net: ipv6: ping: Use socket mark in routing lookup

[net-next commit bf439b3154ce49d81a79b14f9fab18af99018ae2]

Change-Id: I8356e9132088c75d4510021c6e4c2641d772087a
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Git-commit: a5d5c168c37e0ab30ba07b2c79c7cba9615f4e87
Git-repo: https://android.googlesource.com/kernel/common.git
Signed-off-by: Ian Maund <imaund@codeaurora.org>
net: ipv6: autoconf routes into per-device tables

Currently, IPv6 router discovery always puts routes into
RT6_TABLE_MAIN. This causes problems for connection managers
that want to support multiple simultaneous network connections
and want control over which one is used by default (e.g., wifi
and wired).

To work around this connection managers typically take the routes
they prefer and copy them to static routes with low metrics in
the main table. This puts the burden on the connection manager
to watch netlink to see if the routes have changed, delete the
routes when their lifetime expires, etc.

Instead, this patch adds a per-interface sysctl to have the
kernel put autoconf routes into different tables. This allows
each interface to have its own autoconf table, and choosing the
default interface (or using different interfaces at the same
time for different types of traffic) can be done using
appropriate ip rules.

The sysctl behaves as follows:

- = 0: default. Put routes into RT6_TABLE_MAIN as before.
- > 0: manual. Put routes into the specified table.
- < 0: automatic. Add the absolute value of the sysctl to the
       device's ifindex, and use that table.

The automatic mode is most useful in conjunction with
net.ipv6.conf.default.accept_ra_rt_table. A connection manager
or distribution could set it to, say, -100 on boot, and
thereafter just use IP rules.

Change-Id: I093d39fb06ec413905dc0d0d5792c1bc5d5c73a9
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Git-commit: 5fe5c512af518d0abbbc0d2fafa8e355f518c2a9
Git-repo: https://android.googlesource.com/kernel/common.git
[imaund@codeaurora.org: Resolve trivial merge conflicts]
Signed-off-by: Ian Maund <imaund@codeaurora.org>
net: add a sysctl to reflect the fwmark on replies

Kernel-originated IP packets that have no user socket associated
with them (e.g., ICMP errors and echo replies, TCP RSTs, etc.)
are emitted with a mark of zero. Add a sysctl to make them have
the same mark as the packet they are replying to.

This allows an administrator that wishes to do so to use
mark-based routing, firewalling, etc. for these replies by
marking the original packets inbound.

Tested using user-mode linux:
 - ICMP/ICMPv6 echo replies and errors.
 - TCP RST packets (IPv4 and IPv6).

Change-Id: I95d896647b278d092ef331d1377b959da1deb042
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Git-commit: 3356997e1e1b2aa9959f046203e6d0b193bbd7f7
Git-repo: https://android.googlesource.com/kernel/common.git
[imaund@codeaurora.org: Resolve trivial merge conflicts.]
Signed-off-by: Ian Maund <imaund@codeaurora.org>
net: support marking accepting TCP sockets

When using mark-based routing, sockets returned from accept()
may need to be marked differently depending on the incoming
connection request.

This is the case, for example, if different socket marks identify
different networks: a listening socket may want to accept
connections from all networks, but each connection should be
marked with the network that the request came in on, so that
subsequent packets are sent on the correct network.

This patch adds a sysctl to mark TCP sockets based on the fwmark
of the incoming SYN packet. If enabled, and an unmarked socket
receives a SYN, then the SYN packet's fwmark is written to the
connection's inet_request_sock, and later written back to the
accepted socket when the connection is established.  If the
socket already has a nonzero mark, then the behaviour is the same
as it is today, i.e., the listening socket's fwmark is used.

Black-box tested using user-mode linux:

- IPv4/IPv6 SYN+ACK, FIN, etc. packets are routed based on the
  mark of the incoming SYN packet.
- The socket returned by accept() is marked with the mark of the
  incoming SYN packet.
- Tested with syncookies=1 and syncookies=2.

Change-Id: I5e8c9b989762a93f3eb5a0c1b4df44f62d57f3cb
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
[imaund@codeaurora.org: Resolve trivial merge conflicts.]
Git-commit: 4593f09b1f9939ec6ed2f8d7848def26b98c47ac
Git-repo: https://android.googlesource.com/kernel/common.git
Signed-off-by: Ian Maund <imaund@codeaurora.org>
netfilter: nf_conntrack: decrement global counter after object release

nf_conntrack_free() decrements our counter (net->ct.count)
before releasing the conntrack object. That counter is used in the
nf_conntrack_cleanup_net_list path to check if it's time to
kmem_cache_destroy our cache of conntrack objects. I think we have
a race there that should be easier to trigger (although still hard)
with CONFIG_DEBUG_OBJECTS_FREE as object releases become slowier
according to the following splat:

[ 1136.321305] WARNING: CPU: 2 PID: 2483 at lib/debugobjects.c:260
debug_print_object+0x83/0xa0()
[ 1136.321311] ODEBUG: free active (active state 0) object type:
timer_list hint: delayed_work_timer_fn+0x0/0x20
...
[ 1136.321390] Call Trace:
[ 1136.321398]  [<ffffffff8160d4a2>] dump_stack+0x45/0x56
[ 1136.321405]  [<ffffffff810514e8>] warn_slowpath_common+0x78/0xa0
[ 1136.321410]  [<ffffffff81051557>] warn_slowpath_fmt+0x47/0x50
[ 1136.321414]  [<ffffffff812f8883>] debug_print_object+0x83/0xa0
[ 1136.321420]  [<ffffffff8106aa90>] ? execute_in_process_context+0x90/0x90
[ 1136.321424]  [<ffffffff812f99fb>] debug_check_no_obj_freed+0x20b/0x250
[ 1136.321429]  [<ffffffff8112e7f2>] ? kmem_cache_destroy+0x92/0x100
[ 1136.321433]  [<ffffffff8115d945>] kmem_cache_free+0x125/0x210
[ 1136.321436]  [<ffffffff8112e7f2>] kmem_cache_destroy+0x92/0x100
[ 1136.321443]  [<ffffffffa046b806>] nf_conntrack_cleanup_net_list+0x126/0x160 [nf_conntrack]
[ 1136.321449]  [<ffffffffa046c43d>] nf_conntrack_pernet_exit+0x6d/0x80 [nf_conntrack]
[ 1136.321453]  [<ffffffff81511cc3>] ops_exit_list.isra.3+0x53/0x60
[ 1136.321457]  [<ffffffff815124f0>] cleanup_net+0x100/0x1b0
[ 1136.321460]  [<ffffffff8106b31e>] process_one_work+0x18e/0x430
[ 1136.321463]  [<ffffffff8106bf49>] worker_thread+0x119/0x390
[ 1136.321467]  [<ffffffff8106be30>] ? manage_workers.isra.23+0x2a0/0x2a0
[ 1136.321470]  [<ffffffff8107210b>] kthread+0xbb/0xc0
[ 1136.321472]  [<ffffffff81072050>] ? kthread_create_on_node+0x110/0x110
[ 1136.321477]  [<ffffffff8161b8fc>] ret_from_fork+0x7c/0xb0
[ 1136.321479]  [<ffffffff81072050>] ? kthread_create_on_node+0x110/0x110
[ 1136.321481] ---[ end trace 25f53c192da70825 ]---

CRs-fixed: 717356
Change-Id: I5e4aff3390cadadbac9ffe8fcdb651c79e42c685
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Git-commit: 0c3c6c00c69649f4749642b3e5d82125fde1600c
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>
net: ipv6: Add a sysctl to make optimistic addresses useful candidates

Add a sysctl that causes an interface's optimistic addresses
to be considered equivalent to other non-deprecated addresses
for source address selection purposes.  Preferred addresses
will still take precedence over optimistic addresses, subject
to other ranking in the source address selection algorithm.

This is useful where different interfaces are connected to
different networks from different ISPs (e.g., a cell network
and a home wifi network).

The current behaviour complies with RFC 3484/6724, and it
makes sense if the host has only one interface, or has
multiple interfaces on the same network (same or cooperating
administrative domain(s), but not in the multiple distinct
networks case.

For example, if a mobile device has an IPv6 address on an LTE
network and then connects to IPv6-enabled wifi, while the wifi
IPv6 address is undergoing DAD, IPv6 connections will try use
the wifi default route with the LTE IPv6 address, and will get
stuck until they time out.

Also, because optimistic nodes can receive frames, issue
an RTM_NEWADDR as soon as DAD starts (with the IFA_F_OPTIMSTIC
flag appropriately set).  A second RTM_NEWADDR is sent if DAD
completes (the address flags have changed), otherwise an
RTM_DELADDR is sent.

