** Description changed:
Hello.
On Thu Feb 8, Linux kernel for Ubuntu 16.04.3 LTS has been updated to
the 4.4.0-113.136 version (xenial-proposed). However, after reboot,
plymouth freezes during start, and keys on an USB keyboard were in-
active. After several seconds, the BusyBox shell screen appeared. It
looks this way:
,------
| BusyBox v1.22.1 (Ubuntu 1:1.22.0-15ubuntu1) built-in shell (ash)
| Enter 'help' for a list of built-in commands.
|
| (initramfs) _
`------
Unfortunately, the USB keyboard does not work and does not respond. The
only way to solve this issue is a "hard reset" and in GRUB menu choosing
an earlier kernel, which is linux 4.4.0-112.135. Now, everything works
okay.
Proposed update to the Linux 4.4.0-113.136 contains many new updates
(please see 1.) It's an i386/x86_32 architecture, which does not contain
PTI yet, right? I'm asking, because mentioned -proposed updates contains
a couple of PTI-related patches and bugs in PTI can cause a few
different signatures of crashes etc. For example:
- ✗ Crashes in early boot, especially around CPU bringup. Bugs in the
trampoline code or mappings cause these.
- ✗ Userspace segfaults early in boot, sometimes manifesting as mount(8)
failing to mount the rootfs. These have tended to be TLB invalidation issues.
Usually invalidating the wrong PCID, or otherwise missing an invalidation.
+ → Crashes in early boot, especially around CPU bringup. Bugs in the
trampoline code or mappings cause these.
+ → Userspace segfaults early in boot, sometimes manifesting as mount(8)
failing to mount the rootfs. These have tended to be TLB invalidation issues.
Usually invalidating the wrong PCID, or otherwise missing an invalidation.
NOTE: if it's about PCID, which is mentioned in a second point, there is
one patch in -proposed update: "x86/mm/32: Move
setup_clear_cpu_cap(X86_FEATURE_PCID) earlier". Maybe that's is the
cause of a boot failure? There are no errors in log files, such as
'/var/log/syslog' or '/var/log/kern.log'. However, it's a Celeron, "E"
series. So, I don't know if mentioned patches are good for this type of
processor etc.? Especially on i386/x86_32 architecture.
- I hope, that all mitigations and fixes for "Metldown & Spectre_v1.2"
- atacks will be available for 32-bit x86 architecture. (OpenSUSE
- Developers are working on such a fixes/patches, right?) If I could
- provide some more informations, please let me know. Here are some
- technical informations:
+ ● UPDATE/WARNING: It seems, that 'kaslr' option is responsible for this
+ issue. After booting the latest v4.4.0-115.139 kernel, I've had the same
+ problems as described above. However, after removing 'kaslr' option from
+ a command line via GRUB menu, system started normally etc. The latest,
+ working kernel with 'kaslr' option is v4.4.0-112.135. According to all
+ of this I think, that 'kaslr' is not compatible with some "Spectre &
+ Meltdown" mitigation patches and fixes etc.
- ● Release ('/proc/version_signature'): Ubuntu 4.4.0-112.135-generic 4.4.98
- ● Architecture: i386/x86_32
- ● PCI ('lspci -vnvn'): 00:0a.0 PCI bridge [0604]: NVIDIA Corporation MCP73
PCI Express bridge [10de:056d] (rev a1) (prog-if 01 [Subtractive decode])
Capabilities: [b8] Subsystem: Gigabyte Technology Co., Ltd MCP73 PCI Express
bridge [1458:026f]
+ ✗ Release ('/proc/version_signature'): Ubuntu 4.4.0-112.135-generic 4.4.98
+ ✗ Architecture: i386/x86_32
+ ✗ PCI ('lspci -vnvn'): 00:0a.0 PCI bridge [0604]: NVIDIA Corporation MCP73
PCI Express bridge [10de:056d] (rev a1) (prog-if 01 [Subtractive decode])
Capabilities: [b8] Subsystem: Gigabyte Technology Co., Ltd MCP73 PCI Express
bridge [1458:026f]
Thanks, regards.
________________
1. https://lists.ubuntu.com/archives/xenial-
changes/2018-February/020108.html
** Tags added: kaslr
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https://bugs.launchpad.net/bugs/1748710
Title:
Linux 4.4.0-113.136 (i386/x86_32): failed to boot and BusyBox v1.22.1
built-in shell (initramfs).
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