<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/lib, branch v5.10-rc2</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge tag 'driver-core-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core</title>
<updated>2020-11-01T17:59:13+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-11-01T17:59:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=9c75b68b91ff010d8d4c703b93954f605e2ef516'/>
<id>9c75b68b91ff010d8d4c703b93954f605e2ef516</id>
<content type='text'>
Pull driver core and documentation fixes from Greg KH:
 "Here is one tiny debugfs change to fix up an API where the last user
  was successfully fixed up in 5.10-rc1 (so it couldn't be merged
  earlier), and a much larger Documentation/ABI/ update to the files so
  they can be automatically parsed by our tools.

  The Documentation/ABI/ updates are just formatting issues, small ones
  to bring the files into parsable format, and have been acked by
  numerous subsystem maintainers and the documentation maintainer. I
  figured it was good to get this into 5.10-rc2 to help wih the merge
  issues that would arise if these were to stick in linux-next until
  5.11-rc1.

  The debugfs change has been in linux-next for a long time, and the
  Documentation updates only for the last linux-next release"

* tag 'driver-core-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (40 commits)
  scripts: get_abi.pl: assume ReST format by default
  docs: ABI: sysfs-class-led-trigger-pattern: remove hw_pattern duplication
  docs: ABI: sysfs-class-backlight: unify ABI documentation
  docs: ABI: sysfs-c2port: remove a duplicated entry
  docs: ABI: sysfs-class-power: unify duplicated properties
  docs: ABI: unify /sys/class/leds/&lt;led&gt;/brightness documentation
  docs: ABI: stable: remove a duplicated documentation
  docs: ABI: change read/write attributes
  docs: ABI: cleanup several ABI documents
  docs: ABI: sysfs-bus-nvdimm: use the right format for ABI
  docs: ABI: vdso: use the right format for ABI
  docs: ABI: fix syntax to be parsed using ReST notation
  docs: ABI: convert testing/configfs-acpi to ReST
  docs: Kconfig/Makefile: add a check for broken ABI files
  docs: abi-testing.rst: enable --rst-sources when building docs
  docs: ABI: don't escape ReST-incompatible chars from obsolete and removed
  docs: ABI: create a 2-depth index for ABI
  docs: ABI: make it parse ABI/stable as ReST-compatible files
  docs: ABI: sysfs-uevent: make it compatible with ReST output
  docs: ABI: testing: make the files compatible with ReST output
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull driver core and documentation fixes from Greg KH:
 "Here is one tiny debugfs change to fix up an API where the last user
  was successfully fixed up in 5.10-rc1 (so it couldn't be merged
  earlier), and a much larger Documentation/ABI/ update to the files so
  they can be automatically parsed by our tools.

  The Documentation/ABI/ updates are just formatting issues, small ones
  to bring the files into parsable format, and have been acked by
  numerous subsystem maintainers and the documentation maintainer. I
  figured it was good to get this into 5.10-rc2 to help wih the merge
  issues that would arise if these were to stick in linux-next until
  5.11-rc1.

  The debugfs change has been in linux-next for a long time, and the
  Documentation updates only for the last linux-next release"

* tag 'driver-core-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (40 commits)
  scripts: get_abi.pl: assume ReST format by default
  docs: ABI: sysfs-class-led-trigger-pattern: remove hw_pattern duplication
  docs: ABI: sysfs-class-backlight: unify ABI documentation
  docs: ABI: sysfs-c2port: remove a duplicated entry
  docs: ABI: sysfs-class-power: unify duplicated properties
  docs: ABI: unify /sys/class/leds/&lt;led&gt;/brightness documentation
  docs: ABI: stable: remove a duplicated documentation
  docs: ABI: change read/write attributes
  docs: ABI: cleanup several ABI documents
  docs: ABI: sysfs-bus-nvdimm: use the right format for ABI
  docs: ABI: vdso: use the right format for ABI
  docs: ABI: fix syntax to be parsed using ReST notation
  docs: ABI: convert testing/configfs-acpi to ReST
  docs: Kconfig/Makefile: add a check for broken ABI files
  docs: abi-testing.rst: enable --rst-sources when building docs
  docs: ABI: don't escape ReST-incompatible chars from obsolete and removed
  docs: ABI: create a 2-depth index for ABI
  docs: ABI: make it parse ABI/stable as ReST-compatible files
  docs: ABI: sysfs-uevent: make it compatible with ReST output
  docs: ABI: testing: make the files compatible with ReST output
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>docs: Kconfig/Makefile: add a check for broken ABI files</title>
<updated>2020-10-30T12:08:07+00:00</updated>
<author>
<name>Mauro Carvalho Chehab</name>
<email>mchehab+huawei@kernel.org</email>
</author>
<published>2020-10-30T07:40:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=75442fb0ccaacddf1654a5304401a9f556c61004'/>
<id>75442fb0ccaacddf1654a5304401a9f556c61004</id>
<content type='text'>
The files under Documentation/ABI should follow the syntax
as defined at Documentation/ABI/README.

