runtime: use .openbsd.randomdata for startupRand

[FiloSottile]

OpenBSD has its version of AT_RANDOM, the .openbsd.randomdata ELF section documented at SPECS.randomdata. We should use that instead of reading from /dev/urandom.

[jharshman]

Looking at this, just want to make sure this is the documentation you're referring to:
https://github.com/openbsd/src/blob/master/libexec/ld.so/SPECS.randomdata

[gopherbot]

Change https://go.dev/cl/618155 mentions this issue: runtime: Use OpenBSD AT_RANDOM for startupRand

[jharshman]

In https://go.dev/cl/618155 I had a few misunderstandings so I am closing that CL.

It seems to me that the solution can be broken down into two parts -

The first part would be to make a change to the linker code to include the new ELF segment (described here) .

The second part would be to update the runtime code in os_openbsd.go to read from this new segment to get the random data and set the startupRand global variable. This can be done in the existing readRandom(r []byte) function that currently reads from /dev/urandom.

https://go-review.googlesource.com/c/go/+/618155/comments/6d91fc6f_716738ce

[gopherbot]

Change https://go.dev/cl/641615 mentions this issue: cmd/link: Implement openbsd.randomdata ELF section

[alirezaarzehgar]

Hey, why is this issue still open? I want to help with the Go project. How can I fix this issue? I need some guidance on researching and trying to resolve it. However, I have time to do R&D and learn about my task.

My goal is to actively contribute to Go and I am willing to learn the necessary technical skills. Thank you for your time and attention

[ianlancetaylor]

@alirezaarzehgar As noted above, there is a patch pending for this issue: https://go.dev/cl/641615. If you look at the issue, it is waiting for a test.