks.  Stored pointer
is ignored in all cases except the last one.

Storing NULL for opaque pointer (or not storing it at all) means no call
of ->put_link().

b) the body used to be passed to ->put_link() implicitly (via nameidata).
Now only the opaque pointer is.  In the cases when we used the symlink body
to free stuff, ->follow_link() now should store it as opaque pointer in addition
to returning it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-10 22:19:45 -04:00
Linus Torvalds
9ec3a646fe Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull fourth vfs update from Al Viro:
 "d_inode() annotations from David Howells (sat in for-next since before
  the beginning of merge window) + four assorted fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  RCU pathwalk breakage when running into a symlink overmounting something
  fix I_DIO_WAKEUP definition
  direct-io: only inc/dec inode->i_dio_count for file systems
  fs/9p: fix readdir()
  VFS: assorted d_backing_inode() annotations
  VFS: fs/inode.c helpers: d_inode() annotations
  VFS: fs/cachefiles: d_backing_inode() annotations
  VFS: fs library helpers: d_inode() annotations
  VFS: assorted weird filesystems: d_inode() annotations
  VFS: normal filesystems (and lustre): d_inode() annotations
  VFS: security/: d_inode() annotations
  VFS: security/: d_backing_inode() annotations
  VFS: net/: d_inode() annotations
  VFS: net/unix: d_backing_inode() annotations
  VFS: kernel/: d_inode() annotations
  VFS: audit: d_backing_inode() annotations
  VFS: Fix up some ->d_inode accesses in the chelsio driver
  VFS: Cachefiles should perform fs modifications on the top layer only
  VFS: AF_UNIX sockets should call mknod on the top layer only
2015-04-26 17:22:07 -07:00
Andrey Vagin
6c8c90319c proc: show locks in /proc/pid/fdinfo/X
Let's show locks which are associated with a file descriptor in
its fdinfo file.

Currently we don't have a reliable way to determine who holds a lock.  We
can find some information in /proc/locks, but PID which is reported there
can be wrong.  For example, a process takes a lock, then forks a child and
dies.  In this case /proc/locks contains the parent pid, which can be
reused by another process.

$ cat /proc/locks
...
6: FLOCK  ADVISORY  WRITE 324 00:13:13431 0 EOF
...

$ ps -C rpcbind
  PID TTY          TIME CMD
  332 ?        00:00:00 rpcbind

$ cat /proc/332/fdinfo/4
pos:	0
flags:	0100000
mnt_id:	22
lock:	1: FLOCK  ADVISORY  WRITE 324 00:13:13431 0 EOF

$ ls -l /proc/332/fd/4
lr-x------ 1 root root 64 Mar  5 14:43 /proc/332/fd/4 -> /run/rpcbind.lock

$ ls -l /proc/324/fd/
total 0
lrwx------ 1 root root 64 Feb 27 14:50 0 -> /dev/pts/0
lrwx------ 1 root root 64 Feb 27 14:50 1 -> /dev/pts/0
lrwx------ 1 root root 64 Feb 27 14:49 2 -> /dev/pts/0

You can see that the process with the 324 pid doesn't hold the lock.

This information is required for proper dumping and restoring file
locks.

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Acked-by: Jeff Layton <jlayton@poochiereds.net>
Acked-by: "J. Bruce Fields" <bfields@fieldses.org>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:12 -04:00
Joe Perches
25ce319167 proc: remove use of seq_printf return value
The seq_printf return value, because it's frequently misused,
will eventually be converted to void.

See: commit 1f33c41c03 ("seq_file: Rename seq_overflow() to
     seq_has_overflowed() and make public")

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 16:35:25 -07:00
Rasmus Villemoes
41416f2330 lib/string_helpers.c: change semantics of string_escape_mem
The current semantics of string_escape_mem are inadequate for one of its
current users, vsnprintf().  If that is to honour its contract, it must
know how much space would be needed for the entire escaped buffer, and
string_escape_mem provides no way of obtaining that (short of allocating a
large enough buffer (~4 times input string) to let it play with, and
that's definitely a big no-no inside vsnprintf).

So change the semantics for string_escape_mem to be more snprintf-like:
Return the size of the output that would be generated if the destination
buffer was big enough, but of course still only write to the part of dst
it is allowed to, and (contrary to snprintf) don't do '\0'-termination.
It is then up to the caller to detect whether output was truncated and to
append a '\0' if desired.  Also, we must output partial escape sequences,
otherwise a call such as snprintf(buf, 3, "%1pE", "\123") would cause
printf to write a \0 to buf[2] but leaving buf[0] and buf[1] with whatever
they previously contained.

This also fixes a bug in the escaped_string() helper function, which used
to unconditionally pass a length of "end-buf" to string_escape_mem();
since the latter doesn't check osz for being insanely large, it would
happily write to dst.  For example, kasprintf(GFP_KERNEL, "something and
then %pE", ...); is an easy way to trigger an oops.