Allow checking if they're following the syntax by running
the ABI parser script on COMPILE_TEST.

With that, when there's a problem with a file under
Documentation/ABI, it would produce a warning like:

	Warning: file ./Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats#14:
		What '/sys/bus/pci/devices/&lt;dev&gt;/aer_stats/aer_rootport_total_err_cor' doesn't have a description
	Warning: file ./Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats#21:
		What '/sys/bus/pci/devices/&lt;dev&gt;/aer_stats/aer_rootport_total_err_fatal' doesn't have a description

Acked-by: Jonathan Corbet &lt;corbet@lwn.net&gt;
Signed-off-by: Mauro Carvalho Chehab &lt;mchehab+huawei@kernel.org&gt;
Link: https://lore.kernel.org/r/57a38de85cb4b548857207cf1fc1bf1ee08613c9.1604042072.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The files under Documentation/ABI should follow the syntax
as defined at Documentation/ABI/README.

Allow checking if they're following the syntax by running
the ABI parser script on COMPILE_TEST.

With that, when there's a problem with a file under
Documentation/ABI, it would produce a warning like:

	Warning: file ./Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats#14:
		What '/sys/bus/pci/devices/&lt;dev&gt;/aer_stats/aer_rootport_total_err_cor' doesn't have a description
	Warning: file ./Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats#21:
		What '/sys/bus/pci/devices/&lt;dev&gt;/aer_stats/aer_rootport_total_err_fatal' doesn't have a description

Acked-by: Jonathan Corbet &lt;corbet@lwn.net&gt;
Signed-off-by: Mauro Carvalho Chehab &lt;mchehab+huawei@kernel.org&gt;
Link: https://lore.kernel.org/r/57a38de85cb4b548857207cf1fc1bf1ee08613c9.1604042072.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>lib/scatterlist: use consistent sg_copy_buffer() return type</title>
<updated>2020-10-29T14:55:45+00:00</updated>
<author>
<name>David Disseldorp</name>
<email>ddiss@suse.de</email>
</author>
<published>2020-10-26T21:03:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1f41be7d4e90e36084037cecba5978b3d7f849db'/>
<id>1f41be7d4e90e36084037cecba5978b3d7f849db</id>
<content type='text'>
sg_copy_buffer() returns a size_t with the number of bytes copied.
Return 0 instead of false if the copy is skipped.

Signed-off-by: David Disseldorp &lt;ddiss@suse.de&gt;
Reviewed-by: Douglas Gilbert &lt;dgilbert@interlog.com&gt;
Reviewed-by: Johannes Thumshirn &lt;johannes.thumshirn@wdc.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
sg_copy_buffer() returns a size_t with the number of bytes copied.
Return 0 instead of false if the copy is skipped.

Signed-off-by: David Disseldorp &lt;ddiss@suse.de&gt;
Reviewed-by: Douglas Gilbert &lt;dgilbert@interlog.com&gt;
Reviewed-by: Johannes Thumshirn &lt;johannes.thumshirn@wdc.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag '20201024-v4-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/prandom</title>
<updated>2020-10-25T17:40:08+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-10-25T17:40:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=91f28da8c9a054286d6917ce191349455c479478'/>
<id>91f28da8c9a054286d6917ce191349455c479478</id>
<content type='text'>
Pull random32 updates from Willy Tarreau:
 "Make prandom_u32() less predictable.

  This is the cleanup of the latest series of prandom_u32
  experimentations consisting in using SipHash instead of Tausworthe to
  produce the randoms used by the network stack.

  The changes to the files were kept minimal, and the controversial
  commit that used to take noise from the fast_pool (f227e3ec3b5c) was
  reverted. Instead, a dedicated "net_rand_noise" per_cpu variable is
  fed from various sources of activities (networking, scheduling) to
  perturb the SipHash state using fast, non-trivially predictable data,
  instead of keeping it fully deterministic. The goal is essentially to
  make any occasional memory leakage or brute-force attempt useless.

