Re: [PATCH] x86/tlb_uv: Fixing some memory allocation failure in x86 UV

[David Rientjes <rientjes@google.com>]

On Tue, 10 Jun 2014, Zhouyi Zhou wrote:

> Fixing some memory allocation failure handling in x86 UV
> 
> Signed-off-by: Zhouyi Zhou <yizhouzhou@ict.ac.cn>
> ---
>  arch/x86/platform/uv/tlb_uv.c |   17 +++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/arch/x86/platform/uv/tlb_uv.c b/arch/x86/platform/uv/tlb_uv.c
> index dfe605a..a434768 100644
> --- a/arch/x86/platform/uv/tlb_uv.c
> +++ b/arch/x86/platform/uv/tlb_uv.c
> @@ -1965,6 +1966,10 @@ static void make_per_cpu_thp(struct bau_control *smaster)
>  	size_t hpsz = sizeof(struct hub_and_pnode) * num_possible_cpus();
>  
>  	smaster->thp = kmalloc_node(hpsz, GFP_KERNEL, smaster->osnode);
> +	if (!smaster->thp) {
> +		pr_err("ERROR: out of memory, can not create hub and pnode!\n");
> +		return;
> +	}
>  	memset(smaster->thp, 0, hpsz);
>  	for_each_present_cpu(cpu) {
>  		smaster->thp[cpu].pnode = uv_cpu_hub_info(cpu)->pnode;
> @@ -1980,6 +1985,8 @@ static void make_per_hub_cpumask(struct bau_control *hmaster)
>  	int sz = sizeof(cpumask_t);
>  
>  	hmaster->cpumask = kzalloc_node(sz, GFP_KERNEL, hmaster->osnode);
> +	if (!hmaster->cpumask)
> +		pr_err("ERROR: out of memory, can not create cpumask!\n");
>  }
>  
>  /*
> @@ -2056,11 +2063,15 @@ static int __init summarize_uvhub_sockets(int nuvhubs,
>  				if (scan_sock(sdp, bdp, &smaster, &hmaster))
>  					return 1;
>  				make_per_cpu_thp(smaster);
> +				if (!smaster->thp)
> +					return 1;
>  			}
>  			socket++;
>  			socket_mask = (socket_mask >> 1);
>  		}
>  		make_per_hub_cpumask(hmaster);
> +		if (!hmaster->cpumask)
> +			return 1;
>  	}
>  	return 0;
>  }

You're missing that make_per_hub_cpumask() isn't marked __init or freed 
after bootstrap so the correct fix would be to fold its implementation 
into summarize_uvhub_sockets() and return non-zero when the kzalloc_node() 
fails.

> @@ -2077,9 +2088,16 @@ static int __init init_per_cpu(int nuvhubs, int base_part_pnode)
>  	timeout_us = calculate_destination_timeout();
>  
>  	vp = kmalloc(nuvhubs * sizeof(struct uvhub_desc), GFP_KERNEL);

This should also be a kcalloc().

> +	if (!vp)
> +		return 1;
> +
>  	uvhub_descs = (struct uvhub_desc *)vp;
>  	memset(uvhub_descs, 0, nuvhubs * sizeof(struct uvhub_desc));
>  	uvhub_mask = kzalloc((nuvhubs+7)/8, GFP_KERNEL);
> +	if (!uvhub_mask) {
> +		kfree(uvhub_descs);
> +		return 1;
> +	}
>  
>  	if (get_cpu_topology(base_part_pnode, uvhub_descs, uvhub_mask))
>  		goto fail;