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Message-ID: <6f356fec-4384-4367-8812-a18b71156116@baylibre.com>
Date: Wed, 10 Apr 2024 10:36:16 +0200
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Subject: Re: [PATCH net-next v8 2/3] net: ethernet: ti: Add desc_infos member
 to struct k3_cppi_desc_pool
To: Jakub Kicinski <kuba@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>,
 Eric Dumazet <edumazet@google.com>, Paolo Abeni <pabeni@redhat.com>,
 Russell King <linux@armlinux.org.uk>, Alexei Starovoitov <ast@kernel.org>,
 Daniel Borkmann <daniel@iogearbox.net>,
 Jesper Dangaard Brouer <hawk@kernel.org>,
 John Fastabend <john.fastabend@gmail.com>,
 Sumit Semwal <sumit.semwal@linaro.org>,
 =?UTF-8?Q?Christian_K=C3=B6nig?= <christian.koenig@amd.com>,
 Simon Horman <horms@kernel.org>, Andrew Lunn <andrew@lunn.ch>,
 Ratheesh Kannoth <rkannoth@marvell.com>,
 Naveen Mamindlapalli <naveenm@marvell.com>, danishanwar@ti.com,
 yuehaibing@huawei.com, rogerq@kernel.org, netdev@vger.kernel.org,
 linux-kernel@vger.kernel.org, bpf@vger.kernel.org,
 linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org,
 linaro-mm-sig@lists.linaro.org
References: <20240223-am65-cpsw-xdp-basic-v8-0-f3421b58da09@baylibre.com>
 <20240223-am65-cpsw-xdp-basic-v8-2-f3421b58da09@baylibre.com>
 <20240409173948.66abe6fa@kernel.org>
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From: Julien Panis <jpanis@baylibre.com>
In-Reply-To: <20240409173948.66abe6fa@kernel.org>
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On 4/10/24 02:39, Jakub Kicinski wrote:
> On Mon, 08 Apr 2024 11:38:03 +0200 Julien Panis wrote:
>>   		goto gen_pool_create_fail;
>>   	}
>>   
>> +	pool->desc_infos = kcalloc(pool->num_desc,
>> +				   sizeof(*pool->desc_infos), GFP_KERNEL);
>> +	if (!pool->desc_infos) {
>> +		ret = -ENOMEM;
>> +		dev_err(pool->dev,
>> +			"pool descriptor infos alloc failed %d\n", ret);
> Please don't add errors on mem alloc failures. They just bloat the
> kernel, there will be a rather large OOM splat in the logs if GFP_KERNEL
> allocation fails.
>
>> +		kfree_const(pool_name);
>> +		goto gen_pool_desc_infos_alloc_fail;
>> +	}
>> +
>>   	pool->gen_pool->name = pool_name;
> If you add the new allocation after this line, I think you wouldn't
> have to free pool_name under the if () explicitly.

Hello Jakub,

Thanks for these suggestions, I'll implement them in next version.

Also, about mem alloc failures, shouldn't we free 'pool' on kstrdup_const()
error at the beginning of k3_cppi_desc_pool_create_name() ?
I mean, it's not visible in my patch but I now wonder if this was done
properly even before I modify the file.

Currently, we have:
     pool_name = kstrdup_const(...)
     if (!pool_name)
         return ERR_PTR(ret);

Shouldnt we have instead:
     pool_name = kstrdup_const(...)
     if (!pool_name)
         goto gen_pool_create_fail;
(maybe label to be renamed)
..so that 'pool' can be freed before returning error.

Julien