[LEDE-DEV] Update to util-linux 2.30.1 breaks x86_64 squashfs-combined

[Florian Fainelli]

On 09/29/2017 06:01 PM, Philip Prindeville wrote:
> 
>> On Sep 29, 2017, at 4:39 AM, Felix Fietkau <nbd at nbd.name> wrote:
>>
>> On 2017-09-29 12:20, Felix Fietkau wrote:
>>> On 2017-09-11 02:33, Philip Prindeville wrote:
>>>> Changing the subject from the previous thread as it turned out to not have to do with sysupgrade at all.
>>>>
>>>> What I can tell is this, having added some tracing to fstools.
>>>>
>>>> We get to the call to system() in rootdisk_volume_init():
>>>>
>>>> https://git.lede-project.org/?p=project/fstools.git;a=blob;f=libfstools/rootdisk.c;h=dd00c1b4e5b4aa9b748610fa3e93d301a67101a7;hb=HEAD#l269
>>>>
>>>> and it never seems to return.  The value of “str” is “mkfs.f2fs -q -l rootfs_data /dev/loop0”.
>>>>
>>>> What would cause this to hang rather than return an error?
>>> I've used sysrq to trace this and found out that it's hanging in the
>>> getrandom system call, which could be used through util-linux library
>>> code. That also explains why the update broke it.
>>>
>>> I will prepare a patch that forces util-linux to stick to /dev/urandom
>>> instead - that should hopefully fix this for good.
>> Pushed the fix, please test.
>>
>> - Felix
> 
> 
> Tested on x86_64.  Seems to work.

To avoid patching mored packages in the future, would it make sense to
LD_PRELOAD a library which overrides the SYS_getrandom() with a non
blocking version/early return at appropriate times during system
boot/upgrades which would suffer from low entropy?
-- 
Florian