ipv4: fix dst race in sk_dst_get()

When IP route cache had been removed in linux-3.6, we broke assumption
that dst entries were all freed after rcu grace period. DST_NOCACHE
dst were supposed to be freed from dst_release(). But it appears
we want to keep such dst around, either in UDP sockets or tunnels.

In sk_dst_get() we need to make sure dst refcount is not 0
before incrementing it, or else we might end up freeing a dst
twice.

DST_NOCACHE set on a dst does not mean this dst can not be attached
to a socket or a tunnel.

Then, before actual freeing, we need to observe a rcu grace period
to make sure all other cpus can catch the fact the dst is no longer
usable.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dormando <dormando@rydia.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
fs/mbcache: replace __builtin_log2() with ilog2()

Fix compiler error with some gcc version(s) that do not
support __builtin_log2() by replacing __builtin_log2() with
ilog2().

Signed-off-by: T. Makphaibulchoke <tmac@hp.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Maciej W. Rozycki <macro@linux-mips.org>
Merge tag 'nfs-for-3.16-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client fixes from Trond Myklebust:
 "Highlights include:

   - Stable fix for a data corruption case due to incorrect cache
     validation
   - Fix a couple of false positive cache invalidations
   - Fix NFSv4 security negotiation issues"

* tag 'nfs-for-3.16-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFSv4: test SECINFO RPC_AUTH_GSS pseudoflavors for support
  NFS Return -EPERM if no supported or matching SECINFO flavor
  NFS check the return of nfs4_negotiate_security in nfs4_submount
  NFS: Don't mark the data cache as invalid if it has been flushed
  NFS: Clear NFS_INO_REVAL_PAGECACHE when we update the file size
  nfs: Fix cache_validity check in nfs_write_pageuptodate()
net: fix setting csum_start in skb_segment()

Dave Jones reported that a crash is occurring in

csum_partial
tcp_gso_segment
inet_gso_segment
? update_dl_migration
skb_mac_gso_segment
__skb_gso_segment
dev_hard_start_xmit
sch_direct_xmit
__dev_queue_xmit
? dev_hard_start_xmit
dev_queue_xmit
ip_finish_output
? ip_output
ip_output
ip_forward_finish
ip_forward
ip_rcv_finish
ip_rcv
__netif_receive_skb_core
? __netif_receive_skb_core
? trace_hardirqs_on
__netif_receive_skb
netif_receive_skb_internal
napi_gro_complete
? napi_gro_complete
dev_gro_receive
? dev_gro_receive
napi_gro_receive

It looks like a likely culprit is that SKB_GSO_CB()->csum_start is
not set correctly when doing non-scatter gather. We are using
offset as opposed to doffset.

Reported-by: Dave Jones <davej@redhat.com>
Tested-by: Dave Jones <davej@redhat.com>
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 7e2b10c1e52ca ("net: Support for multiple checksums with gso")
Acked-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

Pull networking fixes from David Miller:

 1) Fix crash in ipvs tot_stats estimator, from Julian Anastasov.

 2) Fix OOPS in nf_nat on netns removal, from Florian Westphal.

 3) Really really really fix locking issues in slip and slcan tty write
    wakeups, from Tyler Hall.

 4) Fix checksum offloading in fec driver, from Fugang Duan.

 5) Off by one in BPF instruction limit test, from Kees Cook.

 6) Need to clear all TSO capability flags when doing software TSO in
    tg3 driver, from Prashant Sreedharan.

 7) Fix memory leak in vlan_reorder_header() error path, from Li
    RongQing.

 8) Fix various bugs in xen-netfront and xen-netback multiqueue support,
    from David Vrabel and Wei Liu.

 9) Fix deadlock in cxgb4 driver, from Li RongQing.

10) Prevent double free of no-cache DST entries, from Eric Dumazet.

11) Bad csum_start handling in skb_segment() leads to crashes when
    forwarding, from Tom Herbert.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (76 commits)
  net: fix setting csum_start in skb_segment()
  ipv4: fix dst race in sk_dst_get()
  net: filter: Use kcalloc/kmalloc_array to allocate arrays
  trivial: net: filter: Change kerneldoc parameter order
  trivial: net: filter: Fix typo in comment
  net: allwinner: emac: Add missing free_irq
  cxgb4: use dev_port to identify ports
  xen-netback: bookkeep number of active queues in our own module
  tg3: Change nvram command timeout value to 50ms
  cxgb4: Not need to hold the adap_rcu_lock lock when read adap_rcu_list
  be2net: fix qnq mode detection on VFs
  of: mdio: fixup of_phy_register_fixed_link parsing of new bindings
  at86rf230: fix irq setup
  net: phy: at803x: fix coccinelle warnings
  net/mlx4_core: Fix the error flow when probing with invalid VF configuration
  tulip: Poll link status more frequently for Comet chips
  net: huawei_cdc_ncm: increase command buffer size
  drivers: net: cpsw: fix dual EMAC stall when connected to same switch
  xen-netfront: recreate queues correctly when reconnecting
  xen-netfront: fix oops when disconnected from backend
  ...
Merge tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull hwmon fixes from Guenter Roeck:
 "Various minor fixes"

* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (gpio-fan) Change name used in hwmon_device_register_with_groups
  hwmon: (emc1403) Fix missing 'select REGMAP_I2C' in Kconfig
  hwmon: (ntc_thermistor) Use the manufacturer name properly
  devicetree: bindings: Document murata vendor prefix
  hwmon: (w83l786ng) Report correct minimum fan speed
ARC: Fix build breakage for !CONFIG_ARC_DW2_UNWIND

Fixes: ec7ac6afd07b (ARC: switch to generic ENTRY/END assembler annotations)
Reported-by: Anton Kolesov <akolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC: optimize kernel bss clearing in early boot code

using ARC ZOL which reduces tot num of instructions by half

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC: Implement ptrace(PTRACE_GET_THREAD_AREA)

This patch adds implementation of GET_THREAD_AREA ptrace request type. This
is required by GDB to debug NPTL applications.

Signed-off-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6

Pull CIFS fixes from Steve French:
 "Small set of misc cifs/smb3 fixes"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
  [CIFS] fix mount failure with broken pathnames when smb3 mount with mapchars option
  cifs: revalidate mapping prior to satisfying read_iter request with cache=loose
  fs/cifs: fix regression in cifs_create_mf_symlink()
xfrm: Fix refcount imbalance in xfrm_lookup

xfrm_lookup must return a dst_entry with a refcount for the caller.
Git commit 1a1ccc96abb ("xfrm: Remove caching of xfrm_policy_sk_bundles")
removed this refcount for the socket policy case accidentally.
This patch restores it and sets DST_NOCACHE flag to make sure
that the dst_entry is freed when the refcount becomes null.

Fixes: 1a1ccc96abb ("xfrm: Remove caching of xfrm_policy_sk_bundles")
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
ARC: [SMP] Fix IPI IRQ registration

Handle it just like timer. Current request_percpu_irq() would fail on
non-boot cpus and thus IRQ will remian unmasked on those cpus.

[vgupta: fix changelong]
Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC: [SMP] Enable icache coherency

icaches are not snooped hence not cohrent in SMP setups which means
kernel has to do cross core calls to ensure the same.

The leaf routine __ic_line_inv_vaddr() now does cross core calls.

__sync_icache_dcache() is affected due to this:

* local dcache line flushed ahead of remote icache inv requests
* can't disable interrupts anymore, since
      __ic_line_inv_vaddr()->on_each_cpu() can deadlock.

| WARNING: CPU: 0 PID: 1 at kernel/smp.c:374
| smp_call_function_many+0x25a/0x2c4()
|
|  init_kprobes+0x90/0xc8
|     register_kprobe+0x1d6/0x510
|	__sync_icache_dcache+0x28/0x80
|
|	    DISABLE IRQ
|
|	    __ic_line_inv_vaddr
|		on_each_cpu
|		     smp_call_function_many+0x25a/0x2c4   --> WARN
|			__ic_line_inv_vaddr_local
|	    __dc_line_op

* TODO: Needs to use mask of relevant CPUs to avoid broadcasting

Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ALSA: usb-audio: Fix races at disconnection and PCM closing

When a USB-audio device is disconnected while PCM is still running, we
still see some race: the disconnect callback calls
snd_usb_endpoint_free() that calls release_urbs() and then kfree()
while a PCM stream would be closed at the same time and calls
stop_endpoints() that leads to wait_clear_urbs().  That is, the EP
object might be deallocated while a PCM stream is syncing with
wait_clear_urbs() with the same EP.

Basically calling multiple wait_clear_urbs() would work fine, also
calling wait_clear_urbs() and release_urbs() would work, too, as
wait_clear_urbs() just reads some fields in ep.  The problem is the
succeeding kfree() in snd_pcm_endpoint_free().

This patch moves out the EP deallocation into the later point, the
destructor callback.  At this stage, all PCMs must have been already
closed, so it's safe to free the objects.

