** Description changed: - Since kernel v4.5, the correct parameter to disable USB subsystem - initialization is "usbcore.nousb" always (instead of "nousb" in case the - subsystem is built-in). This was changed by commit 097a9ea0e48 ("usb: - make "nousb" a clear module parameter"). + [Impact] + Crash kernels come up with the usb subsystem enabled, even when it should be disabled by default. + + + [Description] + Since kernel v4.5, the correct parameter to disable USB subsystem initialization is "usbcore.nousb" always (instead of "nousb" in case the subsystem is built-in). This was changed by commit 097a9ea0e48 ("usb: make "nousb" a clear module parameter"). We need to take this into account in kdump-tools, or else we may boot with USB in kdump even the command-line saying the opposite. + + This affects Xenial onwards, since the system may be running an HWE or + other supported v4.5+ kernel. + + [Test Case] + 1) Deploy a Disco VM e.g. with uvt-kvm + 2) Install the kdump-tools package + 3) Run `kdump-config test`and check for the 'usbcore.nousb' parameter: + + $ kdump-config test + [...] + kexec command to be used: + /sbin/kexec -p --command-line="BOOT_IMAGE=/boot/vmlinuz-4.15.0-45-generic root=LABEL=cloudimg-rootfs ro console=tty1 console=ttyS0 nr_cpus=1 systemd.unit=kdump-tools.service irqpoll nousb ata_piix.prefer_ms_hyperv=0" /var/lib/kdump/vmlinuz + + [Regression Potential] + The regression potential is very low, since it doesn't need any changes in makedumpfile and we're only adding a parameter on the crashkernel cmdline. + According to kernel documentation [0], unknown parameters will be ignored if they contain a dot (usbcore.nousb), so this change should have no impact on v4.4 and earlier kernels. + Nonetheless, the fix will be tested with autopkgtests and normal kdump use-case scenarios.
** Description changed: [Impact] Crash kernels come up with the usb subsystem enabled, even when it should be disabled by default. - [Description] Since kernel v4.5, the correct parameter to disable USB subsystem initialization is "usbcore.nousb" always (instead of "nousb" in case the subsystem is built-in). This was changed by commit 097a9ea0e48 ("usb: make "nousb" a clear module parameter"). We need to take this into account in kdump-tools, or else we may boot with USB in kdump even the command-line saying the opposite. This affects Xenial onwards, since the system may be running an HWE or other supported v4.5+ kernel. [Test Case] 1) Deploy a Disco VM e.g. with uvt-kvm 2) Install the kdump-tools package 3) Run `kdump-config test`and check for the 'usbcore.nousb' parameter: $ kdump-config test [...] kexec command to be used: - /sbin/kexec -p --command-line="BOOT_IMAGE=/boot/vmlinuz-4.15.0-45-generic root=LABEL=cloudimg-rootfs ro console=tty1 console=ttyS0 nr_cpus=1 systemd.unit=kdump-tools.service irqpoll nousb ata_piix.prefer_ms_hyperv=0" /var/lib/kdump/vmlinuz + /sbin/kexec -p --command-line="BOOT_IMAGE=/boot/vmlinuz-4.15.0-45-generic root=LABEL=cloudimg-rootfs ro console=tty1 console=ttyS0 nr_cpus=1 systemd.unit=kdump-tools.service irqpoll nousb ata_piix.prefer_ms_hyperv=0" /var/lib/kdump/vmlinuz [Regression Potential] The regression potential is very low, since it doesn't need any changes in makedumpfile and we're only adding a parameter on the crashkernel cmdline. According to kernel documentation [0], unknown parameters will be ignored if they contain a dot (usbcore.nousb), so this change should have no impact on v4.4 and earlier kernels. Nonetheless, the fix will be tested with autopkgtests and normal kdump use-case scenarios. + + [0] https://www.kernel.org/doc/Documentation/admin-guide/kernel- + parameters.rst -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1800562 Title: Replace "nousb" option in kdump command-line for the newer "usbcore.nousb" To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/makedumpfile/+bug/1800562/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs