Re: [PATCH 1/2] mm/hwpoison-inject: fix refcounting in no-injection case

From: Dean Nelson
Date: Thu Apr 23 2015 - 20:42:45 EST


On 04/16/2015 09:08 PM, Naoya Horiguchi wrote:
> Hwpoison injection via debugfs:hwpoison/corrupt-pfn takes a refcount of
> the target page. But current code doesn't release it if the target page
> is not supposed to be injected, which results in memory leak.
> This patch simply adds the refcount releasing code.
>
> Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>

Acked-by: Dean Nelson <dnelson@xxxxxxxxxx>


> ---
> mm/hwpoison-inject.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git v4.0.orig/mm/hwpoison-inject.c v4.0/mm/hwpoison-inject.c
> index 329caf56df22..2b3f933e3282 100644
> --- v4.0.orig/mm/hwpoison-inject.c
> +++ v4.0/mm/hwpoison-inject.c
> @@ -40,7 +40,7 @@ static int hwpoison_inject(void *data, u64 val)
> * This implies unable to support non-LRU pages.
> */
> if (!PageLRU(p) && !PageHuge(p))
> - return 0;
> + goto put_out;
>
> /*
> * do a racy check with elevated page count, to make sure PG_hwpoison
> @@ -52,11 +52,14 @@ static int hwpoison_inject(void *data, u64 val)
> err = hwpoison_filter(hpage);
> unlock_page(hpage);
> if (err)
> - return 0;
> + goto put_out;
>
> inject:
> pr_info("Injecting memory failure at pfn %#lx\n", pfn);
> return memory_failure(pfn, 18, MF_COUNT_INCREASED);
> +put_out:
> + put_page(hpage);
> + return 0;
> }
>
> static int hwpoison_unpoison(void *data, u64 val)
>

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