linux/drivers/char
Jason A. Donenfeld 829d680e82 random: cap jitter samples per bit to factor of HZ
Currently the jitter mechanism will require two timer ticks per
iteration, and it requires N iterations per bit. This N is determined
with a small measurement, and if it's too big, it won't waste time with
jitter entropy because it'd take too long or not have sufficient entropy
anyway.

With the current max N of 32, there are large timeouts on systems with a
small CONFIG_HZ. Rather than set that maximum to 32, instead choose a
factor of CONFIG_HZ. In this case, 1/30 seems to yield sane values for
different configurations of CONFIG_HZ.

Reported-by: Vladimir Murzin <vladimir.murzin@arm.com>
Fixes: 78c768e619 ("random: vary jitter iterations based on cycle counter speed")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-07-16 10:42:12 -07:00
..
agp x86/amd_nb: Unexport amd_cache_northbridges() 2022-04-05 19:22:27 +02:00
hw_random virtio-rng: make device ready before making request 2022-06-08 08:56:03 -04:00
ipmi ipmi:ipmb: Fix refcount leak in ipmi_ipmb_probe 2022-05-12 10:00:04 -05:00
mwave char/mwave: Adjust io port register size 2021-12-03 14:27:06 +01:00
pcmcia Char / Misc / Other smaller driver subsystem updates for 5.19-rc1 2022-06-03 11:36:34 -07:00
tpm tpmdd updates for v5.19-rc1 2022-05-24 13:16:50 -07:00
xilinx_hwicap xilinx_hwicap: cleanup comments 2022-02-25 12:08:57 +01:00
xillybus char: xillybus: fix a refcount leak in cleanup_dev() 2022-04-24 17:30:45 +02:00
adi.c
apm-emulation.c
applicom.c applicom: unneed to initialise statics to 0 2021-12-21 10:14:08 +01:00
applicom.h
bsr.c powerpc/BSR: Make use of the helper macro LIST_HEAD() 2022-02-25 12:10:15 +01:00
ds1620.c
dsp56k.c
dtlk.c
hangcheck-timer.c
hpet.c hpet: remove unused writeq/readq function definitions 2022-02-04 16:45:39 +01:00
Kconfig random: credit cpu and bootloader seeds by default 2022-06-10 11:29:48 +02:00
lp.c char: lp: remove redundant initialization of err 2022-06-10 15:29:50 +02:00
Makefile remove the raw driver 2021-06-04 15:35:03 +02:00
mem.c /dev/mem: make reads and writes interruptible 2022-04-24 17:31:01 +02:00
misc.c char: misc: remove usage of list iterator past the loop body 2022-04-24 17:15:12 +02:00
mspec.c char: mspec: Use kvzalloc() in mspec_mmap() 2020-08-28 12:10:04 +02:00
nsc_gpio.c
nvram.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
nwbutton.c
nwbutton.h
nwflash.c
pc8736x_gpio.c
powernv-op-panel.c powerpc/powernv: Fix fall-through warning for Clang 2021-07-13 19:21:41 -05:00
ppdev.c
ps3flash.c powerpc/ps3: make system bus's remove and shutdown callbacks return void 2020-12-04 01:01:22 +11:00
random.c random: cap jitter samples per bit to factor of HZ 2022-07-16 10:42:12 -07:00
scx200_gpio.c
sonypi.c
tb0219.c
tlclk.c
toshiba.c module: remove never implemented MODULE_SUPPORTED_DEVICE 2021-03-17 13:16:18 -07:00
ttyprintk.c char: ttyprintk: register console 2022-04-22 16:24:47 +02:00
uv_mmtimer.c
virtio_console.c Char/Misc and other driver updates for 5.18-rc1 2022-03-28 12:27:35 -07:00