UPSTREAM: mm/slub: support left redzone

SLUB already has a redzone debugging feature.  But it is only positioned
at the end of object (aka right redzone) so it cannot catch left oob.
Although current object's right redzone acts as left redzone of next
object, first object in a slab cannot take advantage of this effect.
This patch explicitly adds a left red zone to each object to detect left
oob more precisely.

Background:

Someone complained to me that left OOB doesn't catch even if KASAN is
enabled which does page allocation debugging.  That page is out of our
control so it would be allocated when left OOB happens and, in this
case, we can't find OOB.  Moreover, SLUB debugging feature can be
enabled without page allocator debugging and, in this case, we will miss
that OOB.

Before trying to implement, I expected that changes would be too
complex, but, it doesn't look that complex to me now.  Almost changes
are applied to debug specific functions so I feel okay.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change-Id: Ib893a17ecabd692e6c402e864196bf89cd6781a5
(cherry picked from commit d86bd1bece6fc41d59253002db5441fe960a37f6)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

UPSTREAM: Make the hardened user-copy code depend on having a hardened allocator

The kernel test robot reported a usercopy failure in the new hardened
sanity checks, due to a page-crossing copy of the FPU state into the
task structure.

This happened because the kernel test robot was testing with SLOB, which
doesn't actually do the required book-keeping for slab allocations, and
as a result the hardening code didn't realize that the task struct
allocation was one single allocation - and the sanity checks fail.

Since SLOB doesn't even claim to support hardening (and you really
shouldn't use it), the straightforward solution is to just make the
usercopy hardening code depend on the allocator supporting it.

Reported-by: kernel test robot <xiaolong.ye@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change-Id: I37d51f866f873341bf7d5297249899b852e1c6ce
(cherry picked from commit 6040e57658eee6eb1315a26119101ca832d1f854)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

Android: MMC/UFS IO Latency Histograms.

This patch adds a new sysfs node (latency_hist) and reports
IO (svc time) latency histograms. Disabled by default, can be
enabled by echoing 0 into latency_hist, stats can be cleared
by writing 2 into latency_hist. This commit fixes the 32 bit
build breakage in the previous commit. Tested on both 32 bit
and 64 bit arm devices.

Bug: 30677035
Change-Id: I9a615a16616d80f87e75676ac4d078a5c429dcf9
Signed-off-by: Mohan Srinivasan <srmohan@google.com>

UPSTREAM: usercopy: fix overlap check for kernel text

When running with a local patch which moves the '_stext' symbol to the
very beginning of the kernel text area, I got the following panic with
CONFIG_HARDENED_USERCOPY:

  usercopy: kernel memory exposure attempt detected from ffff88103dfff000 (<linear kernel text>) (4096 bytes)
  ------------[ cut here ]------------
  kernel BUG at mm/usercopy.c:79!
  invalid opcode: 0000 [#1] SMP
  ...
  CPU: 0 PID: 4800 Comm: cp Not tainted 4.8.0-rc3.after+ #1
  Hardware name: Dell Inc. PowerEdge R720/0X3D66, BIOS 2.5.4 01/22/2016
  task: ffff880817444140 task.stack: ffff880816274000
  RIP: 0010:[<ffffffff8121c796>] __check_object_size+0x76/0x413
  RSP: 0018:ffff880816277c40 EFLAGS: 00010246
  RAX: 000000000000006b RBX: ffff88103dfff000 RCX: 0000000000000000
  RDX: 0000000000000000 RSI: ffff88081f80dfa8 RDI: ffff88081f80dfa8
  RBP: ffff880816277c90 R08: 000000000000054c R09: 0000000000000000
  R10: 0000000000000005 R11: 0000000000000006 R12: 0000000000001000
  R13: ffff88103e000000 R14: ffff88103dffffff R15: 0000000000000001
  FS:  00007fb9d1750800(0000) GS:ffff88081f800000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00000000021d2000 CR3: 000000081a08f000 CR4: 00000000001406f0
  Stack:
   ffff880816277cc8 0000000000010000 000000043de07000 0000000000000000
   0000000000001000 ffff880816277e60 0000000000001000 ffff880816277e28
   000000000000c000 0000000000001000 ffff880816277ce8 ffffffff8136c3a6
  Call Trace:
   [<ffffffff8136c3a6>] copy_page_to_iter_iovec+0xa6/0x1c0
   [<ffffffff8136e766>] copy_page_to_iter+0x16/0x90
   [<ffffffff811970e3>] generic_file_read_iter+0x3e3/0x7c0
   [<ffffffffa06a738d>] ? xfs_file_buffered_aio_write+0xad/0x260 [xfs]
   [<ffffffff816e6262>] ? down_read+0x12/0x40
   [<ffffffffa06a61b1>] xfs_file_buffered_aio_read+0x51/0xc0 [xfs]
   [<ffffffffa06a6692>] xfs_file_read_iter+0x62/0xb0 [xfs]
   [<ffffffff812224cf>] __vfs_read+0xdf/0x130
   [<ffffffff81222c9e>] vfs_read+0x8e/0x140
   [<ffffffff81224195>] SyS_read+0x55/0xc0
   [<ffffffff81003a47>] do_syscall_64+0x67/0x160
   [<ffffffff816e8421>] entry_SYSCALL64_slow_path+0x25/0x25
  RIP: 0033:[<00007fb9d0c33c00>] 0x7fb9d0c33c00
  RSP: 002b:00007ffc9c262f28 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
  RAX: ffffffffffffffda RBX: fffffffffff8ffff RCX: 00007fb9d0c33c00
  RDX: 0000000000010000 RSI: 00000000021c3000 RDI: 0000000000000004
  RBP: 00000000021c3000 R08: 0000000000000000 R09: 00007ffc9c264d6c
  R10: 00007ffc9c262c50 R11: 0000000000000246 R12: 0000000000010000
  R13: 00007ffc9c2630b0 R14: 0000000000000004 R15: 0000000000010000
  Code: 81 48 0f 44 d0 48 c7 c6 90 4d a3 81 48 c7 c0 bb b3 a2 81 48 0f 44 f0 4d 89 e1 48 89 d9 48 c7 c7 68 16 a3 81 31 c0 e8 f4 57 f7 ff <0f> 0b 48 8d 90 00 40 00 00 48 39 d3 0f 83 22 01 00 00 48 39 c3
  RIP  [<ffffffff8121c796>] __check_object_size+0x76/0x413
   RSP <ffff880816277c40>

The checked object's range [ffff88103dfff000, ffff88103e000000) is
valid, so there shouldn't have been a BUG.  The hardened usercopy code
got confused because the range's ending address is the same as the
kernel's text starting address at 0xffff88103e000000.  The overlap check
is slightly off.

Fixes: f5509cc18daa ("mm: Hardened usercopy")
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Change-Id: I839dbf4ddbb4d9874026a42abed557eb9b3f8bef
(cherry picked from commit 94cd97af690dd9537818dc9841d0ec68bb1dd877)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

UPSTREAM: usercopy: avoid potentially undefined behavior in pointer math

check_bogus_address() checked for pointer overflow using this expression,
where 'ptr' has type 'const void *':

ptr + n < ptr

Since pointer wraparound is undefined behavior, gcc at -O2 by default
treats it like the following, which would not behave as intended:

(long)n < 0

Fortunately, this doesn't currently happen for kernel code because kernel
code is compiled with -fno-strict-overflow.  But the expression should be
fixed anyway to use well-defined integer arithmetic, since it could be
treated differently by different compilers in the future or could be
reported by tools checking for undefined behavior.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Change-Id: I73b13be651cf35c03482f2014bf2c3dd291518ab
(cherry picked from commit 7329a655875a2f4bd6984fe8a7e00a6981e802f3)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

UPSTREAM: unsafe_[get|put]_user: change interface to use a error target label

When I initially added the unsafe_[get|put]_user() helpers in commit
5b24a7a2aa20 ("Add 'unsafe' user access functions for batched
accesses"), I made the mistake of modeling the interface on our
traditional __[get|put]_user() functions, which return zero on success,
or -EFAULT on failure.

That interface is fairly easy to use, but it's actually fairly nasty for
good code generation, since it essentially forces the caller to check
the error value for each access.

In particular, since the error handling is already internally
implemented with an exception handler, and we already use "asm goto" for
various other things, we could fairly easily make the error cases just
jump directly to an error label instead, and avoid the need for explicit
checking after each operation.

So switch the interface to pass in an error label, rather than checking
the error value in the caller.  Best do it now before we start growing
more users (the signal handling code in particular would be a good place
to use the new interface).

So rather than

if (unsafe_get_user(x, ptr))
... handle error ..

the interface is now

unsafe_get_user(x, ptr, label);

where an error during the user mode fetch will now just cause a jump to
'label' in the caller.

Right now the actual _implementation_ of this all still ends up being a
"if (err) goto label", and does not take advantage of any exception
label tricks, but for "unsafe_put_user()" in particular it should be
fairly straightforward to convert to using the exception table model.

Note that "unsafe_get_user()" is much harder to convert to a clever
exception table model, because current versions of gcc do not allow the
use of "asm goto" (for the exception) with output values (for the actual
value to be fetched).  But that is hopefully not a limitation in the
long term.

[ Also note that it might be a good idea to switch unsafe_get_user() to
  actually _return_ the value it fetches from user space, but this
  commit only changes the error handling semantics ]

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change-Id: Ib905a84a04d46984320f6fd1056da4d72f3d6b53
(cherry picked from commit 1bd4403d86a1c06cb6cc9ac87664a0c9d3413d51)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

BACKPORT: arm64: mm: fix location of _etext

As Kees Cook notes in the ARM counterpart of this patch [0]:

  The _etext position is defined to be the end of the kernel text code,
  and should not include any part of the data segments. This interferes
  with things that might check memory ranges and expect executable code
  up to _etext.

In particular, Kees is referring to the HARDENED_USERCOPY patch set [1],
which rejects attempts to call copy_to_user() on kernel ranges containing
executable code, but does allow access to the .rodata segment. Regardless
of whether one may or may not agree with the distinction, it makes sense
for _etext to have the same meaning across architectures.

So let's put _etext where it belongs, between .text and .rodata, and fix
up existing references to use __init_begin instead, which unlike _end_rodata
includes the exception and notes sections as well.

The _etext references in kaslr.c are left untouched, since its references
to [_stext, _etext) are meant to capture potential jump instruction targets,
and so disregarding .rodata is actually an improvement here.

[0] http://article.gmane.org/gmane.linux.kernel/2245084
[1] http://thread.gmane.org/gmane.linux.kernel.hardened.devel/2502

Reported-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 9fdc14c55cd6579d619ccd9d40982e0805e62b6d)
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>

BACKPORT: ARM: 8583/1: mm: fix location of _etext

The _etext position is defined to be the end of the kernel text code,
and should not include any part of the data segments. This interferes
with things that might check memory ranges and expect executable code
up to _etext. Just to be conservative, leave the kernel resource as
it was, using __init_begin instead of _etext as the end mark.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Change-Id: Ida514d1359dbe6f782f562ce29b4ba09ae72bfc0
(cherry picked from commit 14c4a533e0996f95a0a64dfd0b6252d788cebc74)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

BACKPORT: Don't show empty tag stats for unprivileged uids

BUG: 27577101
BUG: 27532522
Signed-off-by: Mohamad Ayyash <mkayyash@google.com>

UPSTREAM: tcp: fix use after free in tcp_xmit_retransmit_queue()

(cherry picked from commit bb1fceca22492109be12640d49f5ea5a544c6bb4)

When tcp_sendmsg() allocates a fresh and empty skb, it puts it at the
tail of the write queue using tcp_add_write_queue_tail()

Then it attempts to copy user data into this fresh skb.

If the copy fails, we undo the work and remove the fresh skb.

Unfortunately, this undo lacks the change done to tp->highest_sack and
we can leave a dangling pointer (to a freed skb)

Later, tcp_xmit_retransmit_queue() can dereference this pointer and
access freed memory. For regular kernels where memory is not unmapped,
this might cause SACK bugs because tcp_highest_sack_seq() is buggy,
returning garbage instead of tp->snd_nxt, but with various debug
features like CONFIG_DEBUG_PAGEALLOC, this can crash the kernel.

