** Description changed: + [Impact] + + * Systems with AMD Ryzen 3000 series CPUs don't boot. + + [Test Case] + + * Boot with fixed systemd on an AMD Ryzen 3000 series system. + + [Regression Potential] + + * The fix itself is very small, it ignores known to be faulty random + values returned by the rdrand instruction and use a different random + source. Those values can still be returned by a properly working rdrand + implementation in 2 in 2^32 cases on 32 bit arches and in 2 in 2^64 + cases on 64 bit arches, but the fallback to the other random source + ensures that in those rare occasions a random number can be generated. + + [Original Bug Text] + On the new AMD Ryzen 3000 series CPUs, there is an issue with systemd preventing the boot process from completing. This issue does not affect the older systemd version in 18.04, but affects the 19.04 version. Here is a screenshot showing what happens: https://www.phoronix.net/image.php?id=ryzen-3700x-3900x-linux&image=amd_zen2_14_show I am currently testing a patch to systemd, derived from this pull request: https://github.com/systemd/systemd/pull/12536 This is a high severity issue, as I do not believe there is no potential workaround without either a firmware update or an ISO respin. I have attached a rebase of the potential patch on the current 19.04 version of systemd for reference. I will provide more details after testing.
-- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1835809 Title: AMD Ryzen 3000 series fails to boot Status in systemd package in Ubuntu: In Progress Status in systemd source package in Disco: In Progress Bug description: [Impact] * Systems with AMD Ryzen 3000 series CPUs don't boot. [Test Case] * Boot with fixed systemd on an AMD Ryzen 3000 series system. [Regression Potential] * The fix itself is very small, it ignores known to be faulty random values returned by the rdrand instruction and use a different random source. Those values can still be returned by a properly working rdrand implementation in 2 in 2^32 cases on 32 bit arches and in 2 in 2^64 cases on 64 bit arches, but the fallback to the other random source ensures that in those rare occasions a random number can be generated. [Original Bug Text] On the new AMD Ryzen 3000 series CPUs, there is an issue with systemd preventing the boot process from completing. This issue does not affect the older systemd version in 18.04, but affects the 19.04 version. Here is a screenshot showing what happens: https://www.phoronix.net/image.php?id=ryzen-3700x-3900x-linux&image=amd_zen2_14_show I am currently testing a patch to systemd, derived from this pull request: https://github.com/systemd/systemd/pull/12536 This is a high severity issue, as I do not believe there is no potential workaround without either a firmware update or an ISO respin. I have attached a rebase of the potential patch on the current 19.04 version of systemd for reference. I will provide more details after testing. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1835809/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
