15360 2024-01-18 17:41:38 +0000 Add a boot-time random number generation (entropy pool) test 2025-01-30 16:08:03 +0000 1 1 11 Runtime System Startup system-startup 5.0 x86 Multiple NEW Medium+ enhancement 5.99 1 randy.macleod unassigned kevin.tian scott.murray yoann.congal --- --- Don't know oldest_to_newest 97913 0 randy.macleod 2024-01-18 17:41:38 +0000 When trying to clean up by moving rng-tools from oe-core to meta-oe, it became clear that we don't have a way to confirm that the entropy pool has sufficient sources of randomness to avoid having getrandom() block for "too long". This can be a problem, especially at boot time. rng-tools was brought back into oe-core with the following log: > Revert this commit since: > > - some systems using oe-core master may still be using kernels from > before 5.6 pulled in the rng-tools algorithm, and > > - some hardware platforms may not have a hardware random number generator > and could therefore need to run rngd to avoid long boot-time initialization > due to a depleted entropy pool. and this comment from me: The additional context that doesn't belong in the commit log is that we talked about this change in the YP bug review meeting and decided that we would keep rng-tools in oe-core for 5.0-M2 for the two reasons given above. If we end up adding a test, as described below, we may never move the recipe to meta-oe. It seems to me that we need a test that checks if the entropy pool size ever falls below a critical threshold for "too long" in the first N seconds of boot time. Getting that test written so that: - qemu VMs and - real HW with and without /dev/hwrng all pass without the test being too permissive may take some time. Related email threads: https://lists.openembedded.org/g/openembedded-core/message/193798 https://lists.openembedded.org/g/openembedded-core/message/193994 Also should we document the test or how we recommend that people test their hardware? 98030 1 randy.macleod 2024-01-25 15:33:48 +0000 Scott, will you be able to own this bug and add the test. 100804 2 randy.macleod 2025-01-30 16:06:39 +0000 Bulk move to 5.2-M3.