This bug was found by Marco Grassi thanks to syzkaller.

Fixes: 6859d49475d4 ("[TCP]: Abstract tp->highest_sack accessing & point to next skb")
Reported-by: Marco Grassi <marco.gra@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Change-Id: I58bb02d6e4e399612e8580b9e02d11e661df82f5
Bug: 31183296

ANDROID: base-cfg: drop SECCOMP_FILTER config

Don't need to set SECCOMP_FILTER explicitly since CONFIG_SECCOMP=y will
select that config anyway.

Fixes: a49dcf2e745c ("ANDROID: base-cfg: enable SECCOMP config")
Change-Id: Iff18ed4d2db5a55b9f9480d5ecbeef7b818b3837
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>

UPSTREAM: [media] xc2028: unlock on error in xc2028_set_config()

(cherry picked from commit 210bd104c6acd31c3c6b8b075b3f12d4a9f6b60d)

We have to unlock before returning -ENOMEM.

Fixes: 8dfbcc4351a0 ('[media] xc2028: avoid use after free')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Change-Id: I7b6ba9fde5c6e29467e6de23d398af2fe56e2547
Bug: 30946097

UPSTREAM: [media] xc2028: avoid use after free

(cherry picked from commit 8dfbcc4351a0b6d2f2d77f367552f48ffefafe18)

If struct xc2028_config is passed without a firmware name,
the following trouble may happen:

[11009.907205] xc2028 5-0061: type set to XCeive xc2028/xc3028 tuner
[11009.907491] ==================================================================
[11009.907750] BUG: KASAN: use-after-free in strcmp+0x96/0xb0 at addr ffff8803bd78ab40
[11009.907992] Read of size 1 by task modprobe/28992
[11009.907994] =============================================================================
[11009.907997] BUG kmalloc-16 (Tainted: G        W      ): kasan: bad access detected
[11009.907999] -----------------------------------------------------------------------------

[11009.908008] INFO: Allocated in xhci_urb_enqueue+0x214/0x14c0 [xhci_hcd] age=0 cpu=3 pid=28992
[11009.908012]  ___slab_alloc+0x581/0x5b0
[11009.908014]  __slab_alloc+0x51/0x90
[11009.908017]  __kmalloc+0x27b/0x350
[11009.908022]  xhci_urb_enqueue+0x214/0x14c0 [xhci_hcd]
[11009.908026]  usb_hcd_submit_urb+0x1e8/0x1c60
[11009.908029]  usb_submit_urb+0xb0e/0x1200
[11009.908032]  usb_serial_generic_write_start+0xb6/0x4c0
[11009.908035]  usb_serial_generic_write+0x92/0xc0
[11009.908039]  usb_console_write+0x38a/0x560
[11009.908045]  call_console_drivers.constprop.14+0x1ee/0x2c0
[11009.908051]  console_unlock+0x40d/0x900
[11009.908056]  vprintk_emit+0x4b4/0x830
[11009.908061]  vprintk_default+0x1f/0x30
[11009.908064]  printk+0x99/0xb5
[11009.908067]  kasan_report_error+0x10a/0x550
[11009.908070]  __asan_report_load1_noabort+0x43/0x50
[11009.908074] INFO: Freed in xc2028_set_config+0x90/0x630 [tuner_xc2028] age=1 cpu=3 pid=28992
[11009.908077]  __slab_free+0x2ec/0x460
[11009.908080]  kfree+0x266/0x280
[11009.908083]  xc2028_set_config+0x90/0x630 [tuner_xc2028]
[11009.908086]  xc2028_attach+0x310/0x8a0 [tuner_xc2028]
[11009.908090]  em28xx_attach_xc3028.constprop.7+0x1f9/0x30d [em28xx_dvb]
[11009.908094]  em28xx_dvb_init.part.3+0x8e4/0x5cf4 [em28xx_dvb]
[11009.908098]  em28xx_dvb_init+0x81/0x8a [em28xx_dvb]
[11009.908101]  em28xx_register_extension+0xd9/0x190 [em28xx]
[11009.908105]  em28xx_dvb_register+0x10/0x1000 [em28xx_dvb]
[11009.908108]  do_one_initcall+0x141/0x300
[11009.908111]  do_init_module+0x1d0/0x5ad
[11009.908114]  load_module+0x6666/0x9ba0
[11009.908117]  SyS_finit_module+0x108/0x130
[11009.908120]  entry_SYSCALL_64_fastpath+0x16/0x76
[11009.908123] INFO: Slab 0xffffea000ef5e280 objects=25 used=25 fp=0x          (null) flags=0x2ffff8000004080
[11009.908126] INFO: Object 0xffff8803bd78ab40 @offset=2880 fp=0x0000000000000001

[11009.908130] Bytes b4 ffff8803bd78ab30: 01 00 00 00 2a 07 00 00 9d 28 00 00 01 00 00 00  ....*....(......
[11009.908133] Object ffff8803bd78ab40: 01 00 00 00 00 00 00 00 b0 1d c3 6a 00 88 ff ff  ...........j....
[11009.908137] CPU: 3 PID: 28992 Comm: modprobe Tainted: G    B   W       4.5.0-rc1+ #43
[11009.908140] Hardware name:                  /NUC5i7RYB, BIOS RYBDWi35.86A.0350.2015.0812.1722 08/12/2015
[11009.908142]  ffff8803bd78a000 ffff8802c273f1b8 ffffffff81932007 ffff8803c6407a80
[11009.908148]  ffff8802c273f1e8 ffffffff81556759 ffff8803c6407a80 ffffea000ef5e280
[11009.908153]  ffff8803bd78ab40 dffffc0000000000 ffff8802c273f210 ffffffff8155ccb4
[11009.908158] Call Trace:
[11009.908162]  [<ffffffff81932007>] dump_stack+0x4b/0x64
[11009.908165]  [<ffffffff81556759>] print_trailer+0xf9/0x150
[11009.908168]  [<ffffffff8155ccb4>] object_err+0x34/0x40
[11009.908171]  [<ffffffff8155f260>] kasan_report_error+0x230/0x550
[11009.908175]  [<ffffffff81237d71>] ? trace_hardirqs_off_caller+0x21/0x290
[11009.908179]  [<ffffffff8155e926>] ? kasan_unpoison_shadow+0x36/0x50
[11009.908182]  [<ffffffff8155f5c3>] __asan_report_load1_noabort+0x43/0x50
[11009.908185]  [<ffffffff8155ea00>] ? __asan_register_globals+0x50/0xa0
[11009.908189]  [<ffffffff8194cea6>] ? strcmp+0x96/0xb0
[11009.908192]  [<ffffffff8194cea6>] strcmp+0x96/0xb0
[11009.908196]  [<ffffffffa13ba4ac>] xc2028_set_config+0x15c/0x630 [tuner_xc2028]
[11009.908200]  [<ffffffffa13bac90>] xc2028_attach+0x310/0x8a0 [tuner_xc2028]
[11009.908203]  [<ffffffff8155ea78>] ? memset+0x28/0x30
[11009.908206]  [<ffffffffa13ba980>] ? xc2028_set_config+0x630/0x630 [tuner_xc2028]
[11009.908211]  [<ffffffffa157a59a>] em28xx_attach_xc3028.constprop.7+0x1f9/0x30d [em28xx_dvb]
[11009.908215]  [<ffffffffa157aa2a>] ? em28xx_dvb_init.part.3+0x37c/0x5cf4 [em28xx_dvb]
[11009.908219]  [<ffffffffa157a3a1>] ? hauppauge_hvr930c_init+0x487/0x487 [em28xx_dvb]
[11009.908222]  [<ffffffffa01795ac>] ? lgdt330x_attach+0x1cc/0x370 [lgdt330x]
[11009.908226]  [<ffffffffa01793e0>] ? i2c_read_demod_bytes.isra.2+0x210/0x210 [lgdt330x]
[11009.908230]  [<ffffffff812e87d0>] ? ref_module.part.15+0x10/0x10
[11009.908233]  [<ffffffff812e56e0>] ? module_assert_mutex_or_preempt+0x80/0x80
[11009.908238]  [<ffffffffa157af92>] em28xx_dvb_init.part.3+0x8e4/0x5cf4 [em28xx_dvb]
[11009.908242]  [<ffffffffa157a6ae>] ? em28xx_attach_xc3028.constprop.7+0x30d/0x30d [em28xx_dvb]
[11009.908245]  [<ffffffff8195222d>] ? string+0x14d/0x1f0
[11009.908249]  [<ffffffff8195381f>] ? symbol_string+0xff/0x1a0
[11009.908253]  [<ffffffff81953720>] ? uuid_string+0x6f0/0x6f0
[11009.908257]  [<ffffffff811a775e>] ? __kernel_text_address+0x7e/0xa0
[11009.908260]  [<ffffffff8104b02f>] ? print_context_stack+0x7f/0xf0
[11009.908264]  [<ffffffff812e9846>] ? __module_address+0xb6/0x360
[11009.908268]  [<ffffffff8137fdc9>] ? is_ftrace_trampoline+0x99/0xe0
[11009.908271]  [<ffffffff811a775e>] ? __kernel_text_address+0x7e/0xa0
[11009.908275]  [<ffffffff81240a70>] ? debug_check_no_locks_freed+0x290/0x290
[11009.908278]  [<ffffffff8104a24b>] ? dump_trace+0x11b/0x300
[11009.908282]  [<ffffffffa13e8143>] ? em28xx_register_extension+0x23/0x190 [em28xx]
[11009.908285]  [<ffffffff81237d71>] ? trace_hardirqs_off_caller+0x21/0x290
[11009.908289]  [<ffffffff8123ff56>] ? trace_hardirqs_on_caller+0x16/0x590
[11009.908292]  [<ffffffff812404dd>] ? trace_hardirqs_on+0xd/0x10
[11009.908296]  [<ffffffffa13e8143>] ? em28xx_register_extension+0x23/0x190 [em28xx]
[11009.908299]  [<ffffffff822dcbb0>] ? mutex_trylock+0x400/0x400
[11009.908302]  [<ffffffff810021a1>] ? do_one_initcall+0x131/0x300
[11009.908306]  [<ffffffff81296dc7>] ? call_rcu_sched+0x17/0x20
[11009.908309]  [<ffffffff8159e708>] ? put_object+0x48/0x70
[11009.908314]  [<ffffffffa1579f11>] em28xx_dvb_init+0x81/0x8a [em28xx_dvb]
[11009.908317]  [<ffffffffa13e81f9>] em28xx_register_extension+0xd9/0x190 [em28xx]
[11009.908320]  [<ffffffffa0150000>] ? 0xffffffffa0150000
[11009.908324]  [<ffffffffa0150010>] em28xx_dvb_register+0x10/0x1000 [em28xx_dvb]
[11009.908327]  [<ffffffff810021b1>] do_one_initcall+0x141/0x300
[11009.908330]  [<ffffffff81002070>] ? try_to_run_init_process+0x40/0x40
[11009.908333]  [<ffffffff8123ff56>] ? trace_hardirqs_on_caller+0x16/0x590
[11009.908337]  [<ffffffff8155e926>] ? kasan_unpoison_shadow+0x36/0x50
[11009.908340]  [<ffffffff8155e926>] ? kasan_unpoison_shadow+0x36/0x50
[11009.908343]  [<ffffffff8155e926>] ? kasan_unpoison_shadow+0x36/0x50
[11009.908346]  [<ffffffff8155ea37>] ? __asan_register_globals+0x87/0xa0
[11009.908350]  [<ffffffff8144da7b>] do_init_module+0x1d0/0x5ad
[11009.908353]  [<ffffffff812f2626>] load_module+0x6666/0x9ba0
[11009.908356]  [<ffffffff812e9c90>] ? symbol_put_addr+0x50/0x50
[11009.908361]  [<ffffffffa1580037>] ? em28xx_dvb_init.part.3+0x5989/0x5cf4 [em28xx_dvb]
[11009.908366]  [<ffffffff812ebfc0>] ? module_frob_arch_sections+0x20/0x20
[11009.908369]  [<ffffffff815bc940>] ? open_exec+0x50/0x50
[11009.908374]  [<ffffffff811671bb>] ? ns_capable+0x5b/0xd0
[11009.908377]  [<ffffffff812f5e58>] SyS_finit_module+0x108/0x130
[11009.908379]  [<ffffffff812f5d50>] ? SyS_init_module+0x1f0/0x1f0
[11009.908383]  [<ffffffff81004044>] ? lockdep_sys_exit_thunk+0x12/0x14
[11009.908394]  [<ffffffff822e6936>] entry_SYSCALL_64_fastpath+0x16/0x76
[11009.908396] Memory state around the buggy address:
[11009.908398]  ffff8803bd78aa00: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[11009.908401]  ffff8803bd78aa80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[11009.908403] >ffff8803bd78ab00: fc fc fc fc fc fc fc fc 00 00 fc fc fc fc fc fc
[11009.908405]                                            ^
[11009.908407]  ffff8803bd78ab80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[11009.908409]  ffff8803bd78ac00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[11009.908411] ==================================================================

In order to avoid it, let's set the cached value of the firmware
name to NULL after freeing it. While here, return an error if
the memory allocation fails.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Change-Id: I945c841dcfb45de2056267e4aa50bbe176b527cf
Bug: 30946097

ANDROID: base-cfg: enable SECCOMP config

Enable following seccomp configs

CONFIG_SECCOMP=y
CONFIG_SECCOMP_FILTER=y

Otherwise we will get mediacode error like this on Android N:

E /system/bin/mediaextractor: libminijail: prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER): Invalid argument

Change-Id: I2477b6a2cfdded5c0ebf6ffbb6150b0e5fe2ba12
Signed-off-by: Yongqin Liu <yongqin.liu@linaro.org>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>

ANDROID: rcu_sync: Export rcu_sync_lockdep_assert

x86_64:allmodconfig fails to build with the following error.

