Re: Linux messages full of `random: get_random_u32 called from`

From: Paul Menzel
Date: Tue Apr 24 2018 - 11:56:12 EST

Dear Theodore,


On 04/24/18 17:49, Theodore Y. Ts'o wrote:
On Tue, Apr 24, 2018 at 09:56:21AM -0400, Theodore Y. Ts'o wrote:
On Tue, Apr 24, 2018 at 01:48:16PM +0200, Paul Menzel wrote:

Since Linux 4.17-rcX, Linux spams a lot of `random: get_random_u32 called
from` messages. I believe, this setting should be reverted by default as
otherwise a lot of other messages are not seen.

Can you tell me a bit about your system? What distribution, what
hardware is present in your sytsem (what architecture, what
peripherals are attached, etc.)?

Can you also send me your dmesg or kern.log so I can see where
get_random_u32 is getting called from during your system startup?

Sorry, for just attaching the unedited log file with the coreboot boot messages. But at time stamp 31 second (first column) the Linux messages are also included. An excerpt, and the full log in my last message.

01.515: Jumping to boot code at 00009000(7f733000)
31.117: [ 0.515017] 00:07: ttyS1 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
31.118: [ 0.523260] Linux agpgart interface v0.103
31.119: [ 0.528188] i8042: PNP: PS/2 Controller [PNP0303:PS2K,PNP0f13:PS2M] at 0x60,0x64 irq 1,12
31.130: [ 0.547244] serio: i8042 KBD port at 0x60,0x64 irq 1
31.130: [ 0.552286] serio: i8042 AUX port at 0x60,0x64 irq 12
31.130: [ 0.557653] rtc_cmos 00:03: RTC can wake from S4
31.131: [ 0.562627] rtc_cmos 00:03: registered as rtc0
31.131: [ 0.567197] rtc_cmos 00:03: alarms up to one month, y3k, 242 bytes nvram, hpet irqs
31.131: [ 0.575045] ledtrig-cpu: registered to indicate activity on CPUs
31.132: [ 0.581736] random: get_random_u32 called from cache_random_seq_create+0xa3/0x1f0 with crng_init=0
31.132: [ 0.590831] random: get_random_u32 called from cache_alloc_refill+0x5bb/0x13d0 with crng_init=0
31.132: [ 0.599654] random: get_random_u32 called from cache_random_seq_create+0xa3/0x1f0 with crng_init=0
31.132: [ 0.608722] random: get_random_u32 called from cache_alloc_refill+0x5bb/0x13d0 with crng_init=0
31.132: [ 0.617551] random: get_random_u32 called from cache_random_seq_create+0xa3/0x1f0 with crng_init=0
31.132: [ 0.626630] random: get_random_u32 called from cache_alloc_refill+0x5bb/0x13d0 with crng_init=0
31.132: [ 0.635438] random: get_random_u32 called from cache_random_seq_create+0xa3/0x1f0 with crng_init=0
31.133: [ 0.644556] input: AT Translated Set 2 keyboard as /devices/platform/i8042/serio0/input/input0

The problem on the Lenovo X60 is, that the serial console seems to switch from ttyS0 to ttyS1 during bootup with the dock attached, thatâs why you do not see the messages in the beginning.


Kind regards,

Paul

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