Re: [PATCH] cpufreq: use kzalloc() to allocate memory for cpufreq_frequency_table
From: Gautham R Shenoy
Date: Fri Mar 28 2014 - 06:45:25 EST
On Fri, Mar 28, 2014 at 03:44:24PM +0530, Viresh Kumar wrote:
> Few drivers are using kmalloc() to allocate memory for frequency tables and once
> we have an additional field '.flags' in 'struct cpufreq_frequency_table', these
> might become unstable. Better get these fixed by replacing kmalloc() by
> kzalloc() instead.
>
> Along with that we also remove use of .driver_data from SPEAr driver as it
> doesn't use it at all. Also, writing zero to .driver_data is not required for
> powernow-k8 as it is already zero.
>
> Reported-by: Gautham R. Shenoy <ego@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Reviewed-by: Gautham R. Shenoy <ego@xxxxxxxxxxxxxxxxxx>
> ---
> @Rafael: Please apply this one before:
>
> http://permalink.gmane.org/gmane.linux.kernel/1673994
>
> so that git bisect doesn't break. Though the chances of this field getting
> initialized to a value equal to BOOST, i.e. 0x1 are very rare.
>
> drivers/cpufreq/acpi-cpufreq.c | 2 +-
> drivers/cpufreq/ia64-acpi-cpufreq.c | 2 +-
> drivers/cpufreq/longhaul.c | 2 +-
> drivers/cpufreq/powernow-k8.c | 5 ++---
> drivers/cpufreq/s3c24xx-cpufreq.c | 4 ++--
> drivers/cpufreq/spear-cpufreq.c | 7 ++-----
> 6 files changed, 9 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
> index d5eaedb..000e4e0 100644
> --- a/drivers/cpufreq/acpi-cpufreq.c
> +++ b/drivers/cpufreq/acpi-cpufreq.c
> @@ -754,7 +754,7 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
> goto err_unreg;
> }
>
> - data->freq_table = kmalloc(sizeof(*data->freq_table) *
> + data->freq_table = kzalloc(sizeof(*data->freq_table) *
> (perf->state_count+1), GFP_KERNEL);
> if (!data->freq_table) {
> result = -ENOMEM;
> diff --git a/drivers/cpufreq/ia64-acpi-cpufreq.c b/drivers/cpufreq/ia64-acpi-cpufreq.c
> index beb191b..c30aaa6 100644
> --- a/drivers/cpufreq/ia64-acpi-cpufreq.c
> +++ b/drivers/cpufreq/ia64-acpi-cpufreq.c
> @@ -254,7 +254,7 @@ acpi_cpufreq_cpu_init (
> }
>
> /* alloc freq_table */
> - data->freq_table = kmalloc(sizeof(*data->freq_table) *
> + data->freq_table = kzalloc(sizeof(*data->freq_table) *
> (data->acpi_data.state_count + 1),
> GFP_KERNEL);
> if (!data->freq_table) {
> diff --git a/drivers/cpufreq/longhaul.c b/drivers/cpufreq/longhaul.c
> index 5c440f8..d00e5d1 100644
> --- a/drivers/cpufreq/longhaul.c
> +++ b/drivers/cpufreq/longhaul.c
> @@ -475,7 +475,7 @@ static int longhaul_get_ranges(void)
> return -EINVAL;
> }
>
> - longhaul_table = kmalloc((numscales + 1) * sizeof(*longhaul_table),
> + longhaul_table = kzalloc((numscales + 1) * sizeof(*longhaul_table),
> GFP_KERNEL);
> if (!longhaul_table)
> return -ENOMEM;
> diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c
> index 770a9e1..1b6ae6b 100644