  The resulting code was verified to be very slightly faster on x86_64
  than what is was with the controversial commit above, though this
  remains barely above measurement noise. It was also tested on i386 and
  arm, and build- tested only on arm64"

Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/

* tag '20201024-v4-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/prandom:
  random32: add a selftest for the prandom32 code
  random32: add noise from network and scheduling activity
  random32: make prandom_u32() output unpredictable
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull random32 updates from Willy Tarreau:
 "Make prandom_u32() less predictable.

  This is the cleanup of the latest series of prandom_u32
  experimentations consisting in using SipHash instead of Tausworthe to
  produce the randoms used by the network stack.

  The changes to the files were kept minimal, and the controversial
  commit that used to take noise from the fast_pool (f227e3ec3b5c) was
  reverted. Instead, a dedicated "net_rand_noise" per_cpu variable is
  fed from various sources of activities (networking, scheduling) to
  perturb the SipHash state using fast, non-trivially predictable data,
  instead of keeping it fully deterministic. The goal is essentially to
  make any occasional memory leakage or brute-force attempt useless.

  The resulting code was verified to be very slightly faster on x86_64
  than what is was with the controversial commit above, though this
  remains barely above measurement noise. It was also tested on i386 and
  arm, and build- tested only on arm64"

Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/

* tag '20201024-v4-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/prandom:
  random32: add a selftest for the prandom32 code
  random32: add noise from network and scheduling activity
  random32: make prandom_u32() output unpredictable
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'block-5.10-2020-10-24' of git://git.kernel.dk/linux-block</title>
<updated>2020-10-24T19:46:42+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-10-24T19:46:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d76913908102044f14381df865bb74df17a538cb'/>
<id>d76913908102044f14381df865bb74df17a538cb</id>
<content type='text'>
Pull block fixes from Jens Axboe:

 - NVMe pull request from Christoph
     - rdma error handling fixes (Chao Leng)
     - fc error handling and reconnect fixes (James Smart)
     - fix the qid displace when tracing ioctl command (Keith Busch)
     - don't use BLK_MQ_REQ_NOWAIT for passthru (Chaitanya Kulkarni)
     - fix MTDT for passthru (Logan Gunthorpe)
     - blacklist Write Same on more devices (Kai-Heng Feng)
     - fix an uninitialized work struct (zhenwei pi)"

 - lightnvm out-of-bounds fix (Colin)

 - SG allocation leak fix (Doug)

 - rnbd fixes (Gioh, Guoqing, Jack)

 - zone error translation fixes (Keith)

 - kerneldoc markup fix (Mauro)

 - zram lockdep fix (Peter)

 - Kill unused io_context members (Yufen)

 - NUMA memory allocation cleanup (Xianting)

 - NBD config wakeup fix (Xiubo)

* tag 'block-5.10-2020-10-24' of git://git.kernel.dk/linux-block: (27 commits)
  block: blk-mq: fix a kernel-doc markup
  nvme-fc: shorten reconnect delay if possible for FC
  nvme-fc: wait for queues to freeze before calling update_hr_hw_queues
  nvme-fc: fix error loop in create_hw_io_queues
  nvme-fc: fix io timeout to abort I/O
  null_blk: use zone status for max active/open
  nvmet: don't use BLK_MQ_REQ_NOWAIT for passthru
  nvmet: cleanup nvmet_passthru_map_sg()
  nvmet: limit passthru MTDS by BIO_MAX_PAGES
  nvmet: fix uninitialized work for zero kato
  nvme-pci: disable Write Zeroes on Sandisk Skyhawk
  nvme: use queuedata for nvme_req_qid
  nvme-rdma: fix crash due to incorrect cqe
  nvme-rdma: fix crash when connect rejected
  block: remove unused members for io_context
  blk-mq: remove the calling of local_memory_node()
  zram: Fix __zram_bvec_{read,write}() locking order
  skd_main: remove unused including &lt;linux/version.h&gt;
  sgl_alloc_order: fix memory leak
  lightnvm: fix out-of-bounds write to array devices-&gt;info[]
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull block fixes from Jens Axboe:

 - NVMe pull request from Christoph
     - rdma error handling fixes (Chao Leng)
     - fc error handling and reconnect fixes (James Smart)
     - fix the qid displace when tracing ioctl command (Keith Busch)
     - don't use BLK_MQ_REQ_NOWAIT for passthru (Chaitanya Kulkarni)
     - fix MTDT for passthru (Logan Gunthorpe)
     - blacklist Write Same on more devices (Kai-Heng Feng)
     - fix an uninitialized work struct (zhenwei pi)"

