[tor-bugs] #24500 [Core Tor/Tor]: Confusing log message "Can't get entropy from getrandom()"
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Sun Dec 3 11:30:57 UTC 2017
#24500: Confusing log message "Can't get entropy from getrandom()"
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Reporter: arma | Owner: (none)
Type: defect | Status: new
Priority: Medium | Milestone:
Component: Core Tor/Tor | Version:
Severity: Normal | Resolution:
Keywords: | Actual Points:
Parent ID: | Points:
Reviewer: | Sponsor:
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Comment (by yawning):
> The middle line is confusing -- why can't we get the entropy from it?
It's a system call. The usual case for this failing is that the kernel is
too old (`ENOSYS`), but the distribution they are supposedly using has a
kernel that is 3.17 or newer.
This should probably log errno, though I am uncertain as to how useful
that will be since the code is smart enough to retry on `EINTR` and
`EAGAIN`.
>Does that mean Tor has failed at something important? What should the
relay operator do?
Using `getrandom()` is preferable to reading from `/dev/urandom`, but
there is a fallback path, so it's not fatal, just odd. The relay operator
should figure out why `getrandom()` is failing.
--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/24500#comment:2>
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