[Buildroot] [Bug 13586] New: grub failure with BR2_OPTIMIZE_3
Yann E. MORIN
yann.morin.1998 at free.fr
Thu May 27 20:37:21 UTC 2021
David, All,
On 2021-05-27 16:28 +0000, David Laight spake thusly:
> From: Yann E. MORIN
> > On 2021-05-27 17:33 +0200, Andreas Hilse via buildroot spake thusly:
> > > following up on this because I also encountered this error.
> > >
> > > There is a bug report on the grub bug tracker by Tony Battersby who
> > > bisected the error down to a certain patch/bugfix:
> > > https://savannah.gnu.org/bugs/?60458
> > >
> > > The mentioned patch has also been included in buildroot as
> > > boot/grub2/0132-kern-parser-Fix-a-stack-buffer-overflow.patch with
> > > commit e840f2d469.
> > >
> > > I can also confirm, that removing that patch fixes the issue of grub
> > > loop of endless rebooting.
> > However, this patch is a security fix, so reverting it is not so nice
> > either.
> >
> > Since it seems that using another optimisation level works arorund the
> > issue, I would be more inclined to change that, e.g. to -Os, as the
> > reporter seems to imply it works for them.
> >
> > Would you please send a patch with such a workaround, please?
>
> Hmmmm if the code fails to compile with -O2 it is probably broken.
> (Unlike -O3 which tends to be a compiler bug!)
>
> So they may have replaced one security bug with another one.
Maybe... However, I prefer we keep the patch that is actually known for
fixing a security issue, and workaround the breakage it introduces,
rather than revert it just because it "may have replaced one security
bug with another one."
If/when there is a report that an actual security issue is intriduced in
that patch, then we can reconsider, and evaluate which issue we want to
sacrifice.
Of course, if there is a better fix, then we can use that (I've looked
at their git tree, there is nothing I could identify).
In the meantime, I stand by my position that we should just work around
the isue by building with -Os, because at the very least it makes for a
bootable system again.
> The patch is too big to eyeball for errors.
Indeed.
> I did manage to build grub with AVX support.
> Spent ages working out why it wouldn't boot a kernel on an Atom.
> (I knew userspace was broken.)
> It is probably worth passing -mno-avx when building grub.
But this seems like a totally different issue, is it not?
Regards,
Yann E. MORIN.
--
.-----------------.--------------------.------------------.--------------------.
| Yann E. MORIN | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: |
| +33 662 376 056 | Software Designer | \ / CAMPAIGN | ___ |
| +33 561 099 427 `------------.-------: X AGAINST | \e/ There is no |
| http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL | v conspiracy. |
'------------------------------^-------^------------------^--------------------'
More information about the buildroot
mailing list