 - lightnvm out-of-bounds fix (Colin)

 - SG allocation leak fix (Doug)

 - rnbd fixes (Gioh, Guoqing, Jack)

 - zone error translation fixes (Keith)

 - kerneldoc markup fix (Mauro)

 - zram lockdep fix (Peter)

 - Kill unused io_context members (Yufen)

 - NUMA memory allocation cleanup (Xianting)

 - NBD config wakeup fix (Xiubo)

* tag 'block-5.10-2020-10-24' of git://git.kernel.dk/linux-block: (27 commits)
  block: blk-mq: fix a kernel-doc markup
  nvme-fc: shorten reconnect delay if possible for FC
  nvme-fc: wait for queues to freeze before calling update_hr_hw_queues
  nvme-fc: fix error loop in create_hw_io_queues
  nvme-fc: fix io timeout to abort I/O
  null_blk: use zone status for max active/open
  nvmet: don't use BLK_MQ_REQ_NOWAIT for passthru
  nvmet: cleanup nvmet_passthru_map_sg()
  nvmet: limit passthru MTDS by BIO_MAX_PAGES
  nvmet: fix uninitialized work for zero kato
  nvme-pci: disable Write Zeroes on Sandisk Skyhawk
  nvme: use queuedata for nvme_req_qid
  nvme-rdma: fix crash due to incorrect cqe
  nvme-rdma: fix crash when connect rejected
  block: remove unused members for io_context
  blk-mq: remove the calling of local_memory_node()
  zram: Fix __zram_bvec_{read,write}() locking order
  skd_main: remove unused including &lt;linux/version.h&gt;
  sgl_alloc_order: fix memory leak
  lightnvm: fix out-of-bounds write to array devices-&gt;info[]
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>random32: add a selftest for the prandom32 code</title>
<updated>2020-10-24T18:21:57+00:00</updated>
<author>
<name>Willy Tarreau</name>
<email>w@1wt.eu</email>
</author>
<published>2020-10-24T16:36:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c6e169bc146a76d5ccbf4d3825f705414352bd03'/>
<id>c6e169bc146a76d5ccbf4d3825f705414352bd03</id>
<content type='text'>
Given that this code is new, let's add a selftest for it as well.
It doesn't rely on fixed sets, instead it picks 1024 numbers and
verifies that they're not more correlated than desired.

Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/
Cc: George Spelvin &lt;lkml@sdf.org&gt;
Cc: Amit Klein &lt;aksecurity@gmail.com&gt;
Cc: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: "Jason A. Donenfeld" &lt;Jason@zx2c4.com&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: tytso@mit.edu
Cc: Florian Westphal &lt;fw@strlen.de&gt;
Cc: Marc Plumb &lt;lkml.mplumb@gmail.com&gt;
Signed-off-by: Willy Tarreau &lt;w@1wt.eu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Given that this code is new, let's add a selftest for it as well.
It doesn't rely on fixed sets, instead it picks 1024 numbers and
verifies that they're not more correlated than desired.

Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/
Cc: George Spelvin &lt;lkml@sdf.org&gt;
Cc: Amit Klein &lt;aksecurity@gmail.com&gt;
Cc: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: "Jason A. Donenfeld" &lt;Jason@zx2c4.com&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: tytso@mit.edu
Cc: Florian Westphal &lt;fw@strlen.de&gt;
Cc: Marc Plumb &lt;lkml.mplumb@gmail.com&gt;
Signed-off-by: Willy Tarreau &lt;w@1wt.eu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>random32: add noise from network and scheduling activity</title>
<updated>2020-10-24T18:21:57+00:00</updated>
<author>
<name>Willy Tarreau</name>
<email>w@1wt.eu</email>
</author>
<published>2020-08-10T08:27:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3744741adab6d9195551ce30e65e726c7a408421'/>
<id>3744741adab6d9195551ce30e65e726c7a408421</id>
<content type='text'>
With the removal of the interrupt perturbations in previous random32
change (random32: make prandom_u32() output unpredictable), the PRNG
has become 100% deterministic again. While SipHash is expected to be
way more robust against brute force than the previous Tausworthe LFSR,
there's still the risk that whoever has even one temporary access to
the PRNG's internal state is able to predict all subsequent draws till
the next reseed (roughly every minute). This may happen through a side
channel attack or any data leak.