In test-string_helpers.c, the -ENOMEM test is replaced with testing for
getting the expected return value even if the buffer is too small.  We
also ensure that nothing is written (by relying on a NULL pointer deref)
if the output size is 0 by passing NULL - this has to work for
kasprintf("%pE") to work.

In net/sunrpc/cache.c, I think qword_add still has the same semantics.
Someone should definitely double-check this.

In fs/proc/array.c, I made the minimum possible change, but longer-term it
should stop poking around in seq_file internals.

[andriy.shevchenko@linux.intel.com: simplify qword_add]
[andriy.shevchenko@linux.intel.com: add missed curly braces]
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 16:35:24 -07:00
Chen Hanxiao
e4bc332451 /proc/PID/status: show all sets of pid according to ns
If some issues occurred inside a container guest, host user could not know
which process is in trouble just by guest pid: the users of container
guest only knew the pid inside containers.  This will bring obstacle for
trouble shooting.

This patch adds four fields: NStgid, NSpid, NSpgid and NSsid:

a) In init_pid_ns, nothing changed;

b) In one pidns, will tell the pid inside containers:
  NStgid: 21776   5       1
  NSpid:  21776   5       1
  NSpgid: 21776   5       1
  NSsid:  21729   1       0
  ** Process id is 21776 in level 0, 5 in level 1, 1 in level 2.

c) If pidns is nested, it depends on which pidns are you in.
  NStgid: 5       1
  NSpid:  5       1
  NSpgid: 5       1
  NSsid:  1       0
  ** Views from level 1

[akpm@linux-foundation.org: add CONFIG_PID_NS ifdef]
Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Tested-by: Serge Hallyn <serge.hallyn@canonical.com>
Tested-by: Nathan Scott <nathans@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 16:35:22 -07:00
David Howells
2b0143b5c9 VFS: normal filesystems (and lustre): d_inode() annotations
that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-15 15:06:57 -04:00
Kirill A. Shutemov
ab676b7d6f pagemap: do not leak physical addresses to non-privileged userspace
As pointed by recent post[1] on exploiting DRAM physical imperfection,
/proc/PID/pagemap exposes sensitive information which can be used to do
attacks.

This disallows anybody without CAP_SYS_ADMIN to read the pagemap.

[1] http://googleprojectzero.blogspot.com/2015/03/exploiting-dram-rowhammer-bug-to-gain.html

[ Eventually we might want to do anything more finegrained, but for now
  this is the simple model.   - Linus ]

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mark Seaborn <mseaborn@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-03-17 09:31:30 -07:00
Al Viro
7e0e953bb0 procfs: fix race between symlink removals and traversals
use_pde()/unuse_pde() in ->follow_link()/->put_link() resp.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-22 11:43:12 -05:00
Linus Torvalds
50652963ea Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc VFS updates from Al Viro:
 "This cycle a lot of stuff sits on topical branches, so I'll be sending
  more or less one pull request per branch.

  This is the first pile; more to follow in a few.  In this one are
  several misc commits from early in the cycle (before I went for
  separate branches), plus the rework of mntput/dput ordering on umount,
  switching to use of fs_pin instead of convoluted games in
  namespace_unlock()"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  switch the IO-triggering parts of umount to fs_pin
  new fs_pin killing logics
  allow attaching fs_pin to a group not associated with some superblock
  get rid of the second argument of acct_kill()
  take count and rcu_head out of fs_pin
  dcache: let the dentry count go down to zero without taking d_lock
  pull bumping refcount into ->kill()
  kill pin_put()
  mode_t whack-a-mole: chelsio
  file->f_path.dentry is pinned down for as long as the file is open...
  get rid of lustre_dump_dentry()
  gut proc_register() a bit
  kill d_validate()
  ncpfs: get rid of d_validate() nonsense
  selinuxfs: don't open-code d_genocide()
2015-02-17 14:56:45 -08:00
WANG Chao
34b4776429 vmcore: fix PT_NOTE n_namesz, n_descsz overflow issue
When updating PT_NOTE header size (ie.  p_memsz), an overflow issue
happens with the following bogus note entry:

  n_namesz = 0xFFFFFFFF
  n_descsz = 0x0
  n_type   = 0x0

This kind of note entry should be dropped during updating p_memsz.  But
because n_namesz is 32bit, after (n_namesz + 3) & (~3), it's overflow to
0x0, the note entry size looks sane and reserved.

When userspace (eg.  crash utility) is trying to access such bogus note,
it could lead to an unexpected behavior (eg.  crash utility segment fault
because it's reading bogus address).

The source of bogus note hasn't been identified yet.  At least we could
drop the bogus note so user space wouldn't be surprised.

