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Message-ID: <4d4f4ae4-e5e9-4d9e-ac25-d262e7ea23fc@kylinos.cn>
Date: Thu, 18 Jan 2024 10:16:57 +0800
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Subject: Re: [PATCH] drm/msm/adreno: Add a null pointer check in
 zap_shader_load_mdt()
Content-Language: en-US
To: Markus Elfring <Markus.Elfring@web.de>, freedreno@lists.freedesktop.org,
 dri-devel@lists.freedesktop.org, linux-arm-msm@vger.kernel.org,
 kernel-janitors@vger.kernel.org, Abhinav Kumar <quic_abhinavk@quicinc.com>,
 Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
 Daniel Vetter <daniel@ffwll.ch>, David Airlie <airlied@gmail.com>,
 Marijn Suijten <marijn.suijten@somainline.org>,
 Rob Clark <robdclark@gmail.com>, Sean Paul <sean@poorly.run>
Cc: LKML <linux-kernel@vger.kernel.org>
References: <20240116032732.65262-1-chentao@kylinos.cn>
 <9e390783-05c5-47fc-a0c6-b95e249fe691@web.de>
From: Kunwu Chan <chentao@kylinos.cn>
In-Reply-To: <9e390783-05c5-47fc-a0c6-b95e249fe691@web.de>
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On 2024/1/18 02:50, Markus Elfring wrote:
>> kasprintf() returns a pointer to dynamically allocated memory
>> which can be NULL upon failure. Ensure the allocation was successful
>> by checking the pointer validity.
> =E2=80=A6
>> +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
>> @@ -144,6 +144,10 @@ static int zap_shader_load_mdt(struct msm_gpu *gp=
u, const char *fwname,
>>   		char *newname;
>>
>>   		newname =3D kasprintf(GFP_KERNEL, "qcom/%s", fwname);
>> +		if (!newname) {
>> +			ret =3D -ENOMEM;
>> +			goto out;
>> +		}
> =E2=80=A6
>=20
> How do you think about to avoid the repetition of the pointer check
> for the variable =E2=80=9Cmem_region=E2=80=9D?
"mem_region"? Is this a clerical error, do you mean 'newname'?

No check found in __qcom_mdt_load for 'newname'.
'newname' is used for printing in '__qcom_mdt_load' in some cases, which=20
is a bit dangerous.
So it's necessary check it before using it.

> Can the usage of other labels become more appropriate?
>=20
> Regards,
> Markus
--=20
Thanks,
   Kunwu