Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20220717024615.2106835-1-Liam.Howlett@oracle.com> <20220716212050.562604df2a48683dfbcc7e57@linux-foundation.org>
In-Reply-To: <20220716212050.562604df2a48683dfbcc7e57@linux-foundation.org>
From:   Yu Zhao <yuzhao@google.com>
Date:   Sat, 16 Jul 2022 23:57:18 -0600
Message-ID: <CAOUHufaxubu3_Ee-G8q3o02fkRoTf6M7-5=85_B_PUtsWbNa8Q@mail.gmail.com>
Subject: Re: [PATCH v11 00/69] Introducing the Maple Tree
To:     Andrew Morton <akpm@linux-foundation.org>,
        Liam Howlett <liam.howlett@oracle.com>
Cc:     "maple-tree@lists.infradead.org" <maple-tree@lists.infradead.org>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Hugh Dickins <hughd@google.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Sat, Jul 16, 2022 at 10:20 PM Andrew Morton
<akpm@linux-foundation.org> wrote:
>
> On Sun, 17 Jul 2022 02:46:32 +0000 Liam Howlett <liam.howlett@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);

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