ERROR: "rcu_sync_lockdep_assert" [kernel/locking/locktorture.ko] undefined!

Introduced by commit 3228c5eb7af2 ("RFC: FROMLIST: locking/percpu-rwsem:
Optimize readers and reduce global impact"). The applied upstream version
exports the missing symbol, so let's do the same.

Change-Id: If4e516715c3415fe8c82090f287174857561550d
Fixes: 3228c5eb7af2 ("RFC: FROMLIST: locking/percpu-rwsem: Optimize ...")
Signed-off-by: Guenter Roeck <groeck@chromium.org>

RFC: FROMLIST: cgroup: reduce read locked section of cgroup_threadgroup_rwsem during fork

cgroup_threadgroup_rwsem is acquired in read mode during process exit
and fork.  It is also grabbed in write mode during
__cgroups_proc_write().  I've recently run into a scenario with lots
of memory pressure and OOM and I am beginning to see

systemd

 __switch_to+0x1f8/0x350
 __schedule+0x30c/0x990
 schedule+0x48/0xc0
 percpu_down_write+0x114/0x170
 __cgroup_procs_write.isra.12+0xb8/0x3c0
 cgroup_file_write+0x74/0x1a0
 kernfs_fop_write+0x188/0x200
 __vfs_write+0x6c/0xe0
 vfs_write+0xc0/0x230
 SyS_write+0x6c/0x110
 system_call+0x38/0xb4

This thread is waiting on the reader of cgroup_threadgroup_rwsem to
exit.  The reader itself is under memory pressure and has gone into
reclaim after fork. There are times the reader also ends up waiting on
oom_lock as well.

 __switch_to+0x1f8/0x350
 __schedule+0x30c/0x990
 schedule+0x48/0xc0
 jbd2_log_wait_commit+0xd4/0x180
 ext4_evict_inode+0x88/0x5c0
 evict+0xf8/0x2a0
 dispose_list+0x50/0x80
 prune_icache_sb+0x6c/0x90
 super_cache_scan+0x190/0x210
 shrink_slab.part.15+0x22c/0x4c0
 shrink_zone+0x288/0x3c0
 do_try_to_free_pages+0x1dc/0x590
 try_to_free_pages+0xdc/0x260
 __alloc_pages_nodemask+0x72c/0xc90
 alloc_pages_current+0xb4/0x1a0
 page_table_alloc+0xc0/0x170
 __pte_alloc+0x58/0x1f0
 copy_page_range+0x4ec/0x950
 copy_process.isra.5+0x15a0/0x1870
 _do_fork+0xa8/0x4b0
 ppc_clone+0x8/0xc

In the meanwhile, all processes exiting/forking are blocked almost
stalling the system.

This patch moves the threadgroup_change_begin from before
cgroup_fork() to just before cgroup_canfork().  There is no nee to
worry about threadgroup changes till the task is actually added to the
threadgroup.  This avoids having to call reclaim with
cgroup_threadgroup_rwsem held.

tj: Subject and description edits.

Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Acked-by: Zefan Li <lizefan@huawei.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: Tejun Heo <tj@kernel.org>
[jstultz: Cherry-picked from:
 git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git 568ac888215c7f]
Change-Id: Ie8ece84fb613cf6a7b08cea1468473a8df2b9661
Signed-off-by: John Stultz <john.stultz@linaro.org>

RFC: FROMLIST: cgroup: avoid synchronize_sched() in __cgroup_procs_write()

The current percpu-rwsem read side is entirely free of serializing insns
at the cost of having a synchronize_sched() in the write path.

The latency of the synchronize_sched() is too high for cgroups. The
commit 1ed1328792ff talks about the write path being a fairly cold path
but this is not the case for Android which moves task to the foreground
cgroup and back around binder IPC calls from foreground processes to
background processes, so it is significantly hotter than human initiated
operations.

Switch cgroup_threadgroup_rwsem into the slow mode for now to avoid the
problem, hopefully it should not be that slow after another commit
80127a39681b ("locking/percpu-rwsem: Optimize readers and reduce global
impact").

We could just add rcu_sync_enter() into cgroup_init() but we do not want
another synchronize_sched() at boot time, so this patch adds the new helper
which doesn't block but currently can only be called before the first use.

Cc: Tejun Heo <tj@kernel.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Reported-by: John Stultz <john.stultz@linaro.org>
Reported-by: Dmitry Shmidt <dimitrysh@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
[jstultz: backported to 4.4]
Change-Id: I34aa9c394d3052779b56976693e96d861bd255f2
Mailing-list-URL: https://lkml.org/lkml/2016/8/11/557
Signed-off-by: John Stultz <john.stultz@linaro.org>

RFC: FROMLIST: locking/percpu-rwsem: Optimize readers and reduce global impact

Currently the percpu-rwsem switches to (global) atomic ops while a
writer is waiting; which could be quite a while and slows down
releasing the readers.

This patch cures this problem by ordering the reader-state vs
reader-count (see the comments in __percpu_down_read() and
percpu_down_write()). This changes a global atomic op into a full
memory barrier, which doesn't have the global cacheline contention.

This also enables using the percpu-rwsem with rcu_sync disabled in order
to bias the implementation differently, reducing the writer latency by
adding some cost to readers.

Mailing-list-URL: https://lkml.org/lkml/2016/8/9/181
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[jstultz: Backported to 4.4]
Change-Id: I8ea04b4dca2ec36f1c2469eccafde1423490572f
Signed-off-by: John Stultz <john.stultz@linaro.org>

net: ipv6: Fix ping to link-local addresses.

ping_v6_sendmsg does not set flowi6_oif in response to
sin6_scope_id or sk_bound_dev_if, so it is not possible to use
these APIs to ping an IPv6 address on a different interface.
Instead, it sets flowi6_iif, which is incorrect but harmless.

Stop setting flowi6_iif, and support various ways of setting oif
in the same priority order used by udpv6_sendmsg.

[Backport of net 5e457896986e16c440c97bb94b9ccd95dd157292]

Bug: 29370996
Change-Id: Ibe1b9434c00ed96f1e30acb110734c6570b087b8
Tested: https://android-review.googlesource.com/#/c/254470/
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv6: fix endianness error in icmpv6_err

IPv6 ping socket error handler doesn't correctly convert the new 32 bit
mtu to host endianness before using.

[Cherry-pick of net dcb94b88c09ce82a80e188d49bcffdc83ba215a6]

Bug: 29370996
Change-Id: Iea0ca79f16c2a1366d82b3b0a3097093d18da8b7
Cc: Lorenzo Colitti <lorenzo@google.com>
Fixes: 6d0bfe22611602f ("net: ipv6: Add IPv6 support to the ping socket.")
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ANDROID: dm: android-verity: Allow android-verity to be compiled as an independent module

Exports the device mapper callbacks of linear and dm-verity-target
methods.

Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Change-Id: I0358be0615c431dce3cc78575aaac4ccfe3aacd7

Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android

Conflicts:
arch/arm/Kconfig

Merge remote-tracking branch 'v4.4/topic/mm-kaslr-pax_usercopy' into linux-linaro-lsk-v4.4

mm: SLUB hardened usercopy support

Under CONFIG_HARDENED_USERCOPY, this adds object size checking to the
SLUB allocator to catch any copies that may span objects. Includes a
redzone handling fix discovered by Michael Ellerman.

Based on code from PaX and grsecurity.

Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Reviwed-by: Laura Abbott <labbott@redhat.com>
(cherry picked from commit ed18adc1cdd00a5c55a20fbdaed4804660772281)
Signed-off-by: Alex Shi <alex.shi@linaro.org>

mm: SLAB hardened usercopy support

Under CONFIG_HARDENED_USERCOPY, this adds object size checking to the
SLAB allocator to catch any copies that may span objects.

Based on code from PaX and grsecurity.

Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
(cherry picked from commit 04385fc5e8fffed84425d909a783c0f0c587d847)
Signed-off-by: Alex Shi <alex.shi@linaro.org>

s390/uaccess: Enable hardened usercopy

Enables CONFIG_HARDENED_USERCOPY checks on s390.

Signed-off-by: Kees Cook <keescook@chromium.org>
(cherry picked from commit 97433ea4fda62349bfa42089455593cbcb57e06c)
Signed-off-by: Alex Shi <alex.shi@linaro.org>

sparc/uaccess: Enable hardened usercopy

Enables CONFIG_HARDENED_USERCOPY checks on sparc.

Based on code from PaX and grsecurity.

Signed-off-by: Kees Cook <keescook@chromium.org>
(cherry picked from commit 9d9208a15800f9f06f102f9aac1e8b323c3b8575)
Signed-off-by: Alex Shi <alex.shi@linaro.org>

powerpc/uaccess: Enable hardened usercopy

Enables CONFIG_HARDENED_USERCOPY checks on powerpc.

Based on code from PaX and grsecurity.

Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
(cherry picked from commit 1d3c1324746fed0e34a5b94d3ed303e7521ed603)
Signed-off-by: Alex Shi <alex.shi@linaro.org>

ia64/uaccess: Enable hardened usercopy

Enables CONFIG_HARDENED_USERCOPY checks on ia64.

Based on code from PaX and grsecurity.

Signed-off-by: Kees Cook <keescook@chromium.org>
(cherry picked from commit 73d35887e24da77e8d1321b2e92bd9b9128e2fc2)
Signed-off-by: Alex Shi <alex.shi@linaro.org>

arm64/uaccess: Enable hardened usercopy

Enables CONFIG_HARDENED_USERCOPY checks on arm64. As done by KASAN in -next,
renames the low-level functions to __arch_copy_*_user() so a static inline
can do additional work before the copy.

Signed-off-by: Kees Cook <keescook@chromium.org>
(cherry picked from commit faf5b63e294151d6ac24ca6906d6f221bd3496cd)
Signed-off-by: Alex Shi <alex.shi@linaro.org>

ARM: uaccess: Enable hardened usercopy

Enables CONFIG_HARDENED_USERCOPY checks on arm.

Based on code from PaX and grsecurity.

Signed-off-by: Kees Cook <keescook@chromium.org>
(cherry picked from commit dfd45b6103c973bfcea2341d89e36faf947dbc33)
Signed-off-by: Alex Shi <alex.shi@linaro.org>

x86/uaccess: Enable hardened usercopy

Enables CONFIG_HARDENED_USERCOPY checks on x86. This is done both in
copy_*_user() and __copy_*_user() because copy_*_user() actually calls
down to _copy_*_user() and not __copy_*_user().

Based on code from PaX and grsecurity.

Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
(cherry picked from commit 5b710f34e194c6b7710f69fdb5d798fdf35b98c1)
Signed-off-by: Alex Shi <alex.shi@linaro.org>

x86: remove more uaccess_32.h complexity

I'm looking at trying to possibly merge the 32-bit and 64-bit versions
of the x86 uaccess.h implementation, but first this needs to be cleaned
up.

For example, the 32-bit version of "__copy_from_user_inatomic()" is
mostly the special cases for the constant size, and it's actually almost
never relevant.  Most users aren't actually using a constant size
anyway, and the few cases that do small constant copies are better off
just using __get_user() instead.

So get rid of the unnecessary complexity.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit bd28b14591b98f696bc9f94c5ba2e598ca487dfd)
Signed-off-by: Alex Shi <alex.shi@linaro.org>

x86: remove pointless uaccess_32.h complexity

I'm looking at trying to possibly merge the 32-bit and 64-bit versions
of the x86 uaccess.h implementation, but first this needs to be cleaned
up.

For example, the 32-bit version of "__copy_to_user_inatomic()" is mostly
the special cases for the constant size, and it's actually never
relevant.  Every user except for one aren't actually using a constant
size anyway, and the one user that uses it is better off just using
__put_user() instead.

So get rid of the unnecessary complexity.

[ The same cleanup should likely happen to __copy_from_user_inatomic()
  as well, but that one has a lot more users that I need to take a look
  at first ]

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 5b09c3edecd37ec1a52fbd5ae97a19734edc7a77)
Signed-off-by: Alex Shi <alex.shi@linaro.org>

x86: fix SMAP in 32-bit environments

In commit 11f1a4b9755f ("x86: reorganize SMAP handling in user space
accesses") I changed how the stac/clac instructions were generated
around the user space accesses, which then made it possible to do
batched accesses efficiently for user string copies etc.

However, in doing so, I completely spaced out, and didn't even think
about the 32-bit case.  And nobody really even seemed to notice, because
SMAP doesn't even exist until modern Skylake processors, and you'd have
to be crazy to run 32-bit kernels on a modern CPU.

Which brings us to Andy Lutomirski.

He actually tested the 32-bit kernel on new hardware, and noticed that
it doesn't work.  My bad.  The trivial fix is to add the required
uaccess begin/end markers around the raw accesses in <asm/uaccess_32.h>.

I feel a bit bad about this patch, just because that header file really
should be cleaned up to avoid all the duplicated code in it, and this
commit just expands on the problem.  But this just fixes the bug without
any bigger cleanup surgery.

Reported-and-tested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit de9e478b9d49f3a0214310d921450cf5bb4a21e6)
Signed-off-by: Alex Shi <alex.shi@linaro.org>

Use the new batched user accesses in generic user string handling

This converts the generic user string functions to use the batched user
access functions.

It makes a big difference on Skylake, which is the first x86
microarchitecture to implement SMAP.  The STAC/CLAC instructions are not
very fast, and doing them for each access inside the loop that copies
strings from user space (which is what the pathname handling does for
every pathname the kernel uses, for example) is very inefficient.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 9fd4470ff4974c41b1db43c3b355b9085af9c12a)
Signed-off-by: Alex Shi <alex.shi@linaro.org>

Add 'unsafe' user access functions for batched accesses

The naming is meant to discourage random use: the helper functions are
not really any more "unsafe" than the traditional double-underscore
functions (which need the address range checking), but they do need even
more infrastructure around them, and should not be used willy-nilly.

In addition to checking the access range, these user access functions
require that you wrap the user access with a "user_acess_{begin,end}()"
around it.

That allows architectures that implement kernel user access control
(x86: SMAP, arm64: PAN) to do the user access control in the wrapping
user_access_begin/end part, and then batch up the actual user space
accesses using the new interfaces.

The main (and hopefully only) use for these are for core generic access
helpers, initially just the generic user string functions
(strnlen_user() and strncpy_from_user()).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 5b24a7a2aa2040c8c50c3b71122901d01661ff78)
Signed-off-by: Alex Shi <alex.shi@linaro.org>

x86: reorganize SMAP handling in user space accesses

This reorganizes how we do the stac/clac instructions in the user access
code.  Instead of adding the instructions directly to the same inline
asm that does the actual user level access and exception handling, add
them at a higher level.

This is mainly preparation for the next step, where we will expose an
interface to allow users to mark several accesses together as being user
space accesses, but it does already clean up some code:

 - the inlined trivial cases of copy_in_user() now do stac/clac just
   once over the accesses: they used to do one pair around the user
   space read, and another pair around the write-back.

 - the {get,put}_user_ex() macros that are used with the catch/try
   handling don't do any stac/clac at all, because that happens in the
   try/catch surrounding them.

Other than those two cleanups that happened naturally from the
re-organization, this should not make any difference. Yet.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 11f1a4b9755f5dbc3e822a96502ebe9b044b14d8)
Signed-off-by: Alex Shi <alex.shi@linaro.org>

mm: Hardened usercopy

This is the start of porting PAX_USERCOPY into the mainline kernel. This
is the first set of features, controlled by CONFIG_HARDENED_USERCOPY. The
work is based on code by PaX Team and Brad Spengler, and an earlier port
from Casey Schaufler. Additional non-slab page tests are from Rik van Riel.

This patch contains the logic for validating several conditions when
performing copy_to_user() and copy_from_user() on the kernel object
being copied to/from:
- address range doesn't wrap around
- address range isn't NULL or zero-allocated (with a non-zero copy size)
- if on the slab allocator:
  - object size must be less than or equal to copy size (when check is
    implemented in the allocator, which appear in subsequent patches)
- otherwise, object must not span page allocations (excepting Reserved
  and CMA ranges)
- if on the stack
  - object must not extend before/after the current process stack
  - object must be contained by a valid stack frame (when there is
    arch/build support for identifying stack frames)
- object must not overlap with kernel text

Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
(cherry picked from commit f5509cc18daa7f82bcc553be70df2117c8eedc16)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Conflicts:
skip debug_page_ref and KCOV_INSTRUMENT in mm/Makefile

mm: Implement stack frame object validation

This creates per-architecture function arch_within_stack_frames() that
should validate if a given object is contained by a kernel stack frame.
Initial implementation is on x86.

This is based on code from PaX.

Signed-off-by: Kees Cook <keescook@chromium.org>
(cherry picked from commit 0f60a8efe4005ab5e65ce000724b04d4ca04a199)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Conflicts:
skip EBPF_JIT in arch/x86/Kconfig

mm: Add is_migrate_cma_page

Code such as hardened user copy[1] needs a way to tell if a
page is CMA or not. Add is_migrate_cma_page in a similar way
to is_migrate_isolate_page.

[1]http://article.gmane.org/gmane.linux.kernel.mm/155238

Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
(cherry picked from commit 7c15d9bb8231f998ae7dc0b72415f5215459f7fb)
Signed-off-by: Alex Shi <alex.shi@linaro.org>

UPSTREAM: usb: gadget: configfs: add mutex lock before unregister gadget

There may be a race condition if f_fs calls unregister_gadget_item in
ffs_closed() when unregister_gadget is called by UDC store at the same time.
this leads to a kernel NULL pointer dereference:

[  310.644928] Unable to handle kernel NULL pointer dereference at virtual address 00000004
[  310.645053] init: Service 'adbd' is being killed...
[  310.658938] pgd = c9528000
[  310.662515] [00000004] *pgd=19451831, *pte=00000000, *ppte=00000000
[  310.669702] Internal error: Oops: 817 [#1] PREEMPT SMP ARM
[  310.675211] Modules linked in:
[  310.678294] CPU: 0 PID: 1537 Comm: ->transport Not tainted 4.1.15-03725-g793404c #2
[  310.685958] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[  310.692493] task: c8e24200 ti: c945e000 task.ti: c945e000
[  310.697911] PC is at usb_gadget_unregister_driver+0xb4/0xd0
[  310.703502] LR is at __mutex_lock_slowpath+0x10c/0x16c
[  310.708648] pc : [<c075efc0>]    lr : [<c0bfb0bc>]    psr: 600f0113
<snip..>
[  311.565585] [<c075efc0>] (usb_gadget_unregister_driver) from [<c075e2b8>] (unregister_gadget_item+0x1c/0x34)
[  311.575426] [<c075e2b8>] (unregister_gadget_item) from [<c076fcc8>] (ffs_closed+0x8c/0x9c)
[  311.583702] [<c076fcc8>] (ffs_closed) from [<c07736b8>] (ffs_data_reset+0xc/0xa0)
[  311.591194] [<c07736b8>] (ffs_data_reset) from [<c07738ac>] (ffs_data_closed+0x90/0xd0)
[  311.599208] [<c07738ac>] (ffs_data_closed) from [<c07738f8>] (ffs_ep0_release+0xc/0x14)
[  311.607224] [<c07738f8>] (ffs_ep0_release) from [<c023e030>] (__fput+0x80/0x1d0)
[  311.614635] [<c023e030>] (__fput) from [<c014e688>] (task_work_run+0xb0/0xe8)
[  311.621788] [<c014e688>] (task_work_run) from [<c010afdc>] (do_work_pending+0x7c/0xa4)
[  311.629718] [<c010afdc>] (do_work_pending) from [<c010770c>] (work_pending+0xc/0x20)

for functions using functionFS, i.e. android adbd will close /dev/usb-ffs/adb/ep0
when usb IO thread fails, but switch adb from on to off also triggers write
"none" > UDC. These 2 operations both call unregister_gadget, which will lead
to the panic above.

add a mutex before calling unregister_gadget for api used in f_fs.

Signed-off-by: Winter Wang <wente.wang@nxp.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

ANDROID: dm-verity: adopt changes made to dm callbacks

v4.4 introduced changes to the callbacks used for
dm-linear and dm-verity-target targets. Move to those headers
in dm-android-verity.

Verified on hikey while having
BOARD_USES_RECOVERY_AS_BOOT := true
BOARD_BUILD_SYSTEM_ROOT_IMAGE := true

BUG: 27339727
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Change-Id: Ic64950c3b55f0a6eaa570bcedc2ace83bbf3005e

UPSTREAM: ecryptfs: fix handling of directory opening

(cherry picked from commit 6a480a7842545ec520a91730209ec0bae41694c1)

First of all, trying to open them r/w is idiocy; it's guaranteed to fail.
Moreover, assigning ->f_pos and assuming that everything will work is
blatantly broken - try that with e.g. tmpfs as underlying layer and watch
the fireworks.  There may be a non-trivial amount of state associated with
current IO position, well beyond the numeric offset.  Using the single
struct file associated with underlying inode is really not a good idea;
we ought to open one for each ecryptfs directory struct file.

Additionally, file_operations both for directories and non-directories are
full of pointless methods; non-directories should *not* have ->iterate(),
directories should not have ->flush(), ->fasync() and ->splice_read().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Change-Id: I4813ce803f270fdd364758ce1dc108b76eab226e
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>

ANDROID: net: core: fix UID-based routing

Fix RTA_UID enum to match it with the Android userspace code which
assumes RTA_UID=18.

With this patch all Android kernel networking unit tests mentioned here
https://source.android.com/devices/tech/config/kernel_network_tests.html
are success.

Without this patch multinetwork_test.py unit test fails.

Change-Id: I3ff36670f7d4e5bf5f01dce584ae9d53deabb3ed
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>

ANDROID: net: fib: remove duplicate assignment

Remove duplicate FRA_GOTO assignment.

Fixes: fd2cf795f3ab ("net: core: Support UID-based routing.")
Change-Id: I462c24b16fdef42ae2332571a0b95de3ef9d2e25
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>

FROMLIST: proc: Fix timerslack_ns CAP_SYS_NICE check when adjusting self

In changing from checking ptrace_may_access(p, PTRACE_MODE_ATTACH_FSCREDS)
to capable(CAP_SYS_NICE), I missed that ptrace_my_access succeeds
when p == current, but the CAP_SYS_NICE doesn't.

Thus while the previous commit was intended to loosen the needed
privledges to modify a processes timerslack, it needlessly restricted
a task modifying its own timerslack via the proc/<tid>/timerslack_ns
(which is permitted also via the PR_SET_TIMERSLACK method).

