[PATCH v11 00/69] Introducing the Maple Tree

[Liam Howlett]

* Yu Zhao <yuzhao at google.com> [220717 01:58]:
> On Sat, Jul 16, 2022 at 10:20 PM Andrew Morton
> <akpm at linux-foundation.org> wrote:
> >
> > On Sun, 17 Jul 2022 02:46:32 +0000 Liam Howlett <liam.howlett at oracle.com> wrote:
> ...
> >         gap = mas.index;
> >         gap += (info->align_offset - gap) & info->align_mask;
> > -       VM_BUG_ON(gap + info->length > info->high_limit);
> > -       VM_BUG_ON(gap + info->length > mas.last);

What arch did you hit these on?  David asked for me to restore some of
the BUG_ONs in these functions and I guess I got it wrong.

> 
> These VM_BUG_ONs are new, and I hit the second one quickly:
> 
>   kernel BUG at mm/mmap.c:1631!
>   RIP: 0010:vm_unmapped_area+0xdb/0x1c0
>   Call Trace:
>    <TASK>
>    arch_get_unmapped_area+0x1ee/0x220
>    arch_get_unmapped_area_topdown+0x25a/0x290
>    get_unmapped_area+0x92/0x100
>    do_mmap+0x13f/0x560
>    vm_mmap_pgoff+0xcd/0x170