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From: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
To: yaliang.wang@windriver.com
Cc: rppt@kernel.org, huangpei@loongson.cn, akpm@linux-foundation.org,
	kumba@gentoo.org, geert@linux-m68k.org,
	anshuman.khandual@arm.com, penberg@kernel.org,
	linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] MIPS: pgalloc: fix memory leak caused by pgd_free()
Date: Mon, 14 Mar 2022 15:51:08 +0100	[thread overview]
Message-ID: <20220314145108.GB13438@alpha.franken.de> (raw)
In-Reply-To: <20220310113116.2068859-1-yaliang.wang@windriver.com>

On Thu, Mar 10, 2022 at 07:31:16PM +0800, yaliang.wang@windriver.com wrote:
> From: Yaliang Wang <Yaliang.Wang@windriver.com>
> 
> pgd page is freed by generic implementation pgd_free() since commit
> f9cb654cb550 ("asm-generic: pgalloc: provide generic pgd_free()"),
> however, there are scenarios that the system uses more than one page as
> the pgd table, in such cases the generic implementation pgd_free() won't
> be applicable anymore. For example, when PAGE_SIZE_4KB is enabled and
> MIPS_VA_BITS_48 is not enabled in a 64bit system, the macro "PGD_ORDER"
> will be set as "1", which will cause allocating two pages as the pgd
> table. Well, at the same time, the generic implementation pgd_free()
> just free one pgd page, which will result in the memory leak.
> 
> The memory leak can be easily detected by executing shell command:
> "while true; do ls > /dev/null; grep MemFree /proc/meminfo; done"
> 
> Fixes: f9cb654cb550 ("asm-generic: pgalloc: provide generic pgd_free()")
> Signed-off-by: Yaliang Wang <Yaliang.Wang@windriver.com>
> ---
>  arch/mips/include/asm/pgalloc.h | 6 ++++++
>  1 file changed, 6 insertions(+)

applied to mips-next.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

  reply	other threads:[~2022-03-14 14:53 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-10 11:31 [PATCH] MIPS: pgalloc: fix memory leak caused by pgd_free() yaliang.wang
2022-03-14 14:51 ` Thomas Bogendoerfer [this message]
2022-04-02 13:48 ` Maciej W. Rozycki
2022-04-03  3:34   ` Andrew Holmes
2022-04-03 10:37     ` Maciej W. Rozycki
2022-04-04 13:16       ` Andrew Powers-Holmes
2022-04-05  9:42         ` Maciej W. Rozycki
2022-04-05 10:45           ` Thomas Bogendoerfer
2022-04-05 11:31             ` Maciej W. Rozycki
2022-04-04 21:10       ` Joshua Kinard
2022-04-03  4:15 ` Donald Hoskins

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