Signed-off-by: WANG Chao <chaowang@redhat.com>
Cc: Dave Anderson <anderson@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Randy Wright <rwright@hp.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Rashika Kheria <rashika.kheria@gmail.com>
Cc: Greg Pearson <greg.pearson@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:52 -08:00
Tejun Heo
a0c2e07d6d proc: use %*pb[l] to print bitmaps including cpumasks and nodemasks
printk and friends can now format bitmaps using '%*pb[l]'.  cpumask
and nodemask also provide cpumask_pr_args() and nodemask_pr_args()
respectively which can be used to generate the two printf arguments
necessary to format the specified cpu/nodemask.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 21:21:38 -08:00
Andy Shevchenko
edc924e023 fs/proc/array.c: convert to use string_escape_str()
Instead of custom approach let's use string_escape_str() to escape a given
string (task_name in this case).

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:12 -08:00
Rafael Aquini
198d1597cc fs: proc: task_mmu: show page size in /proc/<pid>/numa_maps
The output of /proc/$pid/numa_maps is in terms of number of pages like
anon=22 or dirty=54.  Here's some output:

  7f4680000000 default file=/hugetlb/bigfile anon=50 dirty=50 N0=50
  7f7659600000 default file=/anon_hugepage\040(deleted) anon=50 dirty=50 N0=50
  7fff8d425000 default stack anon=50 dirty=50 N0=50

Looks like we have a stack and a couple of anonymous hugetlbfs
areas page which both use the same amount of memory.  They don't.

The 'bigfile' uses 1GB pages and takes up ~50GB of space.  The
anon_hugepage uses 2MB pages and takes up ~100MB of space while the stack
uses normal 4k pages.  You can go over to smaps to figure out what the
page size _really_ is with KernelPageSize or MMUPageSize.  But, I think
this is a pretty nasty and counterintuitive interface as it stands.

This patch introduces 'kernelpagesize_kB' line element to
/proc/<pid>/numa_maps report file in order to help identifying the size of
pages that are backing memory areas mapped by a given task.  This is
specially useful to help differentiating between HUGE and GIGANTIC page
backed VMAs.

This patch is based on Dave Hansen's proposal and reviewer's follow-ups
taken from the following dicussion threads:
 * https://lkml.org/lkml/2011/9/21/454
 * https://lkml.org/lkml/2014/12/20/66

Signed-off-by: Rafael Aquini <aquini@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:12 -08:00
Alexander Kuleshov
6bee55f94f fs: proc: use PDE() to get proc_dir_entry
Use the PDE() helper to get proc_dir_entry instead of coding it directly.

Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:12 -08:00
Petr Cermak
695f055936 fs/proc/task_mmu.c: add user-space support for resetting mm->hiwater_rss (peak RSS)
Peak resident size of a process can be reset back to the process's
current rss value by writing "5" to /proc/pid/clear_refs.  The driving
use-case for this would be getting the peak RSS value, which can be
retrieved from the VmHWM field in /proc/pid/status, per benchmark
iteration or test scenario.

[akpm@linux-foundation.org: clarify behaviour in documentation]
Signed-off-by: Petr Cermak <petrcermak@chromium.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Primiano Tucci <primiano@chromium.org>
Cc: Petr Cermak <petrcermak@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:12 -08:00
Kirill A. Shutemov
7d5b3bfaa2 mm: /proc/pid/clear_refs: avoid split_huge_page()
Currently pagewalker splits all THP pages on any clear_refs request.  It's
not necessary.  We can handle this on PMD level.

One side effect is that soft dirty will potentially see more dirty memory,
since we will mark whole THP page dirty at once.

Sanity checked with CRIU test suite. More testing is required.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:06 -08:00
Naoya Horiguchi
48684a65b4 mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP)
walk_page_range() silently skips vma having VM_PFNMAP set, which leads to
undesirable behaviour at client end (who called walk_page_range).  For
example for pagemap_read(), when no callbacks are called against VM_PFNMAP
vma, pagemap_read() may prepare pagemap data for next virtual address
range at wrong index.  That could confuse and/or break userspace
applications.

This patch avoid this misbehavior caused by vma(VM_PFNMAP) like follows:
- for pagemap_read() which has its own ->pte_hole(), call the ->pte_hole()
  over vma(VM_PFNMAP),
- for clear_refs and queue_pages which have their own ->tests_walk,
  just return 1 and skip vma(VM_PFNMAP). This is no problem because
  these are not interested in hole regions,
- for other callers, just skip the vma(VM_PFNMAP) as a default behavior.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Shiraz Hashim <shashim@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:06 -08:00
Naoya Horiguchi
d85f4d6d3b numa_maps: remove numa_maps->vma
pagewalk.c can handle vma in itself, so we don't have to pass vma via
walk->private.  And show_numa_map() walks pages on vma basis, so using
walk_page_vma() is preferable.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:06 -08:00
Naoya Horiguchi
632fd60fe4 numa_maps: fix typo in gather_hugetbl_stats
Just doing s/gather_hugetbl_stats/gather_hugetlb_stats/g, this makes code
grep-friendly.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:06 -08:00
Naoya Horiguchi
f995ece24d pagemap: use walk->vma instead of calling find_vma()
Page table walker has the information of the current vma in mm_walk, so we
don't have to call find_vma() in each pagemap_(pte|hugetlb)_range() call
any longer.  Currently pagemap_pte_range() does vma loop itself, so this
patch reduces many lines of code.