This patch corrects this by checking if p == current before checking
the CAP_SYS_NICE value.

Cc: Kees Cook <keescook@chromium.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
CC: Arjan van de Ven <arjan@linux.intel.com>
Cc: Oren Laadan <orenl@cellrox.com>
Cc: Ruchi Kandoi <kandoiruchi@google.com>
Cc: Rom Lemarchand <romlem@android.com>
Cc: Todd Kjos <tkjos@google.com>
Cc: Colin Cross <ccross@android.com>
Cc: Nick Kralevich <nnk@google.com>
Cc: Dmitry Shmidt <dimitrysh@google.com>
Cc: Elliott Hughes <enh@google.com>
Cc: Android Kernel Team <kernel-team@android.com>
Mailing-list-url: http://www.spinics.net/lists/kernel/msg2317488.html
Change-Id: Ia3e8aff07c2d41f55b6617502d33c39b7d781aac
Signed-off-by: John Stultz <john.stultz@linaro.org>

ANDROID: dm verity fec: pack the fec_header structure

The fec_header structure is generated build time and stored on disk.
The fec_header might be build on a 64 bits machine while it is read
per a 32 bits device or the other way around.  In such situations, the
fec_header fields are not aligned as expected by the device and it
fails to read the fec_header structure.

This patch makes the fec_header packed.

Change-Id: Idb84453e70cc11abd5ef3a0adfbb16f8b5feaf06
Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com>

ANDROID: dm: android-verity: Verify header before fetching table

Move header validation logic before reading the verity_table as
an invalid header implies the table is invalid as well.

(Cherry-picked from:
https://partner-android-review.git.corp.google.com/#/c/625203)

BUG: 29940612
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Change-Id: Ib34d25c0854202f3e70df0a6d0ef1d96f0250c8e

ANDROID: dm: allow adb disable-verity only in userdebug

adb disable-verity was allowed when the phone is in the
unlocked state. Since the driver is now aware of the build
variant, honor "adb disable-verity" only in userdebug
builds.

(Cherry-picked from
https://partner-android-review.git.corp.google.com/#/c/622117)

BUG: 29276559
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Change-Id: I7ce9f38d8c7a62361392c5a8ccebb288f8a3a2ea

ANDROID: dm: mount as linear target if eng build

eng builds dont have verity enabled i.e it does even
have verity metadata appended to the parition. Therefore
add rootdev as linear device and map the entire partition
if build variant is "eng".

(Cherry-picked based on
https://partner-android-review.git.corp.google.com/#/c/618690/)

BUG: 29276559
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Change-Id: I8f5c2289b842b820ca04f5773525e5449bb3f355

ANDROID: dm: use default verity public key

If the dm-android-verity target does not provide a default
key try using the default public key from the system keyring.
The defualt verity keyid is passed as a kernel command line
argument veritykeyid=.

The order of the dm-android-verity params have been reversed
to facilitate the change.

Old format example:
dm="system none ro,0 1 android-verity Android:#7e4333f9bba00adfe0ede979e28ed1920492b40f /dev/mmcblk0p43"

New formats supported:
dm="system none ro,0 1 android-verity /dev/mmcblk0p43 Android:#7e4333f9bba00adfe0ede979e28ed1920492b40f"

(or)

dm="system none ro,0 1 android-verity /dev/mmcblk0p43"
when veritykeyid= is set in the kernel command line.

BUG: 28384658
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Change-Id: I506c89b053d835ab579e703eef2bc1f8487250de
(cherry picked from commit c5c74d0327729f35b576564976885596c6d0e7fb)

ANDROID: dm: fix signature verification flag

The bug was that the signature verification was only
happening when verity was disabled. It should always
happen when verity is enabled.

Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Change-Id: I2d9354e240d36ea06fc68c2d18d8e87b823a4c2f
(cherry picked from commit 5364b5ca0b1a12a58283b51408e43fc36d4e4fe7)

ANDROID: dm: use name_to_dev_t

This patch makes android_verity_ctr() parse its block device string
parameter with name_to_dev_t().  It allows the use of less hardware
related block device reference like PARTUUID for instance.

Change-Id: Idb84453e70cc11abd5ef3a0adfbb16f8b5feaf07
Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com>

ANDROID: dm: rename dm-linear methods for dm-android-verity

This keeps linear_target as static variable and just exposes
the linear target methods for android-verity

Cherry-picked: https://android-review.googlesource.com/#/c/212858

Change-Id: I4a377e417b00afd9ecccdb3e605fea31a7df112e
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
(cherry picked from commit a6d1b091f40b25d97849487e29ec097bc5f568dd)

ANDROID: dm: Minor cleanup

Compacts the linear device arguments removing the
unnecessary variables.

Bug: 27175947
Change-Id: I157170eebe3c0f89a68ae05870a1060f188d0da0
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>

ANDROID: dm: Mounting root as linear device when verity disabled

This CL makes android-verity target to be added as linear
dm device if when bootloader is unlocked and verity is disabled.

Bug: 27175947
Change-Id: Ic41ca4b8908fb2777263799cf3a3e25934d70f18
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>

ANDROID: dm-android-verity: Rebase on top of 4.1

Following CLs in upstream causes minor changes to dm-android-verity target.
1. keys: change asymmetric keys to use common hash definitions
2. block: Abstract out bvec iterator
Rebase dm-android-verity on top of these changes.

Bug: 27175947

Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Change-Id: Icfdc3e7b3ead5de335a059cade1aca70414db415

ANDROID: dm: Add android verity target

This device-mapper target is virtually a VERITY target. This
target is setup by reading the metadata contents piggybacked
to the actual data blocks in the block device. The signature
of the metadata contents are verified against the key included
in the system keyring. Upon success, the underlying verity
target is setup.

BUG: 27175947

Change-Id: I7e99644a0960ac8279f02c0158ed20999510ea97
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>

ANDROID: dm: fix dm_substitute_devices()

When candidate is the last parameter, candidate_end points to the '\0'
character and not the DM_FIELD_SEP character.  In such a situation, we
should not move the candidate_end pointer one character backward.

Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com>

ANDROID: dm: Rebase on top of 4.1

1. "dm: optimize use SRCU and RCU" removes the use of dm_table_put.
2. "dm: remove request-based logic from make_request_fn wrapper" necessitates
    calling dm_setup_md_queue or else the request_queue's make_request_fn
    pointer ends being unset.

[    7.711600] Internal error: Oops - bad mode: 0 [#1] PREEMPT SMP
[    7.717519] CPU: 1 PID: 1 Comm: swapper/0 Tainted: G        W       4.1.15-02273-gb057d16-dirty #33
[    7.726559] Hardware name: HiKey Development Board (DT)
[    7.731779] task: ffffffc005f8acc0 ti: ffffffc005f8c000 task.ti: ffffffc005f8c000
[    7.739257] PC is at 0x0
[    7.741787] LR is at generic_make_request+0x8c/0x108
....
[    9.082931] Call trace:
[    9.085372] [<          (null)>]           (null)
[    9.090074] [<ffffffc0003f4ac0>] submit_bio+0x98/0x1e0
[    9.095212] [<ffffffc0001e2618>] _submit_bh+0x120/0x1f0
[    9.096165] cfg80211: Calling CRDA to update world regulatory domain
[    9.106781] [<ffffffc0001e5450>] __bread_gfp+0x94/0x114
[    9.112004] [<ffffffc00024a748>] ext4_fill_super+0x18c/0x2d64
[    9.117750] [<ffffffc0001b275c>] mount_bdev+0x194/0x1c0
[    9.122973] [<ffffffc0002450dc>] ext4_mount+0x14/0x1c
[    9.128021] [<ffffffc0001b29a0>] mount_fs+0x3c/0x194
[    9.132985] [<ffffffc0001d059c>] vfs_kern_mount+0x4c/0x134
[    9.138467] [<ffffffc0001d2168>] do_mount+0x204/0xbbc
[    9.143514] [<ffffffc0001d2ec4>] SyS_mount+0x94/0xe8
[    9.148479] [<ffffffc000c54074>] mount_block_root+0x120/0x24c
[    9.154222] [<ffffffc000c543e8>] mount_root+0x110/0x12c
[    9.159443] [<ffffffc000c54574>] prepare_namespace+0x170/0x1b8
[    9.165273] [<ffffffc000c53d98>] kernel_init_freeable+0x23c/0x260
[    9.171365] [<ffffffc0009b1748>] kernel_init+0x10/0x118
[    9.176589] Code: bad PC value
[    9.179807] ---[ end trace 75e1bc52ba364d13 ]---

Bug: 27175947

Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Change-Id: I952d86fd1475f0825f9be1386e3497b36127abd0

CHROMIUM: dm: boot time specification of dm=

This is a wrap-up of three patches pending upstream approval.
I'm bundling them because they are interdependent, and it'll be
easier to drop it on rebase later.

1. dm: allow a dm-fs-style device to be shared via dm-ioctl

Integrates feedback from Alisdair, Mike, and Kiyoshi.

Two main changes occur here:

- One function is added which allows for a programmatically created
mapped device to be inserted into the dm-ioctl hash table.  This binds
the device to a name and, optional, uuid which is needed by udev and
allows for userspace management of the mapped device.

- dm_table_complete() was extended to handle all of the final
functional changes required for the table to be operational once
called.

2. init: boot to device-mapper targets without an initr*

Add a dm= kernel parameter modeled after the md= parameter from
do_mounts_md.  It allows for device-mapper targets to be configured at
boot time for use early in the boot process (as the root device or
otherwise).  It also replaces /dev/XXX calls with major:minor opportunistically.

The format is dm="name uuid ro,table line 1,table line 2,...".  The
parser expects the comma to be safe to use as a newline substitute but,
otherwise, uses the normal separator of space.  Some attempt has been
made to make it forgiving of additional spaces (using skip_spaces()).

A mapped device created during boot will be assigned a minor of 0 and
may be access via /dev/dm-0.

An example dm-linear root with no uuid may look like:

root=/dev/dm-0  dm="lroot none ro, 0 4096 linear /dev/ubdb 0, 4096 4096 linear /dv/ubdc 0"

Once udev is started, /dev/dm-0 will become /dev/mapper/lroot.

Older upstream threads:
http://marc.info/?l=dm-devel&m=127429492521964&w=2
http://marc.info/?l=dm-devel&m=127429499422096&w=2
http://marc.info/?l=dm-devel&m=127429493922000&w=2

Latest upstream threads:
https://patchwork.kernel.org/patch/104859/
https://patchwork.kernel.org/patch/104860/
https://patchwork.kernel.org/patch/104861/

Bug: 27175947

Signed-off-by: Will Drewry <wad@chromium.org>
Review URL: http://codereview.chromium.org/2020011

Change-Id: I92bd53432a11241228d2e5ac89a3b20d19b05a31

Implement memory_state_time, used by qcom,cpubw

New driver memory_state_time tracks time spent in different DDR
frequency and bandwidth states.

Memory drivers such as qcom,cpubw can post updated state to the driver
after registering a callback. Processed by a workqueue

Bandwidth buckets are read in from device tree in the relevant qualcomm
section, can be defined in any quantity and spacing.

The data is exposed at /sys/kernel/memory_state_time, able to be read by
the Android framework.

Functionality is behind a config option CONFIG_MEMORY_STATE_TIME

Change-Id: I4fee165571cb975fb9eacbc9aada5e6d7dd748f0
Signed-off-by: James Carr <carrja@google.com>

Revert "panic: Add board ID to panic output"

This reverts commit 4e09c510185cb4db2277ce81cce81b7aa06bea45.

I checked for the usage of this debug helper in AOSP common kernels as
well as vendor kernels (e.g exynos, msm, mediatek, omap, tegra, x86,
x86_64) hosted at https://android.googlesource.com/kernel/ and I found
out that other than few fairly obsolete Omap trees (for tuna & Glass)
and Exynos tree (for Manta), there is no active user of this debug
helper. So we can safely remove this helper code.

Signed-off-by: Amit Pundir <amit.pundir@linaro.org>

usb: gadget: f_accessory: remove duplicate endpoint alloc

usb_ep_autoconfig is called twice for allocating
bulk out endpoint.

Removed the unwanted call.