This patch restores the spirit of commit f227e3ec3b5c ("random32: update
the net random state on interrupt and activity") in that it will perturb
the internal PRNG's statee using externally collected noise, except that
it will not pick that noise from the random pool's bits nor upon
interrupt, but will rather combine a few elements along the Tx path
that are collectively hard to predict, such as dev, skb and txq
pointers, packet length and jiffies values. These ones are combined
using a single round of SipHash into a single long variable that is
mixed with the net_rand_state upon each invocation.

The operation was inlined because it produces very small and efficient
code, typically 3 xor, 2 add and 2 rol. The performance was measured
to be the same (even very slightly better) than before the switch to
SipHash; on a 6-core 12-thread Core i7-8700k equipped with a 40G NIC
(i40e), the connection rate dropped from 556k/s to 555k/s while the
SYN cookie rate grew from 5.38 Mpps to 5.45 Mpps.

Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/
Cc: George Spelvin &lt;lkml@sdf.org&gt;
Cc: Amit Klein &lt;aksecurity@gmail.com&gt;
Cc: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: "Jason A. Donenfeld" &lt;Jason@zx2c4.com&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: tytso@mit.edu
Cc: Florian Westphal &lt;fw@strlen.de&gt;
Cc: Marc Plumb &lt;lkml.mplumb@gmail.com&gt;
Tested-by: Sedat Dilek &lt;sedat.dilek@gmail.com&gt;
Signed-off-by: Willy Tarreau &lt;w@1wt.eu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
With the removal of the interrupt perturbations in previous random32
change (random32: make prandom_u32() output unpredictable), the PRNG
has become 100% deterministic again. While SipHash is expected to be
way more robust against brute force than the previous Tausworthe LFSR,
there's still the risk that whoever has even one temporary access to
the PRNG's internal state is able to predict all subsequent draws till
the next reseed (roughly every minute). This may happen through a side
channel attack or any data leak.

This patch restores the spirit of commit f227e3ec3b5c ("random32: update
the net random state on interrupt and activity") in that it will perturb
the internal PRNG's statee using externally collected noise, except that
it will not pick that noise from the random pool's bits nor upon
interrupt, but will rather combine a few elements along the Tx path
that are collectively hard to predict, such as dev, skb and txq
pointers, packet length and jiffies values. These ones are combined
using a single round of SipHash into a single long variable that is
mixed with the net_rand_state upon each invocation.

The operation was inlined because it produces very small and efficient
code, typically 3 xor, 2 add and 2 rol. The performance was measured
to be the same (even very slightly better) than before the switch to
SipHash; on a 6-core 12-thread Core i7-8700k equipped with a 40G NIC
(i40e), the connection rate dropped from 556k/s to 555k/s while the
SYN cookie rate grew from 5.38 Mpps to 5.45 Mpps.

Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/
Cc: George Spelvin &lt;lkml@sdf.org&gt;
Cc: Amit Klein &lt;aksecurity@gmail.com&gt;
Cc: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: "Jason A. Donenfeld" &lt;Jason@zx2c4.com&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: tytso@mit.edu
Cc: Florian Westphal &lt;fw@strlen.de&gt;
Cc: Marc Plumb &lt;lkml.mplumb@gmail.com&gt;
Tested-by: Sedat Dilek &lt;sedat.dilek@gmail.com&gt;
Signed-off-by: Willy Tarreau &lt;w@1wt.eu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>random32: make prandom_u32() output unpredictable</title>
<updated>2020-10-24T18:21:57+00:00</updated>
<author>
<name>George Spelvin</name>
<email>lkml@sdf.org</email>
</author>
<published>2020-08-09T06:57:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c51f8f88d705e06bd696d7510aff22b33eb8e638'/>
<id>c51f8f88d705e06bd696d7510aff22b33eb8e638</id>
<content type='text'>
Non-cryptographic PRNGs may have great statistical properties, but
are usually trivially predictable to someone who knows the algorithm,
given a small sample of their output.  An LFSR like prandom_u32() is
particularly simple, even if the sample is widely scattered bits.

It turns out the network stack uses prandom_u32() for some things like
random port numbers which it would prefer are *not* trivially predictable.
Predictability led to a practical DNS spoofing attack.  Oops.

This patch replaces the LFSR with a homebrew cryptographic PRNG based
on the SipHash round function, which is in turn seeded with 128 bits
of strong random key.  (The authors of SipHash have *not* been consulted
about this abuse of their algorithm.)  Speed is prioritized over security;
attacks are rare, while performance is always wanted.

