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Date:   Fri, 6 Sep 2019 11:32:52 +0200
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Austin Kim <austindh.kim@gmail.com>
Cc:     tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org,
        dvhart@infradead.org, andy@infradead.org, hpa@zytor.com,
        allison@lohutok.net, armijn@tjaldur.nl, kjlu@umn.edu,
        platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86/platform/uv: move kmalloc() NULL check routine
Message-ID: <20190906093252.GB16843@kroah.com>
References: <20190905232951.GA28779@LGEARND20B15>
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On Fri, Sep 06, 2019 at 08:29:51AM +0900, Austin Kim wrote:
> The result of kmalloc should have been checked ahead of below statement:
> 	pqp = (struct bau_pq_entry *)vp;
> 
> Move BUG_ON(!vp) before above statement.
> 
> Signed-off-by: Austin Kim <austindh.kim@gmail.com>
> ---
>  arch/x86/platform/uv/tlb_uv.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/platform/uv/tlb_uv.c b/arch/x86/platform/uv/tlb_uv.c
> index 20c389a..5f0a96bf 100644
> --- a/arch/x86/platform/uv/tlb_uv.c
> +++ b/arch/x86/platform/uv/tlb_uv.c
> @@ -1804,9 +1804,9 @@ static void pq_init(int node, int pnode)
>  
>  	plsize = (DEST_Q_SIZE + 1) * sizeof(struct bau_pq_entry);
>  	vp = kmalloc_node(plsize, GFP_KERNEL, node);
> -	pqp = (struct bau_pq_entry *)vp;
> -	BUG_ON(!pqp);
> +	BUG_ON(!vp);

Ick!  Don't crash the whole machine if you are out of memory, that's a
totally lazy and broken driver.  Fix this up properly please.

But the original code is just fine (from a this is doing what I want it
to do point of view), I don't see the need to change anything here, you
did not modify any logic at all.

thanks,

greg k-h