NULL-vma check is omitted because we assume that we never run these
callbacks on any address outside vma.  And even if it were broken, NULL
pointer dereference would be detected, so we can get enough information
for debugging.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:05 -08:00
Naoya Horiguchi
5c64f52acd clear_refs: remove clear_refs_private->vma and introduce clear_refs_test_walk()
clear_refs_write() has some prechecks to determine if we really walk over
a given vma.  Now we have a test_walk() callback to filter vmas, so let's
utilize it.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:05 -08:00
Naoya Horiguchi
14eb6fdd42 smaps: remove mem_size_stats->vma and use walk_page_vma()
pagewalk.c can handle vma in itself, so we don't have to pass vma via
walk->private.  And show_smap() walks pages on vma basis, so using
walk_page_vma() is preferable.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:05 -08:00
Konstantin Khlebnikov
05fbf357d9 proc/pagemap: walk page tables under pte lock
Lockless access to pte in pagemap_pte_range() might race with page
migration and trigger BUG_ON(!PageLocked()) in migration_entry_to_page():

CPU A (pagemap)                           CPU B (migration)
                                          lock_page()
                                          try_to_unmap(page, TTU_MIGRATION...)
                                               make_migration_entry()
                                               set_pte_at()
<read *pte>
pte_to_pagemap_entry()
                                          remove_migration_ptes()
                                          unlock_page()
    if(is_migration_entry())
        migration_entry_to_page()
            BUG_ON(!PageLocked(page))

Also lockless read might be non-atomic if pte is larger than wordsize.
Other pte walkers (smaps, numa_maps, clear_refs) already lock ptes.

Fixes: 052fb0d635 ("proc: report file/anon bit in /proc/pid/pagemap")
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reported-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org>	[3.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:05 -08:00
Kirill A. Shutemov
dc6c9a35b6 mm: account pmd page tables to the process
Dave noticed that unprivileged process can allocate significant amount of
memory -- >500 MiB on x86_64 -- and stay unnoticed by oom-killer and
memory cgroup.  The trick is to allocate a lot of PMD page tables.  Linux
kernel doesn't account PMD tables to the process, only PTE.

The use-cases below use few tricks to allocate a lot of PMD page tables
while keeping VmRSS and VmPTE low.  oom_score for the process will be 0.

	#include <errno.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <unistd.h>
	#include <sys/mman.h>
	#include <sys/prctl.h>

	#define PUD_SIZE (1UL << 30)
	#define PMD_SIZE (1UL << 21)

	#define NR_PUD 130000

	int main(void)
	{
		char *addr = NULL;
		unsigned long i;

		prctl(PR_SET_THP_DISABLE);
		for (i = 0; i < NR_PUD ; i++) {
			addr = mmap(addr + PUD_SIZE, PUD_SIZE, PROT_WRITE|PROT_READ,
					MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
			if (addr == MAP_FAILED) {
				perror("mmap");
				break;
			}
			*addr = 'x';
			munmap(addr, PMD_SIZE);
			mmap(addr, PMD_SIZE, PROT_WRITE|PROT_READ,
					MAP_ANONYMOUS|MAP_PRIVATE|MAP_FIXED, -1, 0);
			if (addr == MAP_FAILED)
				perror("re-mmap"), exit(1);
		}
		printf("PID %d consumed %lu KiB in PMD page tables\n",
				getpid(), i * 4096 >> 10);
		return pause();
	}

The patch addresses the issue by account PMD tables to the process the
same way we account PTE.

The main place where PMD tables is accounted is __pmd_alloc() and
free_pmd_range(). But there're few corner cases:

 - HugeTLB can share PMD page tables. The patch handles by accounting
   the table to all processes who share it.

 - x86 PAE pre-allocates few PMD tables on fork.

 - Architectures with FIRST_USER_ADDRESS > 0. We need to adjust sanity
   check on exit(2).

Accounting only happens on configuration where PMD page table's level is
present (PMD is not folded).  As with nr_ptes we use per-mm counter.  The
counter value is used to calculate baseline for badness score by
oom-killer.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: David Rientjes <rientjes@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:04 -08:00
Wang, Yalin
56873f43ab mm:add KPF_ZERO_PAGE flag for /proc/kpageflags
Add KPF_ZERO_PAGE flag for zero_page, so that userspace processes can
detect zero_page in /proc/kpageflags, and then do memory analysis more
accurately.

