Re: [PATCH] x86/platform/uv: move kmalloc() NULL check routine

[Greg KH]

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@xxxxxxxxx>
> ---
>  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