Also: add an entry in ip-sysctl.txt for optimistic_dad.

[backport of net-next 7fd2561e4ebdd070ebba6d3326c4c5b13942323f]

Signed-off-by: Erik Kline <ek@google.com>
Acked-by: Lorenzo Colitti <lorenzo@google.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Bug: 17769720
Change-Id: I440a9b8c788db6767d191bbebfd2dff481aa9e0d
net: Fix "ip rule delete table 256"

[ Upstream commit 13eb2ab2d33c57ebddc57437a7d341995fc9138c ]

When trying to delete a table >= 256 using iproute2 the local table
will be deleted.
The table id is specified as a netlink attribute when it needs more then
8 bits and iproute2 then sets the table field to RT_TABLE_UNSPEC (0).
Preconditions to matching the table id in the rule delete code
doesn't seem to take the "table id in netlink attribute" into condition
so the frh_get_table helper function never gets to do its job when
matching against current rule.
Use the helper function twice instead of peaking at the table value directly.

Originally reported at: http://bugs.debian.org/724783

Reported-by: Nicolas HICHER <nhicher@avencall.com>
Signed-off-by: Andreas Henriksson <andreas@fatal.se>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ext4: Add support for FIDTRIM, a best-effort ioctl for deep discard trim

* What
This provides an interface for issuing an FITRIM which uses the
secure discard instead of just a discard.
Only the eMMC command is "secure", and not how the FS uses it:
due to the fact that the FS might reassign a region somewhere else,
the original deleted data will not be affected by the "trim" which only
handles un-used regions.
So we'll just call it "deep discard", and note that this is a
"best effort" cleanup.

* Why
Once in a while, We want to be able to cleanup most of the unused blocks
after erasing a bunch of files.
We don't want to constantly secure-discard via a mount option.

From an eMMC spec perspective, it tells the device to really get rid of
all the data for the specified blocks and not just put them back into the
pool of free ones (unlike the normal TRIM). The eMMC spec says the
secure trim handling must make sure the data (and metadata) is not available
anymore. A simple TRIM doesn't clear the data, it just puts blocks in the
free pool.
JEDEC Standard No. 84-A441
  7.6.9 Secure Erase
  7.6.10 Secure Trim

From an FS perspective, it is acceptable to leave some data behind.
 - directory entries related to deleted files
 - databases entries related to deleted files
 - small-file data stored in inode extents
 - blocks held by the FS waiting to be re-used (mitigated by sync).
 - blocks reassigned by the FS prior to FIDTRIM.

Change-Id: I676a1404a80130d93930c84898360f2e6fb2f81e
Signed-off-by: Geremy Condra <gcondra@google.com>
Signed-off-by: JP Abgrall <jpa@google.com>
HID: add missing hid usages mappings
Power: add an API to log wakeup reasons

Add API log_wakeup_reason() and expose it to userspace via sysfs path
/sys/kernel/wakeup_reasons/last_resume_reason

Change-Id: I81addaf420f1338255c5d0638b0d244a99d777d1
Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
POWER: fix compile warnings in log_wakeup_reason

Change I81addaf420f1338255c5d0638b0d244a99d777d1 introduced compile
warnings, fix these.

Change-Id: I05482a5335599ab96c0a088a7d175c8d4cf1cf69
Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
Power: Add guard condition for maximum wakeup reasons

Ensure the array for the wakeup reason IRQs does not overflow.

Change-Id: Iddc57a3aeb1888f39d4e7b004164611803a4d37c
Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
Power: Changes the permission to read only for sysfs file
/sys/kernel/wakeup_reasons/last_resume_reason

Change-Id: If25e8e416ee9726996518b58b6551a61dc1591e3
Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
selinux: Report permissive mode in avc: denied messages.

We cannot presently tell from an avc: denied message whether access was in
fact denied or was allowed due to global or per-domain permissive mode.
Add a permissive= field to the avc message to reflect this information.

Change-Id: I23adf43e417687f1da7354d392d37f5fabbd805e
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
cgroup: Take css_set_lock from cgroup_css_sets_empty()

As indicated in the comment above cgroup_css_sets_empty it needs the
css_set_lock. But neither of the 2 call points have it, so rather then fixing
the callers just take the lock inside cgroup_css_sets_empty().

