2017-11-17 14:32:33

by Florian Weimer

[permalink] [raw]
Subject: Re: [RFC PATCH 1/2] mm: introduce MAP_FIXED_SAFE

On 11/16/2017 11:18 AM, Michal Hocko wrote:
> + if (flags & MAP_FIXED_SAFE) {
> + struct vm_area_struct *vma = find_vma(mm, addr);
> +
> + if (vma && vma->vm_start <= addr)
> + return -ENOMEM;
> + }

Could you pick a different error code which cannot also be caused by a
an unrelated, possibly temporary condition? Maybe EBUSY or EEXIST?

This would definitely help with application-based randomization of
mappings, and there, actual ENOMEM and this error would have to be
handled differently.

Thanks,
Florian

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