<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux/drivers/char/random.c, branch v4.7</title>
<subtitle>Mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
</subtitle>
<id>https://git.shady.money/linux/atom?h=v4.7</id>
<link rel='self' href='https://git.shady.money/linux/atom?h=v4.7'/>
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<updated>2016-05-21T00:58:30Z</updated>
<entry>
<title>lib/uuid.c: move generate_random_uuid() to uuid.c</title>
<updated>2016-05-21T00:58:30Z</updated>
<author>
<name>Andy Shevchenko</name>
<email>andriy.shevchenko@linux.intel.com</email>
</author>
<published>2016-05-21T00:01:00Z</published>
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<id>urn:sha1:8da4b8c48e7b43cb16d05e1dbb34ad9f73ab7efd</id>
<content type='text'>
Let's gather the UUID related functions under one hood.

Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Reviewed-by: Matt Fleming &lt;matt@codeblueprint.co.uk&gt;
Cc: Dmitry Kasatkin &lt;dmitry.kasatkin@gmail.com&gt;
Cc: Mimi Zohar &lt;zohar@linux.vnet.ibm.com&gt;
Cc: Rasmus Villemoes &lt;linux@rasmusvillemoes.dk&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>drivers: char: random: add get_random_long()</title>
<updated>2016-02-27T18:28:52Z</updated>
<author>
<name>Daniel Cashman</name>
<email>dcashman@android.com</email>
</author>
<published>2016-02-26T23:19:34Z</published>
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<id>urn:sha1:ec9ee4acd97c0039a61c0ae4f12705767ae62153</id>
<content type='text'>
Commit d07e22597d1d ("mm: mmap: add new /proc tunable for mmap_base
ASLR") added the ability to choose from a range of values to use for
entropy count in generating the random offset to the mmap_base address.

The maximum value on this range was set to 32 bits for 64-bit x86
systems, but this value could be increased further, requiring more than
the 32 bits of randomness provided by get_random_int(), as is already
possible for arm64.  Add a new function: get_random_long() which more
naturally fits with the mmap usage of get_random_int() but operates
exactly the same as get_random_int().

Also, fix the shifting constant in mmap_rnd() to be an unsigned long so
that values greater than 31 bits generate an appropriate mask without
overflow.  This is especially important on x86, as its shift instruction
uses a 5-bit mask for the shift operand, which meant that any value for
mmap_rnd_bits over 31 acts as a no-op and effectively disables mmap_base
randomization.

Finally, replace calls to get_random_int() with get_random_long() where
appropriate.

This patch (of 2):

Add get_random_long().

Signed-off-by: Daniel Cashman &lt;dcashman@android.com&gt;
Acked-by: Kees Cook &lt;keescook@chromium.org&gt;
Cc: "Theodore Ts'o" &lt;tytso@mit.edu&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: David S. Miller &lt;davem@davemloft.net&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Nick Kralevich &lt;nnk@google.com&gt;
Cc: Jeff Vander Stoep &lt;jeffv@google.com&gt;
Cc: Mark Salyzyn &lt;salyzyn@android.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>random: Remove kernel blocking API</title>
<updated>2015-06-10T11:14:04Z</updated>
<author>
<name>Herbert Xu</name>
<email>herbert@gondor.apana.org.au</email>
</author>
<published>2015-06-09T10:19:42Z</published>
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<id>urn:sha1:c2719503f5e1e6213d716bb078bdad01e28ebcbf</id>
<content type='text'>
This patch removes the kernel blocking API as it has been completely
replaced by the callback API.

Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
</content>
</entry>
<entry>
<title>random: Add callback API for random pool readiness</title>
<updated>2015-06-10T11:13:56Z</updated>
<author>
<name>Herbert Xu</name>
<email>herbert@gondor.apana.org.au</email>
</author>
<published>2015-06-09T10:19:39Z</published>
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<id>urn:sha1:205a525c334295e3cd4cc7755fd2c0398e3a787f</id>
<content type='text'>
The get_blocking_random_bytes API is broken because the wait can
be arbitrarily long (potentially forever) so there is no safe way
of calling it from within the kernel.

This patch replaces it with a callback API instead.  The callback
is invoked potentially from interrupt context so the user needs
to schedule their own work thread if necessary.

In addition to adding callbacks, they can also be removed as
otherwise this opens up a way for user-space to allocate kernel
memory with no bound (by opening algif_rng descriptors and then
closing them).

Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
</content>
</entry>
<entry>
<title>random: Blocking API for accessing nonblocking_pool</title>
<updated>2015-05-27T09:51:53Z</updated>
<author>
<name>Stephan Mueller</name>
<email>smueller@chronox.de</email>
</author>
<published>2015-05-25T13:08:47Z</published>
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<id>urn:sha1:16b369a91d0dd80be214b7f7801fbc51875454cc</id>
<content type='text'>
The added API calls provide a synchronous function call
get_blocking_random_bytes where the caller is blocked until
the nonblocking_pool is initialized.

