| Message ID | 20220902122928.632602-1-cezary.rojewski@intel.com |
|---|---|
| Headers | show |
| Series | lib/string_helpers: Introduce parse_int_array_user() | expand |
On 9/2/2022 2:29 PM, Cezary Rojewski wrote: > Add new helper function to allow for splitting specified user string > into a sequence of integers. Internally it makes use of get_options() so > the returned sequence contains the integers extracted plus an additional > element that begins the sequence and specifies the integers count. > > Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com> > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> > Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com> > --- > include/linux/string_helpers.h | 2 ++ > lib/string_helpers.c | 45 ++++++++++++++++++++++++++++++++++ > 2 files changed, 47 insertions(+) > > diff --git a/include/linux/string_helpers.h b/include/linux/string_helpers.h > index 4d72258d42fd..dc2e726fd820 100644 > --- a/include/linux/string_helpers.h > +++ b/include/linux/string_helpers.h > @@ -21,6 +21,8 @@ enum string_size_units { > void string_get_size(u64 size, u64 blk_size, enum string_size_units units, > char *buf, int len); > > +int parse_int_array_user(const char __user *from, size_t count, int **array); > + > #define UNESCAPE_SPACE BIT(0) > #define UNESCAPE_OCTAL BIT(1) > #define UNESCAPE_HEX BIT(2) > diff --git a/lib/string_helpers.c b/lib/string_helpers.c > index 5ed3beb066e6..d0c8f6ecf84c 100644 > --- a/lib/string_helpers.c > +++ b/lib/string_helpers.c > @@ -131,6 +131,51 @@ void string_get_size(u64 size, u64 blk_size, const enum string_size_units units, > } > EXPORT_SYMBOL(string_get_size); > > +/** > + * parse_int_array_user - Split string into a sequence of integers > + * @from: The user space buffer to read from > + * @ppos: The current position in the buffer There is no such parameter? > + * @count: The maximum number of bytes to read > + * @tkns: Returned pointer to sequence of integers s/tkns/array/ ? > + * > + * On success @tkns is allocated and initialized with a sequence of ditto > + * integers extracted from the @from plus an additional element that > + * begins the sequence and specifies the integers count. > + * > + * Caller takes responsibility for freeing @tkns when it is no longer ditto > + * needed. > + */ > +int parse_int_array_user(const char __user *from, size_t count, int **array) > +{ > + int *ints, nints; > + char *buf; > + int ret = 0; > + > + buf = memdup_user_nul(from, count); > + if (IS_ERR(buf)) > + return PTR_ERR(buf); > + > + get_options(buf, 0, &nints); > + if (!nints) { > + ret = -ENOENT; > + goto free_buf; > + } > + > + ints = kcalloc(nints + 1, sizeof(*ints), GFP_KERNEL); > + if (!ints) { > + ret = -ENOMEM; > + goto free_buf; > + } > + > + get_options(buf, nints + 1, ints); > + *array = ints; > + > +free_buf: > + kfree(buf); > + return ret; > +} > +EXPORT_SYMBOL(parse_int_array_user); > + > static bool unescape_space(char **src, char **dst) > { > char *p = *dst, *q = *src;