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  1. 14 3月, 2016 1 次提交
  3. 10 3月, 2016 3 次提交
  5. 15 1月, 2016 1 次提交
    • V
      kmemcg: account certain kmem allocations to memcg · 5d097056
      由 Vladimir Davydov 提交于 
      Mark those kmem allocations that are known to be easily triggered from
userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to
memcg.  For the list, see below:

 - threadinfo
 - task_struct
 - task_delay_info
 - pid
 - cred
 - mm_struct
 - vm_area_struct and vm_region (nommu)
 - anon_vma and anon_vma_chain
 - signal_struct
 - sighand_struct
 - fs_struct
 - files_struct
 - fdtable and fdtable->full_fds_bits
 - dentry and external_name
 - inode for all filesystems. This is the most tedious part, because
   most filesystems overwrite the alloc_inode method.

The list is far from complete, so feel free to add more objects.
Nevertheless, it should be close to "account everything" approach and
keep most workloads within bounds.  Malevolent users will be able to
breach the limit, but this was possible even with the former "account
everything" approach (simply because it did not account everything in
fact).

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NVladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      5d097056
  7. 11 1月, 2016 1 次提交
  9. 31 12月, 2015 1 次提交
    • N
      net, socket, socket_wq: fix missing initialization of flags · 574aab1e
      由 Nicolai Stange 提交于 
      Commit ceb5d58b ("net: fix sock_wake_async() rcu protection") from
the current 4.4 release cycle introduced a new flags member in
struct socket_wq and moved SOCKWQ_ASYNC_NOSPACE and SOCKWQ_ASYNC_WAITDATA
from struct socket's flags member into that new place.

Unfortunately, the new flags field is never initialized properly, at least
not for the struct socket_wq instance created in sock_alloc_inode().

One particular issue I encountered because of this is that my GNU Emacs
failed to draw anything on my desktop -- i.e. what I got is a transparent
window, including the title bar. Bisection lead to the commit mentioned
above and further investigation by means of strace told me that Emacs
is indeed speaking to my Xorg through an O_ASYNC AF_UNIX socket. This is
reproducible 100% of times and the fact that properly initializing the
struct socket_wq ->flags fixes the issue leads me to the conclusion that
somehow SOCKWQ_ASYNC_WAITDATA got set in the uninitialized ->flags,
preventing my Emacs from receiving any SIGIO's due to data becoming
available and it got stuck.

Make sock_alloc_inode() set the newly created struct socket_wq's ->flags
member to zero.

Fixes: ceb5d58b ("net: fix sock_wake_async() rcu protection")
Signed-off-by: NNicolai Stange <nicstange@gmail.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      574aab1e
  11. 16 12月, 2015 1 次提交
  13. 02 12月, 2015 2 次提交
    • E
      net: fix sock_wake_async() rcu protection · ceb5d58b
      由 Eric Dumazet 提交于 
      Dmitry provided a syzkaller (http://github.com/google/syzkaller)
triggering a fault in sock_wake_async() when async IO is requested.

Said program stressed af_unix sockets, but the issue is generic
and should be addressed in core networking stack.

The problem is that by the time sock_wake_async() is called,
we should not access the @flags field of 'struct socket',
as the inode containing this socket might be freed without
further notice, and without RCU grace period.

We already maintain an RCU protected structure, "struct socket_wq"
so moving SOCKWQ_ASYNC_NOSPACE & SOCKWQ_ASYNC_WAITDATA into it
is the safe route.

It also reduces number of cache lines needing dirtying, so might
provide a performance improvement anyway.

In followup patches, we might move remaining flags (SOCK_NOSPACE,
SOCK_PASSCRED, SOCK_PASSSEC) to save 8 bytes and let 'struct socket'
being mostly read and let it being shared between cpus.
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      ceb5d58b
    • E
      net: rename SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATA · 9cd3e072
      由 Eric Dumazet 提交于 
      This patch is a cleanup to make following patch easier to
review.

Goal is to move SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATA
from (struct socket)->flags to a (struct socket_wq)->flags
to benefit from RCU protection in sock_wake_async()

To ease backports, we rename both constants.

Two new helpers, sk_set_bit(int nr, struct sock *sk)
and sk_clear_bit(int net, struct sock *sk) are added so that
following patch can change their implementation.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      9cd3e072
  15. 29 9月, 2015 1 次提交
  17. 11 5月, 2015 2 次提交
  19. 16 4月, 2015 1 次提交
  21. 12 4月, 2015 3 次提交
  23. 09 4月, 2015 3 次提交
  25. 24 3月, 2015 1 次提交
  27. 21 3月, 2015 1 次提交
  29. 14 3月, 2015 1 次提交
  31. 13 3月, 2015 1 次提交
  33. 03 3月, 2015 1 次提交
  35. 02 3月, 2015 1 次提交
    • E
      net: move skb->dropcount to skb->cb[] · 744d5a3e
      由 Eyal Birger 提交于 
      Commit 97775007 ("af_packet: add interframe drop cmsg (v6)")
unionized skb->mark and skb->dropcount in order to allow recording
of the socket drop count while maintaining struct sk_buff size.

skb->dropcount was introduced since there was no available room
in skb->cb[] in packet sockets. However, its introduction led to
the inability to export skb->mark, or any other aliased field to
userspace if so desired.

