Change Details

Strange that we don't have a PR about this, as everyone who debootstrap Ubuntu faces this problem, as Ubuntu 22.04 contains many symlinks, including rtld, which point to the absolute path. People are forced to fix such symlinks by hand or use something like https://github.com/brandt/symlinks. It would be nice to merge it into releng/13.2.

For now a non-native ABI (i.e., Linux) uses the kern_alternate_path() facility to dynamically reroot lookups. First, an attempt is made to lookup the file in /compat/linux/original-path. If that fails, the lookup is done in /original-path. Thats requires a bit of code in every ABI syscall implementation where path name translation is needed. Also our kern_alternate_path() does not properly lookups absolute symlinks in second attempt, i.e., does not append /compat/linux part to the resolved link. The change is intended to avoid this by specifiyng the ABI root directory for namei(), using one call to pwd_exec() during exec-time into the ABI. In that case namei() will dynamically reroot lookups as mentioned above. PR: 72920 MFC after: 1 month

Strange that we don't have a PR about thisFor now a non-native ABI (i.e., as everyone who debootstrap UbuntuLinux) uses the kern_alternate_path() faces this problem,facility to dynamically reroot lookups. as Ubuntu 22.04 contains many symlinksFirst, including rtld,an attempt is made to which point to the absolute path.lookup the file in /compat/linux/original-path. If that fails, People are forced to fix such symlinks by handthe or use something like https://github.com/brandt/symlinkslookup is done in /original-path. Thats requires a bit of code in every ABI syscall implementation where path name translation is needed. Also our kern_alternate_path() does not properly lookups absolute symlinks in second attempt, i.e., does not append /compat/linux part to the resolved link. The change is intended to avoid this by specifiyng the ABI root directory for namei(), using one call to pwd_exec() during exec-time into the ABI. In that case namei() will dynamically reroot lookups as mentioned above. It would be nice to merge it into releng/13.2.PR: 72920 MFC after: 1 month