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Change-Id: If7aea71824f6d0e3f2cc6c1ce236c3ae6be2037b
cgroup: Fix use after free of cgrp (cgrp->css_sets)

Running a 3.4 kernel + Fedora-18 (systemd) userland on my Allwinner A10
(arm cortex a8), I'm seeing repeated, reproducable list_del list corruption
errors when build with CONFIG_DEBUG_LIST, and the backtrace always shows
free_css_set_work as the function making the problematic list_del call.

I've tracked this doen to a use after free of the cgrp struct, specifically
of the cgrp->css_sets list_head, which gets cleared by free_css_set_work.

Since free_css_set_work runs form a workqueue, it is possible for it to not be
done with clearing the list when the cgrp gets free-ed. To avoid this the code
adding the links increases cgrp->count, and the freeing code running from the
workqueue decreases cgrp->count *after* doing list_del, and then if the count
goes to 0 calls cgroup_wakeup_rmdir_waiter().

However cgroup_rmdir() is missing a check for cgrp->count != 0, causing it
to still continue with the rmdir (which leads to the free-ing of the cgrp),
before free_css_set_work is done. Sometimes the free-ed memory is re-used
before free_css_set_work gets around to unlinking link->cgrp_link_list,
triggering the list_del list corruption messages.

This patch fixes this by properly checking for cgrp->count != 0 and waiting
for the cgroup_rmdir_waitq in that case.

Change-Id: I9dbc02a0a75d5dffa1b65d67456e00139dea57c3
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
net: wireless: Increase scan entry expiration to fit new scan time
prctl: adds PR_SET_TIMERSLACK_PID for setting timer slack of an arbitrary thread.

Second argument is similar to PR_SET_TIMERSLACK, if non-zero then the
slack is set to that value otherwise sets it to the default for the thread.

Takes PID of the thread as the third argument.

This allows power/performance management software to set timer slack for
other threads according to its policy for the thread (such as when the
thread is designated foreground vs. background activity)

Change-Id: I744d451ff4e60dae69f38f53948ff36c51c14a3f
Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
prctl: adds the capable(CAP_SYS_NICE) check to PR_SET_TIMERSLACK_PID.

Adds a capable() check to make sure that arbitary apps do not change the
timer slack for other apps.

Bug: 15000427
Change-Id: I558a2551a0e3579c7f7e7aae54b28aa9d982b209
Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
introduce for_each_thread() to replace the buggy while_each_thread()

while_each_thread() and next_thread() should die, almost every lockless
usage is wrong.

1. Unless g == current, the lockless while_each_thread() is not safe.

   while_each_thread(g, t) can loop forever if g exits, next_thread()
   can't reach the unhashed thread in this case. Note that this can
   happen even if g is the group leader, it can exec.

2. Even if while_each_thread() itself was correct, people often use
   it wrongly.

   It was never safe to just take rcu_read_lock() and loop unless
   you verify that pid_alive(g) == T, even the first next_thread()
   can point to the already freed/reused memory.

This patch adds signal_struct->thread_head and task->thread_node to
create the normal rcu-safe list with the stable head.  The new
for_each_thread(g, t) helper is always safe under rcu_read_lock() as
long as this task_struct can't go away.

Note: of course it is ugly to have both task_struct->thread_node and the
old task_struct->thread_group, we will kill it later, after we change
the users of while_each_thread() to use for_each_thread().

Perhaps we can kill it even before we convert all users, we can
reimplement next_thread(t) using the new thread_head/thread_node.  But
we can't do this right now because this will lead to subtle behavioural
changes.  For example, do/while_each_thread() always sees at least one
task, while for_each_thread() can do nothing if the whole thread group
has died.  Or thread_group_empty(), currently its semantics is not clear
unless thread_group_leader(p) and we need to audit the callers before we
can change it.

So this patch adds the new interface which has to coexist with the old
one for some time, hopefully the next changes will be more or less
straightforward and the old one will go away soon.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Sergey Dyasly <dserrg@gmail.com>
Tested-by: Sergey Dyasly <dserrg@gmail.com>
Reviewed-by: Sameer Nanda <snanda@chromium.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mandeep Singh Baines <msb@chromium.org>
Cc: "Ma, Xindong" <xindong.ma@intel.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: "Tu, Xiaobing" <xiaobing.tu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Conflicts:
	kernel/fork.c