Fixes Issue: 67180

Change-Id: I03e87a86fbbbc85831ff7f0496adf038d1de2956
Signed-off-by: Anson Jacob <ansonjacob.aj@gmail.com>

BACKPORT: brcmfmac: defer DPC processing during probe

The sdio dpc starts processing when in SDIOD_STATE_DATA. This state was
entered right after firmware download. This patch moves that transition
just before enabling sdio interrupt handling thus avoiding watchdog
expiry which would put the bus to sleep while probing.

Change-Id: I09c60752374b8145da78000935062be08c5c8a52
Reviewed-by: Hante Meuleman <hante.meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Reviewed-by: Franky Lin <franky.lin@broadcom.com>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>

FROMLIST: proc: Add LSM hook checks to /proc/<tid>/timerslack_ns

As requested, this patch checks the existing LSM hooks
task_getscheduler/task_setscheduler when reading or modifying
the task's timerslack value.

Previous versions added new get/settimerslack LSM hooks, but
since they checked the same PROCESS__SET/GETSCHED values as
existing hooks, it was suggested we just use the existing ones.

Cc: Kees Cook <keescook@chromium.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
CC: Arjan van de Ven <arjan@linux.intel.com>
Cc: Oren Laadan <orenl@cellrox.com>
Cc: Ruchi Kandoi <kandoiruchi@google.com>
Cc: Rom Lemarchand <romlem@android.com>
Cc: Todd Kjos <tkjos@google.com>
Cc: Colin Cross <ccross@android.com>
Cc: Nick Kralevich <nnk@google.com>
Cc: Dmitry Shmidt <dimitrysh@google.com>
Cc: Elliott Hughes <enh@google.com>
Cc: James Morris <jmorris@namei.org>
Cc: Android Kernel Team <kernel-team@android.com>
Cc: linux-security-module@vger.kernel.org
Cc: selinux@tycho.nsa.gov
Signed-off-by: John Stultz <john.stultz@linaro.org>
FROMLIST URL: https://lkml.org/lkml/2016/7/21/523
Change-Id: Id157d10e2fe0b85f1be45035a6117358a42af028
(Cherry picked back to common/android-4.4)
Signed-off-by: John Stultz <john.stultz@linaro.org>

FROMLIST: proc: Relax /proc/<tid>/timerslack_ns capability requirements

When an interface to allow a task to change another tasks
timerslack was first proposed, it was suggested that something
greater then CAP_SYS_NICE would be needed, as a task could be
delayed further then what normally could be done with nice
adjustments.

So CAP_SYS_PTRACE was adopted instead for what became the
/proc/<tid>/timerslack_ns interface. However, for Android (where
this feature originates), giving the system_server
CAP_SYS_PTRACE would allow it to observe and modify all tasks
memory. This is considered too high a privilege level for only
needing to change the timerslack.

After some discussion, it was realized that a CAP_SYS_NICE
process can set a task as SCHED_FIFO, so they could fork some
spinning processes and set them all SCHED_FIFO 99, in effect
delaying all other tasks for an infinite amount of time.

So as a CAP_SYS_NICE task can already cause trouble for other
tasks, using it as a required capability for accessing and
modifying /proc/<tid>/timerslack_ns seems sufficient.

Thus, this patch loosens the capability requirements to
CAP_SYS_NICE and removes CAP_SYS_PTRACE, simplifying some
of the code flow as well.

This is technically an ABI change, but as the feature just
landed in 4.6, I suspect no one is yet using it.

Cc: Kees Cook <keescook@chromium.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
CC: Arjan van de Ven <arjan@linux.intel.com>
Cc: Oren Laadan <orenl@cellrox.com>
Cc: Ruchi Kandoi <kandoiruchi@google.com>
Cc: Rom Lemarchand <romlem@android.com>
Cc: Todd Kjos <tkjos@google.com>
Cc: Colin Cross <ccross@android.com>
Cc: Nick Kralevich <nnk@google.com>
Cc: Dmitry Shmidt <dimitrysh@google.com>
Cc: Elliott Hughes <enh@google.com>
Cc: Android Kernel Team <kernel-team@android.com>
Reviewed-by: Nick Kralevich <nnk@google.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
FROMLIST URL: https://lkml.org/lkml/2016/7/21/522
Change-Id: Ia75481402e3948165a1b7c1551c539530cb25509
(Cherry picked against common/android-4.4)
Signed-off-by: John Stultz <john.stultz@linaro.org>

UPSTREAM: ppp: defer netns reference release for ppp channel

(cherry pick from commit 205e1e255c479f3fd77446415706463b282f94e4)

Matt reported that we have a NULL pointer dereference
in ppp_pernet() from ppp_connect_channel(),
i.e. pch->chan_net is NULL.

This is due to that a parallel ppp_unregister_channel()
could happen while we are in ppp_connect_channel(), during
which pch->chan_net set to NULL. Since we need a reference
to net per channel, it makes sense to sync the refcnt
with the life time of the channel, therefore we should
release this reference when we destroy it.

Fixes: 1f461dcdd296 ("ppp: take reference on channels netns")
Reported-by: Matt Bennett <Matt.Bennett@alliedtelesis.co.nz>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linux-ppp@vger.kernel.org
Cc: Guillaume Nault <g.nault@alphalink.fr>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fixes: Change-Id: Iee0015eca5bd181954bb4896a3720f7549c5ed0b ("UPSTREAM:
ppp: take reference on channels netns")
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Change-Id: I24d0bb6f349ab3829f63cfe935ed97b6913a3508

cpuset: Add allow_attach hook for cpusets on android.

This patch provides a allow_attach hook for cpusets,
which resolves lots of the following logcat noise.

W SchedPolicy: add_tid_to_cgroup failed to write '2816' (Permission denied); fd=29
W ActivityManager: Failed setting process group of 2816 to 0
W System.err: java.lang.IllegalArgumentException
W System.err:    at android.os.Process.setProcessGroup(Native Method)
W System.err:    at com.android.server.am.ActivityManagerService.applyOomAdjLocked(ActivityManagerService.java:18763)
W System.err:    at com.android.server.am.ActivityManagerService.updateOomAdjLocked(ActivityManagerService.java:19028)
W System.err:    at com.android.server.am.ActivityManagerService.updateOomAdjLocked(ActivityManagerService.java:19106)
W System.err:    at com.android.server.am.ActiveServices.serviceDoneExecutingLocked(ActiveServices.java:2015)
W System.err:    at com.android.server.am.ActiveServices.publishServiceLocked(ActiveServices.java:905)
W System.err:    at com.android.server.am.ActivityManagerService.publishService(ActivityManagerService.java:16065)
W System.err:    at android.app.ActivityManagerNative.onTransact(ActivityManagerNative.java:1007)
W System.err:    at com.android.server.am.ActivityManagerService.onTransact(ActivityManagerService.java:2493)
W System.err:    at android.os.Binder.execTransact(Binder.java:453)

Change-Id: Ic1b61b2bbb7ce74c9e9422b5e22ee9078251de21
[Ported to 4.4, added commit message]
Signed-off-by: John Stultz <john.stultz@linaro.org>

UPSTREAM: KEYS: Fix ASN.1 indefinite length object parsing

(cherry pick from commit 23c8a812dc3c621009e4f0e5342aa4e2ede1ceaa)

This fixes CVE-2016-0758.

In the ASN.1 decoder, when the length field of an ASN.1 value is extracted,
it isn't validated against the remaining amount of data before being added
to the cursor.  With a sufficiently large size indicated, the check:

datalen - dp < 2

may then fail due to integer overflow.

Fix this by checking the length indicated against the amount of remaining
data in both places a definite length is determined.

Whilst we're at it, make the following changes:

 (1) Check the maximum size of extended length does not exceed the capacity
     of the variable it's being stored in (len) rather than the type that
     variable is assumed to be (size_t).

 (2) Compare the EOC tag to the symbolic constant ASN1_EOC rather than the
     integer 0.

 (3) To reduce confusion, move the initialisation of len outside of:

for (len = 0; n > 0; n--) {

     since it doesn't have anything to do with the loop counter n.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: David Woodhouse <David.Woodhouse@intel.com>
Acked-by: Peter Jones <pjones@redhat.com>
Change-Id: If760bc3b8ab0e59fefc24fa687514324348fb8e8
Bug: 29814470

ANDROID: sdcardfs: fix itnull.cocci warnings

List_for_each_entry has the property that the first argument is always
bound to a real list element, never NULL, so testing dentry is not needed.

Generated by: scripts/coccinelle/iterators/itnull.cocci

Cc: Daniel Rosenberg <drosen@google.com>
Signed-off-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Guenter Roeck <groeck@chromium.org>

android-recommended.cfg: enable fstack-protector-strong

If compiler has stack protector support, set
CONFIG_CC_STACKPROTECTOR_STRONG.

Bug: 28967314
Change-Id: I588c2d544250e9e4b5082b43c237b8f85b7313ca
Signed-off-by: Jeff Vander Stoep <jeffv@google.com>

Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android

 Merge tag 'v4.4.18' into linux-linaro-lsk-v4.4

 This is the 4.4.18 stable release

Linux 4.4.18

mm: memcontrol: fix memcg id ref counter on swap charge move

commit 615d66c37c755c49ce022c9e5ac0875d27d2603d upstream.

Since commit 73f576c04b94 ("mm: memcontrol: fix cgroup creation failure
after many small jobs") swap entries do not pin memcg->css.refcnt
directly.  Instead, they pin memcg->id.ref.  So we should adjust the
reference counters accordingly when moving swap charges between cgroups.

Fixes: 73f576c04b941 ("mm: memcontrol: fix cgroup creation failure after many small jobs")
Link: http://lkml.kernel.org/r/9ce297c64954a42dc90b543bc76106c4a94f07e8.1470219853.git.vdavydov@virtuozzo.com
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mm: memcontrol: fix swap counter leak on swapout from offline cgroup

commit 1f47b61fb4077936465dcde872a4e5cc4fe708da upstream.

An offline memory cgroup might have anonymous memory or shmem left
charged to it and no swap.  Since only swap entries pin the id of an
offline cgroup, such a cgroup will have no id and so an attempt to
swapout its anon/shmem will not store memory cgroup info in the swap
cgroup map.  As a result, memcg->swap or memcg->memsw will never get
uncharged from it and any of its ascendants.

Fix this by always charging swapout to the first ancestor cgroup that
hasn't released its id yet.

[hannes@cmpxchg.org: add comment to mem_cgroup_swapout]
[vdavydov@virtuozzo.com: use WARN_ON_ONCE() in mem_cgroup_id_get_online()]
Link: http://lkml.kernel.org/r/20160803123445.GJ13263@esperanza
Fixes: 73f576c04b941 ("mm: memcontrol: fix cgroup creation failure after many small jobs")
Link: http://lkml.kernel.org/r/5336daa5c9a32e776067773d9da655d2dc126491.1470219853.git.vdavydov@virtuozzo.com
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org> [3.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mm: memcontrol: fix cgroup creation failure after many small jobs

commit 73f576c04b9410ed19660f74f97521bee6e1c546 upstream.

The memory controller has quite a bit of state that usually outlives the
cgroup and pins its CSS until said state disappears.  At the same time
it imposes a 16-bit limit on the CSS ID space to economically store IDs
in the wild.  Consequently, when we use cgroups to contain frequent but
small and short-lived jobs that leave behind some page cache, we quickly
run into the 64k limitations of outstanding CSSs.  Creating a new cgroup
fails with -ENOSPC while there are only a few, or even no user-visible
cgroups in existence.

Although pinning CSSs past cgroup removal is common, there are only two
instances that actually need an ID after a cgroup is deleted: cache
shadow entries and swapout records.

Cache shadow entries reference the ID weakly and can deal with the CSS
having disappeared when it's looked up later.  They pose no hurdle.

Swap-out records do need to pin the css to hierarchically attribute
swapins after the cgroup has been deleted; though the only pages that
remain swapped out after offlining are tmpfs/shmem pages.  And those
references are under the user's control, so they are manageable.

This patch introduces a private 16-bit memcg ID and switches swap and
cache shadow entries over to using that.  This ID can then be recycled
after offlining when the CSS remains pinned only by objects that don't
specifically need it.

