Re: [PATCH v7 6/7] mseal, system mappings: uprobe mapping
From: Lorenzo Stoakes
Date: Wed Feb 26 2025 - 13:28:36 EST
On Wed, Feb 26, 2025 at 07:20:50PM +0100, Oleg Nesterov wrote:
> On 02/26, Lorenzo Stoakes wrote:
> >
> > Like I said, Jeff opposes the change. I disagree with him, and agree with you,
> > because this is very silly.
> >
> > But I don't want to hold up this series with that discussion (this is for his
> > sake...)
>
> Neither me, so lets go with VM_SEALED_SYSMAP.
>
> My only objection is that
>
> vm_flags = VM_EXEC|VM_MAYEXEC|VM_DONTCOPY|VM_IO;
> vm_flags |= VM_SEALED_SYSMAP;
>
> looks unnecessarily confusing to me,
>
> vm_flags = VM_EXEC|VM_MAYEXEC|VM_DONTCOPY|VM_IO|VM_SEALED_SYSMAP;
>
> or just
>
> vma = _install_special_mapping(...,
> VM_EXEC|VM_MAYEXEC|VM_DONTCOPY|VM_IO|VM_SEALED_SYSMAP,
> ...
>
> looks more readable. But this is cosmetic/subjective, so I won't argue/insist.
Agreed. This would be good.
>
> > Jeff - perhaps drop this and let's return to it in a follow up so this series
> > isn't held up?
>
> Up to you and Jeff.
>
> But this patch looks "natural" to me in this series.
OK, I mean in that case I'm ok with it as-is, as you confirms there's no
issue, I've looked at the code and there's no issue.
It was only if we wanted to try the VM_SEALED thing, i.e. _always_ seal
then it'd do better outside of the series as there'd be a discussion about
maybe changing this CONFIG_64BIT thing yada yada.
>
> Oleg.
>
Jeff - in that case, do NOT drop this one :P but do please look at the
above style nit.
Let's keep things moving... :)