Automatic testing could have caught this, maybe.
The email mentions that normal testing didn't catch it as it's not a typical use-case for the devs apparently.
A warning about 5.12-rc1
31–40 of 115 posts
Re: A warning about 5.12-rc1
#32Earlier quoted context omitted.
Dual boot is probably not typical for people who install rc kernels right away? I remember trying to do kernel dev on a dual-boot laptop in college, and I spent a lot of time trying to repair the bootloader while running off of a live-USB environment. Besides, most Linux installs by the numbers are probably web servers/data centers, or large enterprises (think movie studios, large tech companies). I realize this come…
It is a lot more uncommon for MBR-based boot partitions these days. It is no longer the default for Windows. With EFI and GPT, it is a lot simpler. Linux can use a Windows EFI boot partition, or vice-versa. Additionally, in my specific case I have a separate EFI partition saved on a USB stick for booting my encrypted root partition. It adds plausible deniability.
> It adds plausible deniability.
How so?
Re: A warning about 5.12-rc1
#33[deleted]
Re: A warning about 5.12-rc1
#34> it didn't even show up in normal testing, exactly because swapfiles just aren't normal. Uhh, does it mean swapfiles are undertested in the Linux kernel? Or is there some "non-normal" extra testing that is being run for non-rc releases, but not for rc ones? (!?)
I fear you grossly overestimate how detailed the kernel's testing is.
(Do please note that the word "detailed" above was carefully chosen.)
Re: A warning about 5.12-rc1
#35Re: A warning about 5.12-rc1
#36> And, as far as I know, all the normal distributions set things up with swap partitions, not files I guess Ubuntu is not a "normal" distribution then? Because it uses a swap file by default.
I'd venture that most people who are compiling their own -rc1 kernel are not running Ubuntu, and most of those that are probably chose the swap partition option when installing it.
Re: A warning about 5.12-rc1
#37Re: A warning about 5.12-rc1
#38Earlier quoted context omitted.
While maybe not the most performant my favorite is LVM2 on top of a single large LUKS-encrypted partition (+no boot partition and a single (custom platform key) signed EFI bootable kernel blob containing the initram fs in the EFI partition). This: - Allows a encrypted swap partition (on in lvm2 on top of luks, sure not perfect but I don't really use swap) - Allows hibernation (which I don't really use tbh.) - Fully e…
Would the bug Linus is describing still bite you if your swap is in a separate LVM partition? (That's how Ubuntu 20.04 sets things up by default.)
Only if it's a swap file on a filesystem on that LVM partition, and even then if the filesystem is otherwise empty then there's no other data to accidentally overwrite, you might just trash the filesystem structure.
Re: A warning about 5.12-rc1
#39Earlier quoted context omitted.
The email mentions that normal testing didn't catch it as it's not a typical use-case for the devs apparently.
Which is exactly why automated testing exists, to catch cases like this.
If the devs foresaw the set of conditions that trigger the bug and wrote a test that produces those conditions.
Re: A warning about 5.12-rc1
#40> And, as far as I know, all the normal distributions set things up with swap partitions, not files I guess Ubuntu is not a "normal" distribution then? Because it uses a swap file by default.
ubuntu does a lot of things where the design decision is better understood in the context of being as easy to use as possible, for the widest possible spectrum of people with zero prior linux experience, or even computer knowledge in general.