Moving the dropcount metric to skb->cb[] eliminates this problem
at the expense of 4 bytes less in skb->cb[] for protocol families
using it.
Signed-off-by: NEyal Birger <eyal.birger@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      744d5a3e
  37. 04 2月, 2015 2 次提交
  39. 29 1月, 2015 1 次提交
    • C
      net: remove sock_iocb · 7cc05662
      由 Christoph Hellwig 提交于 
      The sock_iocb structure is allocate on stack for each read/write-like
operation on sockets, and contains various fields of which only the
embedded msghdr and sometimes a pointer to the scm_cookie is ever used.
Get rid of the sock_iocb and put a msghdr directly on the stack and pass
the scm_cookie explicitly to netlink_mmap_sendmsg.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      7cc05662
  41. 28 1月, 2015 1 次提交
  43. 18 1月, 2015 1 次提交
  45. 16 1月, 2015 1 次提交
  47. 19 12月, 2014 1 次提交
  49. 11 12月, 2014 1 次提交
    • A
      make default ->i_fop have ->open() fail with ENXIO · bd9b51e7
      由 Al Viro 提交于 
      As it is, default ->i_fop has NULL ->open() (along with all other methods).
The only case where it matters is reopening (via procfs symlink) a file that
didn't get its ->f_op from ->i_fop - anything else will have ->i_fop assigned
to something sane (default would fail on read/write/ioctl/etc.).

	Unfortunately, such case exists - alloc_file() users, especially
anon_get_file() ones.  There we have tons of opened files of very different
kinds sharing the same inode.  As the result, attempt to reopen those via
procfs succeeds and you get a descriptor you can't do anything with.

	Moreover, in case of sockets we set ->i_fop that will only be used
on such reopen attempts - and put a failing ->open() into it to make sure
those do not succeed.

	It would be simpler to put such ->open() into default ->i_fop and leave
it unchanged both for anon inode (as we do anyway) and for socket ones.  Result:
	* everything going through do_dentry_open() works as it used to
	* sock_no_open() kludge is gone
	* attempts to reopen anon-inode files fail as they really ought to
	* ditto for aio_private_file()
	* ditto for perfmon - this one actually tried to imitate sock_no_open()
trick, but failed to set ->i_fop, so in the current tree reopens succeed and
yield completely useless descriptor.  Intent clearly had been to fail with
-ENXIO on such reopens; now it actually does.
	* everything else that used alloc_file() keeps working - it has ->i_fop
set for its inodes anyway
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      bd9b51e7
  51. 10 12月, 2014 2 次提交
  53. 20 11月, 2014 3 次提交
    • A
      fold verify_iovec() into copy_msghdr_from_user() · 08adb7da
      由 Al Viro 提交于 
      ... and do the same on the compat side of things.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      08adb7da
    • A
      {compat_,}verify_iovec(): switch to generic copying of iovecs · 08449320
      由 Al Viro 提交于 
      use {compat_,}rw_copy_check_uvector().  As the result, we are
guaranteed that all iovecs seen in ->msg_iov by ->sendmsg()
and ->recvmsg() will pass access_ok().
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      08449320
    • A
      separate kernel- and userland-side msghdr · 666547ff
      由 Al Viro 提交于 
      Kernel-side struct msghdr is (currently) using the same layout as
userland one, but it's not a one-to-one copy - even without considering
32bit compat issues, we have msg_iov, msg_name and msg_control copied
to kernel[1].  It's fairly localized, so we get away with a few functions
where that knowledge is needed (and we could shrink that set even
more).  Pretty much everything deals with the kernel-side variant and
the few places that want userland one just use a bunch of force-casts
to paper over the differences.

The thing is, kernel-side definition of struct msghdr is *not* exposed
in include/uapi - libc doesn't see it, etc.  So we can add struct user_msghdr,
with proper annotations and let the few places that ever deal with those
beasts use it for userland pointers.  Saner typechecking aside, that will
allow to change the layout of kernel-side msghdr - e.g. replace
msg_iov/msg_iovlen there with struct iov_iter, getting rid of the need
to modify the iovec as we copy data to/from it, etc.

We could introduce kernel_msghdr instead, but that would create much more
noise - the absolute majority of the instances would need to have the
type switched to kernel_msghdr and definition of struct msghdr in
include/linux/socket.h is not going to be seen by userland anyway.

This commit just introduces user_msghdr and switches the few places that
are dealing with userland-side msghdr to it.

[1] actually, it's even trickier than that - we copy msg_control for
sendmsg, but keep the userland address on recvmsg.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      666547ff
  55. 10 9月, 2014 1 次提交