futex: Take hugepages into account when generating futex_key

commit 13d60f4b6ab5b702dc8d2ee20999f98a93728aec upstream.

The futex_keys of process shared futexes are generated from the page
offset, the mapping host and the mapping index of the futex user space
address. This should result in an unique identifier for each futex.

Though this is not true when futexes are located in different subpages
of an hugepage. The reason is, that the mapping index for all those
futexes evaluates to the index of the base page of the hugetlbfs
mapping. So a futex at offset 0 of the hugepage mapping and another
one at offset PAGE_SIZE of the same hugepage mapping have identical
futex_keys. This happens because the futex code blindly uses
page->index.

Steps to reproduce the bug:

1. Map a file from hugetlbfs. Initialize pthread_mutex1 at offset 0
   and pthread_mutex2 at offset PAGE_SIZE of the hugetlbfs
   mapping.

   The mutexes must be initialized as PTHREAD_PROCESS_SHARED because
   PTHREAD_PROCESS_PRIVATE mutexes are not affected by this issue as
   their keys solely depend on the user space address.

2. Lock mutex1 and mutex2

3. Create thread1 and in the thread function lock mutex1, which
   results in thread1 blocking on the locked mutex1.

4. Create thread2 and in the thread function lock mutex2, which
   results in thread2 blocking on the locked mutex2.

5. Unlock mutex2. Despite the fact that mutex2 got unlocked, thread2
   still blocks on mutex2 because the futex_key points to mutex1.

To solve this issue we need to take the normal page index of the page
which contains the futex into account, if the futex is in an hugetlbfs
mapping. In other words, we calculate the normal page mapping index of
the subpage in the hugetlbfs mapping.

Mappings which are not based on hugetlbfs are not affected and still
use page->index.

Thanks to Mel Gorman who provided a patch for adding proper evaluation
functions to the hugetlbfs code to avoid exposing hugetlbfs specific
details to the futex code.

[ tglx: Massaged changelog ]

Signed-off-by: Zhang Yi <zhang.yi20@zte.com.cn>
Reviewed-by: Jiang Biao <jiang.biao2@zte.com.cn>
Tested-by: Ma Chenggong <ma.chenggong@zte.com.cn>
Reviewed-by: 'Mel Gorman' <mgorman@suse.de>
Acked-by: 'Darren Hart' <dvhart@linux.intel.com>
Cc: 'Peter Zijlstra' <peterz@infradead.org>
Link: http://lkml.kernel.org/r/000101ce71a6%24a83c5880%24f8b50980%24@com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Mike Galbraith <mgalbraith@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CRIS: Add _sdata to vmlinux.lds.S

commit 473e162eea465e60578edb93341752e7f1c1dacc upstream.

Fixes link error:
  LD      vmlinux
kernel/built-in.o: In function `core_kernel_data':
(.text+0x13e44): undefined reference to `_sdata'

Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
af_key: initialize satype in key_notify_policy_flush()

commit 85dfb745ee40232876663ae206cba35f24ab2a40 upstream.

This field was left uninitialized. Some user daemons perform check against this
field.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Luis Henriques <luis.henriques@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
genetlink: fix family dump race

commit 58ad436fcf49810aa006016107f494c9ac9013db upstream.

When dumping generic netlink families, only the first dump call
is locked with genl_lock(), which protects the list of families,
and thus subsequent calls can access the data without locking,
racing against family addition/removal. This can cause a crash.
Fix it - the locking needs to be conditional because the first
time around it's already locked.

A similar bug was reported to me on an old kernel (3.4.47) but
the exact scenario that happened there is no longer possible,
on those kernels the first round wasn't locked either. Looking
at the current code I found the race described above, which had
also existed on the old kernel.

Reported-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: add two quirky touchscreen

commit 304ab4ab079a8ed03ce39f1d274964a532db036b upstream.

These devices tend to become unresponsive after S3

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: mos7720: fix broken control requests

commit ef6c8c1d733e244f0499035be0dabe1f4ed98c6f upstream.

The parallel-port code of the drivers used a stack allocated
control-request buffer for asynchronous (and possibly deferred) control
requests. This not only violates the no-DMA-from-stack requirement but
could also lead to corrupt control requests being submitted.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sparc32: add ucmpdi2

commit de36e66d5fa52bc6e2dacd95c701a1762b5308a7 upstream.

Based on copy from microblaze add ucmpdi2 implementation.
This fixes build of niu driver which failed with:

drivers/built-in.o: In function `niu_get_nfc':
niu.c:(.text+0x91494): undefined reference to `__ucmpdi2'

This driver will never be used on a sparc32 system,
but patch added to fix build breakage with all*config builds.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sparc32: Add ucmpdi2.o to obj-y instead of lib-y.

commit 74c7b28953d4eaa6a479c187aeafcfc0280da5e8 upstream.

Otherwise if no references exist in the static kernel image,
we won't export the symbol properly to modules.

Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
powerpc: Use -mtraceback=no

commit af9719c3062dfe216a0c3de3fa52be6d22b4456c upstream.

gcc 4.7 will be more strict about parsing the -mtraceback option:

 gcc: error: unrecognized argument in option '-mtraceback=none'
 gcc: note: valid arguments to '-mtraceback=' are: full no part

gcc used to do a 2 char compare so both "no" and "none" would
match. Switch to using -mtraceback=no should work everywhere.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
m68k/atari: ARAnyM - Fix NatFeat module support

commit e8184e10f89736a23ea6eea8e24cd524c5c513d2 upstream.

As pointed out by Andreas Schwab, pointers passed to ARAnyM NatFeat calls
should be physical addresses, not virtual addresses.

Fortunately on Atari, physical and virtual kernel addresses are the same,
as long as normal kernel memory is concerned, so this usually worked fine
without conversion.

But for modules, pointers to literal strings are located in vmalloc()ed
memory. Depending on the version of ARAnyM, this causes the nf_get_id()
call to just fail, or worse, crash ARAnyM itself with e.g.

    Gotcha! Illegal memory access. Atari PC = $968c

This is a big issue for distro kernels, who want to have all drivers as
loadable modules in an initrd.

Add a wrapper for nf_get_id() that copies the literal to the stack to
work around this issue.

Reported-by: Thorsten Glaser <tg@debian.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vm: add no-mmu vm_iomap_memory() stub

commit 3c0b9de6d37a481673e81001c57ca0e410c72346 upstream.

I think we could just move the full vm_iomap_memory() function into
util.h or similar, but I didn't get any reply from anybody actually
using nommu even to this trivial patch, so I'm not going to touch it any
more than required.

Here's the fairly minimal stub to make the nommu case at least
potentially work.  It doesn't seem like anybody cares, though.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
m68k: Truncate base in do_div()

commit ea077b1b96e073eac5c3c5590529e964767fc5f7 upstream.

Explicitly truncate the second operand of do_div() to 32 bits to guard
against bogus code calling it with a 64-bit divisor.

[Thorsten]

After upgrading from 3.2 to 3.10, mounting a btrfs volume fails with:

btrfs: setting nodatacow, compression disabled
btrfs: enabling auto recovery
btrfs: disk space caching is enabled
 *** ZERO DIVIDE ***   FORMAT=2
Current process id is 722
BAD KERNEL TRAP: 00000000
Modules linked in: evdev mac_hid ext4 crc16 jbd2 mbcache btrfs xor lzo_compress zlib_deflate raid6_pq crc32c libcrc32c
PC: [<319535b2>] __btrfs_map_block+0x11c/0x119a [btrfs]
SR: 2000  SP: 30c1fab4  a2: 30f0faf0
d0: 00000000    d1: 00001000    d2: 00000000    d3: 00000000
d4: 00010000    d5: 00000000    a0: 3085c72c    a1: 3085c72c
Process mount (pid: 722, task=30f0faf0)
Frame format=2 instr addr=319535ae
Stack from 30c1faec:
        00000000 00000020 00000000 00001000 00000000 01401000 30253928 300ffc00
        00a843ac 3026f640 00000000 00010000 0009e250 00d106c0 00011220 00000000
        00001000 301c6830 0009e32a 000000ff 00000009 3085c72c 00000000 00000000
        30c1fd14 00000000 00000020 00000000 30c1fd14 0009e26c 00000020 00000003
        00000000 0009dd8a 300b0b6c 30253928 00a843ac 00001000 00000000 00000000
        0000a008 3194e76a 30253928 00a843ac 00001000 00000000 00000000 00000002
Call Trace: [<00001000>] kernel_pg_dir+0x0/0x1000

    [...]

Code: 222e ff74 2a2e ff5c 2c2e ff60 4c45 1402 <2d40> ff64 2d41 ff68 2205 4c2e 1800 ff68 4c04 0800 2041 d1c0 2206 4c2e 1400 ff68

[Geert]

As diagnosed by Andreas, fs/btrfs/volumes.c:__btrfs_map_block()
calls

    do_div(stripe_nr, stripe_len);

with stripe_len u64, while do_div() assumes the divisor is a 32-bit number.

Due to the lack of truncation in the m68k-specific implementation of
do_div(), the division is performed using the upper 32-bit word of
stripe_len, which is zero.

This was introduced by commit 53b381b3abeb86f12787a6c40fee9b2f71edc23b
("Btrfs: RAID5 and RAID6"), which changed the divisor from
map->stripe_len (struct map_lookup.stripe_len is int) to a 64-bit temporary.

Reported-by: Thorsten Glaser <tg@debian.org>
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Tested-by: Thorsten Glaser <tg@debian.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux 3.0.92
Revert "genetlink: fix family dump race"

This reverts commit bba2a9f0d381e510ba32f2f984e5ae1e705c90d1 which is
commit 58ad436fcf49810aa006016107f494c9ac9013db upstream, as there are
reported problems with it.

Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux 3.0.93