Replacing all callers of prandom_u32() is the quick fix.
Whether to reinstate a weaker PRNG for uses which can tolerate it
is an open question.

Commit f227e3ec3b5c ("random32: update the net random state on interrupt
and activity") was an earlier attempt at a solution.  This patch replaces
it.

Reported-by: Amit Klein &lt;aksecurity@gmail.com&gt;
Cc: Willy Tarreau &lt;w@1wt.eu&gt;
Cc: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: "Jason A. Donenfeld" &lt;Jason@zx2c4.com&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: tytso@mit.edu
Cc: Florian Westphal &lt;fw@strlen.de&gt;
Cc: Marc Plumb &lt;lkml.mplumb@gmail.com&gt;
Fixes: f227e3ec3b5c ("random32: update the net random state on interrupt and activity")
Signed-off-by: George Spelvin &lt;lkml@sdf.org&gt;
Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/
[ willy: partial reversal of f227e3ec3b5c; moved SIPROUND definitions
  to prandom.h for later use; merged George's prandom_seed() proposal;
  inlined siprand_u32(); replaced the net_rand_state[] array with 4
  members to fix a build issue; cosmetic cleanups to make checkpatch
  happy; fixed RANDOM32_SELFTEST build ]
Signed-off-by: Willy Tarreau &lt;w@1wt.eu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Non-cryptographic PRNGs may have great statistical properties, but
are usually trivially predictable to someone who knows the algorithm,
given a small sample of their output.  An LFSR like prandom_u32() is
particularly simple, even if the sample is widely scattered bits.

It turns out the network stack uses prandom_u32() for some things like
random port numbers which it would prefer are *not* trivially predictable.
Predictability led to a practical DNS spoofing attack.  Oops.

This patch replaces the LFSR with a homebrew cryptographic PRNG based
on the SipHash round function, which is in turn seeded with 128 bits
of strong random key.  (The authors of SipHash have *not* been consulted
about this abuse of their algorithm.)  Speed is prioritized over security;
attacks are rare, while performance is always wanted.

Replacing all callers of prandom_u32() is the quick fix.
Whether to reinstate a weaker PRNG for uses which can tolerate it
is an open question.

Commit f227e3ec3b5c ("random32: update the net random state on interrupt
and activity") was an earlier attempt at a solution.  This patch replaces
it.

Reported-by: Amit Klein &lt;aksecurity@gmail.com&gt;
Cc: Willy Tarreau &lt;w@1wt.eu&gt;
Cc: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: "Jason A. Donenfeld" &lt;Jason@zx2c4.com&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: tytso@mit.edu
Cc: Florian Westphal &lt;fw@strlen.de&gt;
Cc: Marc Plumb &lt;lkml.mplumb@gmail.com&gt;
Fixes: f227e3ec3b5c ("random32: update the net random state on interrupt and activity")
Signed-off-by: George Spelvin &lt;lkml@sdf.org&gt;
Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/
[ willy: partial reversal of f227e3ec3b5c; moved SIPROUND definitions
  to prandom.h for later use; merged George's prandom_seed() proposal;
  inlined siprand_u32(); replaced the net_rand_state[] array with 4
  members to fix a build issue; cosmetic cleanups to make checkpatch
  happy; fixed RANDOM32_SELFTEST build ]
Signed-off-by: Willy Tarreau &lt;w@1wt.eu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'drm-next-2020-10-23' of git://anongit.freedesktop.org/drm/drm</title>
<updated>2020-10-23T20:56:34+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-10-23T20:56:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fc03b2d6a9d1398dc855318d6ddfa3be57bdcf2c'/>
<id>fc03b2d6a9d1398dc855318d6ddfa3be57bdcf2c</id>
<content type='text'>
Pull more drm fixes from Dave Airlie:
 "This should be the last round of things for rc1, a bunch of i915
  fixes, some amdgpu, more font OOB fixes and one ttm fix just found
  reading code:

  fbcon/fonts:
   - Two patches to prevent OOB access

  ttm:
   - fix for evicition value range check

  amdgpu:
   - Sienna Cichlid fixes
   - MST manager resource leak fix
   - GPU reset fix

  amdkfd:
   - Luxmark fix for Navi1x

  i915:
   - Tweak initial DPCD backlight.enabled value (Sean)
   - Initialize reserved MOCS indices (Ayaz)
   - Mark initial fb obj as WT on eLLC machines to avoid rcu lockup (Ville)
   - Support parsing of oversize batches (Chris)
   - Delay execlists processing for TGL (Chris)
   - Use the active reference on the vma during error capture (Chris)
   - Widen CSB pointer (Chris)
   - Wait for CSB entries on TGL (Chris)
   - Fix unwind for scratch page allocation (Chris)
   - Exclude low patches of stolen memory (Chris)
   - Force VT'd workarounds when running as a guest OS (Chris)
   - Drop runtime-pm assert from vpgu io accessors (Chris)"

* tag 'drm-next-2020-10-23' of git://anongit.freedesktop.org/drm/drm: (31 commits)
  drm/amdgpu: correct the cu and rb info for sienna cichlid
  drm/amd/pm: remove the average clock value in sysfs
  drm/amd/pm: fix pp_dpm_fclk
  Revert drm/amdgpu: disable sienna chichlid UMC RAS
  drm/amd/pm: fix pcie information for sienna cichlid
  drm/amdkfd: Use same SQ prefetch setting as amdgpu
  drm/amd/swsmu: correct wrong feature bit mapping
  drm/amd/psp: Fix sysfs: cannot create duplicate filename
  drm/amd/display: Avoid MST manager resource leak.
  drm/amd/display: Revert "drm/amd/display: Fix a list corruption"
  drm/amdgpu: update golden setting for sienna_cichlid
  drm/amd/swsmu: add missing feature map for sienna_cichlid
  drm/amdgpu: correct the gpu reset handling for job != NULL case
  drm/amdgpu: add rlc iram and dram firmware support
  drm/amdgpu: add function to program pbb mode for sienna cichlid
  drm/i915: Drop runtime-pm assert from vgpu io accessors
  drm/i915: Force VT'd workarounds when running as a guest OS
  drm/i915: Exclude low pages (128KiB) of stolen from use
  drm/i915/gt: Onion unwind for scratch page allocation failure
  drm/ttm: fix eviction valuable range check.
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull more drm fixes from Dave Airlie:
 "This should be the last round of things for rc1, a bunch of i915
  fixes, some amdgpu, more font OOB fixes and one ttm fix just found
  reading code:

  fbcon/fonts:
   - Two patches to prevent OOB access

  ttm:
   - fix for evicition value range check

  amdgpu:
   - Sienna Cichlid fixes
   - MST manager resource leak fix
   - GPU reset fix

  amdkfd:
   - Luxmark fix for Navi1x

  i915:
   - Tweak initial DPCD backlight.enabled value (Sean)
   - Initialize reserved MOCS indices (Ayaz)
   - Mark initial fb obj as WT on eLLC machines to avoid rcu lockup (Ville)
   - Support parsing of oversize batches (Chris)
   - Delay execlists processing for TGL (Chris)
   - Use the active reference on the vma during error capture (Chris)
   - Widen CSB pointer (Chris)
   - Wait for CSB entries on TGL (Chris)
   - Fix unwind for scratch page allocation (Chris)
   - Exclude low patches of stolen memory (Chris)
   - Force VT'd workarounds when running as a guest OS (Chris)
   - Drop runtime-pm assert from vpgu io accessors (Chris)"

* tag 'drm-next-2020-10-23' of git://anongit.freedesktop.org/drm/drm: (31 commits)
  drm/amdgpu: correct the cu and rb info for sienna cichlid
  drm/amd/pm: remove the average clock value in sysfs
  drm/amd/pm: fix pp_dpm_fclk
  Revert drm/amdgpu: disable sienna chichlid UMC RAS
  drm/amd/pm: fix pcie information for sienna cichlid
  drm/amdkfd: Use same SQ prefetch setting as amdgpu
  drm/amd/swsmu: correct wrong feature bit mapping
  drm/amd/psp: Fix sysfs: cannot create duplicate filename
  drm/amd/display: Avoid MST manager resource leak.
  drm/amd/display: Revert "drm/amd/display: Fix a list corruption"
  drm/amdgpu: update golden setting for sienna_cichlid
  drm/amd/swsmu: add missing feature map for sienna_cichlid
  drm/amdgpu: correct the gpu reset handling for job != NULL case
  drm/amdgpu: add rlc iram and dram firmware support
  drm/amdgpu: add function to program pbb mode for sienna cichlid
  drm/i915: Drop runtime-pm assert from vgpu io accessors
  drm/i915: Force VT'd workarounds when running as a guest OS
  drm/i915: Exclude low pages (128KiB) of stolen from use
  drm/i915/gt: Onion unwind for scratch page allocation failure
  drm/ttm: fix eviction valuable range check.
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild</title>
<updated>2020-10-22T20:13:57+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-10-22T20:13:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=746b25b1aa0f5736d585728ded70a8141da91edb'/>
<id>746b25b1aa0f5736d585728ded70a8141da91edb</id>
<content type='text'>
Pull Kbuild updates from Masahiro Yamada:

