Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH] drivers: qcom: rpmh: use struct_size() in kzalloc()
To:     Amit Kucheria <amit.kucheria@verdurent.com>
Cc:     Andy Gross <andy.gross@linaro.org>,
        David Brown <david.brown@linaro.org>,
        linux-arm-msm <linux-arm-msm@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
References: <20181224062235.GA27815@embeddedor.com>
 <CAHLCerMrJ9VB7+zNzhj5WUiM6nOGT=GbrDEHzvPTp7fsfi3f8g@mail.gmail.com>
From:   "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Openpgp: preference=signencrypt
Autocrypt: addr=gustavo@embeddedor.com; keydata=
 mQINBFssHAwBEADIy3ZoPq3z5UpsUknd2v+IQud4TMJnJLTeXgTf4biSDSrXn73JQgsISBwG
 2Pm4wnOyEgYUyJd5tRWcIbsURAgei918mck3tugT7AQiTUN3/5aAzqe/4ApDUC+uWNkpNnSV
 tjOx1hBpla0ifywy4bvFobwSh5/I3qohxDx+c1obd8Bp/B/iaOtnq0inli/8rlvKO9hp6Z4e
 DXL3PlD0QsLSc27AkwzLEc/D3ZaqBq7ItvT9Pyg0z3Q+2dtLF00f9+663HVC2EUgP25J3xDd
 496SIeYDTkEgbJ7WYR0HYm9uirSET3lDqOVh1xPqoy+U9zTtuA9NQHVGk+hPcoazSqEtLGBk
 YE2mm2wzX5q2uoyptseSNceJ+HE9L+z1KlWW63HhddgtRGhbP8pj42bKaUSrrfDUsicfeJf6
 m1iJRu0SXYVlMruGUB1PvZQ3O7TsVfAGCv85pFipdgk8KQnlRFkYhUjLft0u7CL1rDGZWDDr
 NaNj54q2CX9zuSxBn9XDXvGKyzKEZ4NY1Jfw+TAMPCp4buawuOsjONi2X0DfivFY+ZsjAIcx
 qQMglPtKk/wBs7q2lvJ+pHpgvLhLZyGqzAvKM1sVtRJ5j+ARKA0w4pYs5a5ufqcfT7dN6TBk
 LXZeD9xlVic93Ju08JSUx2ozlcfxq+BVNyA+dtv7elXUZ2DrYwARAQABtCxHdXN0YXZvIEEu
 IFIuIFNpbHZhIDxndXN0YXZvQGVtYmVkZGVkb3IuY29tPokCPQQTAQgAJwUCWywcDAIbIwUJ
 CWYBgAULCQgHAgYVCAkKCwIEFgIDAQIeAQIXgAAKCRBHBbTLRwbbMZ6tEACk0hmmZ2FWL1Xi
 l/bPqDGFhzzexrdkXSfTTZjBV3a+4hIOe+jl6Rci/CvRicNW4H9yJHKBrqwwWm9fvKqOBAg9
 obq753jydVmLwlXO7xjcfyfcMWyx9QdYLERTeQfDAfRqxir3xMeOiZwgQ6dzX3JjOXs6jHBP
 cgry90aWbaMpQRRhaAKeAS14EEe9TSIly5JepaHoVdASuxklvOC0VB0OwNblVSR2S5i5hSsh
 ewbOJtwSlonsYEj4EW1noQNSxnN/vKuvUNegMe+LTtnbbocFQ7dGMsT3kbYNIyIsp42B5eCu
 JXnyKLih7rSGBtPgJ540CjoPBkw2mCfhj2p5fElRJn1tcX2McsjzLFY5jK9RYFDavez5w3lx
 JFgFkla6sQHcrxH62gTkb9sUtNfXKucAfjjCMJ0iuQIHRbMYCa9v2YEymc0k0RvYr43GkA3N
 PJYd/vf9vU7VtZXaY4a/dz1d9dwIpyQARFQpSyvt++R74S78eY/+lX8wEznQdmRQ27kq7BJS
 R20KI/8knhUNUJR3epJu2YFT/JwHbRYC4BoIqWl+uNvDf+lUlI/D1wP+lCBSGr2LTkQRoU8U
 64iK28BmjJh2K3WHmInC1hbUucWT7Swz/+6+FCuHzap/cjuzRN04Z3Fdj084oeUNpP6+b9yW
 e5YnLxF8ctRAp7K4yVlvA7kCDQRbLBwMARAAsHCE31Ffrm6uig1BQplxMV8WnRBiZqbbsVJB
 H1AAh8tq2ULl7udfQo1bsPLGGQboJSVN9rckQQNahvHAIK8ZGfU4Qj8+CER+fYPp/MDZj+t0
 DbnWSOrG7z9HIZo6PR9z4JZza3Hn/35jFggaqBtuydHwwBANZ7A6DVY+W0COEU4of7CAahQo
 5NwYiwS0lGisLTqks5R0Vh+QpvDVfuaF6I8LUgQR/cSgLkR//V1uCEQYzhsoiJ3zc1HSRyOP
 otJTApqGBq80X0aCVj1LOiOF4rrdvQnj6iIlXQssdb+WhSYHeuJj1wD0ZlC7ds5zovXh+FfF
 l5qH5RFY/qVn3mNIVxeO987WSF0jh+T5ZlvUNdhedGndRmwFTxq2Li6GNMaolgnpO/CPcFpD
 jKxY/HBUSmaE9rNdAa1fCd4RsKLlhXda+IWpJZMHlmIKY8dlUybP+2qDzP2lY7kdFgPZRU+e
 zS/pzC/YTzAvCWM3tDgwoSl17vnZCr8wn2/1rKkcLvTDgiJLPCevqpTb6KFtZosQ02EGMuHQ
 I6Zk91jbx96nrdsSdBLGH3hbvLvjZm3C+fNlVb9uvWbdznObqcJxSH3SGOZ7kCHuVmXUcqoz
 ol6ioMHMb+InrHPP16aVDTBTPEGwgxXI38f7SUEn+NpbizWdLNz2hc907DvoPm6HEGCanpcA
 EQEAAYkCJQQYAQgADwUCWywcDAIbDAUJCWYBgAAKCRBHBbTLRwbbMdsZEACUjmsJx2CAY+QS
 UMebQRFjKavwXB/xE7fTt2ahuhHT8qQ/lWuRQedg4baInw9nhoPE+VenOzhGeGlsJ0Ys52sd
 XvUjUocKgUQq6ekOHbcw919nO5L9J2ejMf/VC/quN3r3xijgRtmuuwZjmmi8ct24TpGeoBK4
 WrZGh/1hAYw4ieARvKvgjXRstcEqM5thUNkOOIheud/VpY+48QcccPKbngy//zNJWKbRbeVn
 imua0OpqRXhCrEVm/xomeOvl1WK1BVO7z8DjSdEBGzbV76sPDJb/fw+y+VWrkEiddD/9CSfg
 fBNOb1p1jVnT2mFgGneIWbU0zdDGhleI9UoQTr0e0b/7TU+Jo6TqwosP9nbk5hXw6uR5k5PF
 8ieyHVq3qatJ9K1jPkBr8YWtI5uNwJJjTKIA1jHlj8McROroxMdI6qZ/wZ1ImuylpJuJwCDC
 ORYf5kW61fcrHEDlIvGc371OOvw6ejF8ksX5+L2zwh43l/pKkSVGFpxtMV6d6J3eqwTafL86
 YJWH93PN+ZUh6i6Rd2U/i8jH5WvzR57UeWxE4P8bQc0hNGrUsHQH6bpHV2lbuhDdqo+cM9eh
 GZEO3+gCDFmKrjspZjkJbB5Gadzvts5fcWGOXEvuT8uQSvl+vEL0g6vczsyPBtqoBLa9SNrS
 VtSixD1uOgytAP7RWS474w==
Message-ID: <c8fc7bfc-122a-14a8-8916-0e020c485c2d@embeddedor.com>
Date:   Tue, 29 Jan 2019 00:57:02 -0600
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101
 Thunderbird/60.2.1
MIME-Version: 1.0
In-Reply-To: <CAHLCerMrJ9VB7+zNzhj5WUiM6nOGT=GbrDEHzvPTp7fsfi3f8g@mail.gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