This script demonstrates the problem by faulting one cache page in a new
cgroup and deleting it again:

  set -e
  mkdir -p pages
  for x in `seq 128000`; do
    [ $((x % 1000)) -eq 0 ] && echo $x
    mkdir /cgroup/foo
    echo $$ >/cgroup/foo/cgroup.procs
    echo trex >pages/$x
    echo $$ >/cgroup/cgroup.procs
    rmdir /cgroup/foo
  done

When run on an unpatched kernel, we eventually run out of possible IDs
even though there are no visible cgroups:

  [root@ham ~]# ./cssidstress.sh
  [...]
  65000
  mkdir: cannot create directory '/cgroup/foo': No space left on device

After this patch, the IDs get released upon cgroup destruction and the
cache and css objects get released once memory reclaim kicks in.

[hannes@cmpxchg.org: init the IDR]
Link: http://lkml.kernel.org/r/20160621154601.GA22431@cmpxchg.org
Fixes: b2052564e66d ("mm: memcontrol: continue cache reclaim from offlined groups")
Link: http://lkml.kernel.org/r/20160617162516.GD19084@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: John Garcia <john.garcia@mesosphere.io>
Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ext4: fix reference counting bug on block allocation error

commit 554a5ccc4e4a20c5f3ec859de0842db4b4b9c77e upstream.

If we hit this error when mounted with errors=continue or
errors=remount-ro:

    EXT4-fs error (device loop0): ext4_mb_mark_diskspace_used:2940: comm ext4.exe: Allocating blocks 5090-6081 which overlap fs metadata

then ext4_mb_new_blocks() will call ext4_mb_release_context() and try to
continue. However, ext4_mb_release_context() is the wrong thing to call
here since we are still actually using the allocation context.

Instead, just error out. We could retry the allocation, but there is a
possibility of getting stuck in an infinite loop instead, so this seems
safer.

[ Fixed up so we don't return EAGAIN to userspace. --tytso ]

Fixes: 8556e8f3b6 ("ext4: Don't allow new groups to be added during block allocation")
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ext4: short-cut orphan cleanup on error

commit c65d5c6c81a1f27dec5f627f67840726fcd146de upstream.

If we encounter a filesystem error during orphan cleanup, we should stop.
Otherwise, we may end up in an infinite loop where the same inode is
processed again and again.

    EXT4-fs (loop0): warning: checktime reached, running e2fsck is recommended
    EXT4-fs error (device loop0): ext4_mb_generate_buddy:758: group 2, block bitmap and bg descriptor inconsistent: 6117 vs 0 free clusters
    Aborting journal on device loop0-8.
    EXT4-fs (loop0): Remounting filesystem read-only
    EXT4-fs error (device loop0) in ext4_free_blocks:4895: Journal has aborted
    EXT4-fs error (device loop0) in ext4_do_update_inode:4893: Journal has aborted
    EXT4-fs error (device loop0) in ext4_do_update_inode:4893: Journal has aborted
    EXT4-fs error (device loop0) in ext4_ext_remove_space:3068: IO failure
    EXT4-fs error (device loop0) in ext4_ext_truncate:4667: Journal has aborted
    EXT4-fs error (device loop0) in ext4_orphan_del:2927: Journal has aborted
    EXT4-fs error (device loop0) in ext4_do_update_inode:4893: Journal has aborted
    EXT4-fs (loop0): Inode 16 (00000000618192a0): orphan list check failed!
    [...]
    EXT4-fs (loop0): Inode 16 (0000000061819748): orphan list check failed!
    [...]
    EXT4-fs (loop0): Inode 16 (0000000061819bf0): orphan list check failed!
    [...]

See-also: c9eb13a9105 ("ext4: fix hang when processing corrupted orphaned inode list")
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ext4: validate s_reserved_gdt_blocks on mount

commit 5b9554dc5bf008ae7f68a52e3d7e76c0920938a2 upstream.

If s_reserved_gdt_blocks is extremely large, it's possible for
ext4_init_block_bitmap(), which is called when ext4 sets up an
uninitialized block bitmap, to corrupt random kernel memory.  Add the
same checks which e2fsck has --- it must never be larger than
blocksize / sizeof(__u32) --- and then add a backup check in
ext4_init_block_bitmap() in case the superblock gets modified after
the file system is mounted.

Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ext4: don't call ext4_should_journal_data() on the journal inode

commit 6a7fd522a7c94cdef0a3b08acf8e6702056e635c upstream.

If ext4_fill_super() fails early, it's possible for ext4_evict_inode()
to call ext4_should_journal_data() before superblock options and flags
are fully set up.  In that case, the iput() on the journal inode can
end up causing a BUG().

Work around this problem by reordering the tests so we only call
ext4_should_journal_data() after we know it's not the journal inode.

Fixes: 2d859db3e4 ("ext4: fix data corruption in inodes with journalled data")
Fixes: 2b405bfa84 ("ext4: fix data=journal fast mount/umount hang")
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ext4: fix deadlock during page writeback

commit 646caa9c8e196880b41cd3e3d33a2ebc752bdb85 upstream.

Commit 06bd3c36a733 (ext4: fix data exposure after a crash) uncovered a
deadlock in ext4_writepages() which was previously much harder to hit.
After this commit xfstest generic/130 reproduces the deadlock on small
filesystems.

The problem happens when ext4_do_update_inode() sets LARGE_FILE feature
and marks current inode handle as synchronous. That subsequently results
in ext4_journal_stop() called from ext4_writepages() to block waiting for
transaction commit while still holding page locks, reference to io_end,
and some prepared bio in mpd structure each of which can possibly block
transaction commit from completing and thus results in deadlock.

Fix the problem by releasing page locks, io_end reference, and
submitting prepared bio before calling ext4_journal_stop().

[ Changed to defer the call to ext4_journal_stop() only if the handle
  is synchronous.  --tytso ]

Reported-and-tested-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ext4: check for extents that wrap around

commit f70749ca42943faa4d4dcce46dfdcaadb1d0c4b6 upstream.

An extent with lblock = 4294967295 and len = 1 will pass the
ext4_valid_extent() test:

ext4_lblk_t last = lblock + len - 1;

if (len == 0 || lblock > last)
return 0;

since last = 4294967295 + 1 - 1 = 4294967295. This would later trigger
the BUG_ON(es->es_lblk + es->es_len < es->es_lblk) in ext4_es_end().

We can simplify it by removing the - 1 altogether and changing the test
to use lblock + len <= lblock, since now if len = 0, then lblock + 0 ==
lblock and it fails, and if len > 0 then lblock + len > lblock in order
to pass (i.e. it doesn't overflow).

Fixes: 5946d0893 ("ext4: check for overlapping extents in ext4_valid_extent_entries()")
Fixes: 2f974865f ("ext4: check for zero length extent explicitly")
Cc: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Phil Turnbull <phil.turnbull@oracle.com>
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

crypto: scatterwalk - Fix test in scatterwalk_done

commit 5f070e81bee35f1b7bd1477bb223a873ff657803 upstream.

When there is more data to be processed, the current test in
scatterwalk_done may prevent us from calling pagedone even when
we should.

In particular, if we're on an SG entry spanning multiple pages
where the last page is not a full page, we will incorrectly skip
calling pagedone on the second last page.

This patch fixes this by adding a separate test for whether we've
reached the end of a page.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

crypto: gcm - Filter out async ghash if necessary

commit b30bdfa86431afbafe15284a3ad5ac19b49b88e3 upstream.

As it is if you ask for a sync gcm you may actually end up with
an async one because it does not filter out async implementations
of ghash.

This patch fixes this by adding the necessary filter when looking
for ghash.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/dcache.c: avoid soft-lockup in dput()

commit 47be61845c775643f1aa4d2a54343549f943c94c upstream.

We triggered soft-lockup under stress test which
open/access/write/close one file concurrently on more than
five different CPUs:

WARN: soft lockup - CPU#0 stuck for 11s! [who:30631]
...
[<ffffffc0003986f8>] dput+0x100/0x298
[<ffffffc00038c2dc>] terminate_walk+0x4c/0x60
[<ffffffc00038f56c>] path_lookupat+0x5cc/0x7a8
[<ffffffc00038f780>] filename_lookup+0x38/0xf0
[<ffffffc000391180>] user_path_at_empty+0x78/0xd0
[<ffffffc0003911f4>] user_path_at+0x1c/0x28
[<ffffffc00037d4fc>] SyS_faccessat+0xb4/0x230

->d_lock trylock may failed many times because of concurrently
operations, and dput() may execute a long time.

Fix this by replacing cpu_relax() with cond_resched().
dput() used to be sleepable, so make it sleepable again
should be safe.

Signed-off-by: Wei Fang <fangwei1@huawei.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fuse: fix wrong assignment of ->flags in fuse_send_init()

commit 9446385f05c9af25fed53dbed3cc75763730be52 upstream.

FUSE_HAS_IOCTL_DIR should be assigned to ->flags, it may be a typo.

Signed-off-by: Wei Fang <fangwei1@huawei.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 69fe05c90ed5 ("fuse: add missing INIT flags")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fuse: fuse_flush must check mapping->flags for errors

commit 9ebce595f63a407c5cec98f98f9da8459b73740a upstream.

fuse_flush() calls write_inode_now() that triggers writeback, but actual
writeback will happen later, on fuse_sync_writes(). If an error happens,
fuse_writepage_end() will set error bit in mapping->flags. So, we have to
check mapping->flags after fuse_sync_writes().

Signed-off-by: Maxim Patlasov <mpatlasov@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 4d99ff8f12eb ("fuse: Turn writeback cache on")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fuse: fsync() did not return IO errors

commit ac7f052b9e1534c8248f814b6f0068ad8d4a06d2 upstream.

Due to implementation of fuse writeback filemap_write_and_wait_range() does
not catch errors. We have to do this directly after fuse_sync_writes()

Signed-off-by: Alexey Kuznetsov <kuznet@virtuozzo.com>
Signed-off-by: Maxim Patlasov <mpatlasov@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 4d99ff8f12eb ("fuse: Turn writeback cache on")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

sysv, ipc: fix security-layer leaking

commit 9b24fef9f0410fb5364245d6cc2bd044cc064007 upstream.

Commit 53dad6d3a8e5 ("ipc: fix race with LSMs") updated ipc_rcu_putref()
to receive rcu freeing function but used generic ipc_rcu_free() instead
of msg_rcu_free() which does security cleaning.

Running LTP msgsnd06 with kmemleak gives the following:

  cat /sys/kernel/debug/kmemleak

  unreferenced object 0xffff88003c0a11f8 (size 8):
    comm "msgsnd06", pid 1645, jiffies 4294672526 (age 6.549s)
    hex dump (first 8 bytes):
      1b 00 00 00 01 00 00 00                          ........
    backtrace:
      kmemleak_alloc+0x23/0x40
      kmem_cache_alloc_trace+0xe1/0x180
      selinux_msg_queue_alloc_security+0x3f/0xd0
      security_msg_queue_alloc+0x2e/0x40
      newque+0x4e/0x150
      ipcget+0x159/0x1b0
      SyS_msgget+0x39/0x40
      entry_SYSCALL_64_fastpath+0x13/0x8f

Manfred Spraul suggested to fix sem.c as well and Davidlohr Bueso to
only use ipc_rcu_free in case of security allocation failure in newary()

Fixes: 53dad6d3a8e ("ipc: fix race with LSMs")
Link: http://lkml.kernel.org/r/1470083552-22966-1-git-send-email-fabf@skynet.be
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

block: fix use-after-free in seq file

commit 77da160530dd1dc94f6ae15a981f24e5f0021e84 upstream.

