Recently a weird file permission issue had popped up with using the Brave browser through the Linuxulator when trying to run it: /usr/local/bin/linux-brave: /compat/ubuntu/opt/brave.com/brave/brave-wrapper: Permission denied The permissions were fine and the problem continued to persist after trying multiple Ubuntu-lator re-installations, even with different versions, e.g.: jammy, lunar, mantic. Eventually I thought to peak into the dmesg output and found the following: linux: jid 0 pid 63533 (systemctl): faccessat2 unsupported flag 0x100 linux: jid 0 pid 64609 (systemctl): faccessat2 unsupported flag 0x100 linux: jid 0 pid 66611 (systemctl): faccessat2 unsupported flag 0x100 linux: jid 0 pid 75500 (systemctl): faccessat2 unsupported flag 0x100 linux: jid 0 pid 77301 (systemctl): faccessat2 unsupported flag 0x100 linux: jid 0 pid 79047 (systemctl): faccessat2 unsupported flag 0x100 linux: jid 0 pid 85152 (systemctl): faccessat2 unsupported flag 0x100 linux: jid 0 pid 88585 (grep): syscall splice not really implemented linux: jid 0 pid 64576 (kbd_mode): linux_ioctl_fallback fd=5, cmd=0x4b33 ('K',51) is not implemented linux: jid 0 pid 64576 (kbd_mode): linux_ioctl_fallback fd=5, cmd=0x4b33 ('K',51) is not implemented linux: jid 0 pid 50603 (systemctl): faccessat2 unsupported flag 0x100 linux: jid 0 pid 44462 (systemctl): faccessat2 unsupported flag 0x100 linux: jid 0 pid 44462 (systemctl): faccessat2 unsupported flag 0x100 linux: jid 0 pid 22 (systemctl): faccessat2 unsupported flag 0x100 linux: jid 0 pid 4658 (systemctl): faccessat2 unsupported flag 0x100 linux: jid 0 pid 11089 (setcap): capset[0] effective=0x80000000, permitted=0x0, inheritable=0x0 is not implemented linux: jid 0 pid 15094 (systemctl): faccessat2 unsupported flag 0x100 linux: jid 0 pid 16805 (systemctl): faccessat2 unsupported flag 0x100 linux: jid 0 pid 18843 (systemctl): faccessat2 unsupported flag 0x100 linux: jid 0 pid 20469 (systemctl): faccessat2 unsupported flag 0x100 linux: jid 0 pid 24832 (systemctl): faccessat2 unsupported flag 0x100 linux: jid 0 pid 84149 (systemctl): faccessat2 unsupported flag 0x100 linux: jid 0 pid 85600 (systemctl): faccessat2 unsupported flag 0x100 linux: jid 0 pid 98160 (curl): unsupported setsockopt level 6 optname 31 linux: jid 0 pid 16546 (gpg-agent): syscall inotify_init not implemented With regards to the "(gpg-agent)" line, I would like to note that I've also been having `apt update` GPG errors in the Ubuntu linuxulation. I've used `deb [trusted=yes] ...` in /compat/ubuntu/etc/apt/sources.list as a workaround to get updates but users shouldn't have to do this either.
Looks like that flag is: #define AT_SYMLINK_NOFOLLOW 0x100 /* Do not follow symbolic links. */ Are you able to apply a patch and build a new kernel to test?
Ah, more extensive change is required, note the XXX comment in linux_faccessat2: int linux_faccessat2(struct thread *td, struct linux_faccessat2_args *args) { int flags, unsupported; /* XXX. AT_SYMLINK_NOFOLLOW is not supported by kern_accessat */ unsupported = args->flags & ~(LINUX_AT_EACCESS | LINUX_AT_EMPTY_PATH); if (unsupported != 0) { linux_msg(td, "faccessat2 unsupported flag 0x%x", unsupported); return (EINVAL); }
(In reply to Ed Maste from comment #1) I would be more than happy to help with testing provided patches. No problem with either patching and building.
(In reply to Kenneth Raplee from comment #3) Great, thanks. I thought I was going to have a straightforward, small patch to test before finding the source code comment that I left in PR comment #2.
(In reply to Ed Maste from comment #4) It's understood. I still wanted to put myself out there for testing. :)