On 1/28/19 11:26 PM, Amit Kucheria wrote:
> On Mon, Dec 24, 2018 at 11:52 AM Gustavo A. R. Silva
> <gustavo@embeddedor.com> wrote:
>>
>> One of the more common cases of allocation size calculations is finding
>> the size of a structure that has a zero-sized array at the end, along
>> with memory for some number of elements for that array. For example:
>>
>> struct foo {
>>     int stuff;
>>     void *entry[];
>> };
>>
>> instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);
>>
>> Instead of leaving these open-coded and prone to type mistakes, we can
>> now use the new struct_size() helper:
>>
>> instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);
>>
>> This issue was detected with the help of Coccinelle.
>>
>> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> 
> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
> 

Thanks, Amit.

--
Gustavo

>> ---
>>  drivers/soc/qcom/rpmh.c | 3 +--
>>  1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c
>> index c7beb6841289..12c057a0b325 100644
>> --- a/drivers/soc/qcom/rpmh.c
>> +++ b/drivers/soc/qcom/rpmh.c
>> @@ -362,8 +362,7 @@ int rpmh_write_batch(const struct device *dev, enum rpmh_state state,
>>         if (!count)
>>                 return -EINVAL;
>>
>> -       req = kzalloc(sizeof(*req) + count * sizeof(req->rpm_msgs[0]),
>> -                     GFP_ATOMIC);
>> +       req = kzalloc(struct_size(req, rpm_msgs, count), GFP_ATOMIC);
>>         if (!req)
>>                 return -ENOMEM;
>>         req->count = count;
>> --
>> 2.17.0
>>