user/sven/linux.git/include/linux/random.h, branch v4.4.265

random32: move the pseudo-random 32-bit definitions to prandom.h

2020-08-21T08:52:55Z

commit c0842fbc1b18c7a044e6ff3e8fa78bfa822c7d1a upstream. The addition of percpu.h to the list of includes in random.h revealed some circular dependencies on arm64 and possibly other platforms. This include was added solely for the pseudo-random definitions, which have nothing to do with the rest of the definitions in this file but are still there for legacy reasons. This patch moves the pseudo-random parts to linux/prandom.h and the percpu.h include with it, which is now guarded by _LINUX_PRANDOM_H and protected against recursive inclusion. A further cleanup step would be to remove this from entirely, and make people who use the prandom infrastructure include just the new header file. That's a bit of a churn patch, but grepping for "prandom_" and "next_pseudo_random32" "struct rnd_state" should catch most users. But it turns out that that nice cleanup step is fairly painful, because a _lot_ of code currently seems to depend on the implicit include of , which can currently come in a lot of ways, including such fairly core headfers as . So the "nice cleanup" part may or may never happen. Fixes: 1c9df907da83 ("random: fix circular include dependency on arm64 after addition of percpu.h") Tested-by: Guenter Roeck Acked-by: Willy Tarreau Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

random32: remove net_rand_state from the latent entropy gcc plugin

2020-08-21T08:52:55Z

commit 83bdc7275e6206f560d247be856bceba3e1ed8f2 upstream. It turns out that the plugin right now ends up being really unhappy about the change from 'static' to 'extern' storage that happened in commit f227e3ec3b5c ("random32: update the net random state on interrupt and activity"). This is probably a trivial fix for the latent_entropy plugin, but for now, just remove net_rand_state from the list of things the plugin worries about. Reported-by: Stephen Rothwell Cc: Emese Revfy Cc: Kees Cook Cc: Willy Tarreau Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

random: fix circular include dependency on arm64 after addition of percpu.h

2020-08-21T08:52:55Z

commit 1c9df907da83812e4f33b59d3d142c864d9da57f upstream. Daniel Díaz and Kees Cook independently reported that commit f227e3ec3b5c ("random32: update the net random state on interrupt and activity") broke arm64 due to a circular dependency on include files since the addition of percpu.h in random.h. The correct fix would definitely be to move all the prandom32 stuff out of random.h but for backporting, a smaller solution is preferred. This one replaces linux/percpu.h with asm/percpu.h, and this fixes the problem on x86_64, arm64, arm, and mips. Note that moving percpu.h around didn't change anything and that removing it entirely broke differently. When backporting, such options might still be considered if this patch fails to help. [ It turns out that an alternate fix seems to be to just remove the troublesome remove from the arm64 that causes the circular dependency. But we might as well do the whole belt-and-suspenders thing, and minimize inclusion in too. Either will fix the problem, and both are good changes. - Linus ] Reported-by: Daniel Díaz Reported-by: Kees Cook Tested-by: Marc Zyngier Fixes: f227e3ec3b5c Cc: Stephen Rothwell Signed-off-by: Willy Tarreau Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

random32: update the net random state on interrupt and activity

2020-08-21T08:52:54Z

commit f227e3ec3b5cad859ad15666874405e8c1bbc1d4 upstream. This modifies the first 32 bits out of the 128 bits of a random CPU's net_rand_state on interrupt or CPU activity to complicate remote observations that could lead to guessing the network RNG's internal state. Note that depending on some network devices' interrupt rate moderation or binding, this re-seeding might happen on every packet or even almost never. In addition, with NOHZ some CPUs might not even get timer interrupts, leaving their local state rarely updated, while they are running networked processes making use of the random state. For this reason, we also perform this update in update_process_times() in order to at least update the state when there is user or system activity, since it's the only case we care about. Reported-by: Amit Klein Suggested-by: Linus Torvalds Cc: Eric Dumazet Cc: "Jason A. Donenfeld" Cc: Andy Lutomirski Cc: Kees Cook Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: Signed-off-by: Willy Tarreau Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

drivers: char: random: add get_random_long()

2017-06-14T11:16:23Z

commit ec9ee4acd97c0039a61c0ae4f12705767ae62153 upstream. 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 Signed-off-by: Greg Kroah-Hartman

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