 - Support 'make compile_commands.json' to generate the compilation
   database more easily, avoiding stale entries

 - Support 'make clang-analyzer' and 'make clang-tidy' for static checks
   using clang-tidy

 - Preprocess scripts/modules.lds.S to allow CONFIG options in the
   module linker script

 - Drop cc-option tests from compiler flags supported by our minimal
   GCC/Clang versions

 - Use always 12-digits commit hash for CONFIG_LOCALVERSION_AUTO=y

 - Use sha1 build id for both BFD linker and LLD

 - Improve deb-pkg for reproducible builds and rootless builds

 - Remove stale, useless scripts/namespace.pl

 - Turn -Wreturn-type warning into error

 - Fix build error of deb-pkg when CONFIG_MODULES=n

 - Replace 'hostname' command with more portable 'uname -n'

 - Various Makefile cleanups

* tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits)
  kbuild: Use uname for LINUX_COMPILE_HOST detection
  kbuild: Only add -fno-var-tracking-assignments for old GCC versions
  kbuild: remove leftover comment for filechk utility
  treewide: remove DISABLE_LTO
  kbuild: deb-pkg: clean up package name variables
  kbuild: deb-pkg: do not build linux-headers package if CONFIG_MODULES=n
  kbuild: enforce -Werror=return-type
  scripts: remove namespace.pl
  builddeb: Add support for all required debian/rules targets
  builddeb: Enable rootless builds
  builddeb: Pass -n to gzip for reproducible packages
  kbuild: split the build log of kallsyms
  kbuild: explicitly specify the build id style
  scripts/setlocalversion: make git describe output more reliable
  kbuild: remove cc-option test of -Werror=date-time
  kbuild: remove cc-option test of -fno-stack-check
  kbuild: remove cc-option test of -fno-strict-overflow
  kbuild: move CFLAGS_{KASAN,UBSAN,KCSAN} exports to relevant Makefiles
  kbuild: remove redundant CONFIG_KASAN check from scripts/Makefile.kasan
  kbuild: do not create built-in objects for external module builds
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull Kbuild updates from Masahiro Yamada:

 - Support 'make compile_commands.json' to generate the compilation
   database more easily, avoiding stale entries

 - Support 'make clang-analyzer' and 'make clang-tidy' for static checks
   using clang-tidy

 - Preprocess scripts/modules.lds.S to allow CONFIG options in the
   module linker script

 - Drop cc-option tests from compiler flags supported by our minimal
   GCC/Clang versions

 - Use always 12-digits commit hash for CONFIG_LOCALVERSION_AUTO=y

 - Use sha1 build id for both BFD linker and LLD

 - Improve deb-pkg for reproducible builds and rootless builds

 - Remove stale, useless scripts/namespace.pl

 - Turn -Wreturn-type warning into error

 - Fix build error of deb-pkg when CONFIG_MODULES=n

 - Replace 'hostname' command with more portable 'uname -n'

 - Various Makefile cleanups

* tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits)
  kbuild: Use uname for LINUX_COMPILE_HOST detection
  kbuild: Only add -fno-var-tracking-assignments for old GCC versions
  kbuild: remove leftover comment for filechk utility
  treewide: remove DISABLE_LTO
  kbuild: deb-pkg: clean up package name variables
  kbuild: deb-pkg: do not build linux-headers package if CONFIG_MODULES=n
  kbuild: enforce -Werror=return-type
  scripts: remove namespace.pl
  builddeb: Add support for all required debian/rules targets
  builddeb: Enable rootless builds
  builddeb: Pass -n to gzip for reproducible packages
  kbuild: split the build log of kallsyms
  kbuild: explicitly specify the build id style
  scripts/setlocalversion: make git describe output more reliable
  kbuild: remove cc-option test of -Werror=date-time
  kbuild: remove cc-option test of -fno-stack-check
  kbuild: remove cc-option test of -fno-strict-overflow
  kbuild: move CFLAGS_{KASAN,UBSAN,KCSAN} exports to relevant Makefiles
  kbuild: remove redundant CONFIG_KASAN check from scripts/Makefile.kasan
  kbuild: do not create built-in objects for external module builds
  ...
</pre>
</div>
</content>
</entry>
</feed>
