linux-dev/drivers/char/hw_random/core.c, branch linus/master

Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

2022-03-21T23:02:36Z

Pull crypto updates from Herbert Xu: "API: - hwrng core now credits for low-quality RNG devices. Algorithms: - Optimisations for neon aes on arm/arm64. - Add accelerated crc32_be on arm64. - Add ffdheXYZ(dh) templates. - Disallow hmac keys < 112 bits in FIPS mode. - Add AVX assembly implementation for sm3 on x86. Drivers: - Add missing local_bh_disable calls for crypto_engine callback. - Ensure BH is disabled in crypto_engine callback path. - Fix zero length DMA mappings in ccree. - Add synchronization between mailbox accesses in octeontx2. - Add Xilinx SHA3 driver. - Add support for the TDES IP available on sama7g5 SoC in atmel" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (137 commits) crypto: xilinx - Turn SHA into a tristate and allow COMPILE_TEST MAINTAINERS: update HPRE/SEC2/TRNG driver maintainers list crypto: dh - Remove the unused function dh_safe_prime_dh_alg() hwrng: nomadik - Change clk_disable to clk_disable_unprepare crypto: arm64 - cleanup comments crypto: qat - fix initialization of pfvf rts_map_msg structures crypto: qat - fix initialization of pfvf cap_msg structures crypto: qat - remove unneeded assignment crypto: qat - disable registration of algorithms crypto: hisilicon/qm - fix memset during queues clearing crypto: xilinx: prevent probing on non-xilinx hardware crypto: marvell/octeontx - Use swap() instead of open coding it crypto: ccree - Fix use after free in cc_cipher_exit() crypto: ccp - ccp_dmaengine_unregister release dma channels crypto: octeontx2 - fix missing unlock hwrng: cavium - fix NULL but dereferenced coccicheck error crypto: cavium/nitrox - don't cast parameter in bit operations crypto: vmx - add missing dependencies MAINTAINERS: Add maintainer for Xilinx ZynqMP SHA3 driver crypto: xilinx - Add Xilinx SHA3 driver ...

random: pull add_hwgenerator_randomness() declaration into random.h

2022-02-21T20:14:21Z

add_hwgenerator_randomness() is a function implemented and documented inside of random.c. It is the way that hardware RNGs push data into it. Therefore, it should be declared in random.h. Otherwise sparse complains with: random.c:1137:6: warning: symbol 'add_hwgenerator_randomness' was not declared. Should it be static? The alternative would be to include hw_random.h into random.c, but that wouldn't really be good for anything except slowing down compile time. Cc: Matt Mackall Cc: Theodore Ts'o Acked-by: Herbert Xu Reviewed-by: Eric Biggers Reviewed-by: Dominik Brodowski Signed-off-by: Jason A. Donenfeld

hwrng: core - introduce rng_quality sysfs attribute

2022-02-18T05:21:11Z

The rng_quality sysfs attribute returns the quality setting for the currently active hw_random device, in entropy bits per 1024 bits of input. Storing a value between 0 and 1024 to this file updates this estimate accordingly. Based on the updates to the quality setting, the rngd kernel thread may be stopped (if no hw_random device is trusted to return entropy), may be started (if the quality setting is increased from zero), or may use a different hw_random source (if that has higher quality output). Cc: Herbert Xu Cc: Jason A. Donenfeld Signed-off-by: Dominik Brodowski Signed-off-by: Herbert Xu

hwrng: core - use per-rng quality value instead of global setting

2022-02-18T05:21:10Z

The current_quality variable exposed as a module parameter is fundamentally broken: If it is set at boot time, it is overwritten once the first hw rng device is loaded; if it is set at runtime, it is without effect if the hw rng device had its quality value set to 0 (and no default_quality was set); and if a new rng is selected, it gets overwritten. Therefore, mark it as obsolete, and replace it by the per-rng quality setting. Cc: Herbert Xu Cc: Jason A. Donenfeld Signed-off-by: Dominik Brodowski Signed-off-by: Herbert Xu

hwrng: core - start and stop in-kernel rngd in separate function

2022-02-18T05:21:10Z

Extract the start/stop logic for the in-kernel rngd thread to a separate function. Cc: Herbert Xu Cc: Jason A. Donenfeld Signed-off-by: Dominik Brodowski Signed-off-by: Herbert Xu

hwrng: core - do not bother to order list of devices by quality

2022-02-18T05:21:10Z

There is no real reason why this list needs to be kept ordered by the driver-provided quality value -- a value which is set only by a handful of hw_random devices anyway. Cc: Herbert Xu Cc: Jason A. Donenfeld Signed-off-by: Dominik Brodowski Signed-off-by: Herbert Xu

hwrng: core - credit entropy for low quality sources of randomness

2022-02-05T04:10:51Z

In case the entropy quality is low, there may be less than one bit to credit in the call to add_hwgenerator_randomness(): The number of bytes returned by rng_get_data() multiplied by the current quality (in entropy bits per 1024 bits of input) must be larger than 128 to credit at least one bit. However, imx-rngc.c sets the quality to 19, but may return less than 32 bytes; hid_u2fzero.c sets the quality to 1; and users may override the quality setting manually. In case there is less than one bit to credit, keep track of it and add that credit to the next iteration. Cc: Herbert Xu Cc: Jason A. Donenfeld Signed-off-by: Dominik Brodowski Signed-off-by: Herbert Xu

hwrng: core - break out of hwrng_fillfn if current rng is not trusted

2022-02-05T04:10:50Z

For two reasons, current_quality may become zero within the rngd kernel thread: (1) The user lowers current_quality to 0 by writing to the sysfs module parameter file (note that increasing the quality from zero is without effect at the moment), or (2) there are two or more hwrng devices registered, and those which provide quality>0 are unregistered, but one with quality==0 remains. If current_quality is 0, the randomness is not trusted and cannot help to increase the entropy count. That will lead to continuous calls to the hwrngd thread and continuous stirring of the input pool with untrusted bits. Cc: Matt Mackall Cc: Herbert Xu Cc: Jason A. Donenfeld Signed-off-by: Dominik Brodowski Signed-off-by: Herbert Xu

hwrng: core - only set cur_rng_set_by_user if it is working

2022-02-05T04:10:49Z

In case the user-specified rng device is not working, it is not used; therefore cur_rng_set_by_user must not be set to 1. Cc: Matt Mackall Cc: Herbert Xu Cc: Jason A. Donenfeld Signed-off-by: Dominik Brodowski Signed-off-by: Herbert Xu

hwrng: core - use rng_fillbuf in add_early_randomness()

2022-02-05T04:10:49Z

Using rng_buffer in add_early_randomness() may race with rng_dev_read(). Use rng_fillbuf instead, as it is otherwise only used within the kernel by hwrng_fillfn() and therefore never exposed to userspace. Cc: Matt Mackall Cc: Herbert Xu Cc: Jason A. Donenfeld Signed-off-by: Dominik Brodowski Signed-off-by: Herbert Xu