Signed-off-by: Yalin Wang <yalin.wang@sonymobile.com>
Acked-by: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11 17:06:00 -08:00
Kirill A. Shutemov
1da4b35b00 proc: drop handling non-linear mappings
We have to handle non-linear mappings for /proc/PID/{smaps,clear_refs}
which is unused now.  Let's drop it.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-10 14:30:31 -08:00
Al Viro
d443b9fd56 gut proc_register() a bit
There are only 3 callers and quite a bit of that thing is executed
exactly in one of those.  Just lift it there...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-25 23:16:26 -05:00
Linus Torvalds
ac88ee3b6c Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq core fix from Thomas Gleixner:
 "A single fix plugging a long standing race between proc/stat and
  proc/interrupts access and freeing of interrupt descriptors"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Prevent proc race against freeing of irq descriptors
2014-12-19 13:26:08 -08:00
Pintu Kumar
47f8f9297d fs/proc/meminfo.c: include cma info in proc/meminfo
This patch include CMA info (CMATotal, CMAFree) in /proc/meminfo.
Currently, in a CMA enabled system, if somebody wants to know the total
CMA size declared, there is no way to tell, other than the dmesg or
/var/log/messages logs.

With this patch we are showing the CMA info as part of meminfo, so that it
can be determined at any point of time.  This will be populated only when
CMA is enabled.

Below is the sample output from a ARM based device with RAM:512MB and CMA:16MB.

  MemTotal:         471172 kB
  MemFree:          111712 kB
  MemAvailable:     271172 kB
  .
  .
  .
  CmaTotal:          16384 kB
  CmaFree:            6144 kB

This patch also fix below checkpatch errors that were found during these changes.

  ERROR: space required after that ',' (ctx:ExV)
  199: FILE: fs/proc/meminfo.c:199:
  +       ,atomic_long_read(&num_poisoned_pages) << (PAGE_SHIFT - 10)
          ^

  ERROR: space required after that ',' (ctx:ExV)
  202: FILE: fs/proc/meminfo.c:202:
  +       ,K(global_page_state(NR_ANON_TRANSPARENT_HUGEPAGES) *
          ^

  ERROR: space required after that ',' (ctx:ExV)
  206: FILE: fs/proc/meminfo.c:206:
  +       ,K(totalcma_pages)
          ^

  total: 3 errors, 0 warnings, 2 checks, 236 lines checked

Signed-off-by: Pintu Kumar <pintu.k@samsung.com>
Signed-off-by: Vishnu Pratap Singh <vishnu.ps@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-18 19:08:10 -08:00
Linus Torvalds
87c31b39ab Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace related fixes from Eric Biederman:
 "As these are bug fixes almost all of thes changes are marked for
  backporting to stable.

  The first change (implicitly adding MNT_NODEV on remount) addresses a
  regression that was created when security issues with unprivileged
  remount were closed.  I go on to update the remount test to make it
  easy to detect if this issue reoccurs.

  Then there are a handful of mount and umount related fixes.

  Then half of the changes deal with the a recently discovered design
  bug in the permission checks of gid_map.  Unix since the beginning has
  allowed setting group permissions on files to less than the user and
  other permissions (aka ---rwx---rwx).  As the unix permission checks
  stop as soon as a group matches, and setgroups allows setting groups
  that can not later be dropped, results in a situtation where it is
  possible to legitimately use a group to assign fewer privileges to a
  process.  Which means dropping a group can increase a processes
  privileges.

  The fix I have adopted is that gid_map is now no longer writable
  without privilege unless the new file /proc/self/setgroups has been
  set to permanently disable setgroups.

  The bulk of user namespace using applications even the applications
  using applications using user namespaces without privilege remain
  unaffected by this change.  Unfortunately this ix breaks a couple user
  space applications, that were relying on the problematic behavior (one
  of which was tools/selftests/mount/unprivileged-remount-test.c).

  To hopefully prevent needing a regression fix on top of my security
  fix I rounded folks who work with the container implementations mostly
  like to be affected and encouraged them to test the changes.

    > So far nothing broke on my libvirt-lxc test bed. :-)
    > Tested with openSUSE 13.2 and libvirt 1.2.9.
    > Tested-by: Richard Weinberger <richard@nod.at>

    > Tested on Fedora20 with libvirt 1.2.11, works fine.
    > Tested-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>

    > Ok, thanks - yes, unprivileged lxc is working fine with your kernels.
    > Just to be sure I was testing the right thing I also tested using
    > my unprivileged nsexec testcases, and they failed on setgroup/setgid
    > as now expected, and succeeded there without your patches.
    > Tested-by: Serge Hallyn <serge.hallyn@ubuntu.com>

    > I tested this with Sandstorm.  It breaks as is and it works if I add
    > the setgroups thing.
    > Tested-by: Andy Lutomirski <luto@amacapital.net> # breaks things as designed :("

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  userns: Unbreak the unprivileged remount tests
  userns; Correct the comment in map_write
  userns: Allow setting gid_maps without privilege when setgroups is disabled
  userns: Add a knob to disable setgroups on a per user namespace basis
  userns: Rename id_map_mutex to userns_state_mutex
  userns: Only allow the creator of the userns unprivileged mappings
  userns: Check euid no fsuid when establishing an unprivileged uid mapping
  userns: Don't allow unprivileged creation of gid mappings
  userns: Don't allow setgroups until a gid mapping has been setablished
  userns: Document what the invariant required for safe unprivileged mappings.
  groups: Consolidate the setgroups permission checks
  mnt: Clear mnt_expire during pivot_root
  mnt: Carefully set CL_UNPRIVILEGED in clone_mnt
  mnt: Move the clear of MNT_LOCKED from copy_tree to it's callers.
  umount: Do not allow unmounting rootfs.
  umount: Disallow unprivileged mount force
  mnt: Update unprivileged remount test
  mnt: Implicitly add MNT_NODEV on remount when it was implicitly added by mount
2014-12-17 12:31:40 -08:00
Linus Torvalds
603ba7e41b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile #2 from Al Viro:
 "Next pile (and there'll be one or two more).

