Public bug reported: [Bug description]
On a jammy installation, which was upgraded from focal, after a full- upgrade and a reboot, I enter the LUKS password to decrypt the disk. Then I get the following error: libgcc_s.so.1 must be installed for pthread_exit to work After the error is shown, the system asks for the password again (which never works, always throwing the same error). [Root cause] I was able to decrypt the disk with the same password by booting from a live usb. Which allowed further investigation. The error shown in the LUKS password prompt menu comes from https://github.com/bminor/glibc/blob/glibc-2.34/nptl/pthread_exit.c#L31-L32, which indeed shows that pthread_exit fails when libgcc_s.so.1 is missing. From https://git.launchpad.net/ubuntu/+source/initramfs-tools/tree/hook-functions?h=import/0.140ubuntu10#n260, we noticed that libgcc_s.so.1 is only copied if 1) copy_exec is called for a binary directly linked to libgcc_s.so.1, or 2) copy_exec is called for a binary linked to libpthread The cryptsetup initramfs hook, calls copy_exec for /sbin/cryptsetup, which is linked to libargon2.so.1, which is linked to libpthread.so.0. This covers case (2) above. As a consequence, libgcc_s.so.1 is copied to the initrd image and the error reported here is not seen. However, since glibc 2.34, libpthread is shipped within glibc, and the binaries are no longer linked to libpthread.so.0. As a consequence, an argon2 package built with glibc 2.32 will no longer be linked to libpthread.so.0 and libgcc_s.so.1 will no longer be copied to the initrd image. Triggering the reported error. This can be verified in these two argon2 builds, from the same sources, but with different glibc versions: https://launchpad.net/ubuntu/+source/argon2/0~20171227-0.2build21.04.0/+build/21066610 https://launchpad.net/ubuntu/+source/argon2/0~20171227-0.2build22/+build/22255217 Still lvm2 is a seeded package, which Recommends thin-provisioning- tools. thin-provisioning-tools ships a initramfs hook that calls copy_exec for /usr/sbin/pdata_tools, which is directly linked to libgcc_s.so.1. This covers the case (1) above and should suffice to ensure the boot process works properly. Since thin-provisioning-tools is just a recommends for lvm2, it could be removed from the system (and indeed, for some reason, was not present in my focal=>jammy installation). In this case, a new kernel installation should trigger the reported error. [Reproducer] - Install jammy with a LUKS encrypted disk - remove thin-provisioning-tools - perform a full-upgrade (make sure the kernel was upgraded or run update-initramfs manually) - reboot and verify you can no longer get past the decrypt password prompt screen [Workaround] A workaround for anyone affected would be to install thin-provisioning- tools and run update-initramfs. [Impact] Users upgrading from focal to jammy will eventually be locked out of their systems [Additional information] While this issue is similar to https://bugs.launchpad.net/ubuntu/+source/initramfs-tools/+bug/1861757, https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=950254, and https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=950551, This is a different bug, with a different root cause. Thanks to sergiodj for the pairing session on the root cause analysis. ** Affects: initramfs-tools (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1958594 Title: Boot error: libgcc_s.so.1 must be installed for pthread_exit to work To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/initramfs-tools/+bug/1958594/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