CC: Andreas Steffen &lt;andreas.steffen@strongswan.org&gt;
CC: Theodore Ts'o &lt;tytso@mit.edu&gt;
CC: Sandy Harris &lt;sandyinchina@gmail.com&gt;
Signed-off-by: Stephan Mueller &lt;smueller@chronox.de&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
</content>
</entry>
<entry>
<title>random: Wake up all getrandom(2) callers when pool is ready</title>
<updated>2015-05-27T09:51:45Z</updated>
<author>
<name>Herbert Xu</name>
<email>herbert@gondor.apana.org.au</email>
</author>
<published>2015-05-21T08:19:54Z</published>
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<id>urn:sha1:1d9de44e268d880cbe2d0bd3be1ef0661f93fd34</id>
<content type='text'>
If more than one application invokes getrandom(2) before the pool
is ready, then all bar one will be stuck forever because we use
wake_up_interruptible which wakes up a single task.

This patch replaces it with wake_up_all.

Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
</content>
</entry>
<entry>
<title>random: Fix fast_mix() function</title>
<updated>2015-02-09T20:28:42Z</updated>
<author>
<name>George Spelvin</name>
<email>linux@horizon.com</email>
</author>
<published>2015-02-07T05:32:06Z</published>
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<id>urn:sha1:19acc77a36970958a4a0e4daeb2c8cb2aab0ffd4</id>
<content type='text'>
There was a bad typo in commit 43759d4f429c ("random: use an improved
fast_mix() function") and I didn't notice because it "looked right", so
I saw what I expected to see when I reviewed it.

Only months later did I look and notice it's not the Threefish-inspired
mix function that I had designed and optimized.

Mea Culpa.  Each input bit still has a chance to affect each output bit,
and the fast pool is spilled *long* before it fills, so it's not a total
disaster, but it's definitely not the intended great improvement.

I'm still working on finding better rotation constants.  These are good
enough, but since it's unrolled twice, it's possible to get better
mixing for free by using eight different constants rather than repeating
the same four.

Signed-off-by: George Spelvin &lt;linux@horizon.com&gt;
Cc: Theodore Ts'o &lt;tytso@mit.edu&gt;
Cc: stable@vger.kernel.org  # v3.16+
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random</title>
<updated>2014-10-24T19:33:32Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2014-10-24T19:33:32Z</published>
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<id>urn:sha1:14d4cc08832efb724e58944ba2ac22e2ca3143dc</id>
<content type='text'>
Pull /dev/random updates from Ted Ts'o:
 "This adds a memzero_explicit() call which is guaranteed not to be
  optimized away by GCC.  This is important when we are wiping
  cryptographically sensitive material"

* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  crypto: memzero_explicit - make sure to clear out sensitive data
  random: add and use memzero_explicit() for clearing data
</content>
</entry>
<entry>
<title>random: add and use memzero_explicit() for clearing data</title>
<updated>2014-10-17T15:37:29Z</updated>
<author>
<name>Daniel Borkmann</name>
<email>dborkman@redhat.com</email>
</author>
<published>2014-08-27T03:16:35Z</published>
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<id>urn:sha1:d4c5efdb97773f59a2b711754ca0953f24516739</id>
<content type='text'>
zatimend has reported that in his environment (3.16/gcc4.8.3/corei7)
memset() calls which clear out sensitive data in extract_{buf,entropy,
entropy_user}() in random driver are being optimized away by gcc.

Add a helper memzero_explicit() (similarly as explicit_bzero() variants)
that can be used in such cases where a variable with sensitive data is
being cleared out in the end. Other use cases might also be in crypto
code. [ I have put this into lib/string.c though, as it's always built-in
and doesn't need any dependencies then. ]

Fixes kernel bugzilla: 82041

Reported-by: zatimend@hotmail.co.uk
Signed-off-by: Daniel Borkmann &lt;dborkman@redhat.com&gt;
Acked-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Cc: Alexey Dobriyan &lt;adobriyan@gmail.com&gt;
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Cc: stable@vger.kernel.org
</content>
</entry>
<entry>
<title>drivers/char/random: Replace __get_cpu_var uses</title>
<updated>2014-08-26T17:45:45Z</updated>
<author>
<name>Christoph Lameter</name>
<email>cl@linux.com</email>
</author>
<published>2014-08-17T17:30:29Z</published>
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<id>urn:sha1:1b2a1a7e8ad1144dc3f676f2651cb84e01548d59</id>
<content type='text'>
A single case of using __get_cpu_var for address calculation.

Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Christoph Lameter &lt;cl@linux.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
</content>
</entry>
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