  The large piece in this one is getting rid of /proc/*/ns/* weirdness;
  among other things, it allows to (finally) make nameidata completely
  opaque outside of fs/namei.c, making for easier further cleanups in
  there"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  coda_venus_readdir(): use file_inode()
  fs/namei.c: fold link_path_walk() call into path_init()
  path_init(): don't bother with LOOKUP_PARENT in argument
  fs/namei.c: new helper (path_cleanup())
  path_init(): store the "base" pointer to file in nameidata itself
  make default ->i_fop have ->open() fail with ENXIO
  make nameidata completely opaque outside of fs/namei.c
  kill proc_ns completely
  take the targets of /proc/*/ns/* symlinks to separate fs
  bury struct proc_ns in fs/proc
  copy address of proc_ns_ops into ns_common
  new helpers: ns_alloc_inum/ns_free_inum
  make proc_ns_operations work with struct ns_common * instead of void *
  switch the rest of proc_ns_operations to working with &...->ns
  netns: switch ->get()/->put()/->install()/->inum() to working with &net->ns
  make mntns ->get()/->put()/->install()/->inum() work with &mnt_ns->ns
  common object embedded into various struct ....ns
2014-12-16 15:53:03 -08:00
Thomas Gleixner
c291ee6221 genirq: Prevent proc race against freeing of irq descriptors
Since the rework of the sparse interrupt code to actually free the
unused interrupt descriptors there exists a race between the /proc
interfaces to the irq subsystem and the code which frees the interrupt
descriptor.

CPU0				CPU1
				show_interrupts()
				  desc = irq_to_desc(X);
free_desc(desc)
  remove_from_radix_tree();
  kfree(desc);
				  raw_spinlock_irq(&desc->lock);

/proc/interrupts is the only interface which can actively corrupt
kernel memory via the lock access. /proc/stat can only read from freed
memory. Extremly hard to trigger, but possible.

The interfaces in /proc/irq/N/ are not affected by this because the
removal of the proc file is serialized in procfs against concurrent
readers/writers. The removal happens before the descriptor is freed.

For architectures which have CONFIG_SPARSE_IRQ=n this is a non issue
as the descriptor is never freed. It's merely cleared out with the irq
descriptor lock held. So any concurrent proc access will either see
the old correct value or the cleared out ones.

Protect the lookup and access to the irq descriptor in
show_interrupts() with the sparse_irq_lock.

Provide kstat_irqs_usr() which is protecting the lookup and access
with sparse_irq_lock and switch /proc/stat to use it.

Document the existing kstat_irqs interfaces so it's clear that the
caller needs to take care about protection. The users of these
interfaces are either not affected due to SPARSE_IRQ=n or already
protected against removal.

Fixes: 1f5a5b87f7 "genirq: Implement a sane sparse_irq allocator"
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
2014-12-13 13:33:07 +01:00
Eric W. Biederman
9cc46516dd userns: Add a knob to disable setgroups on a per user namespace basis
- Expose the knob to user space through a proc file /proc/<pid>/setgroups

  A value of "deny" means the setgroups system call is disabled in the
  current processes user namespace and can not be enabled in the
  future in this user namespace.

  A value of "allow" means the segtoups system call is enabled.

- Descendant user namespaces inherit the value of setgroups from
  their parents.

- A proc file is used (instead of a sysctl) as sysctls currently do
  not allow checking the permissions at open time.

- Writing to the proc file is restricted to before the gid_map
  for the user namespace is set.

  This ensures that disabling setgroups at a user namespace
  level will never remove the ability to call setgroups
  from a process that already has that ability.

  A process may opt in to the setgroups disable for itself by
  creating, entering and configuring a user namespace or by calling
  setns on an existing user namespace with setgroups disabled.
  Processes without privileges already can not call setgroups so this
  is a noop.  Prodcess with privilege become processes without
  privilege when entering a user namespace and as with any other path
  to dropping privilege they would not have the ability to call
  setgroups.  So this remains within the bounds of what is possible
  without a knob to disable setgroups permanently in a user namespace.

Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2014-12-11 18:06:36 -06:00
Linus Torvalds
b6da0076ba Merge branch 'akpm' (patchbomb from Andrew)
Merge first patchbomb from Andrew Morton:
 - a few minor cifs fixes
 - dma-debug upadtes
 - ocfs2
 - slab
 - about half of MM
 - procfs
 - kernel/exit.c
 - panic.c tweaks
 - printk upates
 - lib/ updates
 - checkpatch updates
 - fs/binfmt updates
 - the drivers/rtc tree
 - nilfs
 - kmod fixes
 - more kernel/exit.c
 - various other misc tweaks and fixes

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits)
  exit: pidns: fix/update the comments in zap_pid_ns_processes()
  exit: pidns: alloc_pid() leaks pid_namespace if child_reaper is exiting
  exit: exit_notify: re-use "dead" list to autoreap current
  exit: reparent: call forget_original_parent() under tasklist_lock
  exit: reparent: avoid find_new_reaper() if no children
  exit: reparent: introduce find_alive_thread()
  exit: reparent: introduce find_child_reaper()
  exit: reparent: document the ->has_child_subreaper checks
  exit: reparent: s/while_each_thread/for_each_thread/ in find_new_reaper()
  exit: reparent: fix the cross-namespace PR_SET_CHILD_SUBREAPER reparenting
  exit: reparent: fix the dead-parent PR_SET_CHILD_SUBREAPER reparenting
  exit: proc: don't try to flush /proc/tgid/task/tgid
  exit: release_task: fix the comment about group leader accounting
  exit: wait: drop tasklist_lock before psig->c* accounting
  exit: wait: don't use zombie->real_parent
  exit: wait: cleanup the ptrace_reparented() checks
  usermodehelper: kill the kmod_thread_locker logic
  usermodehelper: don't use CLONE_VFORK for ____call_usermodehelper()
  fs/hfs/catalog.c: fix comparison bug in hfs_cat_keycmp
  nilfs2: fix the nilfs_iget() vs. nilfs_new_inode() races
  ...
2014-12-10 18:34:42 -08:00
Al Viro
707c5960f1 Merge branch 'nsfs' into for-next 2014-12-10 21:31:59 -05:00
Al Viro
3d3d35b1e9 kill proc_ns completely
procfs inodes need only the ns_ops part; nsfs inodes don't need it at all

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-10 21:30:57 -05:00
Al Viro
e149ed2b80 take the targets of /proc/*/ns/* symlinks to separate fs
New pseudo-filesystem: nsfs.  Targets of /proc/*/ns/* live there now.
It's not mountable (not even registered, so it's not in /proc/filesystems,
etc.).  Files on it *are* bindable - we explicitly permit that in do_loopback().

This stuff lives in fs/nsfs.c now; proc_ns_fget() moved there as well.
get_proc_ns() is a macro now (it's simply returning ->i_private; would
have been an inline, if not for header ordering headache).
proc_ns_inode() is an ex-parrot.  The interface used in procfs is
ns_get_path(path, task, ops) and ns_get_name(buf, size, task, ops).

Dentries and inodes are never hashed; a non-counting reference to dentry
is stashed in ns_common (removed by ->d_prune()) and reused by ns_get_path()
if present.  See ns_get_path()/ns_prune_dentry/nsfs_evict() for details
of that mechanism.

As the result, proc_ns_follow_link() has stopped poking in nd->path.mnt;
it does nd_jump_link() on a consistent <vfsmount,dentry> pair it gets
from ns_get_path().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-10 21:30:20 -05:00
Oleg Nesterov
c35a7f18a0 exit: proc: don't try to flush /proc/tgid/task/tgid
proc_flush_task_mnt() always tries to flush task/pid, but this is
pointless if we reap the leader. d_invalidate() is recursive, and
if nothing else the next d_hash_and_lookup(tgid) should fail anyway.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sterling Alexander <stalexan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:17 -08:00
Oleg Nesterov
abdba6e9ea proc: task_state: ptrace_parent() doesn't need pid_alive() check
p->ptrace != 0 means that release_task(p) was not called, so pid_alive()
buys nothing and we can remove this check.  Other callers already use it
directly without additional checks.

Note: with or without this patch ptrace_parent() can return the pointer to
the freed task, this will be explained/fixed later.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
Cc: Sterling Alexander <stalexan@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roland McGrath <roland@hack.frob.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:09 -08:00
Oleg Nesterov
b0fafc1111 proc: task_state: move the main seq_printf() outside of rcu_read_lock()
task_state() does seq_printf() under rcu_read_lock(), but this is only
needed for task_tgid_nr_ns() and task_numa_group_id().  We can calculate
tgid/ngid and drop rcu lock.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
Cc: Sterling Alexander <stalexan@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roland McGrath <roland@hack.frob.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:09 -08:00
Oleg Nesterov
0f4a0d53f2 proc: task_state: deuglify the max_fds calculation
1. The usage of fdt looks very ugly, it can't be NULL if ->files is
   not NULL. We can use "unsigned int max_fds" instead.

