From: Matthew Wilcox <willy@infradead.org>
To: Souptick Joarder <jrdr.linux@gmail.com>
Cc: akpm@linux-foundation.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, John Hubbard <jhubbard@nvidia.com>
Subject: Re: [PATCH] mm/gup.c: Handling ERR within unpin_user_pages()
Date: Sun, 13 Sep 2020 15:55:20 +0100 [thread overview]
Message-ID: <20200913145520.GH6583@casper.infradead.org> (raw)
In-Reply-To: <1600007555-11650-1-git-send-email-jrdr.linux@gmail.com>
On Sun, Sep 13, 2020 at 08:02:35PM +0530, Souptick Joarder wrote:
> It is possible that a buggy caller of unpin_user_pages()
> (specially in error handling path) may end up calling it with
> npages < 0 which is unnecessary.
> @@ -328,6 +328,9 @@ void unpin_user_pages(struct page **pages, unsigned long npages)
> {
> unsigned long index;
>
> + if (WARN_ON_ONCE(npages < 0))
> + return;
But npages is unsigned long. So it can't be less than zero.
next prev parent reply other threads:[~2020-09-13 14:55 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-13 14:32 Souptick Joarder
2020-09-13 14:55 ` Matthew Wilcox [this message]
2020-09-14 1:50 ` Souptick Joarder
2020-09-14 14:08 ` Jason Gunthorpe
2020-09-14 20:52 ` Souptick Joarder
2020-09-14 20:56 ` John Hubbard
2020-09-14 21:01 ` Ira Weiny
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