On Thu, Jul 13, 2017 at 10:58 AM, Andrew Savchenko <birc...@gentoo.org> wrote: > On Thu, 13 Jul 2017 10:29:06 -0400 Mike Gilbert wrote: >> On Thu, Jul 13, 2017 at 7:35 AM, M. J. Everitt <m.j.ever...@iee.org> wrote: >> > On 13/07/17 12:09, Rich Freeman wrote: >> >> Presumably you'd only want to remount it if it was mounted ro to >> >> start, since it sounds like openrc will be diverging from systemd >> >> behavior here. >> >> >> >> While it seems like a good idea I'm not sure how big an improvement it >> >> is in the larger scheme. We're worried about root accidentially >> >> modifying efivars, but we have no safeguards against root writing to >> >> /dev/sda, and the latter seems much more likely to cause harm, and is >> >> harder to fix. >> >> >> > In case you weren't aware, Rich, rewriting the efivars actually writes >> > to the system BIOS, which renders the computer completely unbootable .. >> > not quite the same as erasing the boot sector of your hard disk, where >> > you simply plug in another device, and Off you go ... >> > >> >> We are actually talking about protecting people who run something like >> rm -rf /sys/firmware/efi/efivars/ as root. >> >> If you are dumb enough to do something like that, you almost deserve >> to spend a couple hundred on a new motherboard. > > Or just rm -rf / > [pedantic] > of course with newer rm versions one needs to run: > rm -rf --no-preserve-root / > or > rm -rf /* /.* > [/pedantic] > > But in some scenarios this command is normal. E.g. user installs > Gentoo from some live dvd/flash, makes some mistakes, understands > that system is broken beyond repair and decides to start over again. > If there is no need to recreate filesystem itself or partition > layout, running rm -rf / as above is quite reasonable. > > When running this command user expects to kill the data, but not > the hardware. That is my point. I can't call such action dumb. > > Best regards, > Andrew Savchenko
Point taken. Although, if the user is in the process of installing Gentoo, efivarfs is likely to be mounted rw anyway so that the user can install a boot loader. Having grub-install perform the remount would minimize this small risk I suppose.
