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  1. Oct 12, 2015
  3. Sep 22, 2015
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  9. Sep 11, 2015
  11. Sep 08, 2015
  13. Sep 05, 2015
    • Andy Lutomirski's avatar
      x86/vm86: Block non-root vm86(old) if mmap_min_addr != 0 · 76fc5e7b
      Andy Lutomirski authored 
      

vm86 exposes an interesting attack surface against the entry
code. Since vm86 is mostly useless anyway if mmap_min_addr != 0,
just turn it off in that case.

There are some reports that vbetool can work despite setting
mmap_min_addr to zero.  This shouldn't break that use case,
as CAP_SYS_RAWIO already overrides mmap_min_addr.

Suggested-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Austin S Hemmelgarn <ahferroin7@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stas Sergeev <stsp@list.ru>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      76fc5e7b
  15. Sep 04, 2015
  17. Sep 01, 2015
  19. Aug 29, 2015
    • Dan Williams's avatar
      libnvdimm, pmem: 'struct page' for pmem · 32ab0a3f
      Dan Williams authored 
      

Enable the pmem driver to handle PFN device instances.  Attaching a pmem
namespace to a pfn device triggers the driver to allocate and initialize
struct page entries for pmem.  Memory capacity for this allocation comes
exclusively from RAM for now which is suitable for low PMEM to RAM
ratios.  This mechanism will be expanded later for setting an "allocate
from PMEM" policy.

Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
      32ab0a3f
    • Dan Williams's avatar
      libnvdimm, pfn: 'struct page' provider infrastructure · e1455744
      Dan Williams authored 
      

Implement the base infrastructure for libnvdimm PFN devices. Similar to
BTT devices they take a namespace as a backing device and layer
functionality on top. In this case the functionality is reserving space
for an array of 'struct page' entries to be handed out through
pfn_to_page(). For now this is just the basic libnvdimm-device-model for
configuring the base PFN device.

As the namespace claiming mechanism for PFN devices is mostly identical
to BTT devices drivers/nvdimm/claim.c is created to house the common
bits.

Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
      e1455744
  21. Aug 27, 2015
    • Ross Zwisler's avatar
      nd_blk: change aperture mapping from WC to WB · 67a3e8fe
      Ross Zwisler authored 
      This should result in a pretty sizeable performance gain for reads.  For
rough comparison I did some simple read testing using PMEM to compare
reads of write combining (WC) mappings vs write-back (WB).  This was
done on a random lab machine.

PMEM reads from a write combining mapping:
	# dd of=/dev/null if=/dev/pmem0 bs=4096 count=100000
	100000+0 records in
	100000+0 records out
	409600000 bytes (410 MB) copied, 9.2855 s, 44.1 MB/s

PMEM reads from a write-back mapping:
	# dd of=/dev/null if=/dev/pmem0 bs=4096 count=1000000
	1000000+0 records in
	1000000+0 records out
	4096000000 bytes (4.1 GB) copied, 3.44034 s, 1.2 GB/s

To be able to safely support a write-back aperture I needed to add
support for the "read flush" _DSM flag, as outlined in the DSM spec:

http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf



This flag tells the ND BLK driver that it needs to flush the cache lines
associated with the aperture after the aperture is moved but before any
new data is read.  This ensures that any stale cache lines from the
previous contents of the aperture will be discarded from the processor
cache, and the new data will be read properly from the DIMM.  We know
that the cache lines are clean and will be discarded without any
writeback because either a) the previous aperture operation was a read,
and we never modified the contents of the aperture, or b) the previous
aperture operation was a write and we must have written back the dirtied
contents of the aperture to the DIMM before the I/O was completed.

In order to add support for the "read flush" flag I needed to add a
generic routine to invalidate cache lines, mmio_flush_range().  This is
protected by the ARCH_HAS_MMIO_FLUSH Kconfig variable, and is currently
only supported on x86.

Signed-off-by: default avatarRoss Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
      67a3e8fe
    • Bamvor Jian Zhang's avatar
      selftests: breakpoints: fix installing error on the architecture except x86 · 9fae100c
      Bamvor Jian Zhang authored 
      

Signed-off-by: default avatarBamvor Jian Zhang <bamvor.zhangjian@linaro.org>
Signed-off-by: default avatarShuah Khan <shuahkh@osg.samsung.com>
      9fae100c
    • Bamvor Jian Zhang's avatar
      selftests: check before install · a7d0f078
      Bamvor Jian Zhang authored 
      

When the test cases is not supported by the current architecture
the install files(TEST_PROGS, TEST_PROGS_EXTENDED and TEST_FILES)
will be empty. Check it before installation to dismiss a failure
reported by install program.

Signed-off-by: default avatarBamvor Jian Zhang <bamvor.zhangjian@linaro.org>
Signed-off-by: default avatarShuah Khan <shuahkh@osg.samsung.com>
      a7d0f078
    • Naresh Kamboju's avatar
      selftests/zram: Adding zram tests · f21fb798
      Naresh Kamboju authored 
      

zram: Compressed RAM based block devices
----------------------------------------
The zram module creates RAM based block devices named /dev/zram<id>
(<id> = 0, 1, ...). Pages written to these disks are compressed and stored
in memory itself. These disks allow very fast I/O and compression provides
good amounts of memory savings. Some of the usecases include /tmp storage,
use as swap disks, various caches under /var and maybe many more :)

Statistics for individual zram devices are exported through sysfs nodes at
/sys/block/zram<id>/

This patch is to validate the zram functionality. Test interacts with block
device /dev/zram<id> and sysfs nodes /sys/block/zram<id>/

zram.sh: sanity check of CONFIG_ZRAM and to run zram01 and zram02 tests
zram01.sh: creates general purpose ram disks with different filesystems
zram02.sh: creates block device for swap
zram_lib.sh: create library with initialization/cleanup functions
README: ZRAM introduction and Kconfig required.
Makefile: To run zram tests

zram test output
-----------------
./zram.sh
--------------------
running zram tests
--------------------
/dev/zram0 device file found: OK
set max_comp_streams to zram device(s)
/sys/block/zram0/max_comp_streams = '2' (1/1)
zram max streams: OK
test that we can set compression algorithm
supported algs: [lzo] lz4
/sys/block/zram0/comp_algorithm = 'lzo' (1/1)
zram set compression algorithm: OK
set disk size to zram device(s)
/sys/block/zram0/disksize = '2097152' (1/1)
zram set disksizes: OK
set memory limit to zram device(s)
/sys/block/zram0/mem_limit = '2M' (1/1)
zram set memory limit: OK
make ext4 filesystem on /dev/zram0
zram mkfs.ext4: OK
mount /dev/zram0
zram mount of zram device(s): OK
fill zram0...
zram0 can be filled with '1932' KB
zram used 3M, zram disk sizes 2097152M
zram compression ratio: 699050.66:1: OK
zram cleanup
zram01 : [PASS]

/dev/zram0 device file found: OK
set max_comp_streams to zram device(s)
/sys/block/zram0/max_comp_streams = '2' (1/1)
zram max streams: OK
set disk size to zram device(s)
/sys/block/zram0/disksize = '1048576' (1/1)
zram set disksizes: OK
set memory limit to zram device(s)
/sys/block/zram0/mem_limit = '1M' (1/1)
zram set memory limit: OK
make swap with zram device(s)
done with /dev/zram0
zram making zram mkswap and swapon: OK
zram swapoff: OK
zram cleanup
zram02 : [PASS]

CC: Shuah Khan <shuahkh@osg.samsung.com>
CC: Tyler Baker <tyler.baker@linaro.org>
CC: Milosz Wasilewski <milosz.wasilewski@linaro.org>
CC: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: default avatarNaresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: default avatarAlexey Kodanev <alexey.kodanev@oracle.com>
Reviewed-By: default avatarTyler Baker <tyler.baker@linaro.org>
Signed-off-by: default avatarShuah Khan <shuahkh@osg.samsung.com>
      f21fb798
  23. Aug 19, 2015
    • Dan Williams's avatar
      libnvdimm, e820: make CONFIG_X86_PMEM_LEGACY a tristate option · 7a67832c
      Dan Williams authored 
      

We currently register a platform device for e820 type-12 memory and
register a nvdimm bus beneath it.  Registering the platform device
triggers the device-core machinery to probe for a driver, but that
search currently comes up empty.  Building the nvdimm-bus registration
into the e820_pmem platform device registration in this way forces
libnvdimm to be built-in.  Instead, convert the built-in portion of
CONFIG_X86_PMEM_LEGACY to simply register a platform device and move the
rest of the logic to the driver for e820_pmem, for the following
reasons:

1/ Letting e820_pmem support be a module allows building and testing
   libnvdimm.ko changes without rebooting

2/ All the normal policy around modules can be applied to e820_pmem
   (unbind to disable and/or blacklisting the module from loading by
   default)

3/ Moving the driver to a generic location and converting it to scan
   "iomem_resource" rather than "e820.map" means any other architecture can
   take advantage of this simple nvdimm resource discovery mechanism by
   registering a resource named "Persistent Memory (legacy)"

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
      7a67832c
  25. Aug 18, 2015
  27. Aug 17, 2015
  29. Aug 14, 2015