> --- a/drivers/cpufreq/powernow-k8.c
> +++ b/drivers/cpufreq/powernow-k8.c
> @@ -623,7 +623,7 @@ static int fill_powernow_table(struct powernow_k8_data *data,
> if (check_pst_table(data, pst, maxvid))
> return -EINVAL;
>
> - powernow_table = kmalloc((sizeof(*powernow_table)
> + powernow_table = kzalloc((sizeof(*powernow_table)
> * (data->numps + 1)), GFP_KERNEL);
> if (!powernow_table) {
> printk(KERN_ERR PFX "powernow_table memory alloc failure\n");
> @@ -793,7 +793,7 @@ static int powernow_k8_cpu_init_acpi(struct powernow_k8_data *data)
> }
>
> /* fill in data->powernow_table */
> - powernow_table = kmalloc((sizeof(*powernow_table)
> + powernow_table = kzalloc((sizeof(*powernow_table)
> * (data->acpi_data.state_count + 1)), GFP_KERNEL);
> if (!powernow_table) {
> pr_debug("powernow_table memory alloc failure\n");
> @@ -810,7 +810,6 @@ static int powernow_k8_cpu_init_acpi(struct powernow_k8_data *data)
>
> powernow_table[data->acpi_data.state_count].frequency =
> CPUFREQ_TABLE_END;
> - powernow_table[data->acpi_data.state_count].driver_data = 0;
> data->powernow_table = powernow_table;
>
> if (cpumask_first(cpu_core_mask(data->cpu)) == data->cpu)
> diff --git a/drivers/cpufreq/s3c24xx-cpufreq.c b/drivers/cpufreq/s3c24xx-cpufreq.c
> index a3dc192..be1b2b5 100644
> --- a/drivers/cpufreq/s3c24xx-cpufreq.c
> +++ b/drivers/cpufreq/s3c24xx-cpufreq.c
> @@ -586,7 +586,7 @@ static int s3c_cpufreq_build_freq(void)
> size = cpu_cur.info->calc_freqtable(&cpu_cur, NULL, 0);
> size++;
>
> - ftab = kmalloc(sizeof(*ftab) * size, GFP_KERNEL);
> + ftab = kzalloc(sizeof(*ftab) * size, GFP_KERNEL);
> if (!ftab) {
> printk(KERN_ERR "%s: no memory for tables\n", __func__);
> return -ENOMEM;
> @@ -664,7 +664,7 @@ int __init s3c_plltab_register(struct cpufreq_frequency_table *plls,
>
> size = sizeof(*vals) * (plls_no + 1);
>
> - vals = kmalloc(size, GFP_KERNEL);
> + vals = kzalloc(size, GFP_KERNEL);
> if (vals) {
> memcpy(vals, plls, size);
> pll_reg = vals;
> diff --git a/drivers/cpufreq/spear-cpufreq.c b/drivers/cpufreq/spear-cpufreq.c
> index 4cfdcff..3867839 100644
> --- a/drivers/cpufreq/spear-cpufreq.c
> +++ b/drivers/cpufreq/spear-cpufreq.c
> @@ -195,18 +195,15 @@ static int spear_cpufreq_probe(struct platform_device *pdev)
> cnt = prop->length / sizeof(u32);
> val = prop->value;
>
> - freq_tbl = kmalloc(sizeof(*freq_tbl) * (cnt + 1), GFP_KERNEL);
> + freq_tbl = kzalloc(sizeof(*freq_tbl) * (cnt + 1), GFP_KERNEL);
> if (!freq_tbl) {
> ret = -ENOMEM;
> goto out_put_node;
> }
>
> - for (i = 0; i < cnt; i++) {
> - freq_tbl[i].driver_data = i;
> + for (i = 0; i < cnt; i++)
> freq_tbl[i].frequency = be32_to_cpup(val++);
> - }
>
> - freq_tbl[i].driver_data = i;
> freq_tbl[i].frequency = CPUFREQ_TABLE_END;
>
> spear_cpufreq.freq_tbl = freq_tbl;
> --
> 1.7.12.rc2.18.g61b472e
>
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