From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: [PATCH] cpufreq: e_powersaver: Use struct_size() in kzalloc() Date: Thu, 24 Jan 2019 11:34:28 +0100 Message-ID: <1645829.9I2fkU6ktd@aspire.rjw.lan> References: <20190107173343.GA4258@embeddedor> <20190108050056.quckhd2d5ah4ywax@vireshk-i7> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <20190108050056.quckhd2d5ah4ywax@vireshk-i7> Sender: linux-kernel-owner@vger.kernel.org To: Viresh Kumar , "Gustavo A. R. Silva" Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-pm@vger.kernel.org On Tuesday, January 8, 2019 6:00:56 AM CET Viresh Kumar wrote: > On 07-01-19, 11:33, Gustavo A. R. Silva 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 code was detected with the help of Coccinelle. > > > > Signed-off-by: Gustavo A. R. Silva > > --- > > drivers/cpufreq/e_powersaver.c | 5 ++--- > > 1 file changed, 2 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/cpufreq/e_powersaver.c b/drivers/cpufreq/e_powersaver.c > > index 60bea302abbe..2d3ef208dd70 100644 > > --- a/drivers/cpufreq/e_powersaver.c > > +++ b/drivers/cpufreq/e_powersaver.c > > @@ -323,9 +323,8 @@ static int eps_cpu_init(struct cpufreq_policy *policy) > > states = 2; > > > > /* Allocate private data and frequency table for current cpu */ > > - centaur = kzalloc(sizeof(*centaur) > > - + (states + 1) * sizeof(struct cpufreq_frequency_table), > > - GFP_KERNEL); > > + centaur = kzalloc(struct_size(centaur, freq_table, states + 1), > > + GFP_KERNEL); > > if (!centaur) > > return -ENOMEM; > > eps_cpu[0] = centaur; > > Acked-by: Viresh Kumar Patch applied, thanks!