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Message-ID: <456a78ae-5d7e-9955-5edb-f9f46c22bd75@redhat.com>
Date:   Wed, 19 Jul 2023 10:18:02 +0200
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Subject: Re: [PATCH v2 1/4] mm: factor out VMA stack and heap checks
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To:     Kefeng Wang <wangkefeng.wang@huawei.com>,
        Andrew Morton <akpm@linux-foundation.org>
Cc:     amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-mm@kvack.org, linux-perf-users@vger.kernel.org,
        selinux@vger.kernel.org,
        =?UTF-8?Q?Christian_G=c3=b6ttsche?= <cgzones@googlemail.com>
References: <20230719075127.47736-1-wangkefeng.wang@huawei.com>
 <20230719075127.47736-2-wangkefeng.wang@huawei.com>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat
In-Reply-To: <20230719075127.47736-2-wangkefeng.wang@huawei.com>
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On 19.07.23 09:51, Kefeng Wang wrote:
> Factor out VMA stack and heap checks and name them
> vma_is_initial_stack() and vma_is_initial_heap() for
> general use.
> 
> Cc: Christian Göttsche <cgzones@googlemail.com>
> Cc: David Hildenbrand <david@redhat.com>
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> ---


[...]

> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 2dd73e4f3d8e..51f8c573db74 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -822,6 +822,27 @@ static inline bool vma_is_anonymous(struct vm_area_struct *vma)
>   	return !vma->vm_ops;
>   }
>   

Worth adding a similar comment like for vma_is_initial_stack() ?

> +static inline bool vma_is_initial_heap(const struct vm_area_struct *vma)
> +{
> +       return vma->vm_start <= vma->vm_mm->brk &&
> +		vma->vm_end >= vma->vm_mm->start_brk;
> +}
> +
> +/*
> + * Indicate if the VMA is a stack for the given task; for
> + * /proc/PID/maps that is the stack of the main task.
> + */
> +static inline bool vma_is_initial_stack(const struct vm_area_struct *vma)
> +{
> +	/*
> +	 * We make no effort to guess what a given thread considers to be
> +	 * its "stack".  It's not even well-defined for programs written
> +	 * languages like Go.
> +	 */
> +       return vma->vm_start <= vma->vm_mm->start_stack &&
> +	       vma->vm_end >= vma->vm_mm->start_stack;
> +}
> +
>   static inline bool vma_is_temporary_stack(struct vm_area_struct *vma)
>   {
>   	int maybe_stack = vma->vm_flags & (VM_GROWSDOWN | VM_GROWSUP);

Reviewed-by: David Hildenbrand <david@redhat.com>

-- 
Cheers,

David / dhildenb