2. This also allows to move seq_printf(max_fds) outside of task_lock()
   and join it with the previous seq_printf(). See also the next patch.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
Cc: Sterling Alexander <stalexan@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roland McGrath <roland@hack.frob.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:09 -08:00
Oleg Nesterov
4af1036df4 proc: task_state: read cred->group_info outside of task_lock()
task_state() reads cred->group_info under task_lock() because a long ago
it was task_struct->group_info and it was actually protected by
task->alloc_lock.  Today this task_unlock() after rcu_read_unlock() just
adds the confusion, move task_unlock() up.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
Cc: Sterling Alexander <stalexan@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roland McGrath <roland@hack.frob.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:09 -08:00
Nicolas Dichtel
2fc1e948e8 fs/proc.c: use rb_entry_safe() instead of rb_entry()
Better to use existing macro that rewriting them.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:09 -08:00
Debabrata Banerjee
b208d54b75 procfs: fix error handling of proc_register()
proc_register() error paths are leaking inodes and directory refcounts.

Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:09 -08:00
Nicolas Dichtel
710585d492 fs/proc: use a rb tree for the directory entries
When a lot of netdevices are created, one of the bottleneck is the
creation of proc entries.  This serie aims to accelerate this part.

The current implementation for the directories in /proc is using a single
linked list.  This is slow when handling directories with large numbers of
entries (eg netdevice-related entries when lots of tunnels are opened).

This patch replaces this linked list by a red-black tree.

Here are some numbers:

dummy30000.batch contains 30 000 times 'link add type dummy'.

Before the patch:
  $ time ip -b dummy30000.batch
  real    2m31.950s
  user    0m0.440s
  sys     2m21.440s
  $ time rmmod dummy
  real    1m35.764s
  user    0m0.000s
  sys     1m24.088s

After the patch:
  $ time ip -b dummy30000.batch
  real    2m0.874s
  user    0m0.448s
  sys     1m49.720s
  $ time rmmod dummy
  real    1m13.988s
  user    0m0.000s
  sys     1m1.008s

The idea of improving this part was suggested by Thierry Herbelot.

[akpm@linux-foundation.org: initialise proc_root.subdir at compile time]
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Thierry Herbelot <thierry.herbelot@6wind.com>.
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>
2014-12-10 17:41:09 -08:00
Kirill A. Shutemov
c164e038ee mm: fix huge zero page accounting in smaps report
As a small zero page, huge zero page should not be accounted in smaps
report as normal page.

For small pages we rely on vm_normal_page() to filter out zero page, but
vm_normal_page() is not designed to handle pmds.  We only get here due
hackish cast pmd to pte in smaps_pte_range() -- pte and pmd format is not
necessary compatible on each and every architecture.

Let's add separate codepath to handle pmds.  follow_trans_huge_pmd() will
detect huge zero page for us.

We would need pmd_dirty() helper to do this properly.  The patch adds it
to THP-enabled architectures which don't yet have one.

[akpm@linux-foundation.org: use do_div to fix 32-bit build]
Signed-off-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Tested-by: Fengwei Yin <yfw.kernel@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:08 -08:00
Linus Torvalds
cbfe0de303 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull VFS changes from Al Viro:
 "First pile out of several (there _definitely_ will be more).  Stuff in
  this one:

   - unification of d_splice_alias()/d_materialize_unique()

   - iov_iter rewrite

   - killing a bunch of ->f_path.dentry users (and f_dentry macro).

     Getting that completed will make life much simpler for
     unionmount/overlayfs, since then we'll be able to limit the places
     sensitive to file _dentry_ to reasonably few.  Which allows to have
     file_inode(file) pointing to inode in a covered layer, with dentry
     pointing to (negative) dentry in union one.

     Still not complete, but much closer now.

   - crapectomy in lustre (dead code removal, mostly)

   - "let's make seq_printf return nothing" preparations

   - assorted cleanups and fixes

  There _definitely_ will be more piles"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  copy_from_iter_nocache()
  new helper: iov_iter_kvec()
  csum_and_copy_..._iter()
  iov_iter.c: handle ITER_KVEC directly
  iov_iter.c: convert copy_to_iter() to iterate_and_advance
  iov_iter.c: convert copy_from_iter() to iterate_and_advance
  iov_iter.c: get rid of bvec_copy_page_{to,from}_iter()
  iov_iter.c: convert iov_iter_zero() to iterate_and_advance
  iov_iter.c: convert iov_iter_get_pages_alloc() to iterate_all_kinds
  iov_iter.c: convert iov_iter_get_pages() to iterate_all_kinds
  iov_iter.c: convert iov_iter_npages() to iterate_all_kinds
  iov_iter.c: iterate_and_advance
  iov_iter.c: macros for iterating over iov_iter
  kill f_dentry macro
  dcache: fix kmemcheck warning in switch_names
  new helper: audit_file()
  nfsd_vfs_write(): use file_inode()
  ncpfs: use file_inode()
  kill f_dentry uses
  lockd: get rid of ->f_path.dentry->d_sb
  ...
2014-12-10 16:10:49 -08:00