Re: [PATCH v4 3/4] device property: constify property arrays values

Andy Shevchenko
2017-02-02T16:50:16Z

On Thu, 2017-02-02 at 08:39 -0800, Dmitry Torokhov wrote:
> From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
>
> Data that is fed into property arrays should not be modified, so let's
> mark
> relevant pointers as const. This will allow us making source arrays as
> const/__initconst.
>

> Also fix memory leaks on errors in property_entry_copy().

While the code looks okay, I'm not sure what memory leaks you are
referring to. The idea as far as I remember was to run *free() function
if *copy() fails.

>
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> ---
>
> Not sending the rest of the series as to not clutter mailing lists too
> much...
>
>  drivers/base/property.c  |   66 +++++++++++++++++++++++++++++++----
> -----------
>  include/linux/property.h |   12 ++++----
>  2 files changed, 51 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/base/property.c b/drivers/base/property.c
> index edc09854520b..09fb9757e086 100644
> --- a/drivers/base/property.c
> +++ b/drivers/base/property.c
> @@ -682,44 +682,64 @@ int fwnode_property_match_string(struct
> fwnode_handle *fwnode,
>  }
>  EXPORT_SYMBOL_GPL(fwnode_property_match_string);
>
> +static int property_copy_string_array(struct property_entry *dst,
> +       const struct property_entry
> *src)
> +{
> + char **d;
> + size_t nval = src->length / sizeof(*d);
> + size_t i;
> +
> + d = kcalloc(nval, sizeof(*d), GFP_KERNEL);
> + if (!d)
> + return -ENOMEM;
> +
> + for (i = 0; i < nval; i++) {
> + d[i] = kstrdup(src->pointer.str[i], GFP_KERNEL);
> + if (!d[i] && src->pointer.str[i]) {
> + while (--i >= 0)
> + kfree(d[i]);
> + kfree(d);
> + return -ENOMEM;
> + }
> + }
> +
> + dst->pointer.str = (void *)d;
> + return 0;
> +}
> +
>  static int property_entry_copy(struct property_entry *dst,
>          const struct property_entry *src)
>  {
> - const char **d, **s;
> - size_t i, nval;
> + int error;
>
>   dst->name = kstrdup(src->name, GFP_KERNEL);
>   if (!dst->name)
>   return -ENOMEM;
>
>   if (src->is_array) {
> - if (!src->length)
> - return -ENODATA;
> + if (!src->length) {
> + error = -ENODATA;
> + goto out_free_name;
> + }
>
>   if (src->is_string) {
> - nval = src->length / sizeof(const char *);
> - dst->pointer.str = kcalloc(nval, sizeof(const
> char *),
> -    GFP_KERNEL);
> - if (!dst->pointer.str)
> - return -ENOMEM;
> -
> - d = dst->pointer.str;
> - s = src->pointer.str;
> - for (i = 0; i < nval; i++) {
> - d[i] = kstrdup(s[i], GFP_KERNEL);
> - if (!d[i] && s[i])
> - return -ENOMEM;
> - }
> + error = property_copy_string_array(dst, src);
> + if (error)
> + goto out_free_name;
>   } else {
>   dst->pointer.raw_data = kmemdup(src-
> >pointer.raw_data,
>   src->length,
> GFP_KERNEL);
> - if (!dst->pointer.raw_data)
> - return -ENOMEM;
> + if (!dst->pointer.raw_data) {
> + error = -ENOMEM;
> + goto out_free_name;
> + }
>   }
>   } else if (src->is_string) {
>   dst->value.str = kstrdup(src->value.str, GFP_KERNEL);
> - if (!dst->value.str && src->value.str)
> - return -ENOMEM;
> + if (!dst->value.str && src->value.str) {
> + error = -ENOMEM;
> + goto out_free_name;
> + }
>   } else {
>   dst->value.raw_data = src->value.raw_data;
>   }
> @@ -729,6 +749,10 @@ static int property_entry_copy(struct
> property_entry *dst,
>   dst->is_string = src->is_string;
>
>   return 0;
> +
> +out_free_name:
> + kfree(dst->name);
> + return error;
>  }
>
>  /**
> diff --git a/include/linux/property.h b/include/linux/property.h
> index 5746e9927016..64e3a9c6d95f 100644
> --- a/include/linux/property.h
> +++ b/include/linux/property.h
> @@ -160,12 +160,12 @@ struct property_entry {
>   bool is_string;
>   union {
>   union {
> - void *raw_data;
> - u8 *u8_data;
> - u16 *u16_data;
> - u32 *u32_data;
> - u64 *u64_data;
> - const char **str;
> + const void *raw_data;
> + const u8 *u8_data;
> + const u16 *u16_data;
> + const u32 *u32_data;
> + const u64 *u64_data;
> + const char * const *str;
>   } pointer;
>   union {
>   unsigned long long raw_data;

--
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy