diff options
Diffstat (limited to 'include/linux/overflow.h')
-rw-r--r-- | include/linux/overflow.h | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/include/linux/overflow.h b/include/linux/overflow.h index 154ed0dbb43f..725f95f7e416 100644 --- a/include/linux/overflow.h +++ b/include/linux/overflow.h @@ -239,6 +239,76 @@ static inline bool __must_check __must_check_overflow(bool overflow) __overflows_type(n, T)) /** + * range_overflows() - Check if a range is out of bounds + * @start: Start of the range. + * @size: Size of the range. + * @max: Exclusive upper boundary. + * + * A strict check to determine if the range [@start, @start + @size) is + * invalid with respect to the allowable range [0, @max). Any range + * starting at or beyond @max is considered an overflow, even if @size is 0. + * + * Returns: true if the range is out of bounds. + */ +#define range_overflows(start, size, max) ({ \ + typeof(start) start__ = (start); \ + typeof(size) size__ = (size); \ + typeof(max) max__ = (max); \ + (void)(&start__ == &size__); \ + (void)(&start__ == &max__); \ + start__ >= max__ || size__ > max__ - start__; \ +}) + +/** + * range_overflows_t() - Check if a range is out of bounds + * @type: Data type to use. + * @start: Start of the range. + * @size: Size of the range. + * @max: Exclusive upper boundary. + * + * Same as range_overflows() but forcing the parameters to @type. + * + * Returns: true if the range is out of bounds. + */ +#define range_overflows_t(type, start, size, max) \ + range_overflows((type)(start), (type)(size), (type)(max)) + +/** + * range_end_overflows() - Check if a range's endpoint is out of bounds + * @start: Start of the range. + * @size: Size of the range. + * @max: Exclusive upper boundary. + * + * Checks only if the endpoint of a range (@start + @size) exceeds @max. + * Unlike range_overflows(), a zero-sized range at the boundary (@start == @max) + * is not considered an overflow. Useful for iterator-style checks. + * + * Returns: true if the endpoint exceeds the boundary. + */ +#define range_end_overflows(start, size, max) ({ \ + typeof(start) start__ = (start); \ + typeof(size) size__ = (size); \ + typeof(max) max__ = (max); \ + (void)(&start__ == &size__); \ + (void)(&start__ == &max__); \ + start__ > max__ || size__ > max__ - start__; \ +}) + +/** + * range_end_overflows_t() - Check if a range's endpoint is out of bounds + * @type: Data type to use. + * @start: Start of the range. + * @size: Size of the range. + * @max: Exclusive upper boundary. + * + * Same as range_end_overflows() but forcing the parameters to @type. + * + * Returns: true if the endpoint exceeds the boundary. + */ +#define range_end_overflows_t(type, start, size, max) \ + range_end_overflows((type)(start), (type)(size), (type)(max)) + +/** * castable_to_type - like __same_type(), but also allows for casted literals * * @n: variable or constant value |