Reported-by: Alan Stern <stern@rowland.harvard.edu>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
KVM: s390: add sie.h uapi header file to Kbuild and remove header dependency

sie.h was missing in arch/s390/include/uapi/asm/Kbuild and therefore missed
the "make headers_check" target.
If added it reveals that also arch/s390/include/asm/sigp.h would become uapi.
This is something we certainly do not want. So remove that dependency as well.

The header file was merged with ceae283bb2e0176c "KVM: s390: add sie exit
reasons tables", therefore we never had a kernel release with this commit and
can still change anything.

Acked-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
MAINTAINERS: Update Eduardo Valentin's email address

Eduardo TI address is bouncing, but it looks like he's still
contributing via his Gmail address.

Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
MIPS: math-emu: Reduce code duplication.

The fix in the preceeding commit did do exactly the same thing in two
places showing some code cleanup was due.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Revert "MIPS: Save/restore MSA context around signals"

This reverts commit eec43a224cf1 "MIPS: Save/restore MSA context around
signals" and the MSA parts of ca750649e08c "MIPS: kernel: signal:
Prevent save/restore FPU context in user memory" (the restore path of
which appears incorrect anyway...).

The reverted patch took care not to break compatibility with userland
users of struct sigcontext, but inadvertantly changed the offset of the
uc_sigmask field of struct ucontext. Thus Linux v3.15 breaks the
userland ABI. The MSA context will need to be saved via some other
opt-in mechanism, but for now revert the change to reduce the fallout.

This will have minimal impact upon use of MSA since the only supported
CPU which includes it (the P5600) is 32-bit and therefore requires that
the experimental CONFIG_MIPS_O32_FP64_SUPPORT Kconfig option be selected
before the kernel will set FR=1 for a task, a requirement for MSA use.
Thus the users of MSA are limited to known small groups of people & this
patch won't be breaking any previously working MSA-using userland
outside of experimental settings.

[ralf@linux-mips.org: Fixed rejects.]

Cc: stable@vger.kernel.org
Reported-by: Joseph S. Myers <joseph@codesourcery.com>
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7107/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS: BPF JIT: Fix build error.

  mips: allmodconfig fails in 3.16-rc1 with lots of undefined symbols.

  arch/mips/net/bpf_jit.c: In function 'is_load_to_a':
  arch/mips/net/bpf_jit.c:559:7: error: 'BPF_S_LD_W_LEN' undeclared (first use in this function)
  arch/mips/net/bpf_jit.c:559:7: note: each undeclared identifier is reported only once for each function it appears in
  arch/mips/net/bpf_jit.c:560:7: error: 'BPF_S_LD_W_ABS' undeclared (first use in this function)
  [...]

The reason behind this is that 3480593131e0 ("net: filter: get rid of
BPF_S_* enum") was routed via net-next tree, that takes all BPF-related
changes, at a time where MIPS BPF JIT was not part of net-next, while
c6610de353da ("MIPS: net: Add BPF JIT") was routed via mips arch tree
and went into mainline within the same merge window. Thus, fix it up by
converting BPF_S_* in a similar fashion as in 3480593131e0 for MIPS.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-kernel@vger.kernel.org <linux-kernel@vger.kernel.org>
Cc: Linux MIPS Mailing List <linux-mips@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/7099/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
recordmcount/MIPS: Fix possible incorrect mcount_loc table entries in modules

On MIPS calls to _mcount in modules generate 2 instructions to load
the _mcount address (and therefore 2 relocations). The mcount_loc
table should only reference the first of these, so the second is
filtered out by checking the relocation offset and ignoring ones that
immediately follow the previous one seen.

However if a module has an _mcount call at offset 0, the second
relocation would not be filtered out due to old_r_offset == 0
being taken to mean that the current relocation is the first one
seen, and both would end up in the mcount_loc table.

This results in ftrace_make_nop() patching both (adjacent)
instructions to branches over the _mcount call sequence like so:

  0xffffffffc08a8000:  04 00 00 10     b       0xffffffffc08a8014
  0xffffffffc08a8004:  04 00 00 10     b       0xffffffffc08a8018
  0xffffffffc08a8008:  2d 08 e0 03     move    at,ra
  ...

The second branch is in the delay slot of the first, which is
defined to be unpredictable - on the platform on which this bug was
encountered, it triggers a reserved instruction exception.

Fix by initializing old_r_offset to ~0 and using that instead of 0
to determine whether the current relocation is the first seen.

Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7098/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>