I got a KASAN report of use-after-free:

    ==================================================================
    BUG: KASAN: use-after-free in klist_iter_exit+0x61/0x70 at addr ffff8800b6581508
    Read of size 8 by task trinity-c1/315
    =============================================================================
    BUG kmalloc-32 (Not tainted): kasan: bad access detected
    -----------------------------------------------------------------------------

    Disabling lock debugging due to kernel taint
    INFO: Allocated in disk_seqf_start+0x66/0x110 age=144 cpu=1 pid=315
            ___slab_alloc+0x4f1/0x520
            __slab_alloc.isra.58+0x56/0x80
            kmem_cache_alloc_trace+0x260/0x2a0
            disk_seqf_start+0x66/0x110
            traverse+0x176/0x860
            seq_read+0x7e3/0x11a0
            proc_reg_read+0xbc/0x180
            do_loop_readv_writev+0x134/0x210
            do_readv_writev+0x565/0x660
            vfs_readv+0x67/0xa0
            do_preadv+0x126/0x170
            SyS_preadv+0xc/0x10
            do_syscall_64+0x1a1/0x460
            return_from_SYSCALL_64+0x0/0x6a
    INFO: Freed in disk_seqf_stop+0x42/0x50 age=160 cpu=1 pid=315
            __slab_free+0x17a/0x2c0
            kfree+0x20a/0x220
            disk_seqf_stop+0x42/0x50
            traverse+0x3b5/0x860
            seq_read+0x7e3/0x11a0
            proc_reg_read+0xbc/0x180
            do_loop_readv_writev+0x134/0x210
            do_readv_writev+0x565/0x660
            vfs_readv+0x67/0xa0
            do_preadv+0x126/0x170
            SyS_preadv+0xc/0x10
            do_syscall_64+0x1a1/0x460
            return_from_SYSCALL_64+0x0/0x6a

    CPU: 1 PID: 315 Comm: trinity-c1 Tainted: G    B           4.7.0+ #62
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
     ffffea0002d96000 ffff880119b9f918 ffffffff81d6ce81 ffff88011a804480
     ffff8800b6581500 ffff880119b9f948 ffffffff8146c7bd ffff88011a804480
     ffffea0002d96000 ffff8800b6581500 fffffffffffffff4 ffff880119b9f970
    Call Trace:
     [<ffffffff81d6ce81>] dump_stack+0x65/0x84
     [<ffffffff8146c7bd>] print_trailer+0x10d/0x1a0
     [<ffffffff814704ff>] object_err+0x2f/0x40
     [<ffffffff814754d1>] kasan_report_error+0x221/0x520
     [<ffffffff8147590e>] __asan_report_load8_noabort+0x3e/0x40
     [<ffffffff83888161>] klist_iter_exit+0x61/0x70
     [<ffffffff82404389>] class_dev_iter_exit+0x9/0x10
     [<ffffffff81d2e8ea>] disk_seqf_stop+0x3a/0x50
     [<ffffffff8151f812>] seq_read+0x4b2/0x11a0
     [<ffffffff815f8fdc>] proc_reg_read+0xbc/0x180
     [<ffffffff814b24e4>] do_loop_readv_writev+0x134/0x210
     [<ffffffff814b4c45>] do_readv_writev+0x565/0x660
     [<ffffffff814b8a17>] vfs_readv+0x67/0xa0
     [<ffffffff814b8de6>] do_preadv+0x126/0x170
     [<ffffffff814b92ec>] SyS_preadv+0xc/0x10

This problem can occur in the following situation:

open()
 - pread()
    - .seq_start()
       - iter = kmalloc() // succeeds
       - seqf->private = iter
    - .seq_stop()
       - kfree(seqf->private)
 - pread()
    - .seq_start()
       - iter = kmalloc() // fails
    - .seq_stop()
       - class_dev_iter_exit(seqf->private) // boom! old pointer

As the comment in disk_seqf_stop() says, stop is called even if start
failed, so we need to reinitialise the private pointer to NULL when seq
iteration stops.

An alternative would be to set the private pointer to NULL when the
kmalloc() in disk_seqf_start() fails.

Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

x86/syscalls/64: Add compat_sys_keyctl for 32-bit userspace

commit f7d665627e103e82d34306c7d3f6f46f387c0d8b upstream.

x86_64 needs to use compat_sys_keyctl for 32-bit userspace rather than
calling sys_keyctl(). The latter will work in a lot of cases, thereby
hiding the issue.

Reported-by: Stephan Mueller <smueller@chronox.de>
Tested-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: keyrings@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Link: http://lkml.kernel.org/r/146961615805.14395.5581949237156769439.stgit@warthog.procyon.org.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drm/i915: Pretend cursor is always on for ILK-style WM calculations (v2)

commit e2e407dc093f530b771ee8bf8fe1be41e3cea8b3 upstream.

Due to our lack of two-step watermark programming, our driver has
historically pretended that the cursor plane is always on for the
purpose of watermark calculations; this helps avoid serious flickering
when the cursor turns off/on (e.g., when the user moves the mouse
pointer to a different screen).  That workaround was accidentally
dropped as we started working toward atomic watermark updates.  Since we
still aren't quite there yet with two-stage updates, we need to
resurrect the workaround and treat the cursor as always active.

v2: Tweak cursor width calculations slightly to more closely match the
    logic we used before the atomic overhaul began.  (Ville)

Cc: simdev11@outlook.com
Cc: manfred.kitzbichler@gmail.com
Cc: drm-intel-fixes@lists.freedesktop.org
Reported-by: simdev11@outlook.com
Reported-by: manfred.kitzbichler@gmail.com
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93892
Fixes: 43d59eda1 ("drm/i915: Eliminate usage of plane_wm_parameters from ILK-style WM code (v2)")
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1454479611-6804-1-git-send-email-matthew.d.roper@intel.com
(cherry picked from commit b2435692dbb709d4c8ff3b2f2815c9b8423b72bb)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1454958328-30129-1-git-send-email-matthew.d.roper@intel.com
Tested-by: Jay <mymailclone@t-online.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

x86/mm/pat: Fix BUG_ON() in mmap_mem() on QEMU/i386

commit 1886297ce0c8d563a08c8a8c4c0b97743e06cd37 upstream.

The following BUG_ON() crash was reported on QEMU/i386:

  kernel BUG at arch/x86/mm/physaddr.c:79!
  Call Trace:
  phys_mem_access_prot_allowed
  mmap_mem
  ? mmap_region
  mmap_region
  do_mmap
  vm_mmap_pgoff
  SyS_mmap_pgoff
  do_int80_syscall_32
  entry_INT80_32

after commit:

  edfe63ec97ed ("x86/mtrr: Fix Xorg crashes in Qemu sessions")

PAT is now set to disabled state when MTRRs are disabled.
Thus, reactivating the __pa(high_memory) check in
phys_mem_access_prot_allowed().

When CONFIG_DEBUG_VIRTUAL is set, __pa() calls __phys_addr(),
which in turn calls slow_virt_to_phys() for 'high_memory'.
Because 'high_memory' is set to (the max direct mapped virt
addr + 1), it is not a valid virtual address.  Hence,
slow_virt_to_phys() returns 0 and hit the BUG_ON.  Using
__pa_nodebug() instead of __pa() will fix this BUG_ON.

However, this code block, originally written for Pentiums and
earlier, is no longer adequate since a 32-bit Xen guest has
MTRRs disabled and supports ZONE_HIGHMEM.  In this setup,
this code sets UC attribute for accessing RAM in high memory
range.

Delete this code block as it has been unused for a long time.

Reported-by: kernel test robot <ying.huang@linux.intel.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1460403360-25441-1-git-send-email-toshi.kani@hpe.com
Link: https://lkml.org/lkml/2016/4/1/608
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

x86/pat: Document the PAT initialization sequence

commit b6350c21cfe8aa9d65e189509a23c0ea4b8362c2 upstream.

Update PAT documentation to describe how PAT is initialized under
various configurations.

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: elliott@hpe.com
Cc: konrad.wilk@oracle.com
Cc: paul.gortmaker@windriver.com
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1458769323-24491-8-git-send-email-toshi.kani@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

x86/xen, pat: Remove PAT table init code from Xen

commit 88ba281108ed0c25c9d292b48bd3f272fcb90dd0 upstream.

Xen supports PAT without MTRRs for its guests.  In order to
enable WC attribute, it was necessary for xen_start_kernel()
to call pat_init_cache_modes() to update PAT table before
starting guest kernel.

Now that the kernel initializes PAT table to the BIOS handoff
state when MTRR is disabled, this Xen-specific PAT init code
is no longer necessary.  Delete it from xen_start_kernel().

Also change __init_cache_modes() to a static function since
PAT table should not be tweaked by other modules.

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Juergen Gross <jgross@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: elliott@hpe.com
Cc: paul.gortmaker@windriver.com
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1458769323-24491-7-git-send-email-toshi.kani@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

x86/mtrr: Fix PAT init handling when MTRR is disabled

commit ad025a73f0e9344ac73ffe1b74c184033e08e7d5 upstream.

get_mtrr_state() calls pat_init() on BSP even if MTRR is disabled.
This results in calling pat_init() on BSP only since APs do not call
pat_init() when MTRR is disabled.  This inconsistency between BSP
and APs leads to undefined behavior.

Make BSP's calling condition to pat_init() consistent with AP's,
mtrr_ap_init() and mtrr_aps_init().

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: elliott@hpe.com
Cc: konrad.wilk@oracle.com
Cc: paul.gortmaker@windriver.com
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1458769323-24491-6-git-send-email-toshi.kani@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

x86/mtrr: Fix Xorg crashes in Qemu sessions

commit edfe63ec97ed8d4496225f7ba54c9ce4207c5431 upstream.

A Xorg failure on qemu32 was reported as a regression [1] caused by
commit 9cd25aac1f44 ("x86/mm/pat: Emulate PAT when it is disabled").

This patch fixes the Xorg crash.

Negative effects of this regression were the following two failures [2]
in Xorg on QEMU with QEMU CPU model "qemu32" (-cpu qemu32), which were
triggered by the fact that its virtual CPU does not support MTRRs.

 #1. copy_process() failed in the check in reserve_pfn_range()

    copy_process
     copy_mm
      dup_mm
       dup_mmap
        copy_page_range
         track_pfn_copy
          reserve_pfn_range

 A WC map request was tracked as WC in memtype, which set a PTE as
 UC (pgprot) per __cachemode2pte_tbl[].  This led to this error in
 reserve_pfn_range() called from track_pfn_copy(), which obtained
 a pgprot from a PTE.  It converts pgprot to page_cache_mode, which
 does not necessarily result in the original page_cache_mode since
 __cachemode2pte_tbl[] redirects multiple types to UC.

 #2. error path in copy_process() then hit WARN_ON_ONCE in
     untrack_pfn().

     x86/PAT: Xorg:509 map pfn expected mapping type uncached-
     minus for [mem 0xfd000000-0xfdffffff], got write-combining
      Call Trace:
     dump_stack
     warn_slowpath_common
     ? untrack_pfn
     ? untrack_pfn
     warn_slowpath_null
     untrack_pfn
     ? __kunmap_atomic
     unmap_single_vma
     ? pagevec_move_tail_fn
     unmap_vmas
     exit_mmap
     mmput
     copy_process.part.47
     _do_fork
     SyS_clone
     do_syscall_32_irqs_on
     entry_INT80_32

These negative effects are caused by two separate bugs, but they
can be addressed in separate patches.  Fixing the pat_init() issue
described below addresses the root cause, and avoids Xorg to hit
these cases.

When the CPU does not support MTRRs, MTRR does not call pat_init(),
which leaves PAT enabled without initializing PAT.  This pat_init()
issue is a long-standing issue, but manifested as issue #1 (and then
hit issue #2) with the above-mentioned commit because the memtype
now tracks cache attribute with 'page_cache_mode'.

This pat_init() issue existed before the commit, but we used pgprot
in memtype.  Hence, we did not have issue #1 before.  But WC request
resulted in WT in effect because WC pgrot is actually WT when PAT
is not initialized.  This is not how it was designed to work.  When
PAT is set to disable properly, WC is converted to UC.  The use of
WT can result in a system crash if the target range does not support
WT.  Fortunately, nobody ran into such issue before.

To fix this pat_init() issue, PAT code has been enhanced to provide
pat_disable() interface.  Call this interface when MTRRs are disabled.
By setting PAT to disable properly, PAT bypasses the memtype check,
and avoids issue #1.

  [1]: https://lkml.org/lkml/2016/3/3/828
  [2]: https://lkml.org/lkml/2016/3/4/775

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: elliott@hpe.com
Cc: konrad.wilk@oracle.com
Cc: paul.gortmaker@windriver.com
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1458769323-24491-5-git-send-email-toshi.kani@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>