user/sven/linux.git/include/linux/random.h, branch v4.7

lib/uuid.c: move generate_random_uuid() to uuid.c

2016-05-21T00:58:30Z

Let's gather the UUID related functions under one hood. Signed-off-by: Andy Shevchenko Reviewed-by: Matt Fleming Cc: Dmitry Kasatkin Cc: Mimi Zohar Cc: Rasmus Villemoes Cc: Arnd Bergmann Cc: "Theodore Ts'o" Cc: Al Viro Cc: Jens Axboe Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

drivers: char: random: add get_random_long()

2016-02-27T18:28:52Z

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 Acked-by: Kees Cook Cc: "Theodore Ts'o" Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Cc: Catalin Marinas Cc: Will Deacon Cc: Ralf Baechle Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: David S. Miller Cc: Thomas Gleixner Cc: Ingo Molnar Cc: H. Peter Anvin Cc: Al Viro Cc: Nick Kralevich Cc: Jeff Vander Stoep Cc: Mark Salyzyn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

random32: add prandom_init_once helper for own rngs

2015-10-08T12:26:38Z

Add a prandom_init_once() facility that works on the rnd_state, so that users that are keeping their own state independent from prandom_u32() can initialize their taus113 per cpu states. The motivation here is similar to net_get_random_once(): initialize the state as late as possible in the hope that enough entropy has been collected for the seeding. prandom_init_once() makes use of the recently introduced prandom_seed_full_state() helper and is generic enough so that it could also be used on fast-paths due to the DO_ONCE(). Signed-off-by: Daniel Borkmann Acked-by: Hannes Frederic Sowa Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller

random: Remove kernel blocking API

2015-06-10T11:14:04Z

This patch removes the kernel blocking API as it has been completely replaced by the callback API. Signed-off-by: Herbert Xu

random: Add callback API for random pool readiness

2015-06-10T11:13:56Z

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

random: Blocking API for accessing nonblocking_pool

2015-05-27T09:51:53Z

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 CC: Theodore Ts'o CC: Sandy Harris Signed-off-by: Stephan Mueller Signed-off-by: Herbert Xu

random32: improvements to prandom_bytes

2014-08-25T01:36:01Z

This patch addresses a couple of minor items, mostly addesssing prandom_bytes(): 1) prandom_bytes{,_state}() should use size_t for length arguments, 2) We can use put_unaligned() when filling the array instead of open coding it [ perhaps some archs will further benefit from their own arch specific implementation when GCC cannot make up for it ], 3) Fix a typo, 4) Better use unsigned int as type for getting the arch seed, 5) Make use of prandom_u32_max() for timer slack. Regarding the change to put_unaligned(), callers of prandom_bytes() which internally invoke prandom_bytes_state(), don't bother as they expect the array to be filled randomly and don't have any control of the internal state what-so-ever (that's also why we have periodic reseeding there, etc), so they really don't care. Now for the direct callers of prandom_bytes_state(), which are solely located in test cases for MTD devices, that is, drivers/mtd/tests/{oobtest.c,pagetest.c,subpagetest.c}: These tests basically fill a test write-vector through prandom_bytes_state() with an a-priori defined seed each time and write that to a MTD device. Later on, they set up a read-vector and read back that blocks from the device. So in the verification phase, the write-vector is being re-setup [ so same seed and prandom_bytes_state() called ], and then memcmp()'ed against the read-vector to check if the data is the same. Akinobu, Lothar and I also tested this patch and it runs through the 3 relevant MTD test cases w/o any errors on the nandsim device (simulator for MTD devs) for x86_64, ppc64, ARM (i.MX28, i.MX53 and i.MX6): # modprobe nandsim first_id_byte=0x20 second_id_byte=0xac \ third_id_byte=0x00 fourth_id_byte=0x15 # modprobe mtd_oobtest dev=0 # modprobe mtd_pagetest dev=0 # modprobe mtd_subpagetest dev=0 We also don't have any users depending directly on a particular result of the PRNG (except the PRNG self-test itself), and that's just fine as it e.g. allowed us easily to do things like upgrading from taus88 to taus113. Signed-off-by: Daniel Borkmann Tested-by: Akinobu Mita Tested-by: Lothar Waßmann Cc: Hannes Frederic Sowa Signed-off-by: David S. Miller

random: Add arch_has_random[_seed]()

2014-03-20T02:24:08Z

Add predicate functions for having arch_get_random[_seed]*(). The only current use is to avoid the loop in arch_random_refill() when arch_get_random_seed_long() is unavailable. Signed-off-by: H. Peter Anvin Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Signed-off-by: Theodore Ts'o

x86, random: Enable the RDSEED instruction

2014-03-20T02:22:06Z

Upcoming Intel silicon adds a new RDSEED instruction, which is similar to RDRAND but provides a stronger guarantee: unlike RDRAND, RDSEED will always reseed the PRNG from the true random number source between each read. Thus, the output of RDSEED is guaranteed to be 100% entropic, unlike RDRAND which is only architecturally guaranteed to be 1/512 entropic (although in practice is much more.) The RDSEED instruction takes the same time to execute as RDRAND, but RDSEED unlike RDRAND can legitimately return failure (CF=0) due to entropy exhaustion if too many threads on too many cores are hammering the RDSEED instruction at the same time. Therefore, we have to be more conservative and only use it in places where we can tolerate failures. This patch introduces the primitives arch_get_random_seed_{int,long}() but does not use it yet. Signed-off-by: H. Peter Anvin Reviewed-by: Ingo Molnar Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Signed-off-by: Theodore Ts'o

random32: add prandom_u32_max and convert open coded users

2014-01-22T07:17:20Z

Many functions have open coded a function that returns a random number in range [0,N-1]. Under the assumption that we have a PRNG such as taus113 with being well distributed in [0, ~0U] space, we can implement such a function as uword t = (n*m')>>32, where m' is a random number obtained from PRNG, n the right open interval border and t our resulting random number, with n,m',t in u32 universe. Lets go with Joe and simply call it prandom_u32_max(), although technically we have an right open interval endpoint, but that we have documented. Other users can further be migrated to the new prandom_u32_max() function later on; for now, we need to make sure to migrate reciprocal_divide() users for the reciprocal_divide() follow-up fixup since their function signatures are going to change. Joint work with Hannes Frederic Sowa. Cc: Jakub Zawadzki Cc: Eric Dumazet Cc: linux-kernel@vger.kernel.org Signed-off-by: Hannes Frederic Sowa Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller