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Date: Sun, 21 Jan 2024 14:32:07 -0800
From: Andrew Morton <akpm@linux-foundation.org>
To: Prakash Sangappa <prakash.sangappa@oracle.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, muchun.song@linux.dev,
 mike.kravetz@oracle.com
Subject: Re: [PATCH] Hugetlb pages should not be reserved by shmat() if
 SHM_NORESERVE
Message-Id: <20240121143207.299f0d3df52ac746224dacd8@linux-foundation.org>
In-Reply-To: <1705713472-3537-1-git-send-email-prakash.sangappa@oracle.com>
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On Fri, 19 Jan 2024 17:17:52 -0800 Prakash Sangappa <prakash.sangappa@oracle.com> wrote:

> For shared memory of type SHM_HUGETLB, hugetlb pages are reserved in
> shmget() call. If SHM_NORESERVE flags is specified then the hugetlb
> pages are not reserved. However when the shared memory is attached
> with the shmat() call the hugetlb pages are getting reserved incorrectly
> for SHM_HUGETLB shared memory created with SHM_NORESERVE.
> 
> Ensure that the hugetlb pages are no reserved for SHM_HUGETLB shared
> memory in the shmat() call.

Thanks.

What are the userspace-visible effects of this change?

Based on that, is a -stable backport desirable?

And can we please identify a suitable Fixes: target for this?