diff options
| -rw-r--r-- | src/util/ralloc.c | 25 | ||||
| -rw-r--r-- | src/util/ralloc.h | 62 |
2 files changed, 87 insertions, 0 deletions
diff --git a/src/util/ralloc.c b/src/util/ralloc.c index fc35661996d..0d20223d98f 100644 --- a/src/util/ralloc.c +++ b/src/util/ralloc.c @@ -198,6 +198,21 @@ reralloc_size(const void *ctx, void *ptr, size_t size) } void * +rerzalloc_size(const void *ctx, void *ptr, size_t old_size, size_t new_size) +{ + if (unlikely(ptr == NULL)) + return rzalloc_size(ctx, new_size); + + assert(ralloc_parent(ptr) == ctx); + ptr = resize(ptr, new_size); + + if (new_size > old_size) + memset((char *)ptr + old_size, 0, new_size - old_size); + + return ptr; +} + +void * ralloc_array_size(const void *ctx, size_t size, unsigned count) { if (count > SIZE_MAX/size) @@ -224,6 +239,16 @@ reralloc_array_size(const void *ctx, void *ptr, size_t size, unsigned count) return reralloc_size(ctx, ptr, size * count); } +void * +rerzalloc_array_size(const void *ctx, void *ptr, size_t size, + unsigned old_count, unsigned new_count) +{ + if (new_count > SIZE_MAX/size) + return NULL; + + return rerzalloc_size(ctx, ptr, size * old_count, size * new_count); +} + void ralloc_free(void *ptr) { diff --git a/src/util/ralloc.h b/src/util/ralloc.h index b4f372dfe9b..857ca5f797f 100644 --- a/src/util/ralloc.h +++ b/src/util/ralloc.h @@ -121,6 +121,23 @@ void *rzalloc_size(const void *ctx, size_t size) MALLOCLIKE; */ void *reralloc_size(const void *ctx, void *ptr, size_t size); +/** + * Resize a ralloc-managed array, preserving data and initializing any newly + * allocated data to zero. + * + * Similar to \c realloc. Unlike C89, passing 0 for \p size does not free the + * memory. Instead, it resizes it to a 0-byte ralloc context, just like + * calling ralloc_size(ctx, 0). This is different from talloc. + * + * \param ctx The context to use for new allocation. If \p ptr != NULL, + * it must be the same as ralloc_parent(\p ptr). + * \param ptr Pointer to the memory to be resized. May be NULL. + * \param old_size The amount of memory in the previous allocation, in bytes. + * \param new_size The amount of memory to allocate, in bytes. + */ +void *rerzalloc_size(const void *ctx, void *ptr, + size_t old_size, size_t new_size); + /// \defgroup array Array Allocators @{ /** @@ -178,6 +195,28 @@ void *reralloc_size(const void *ctx, void *ptr, size_t size); ((type *) reralloc_array_size(ctx, ptr, sizeof(type), count)) /** + * \def rerzalloc(ctx, ptr, type, count) + * Resize a ralloc-managed array, preserving data and initializing any newly + * allocated data to zero. + * + * Similar to \c realloc. Unlike C89, passing 0 for \p size does not free the + * memory. Instead, it resizes it to a 0-byte ralloc context, just like + * calling ralloc_size(ctx, 0). This is different from talloc. + * + * More than a convenience function, this also checks for integer overflow when + * multiplying \c sizeof(type) and \p count. This is necessary for security. + * + * \param ctx The context to use for new allocation. If \p ptr != NULL, + * it must be the same as ralloc_parent(\p ptr). + * \param ptr Pointer to the array to be resized. May be NULL. + * \param type The element type. + * \param old_count The number of elements in the previous allocation. + * \param new_count The number of elements to allocate. + */ +#define rerzalloc(ctx, ptr, type, old_count, new_count) \ + ((type *) rerzalloc_array_size(ctx, ptr, sizeof(type), old_count, new_count)) + +/** * Allocate memory for an array chained off the given context. * * Similar to \c calloc, but does not initialize the memory to zero. @@ -217,6 +256,29 @@ void *rzalloc_array_size(const void *ctx, size_t size, unsigned count) MALLOCLIK */ void *reralloc_array_size(const void *ctx, void *ptr, size_t size, unsigned count); + +/** + * Resize a ralloc-managed array, preserving data and initializing any newly + * allocated data to zero. + * + * Similar to \c realloc. Unlike C89, passing 0 for \p size does not free the + * memory. Instead, it resizes it to a 0-byte ralloc context, just like + * calling ralloc_size(ctx, 0). This is different from talloc. + * + * More than a convenience function, this also checks for integer overflow when + * multiplying \c sizeof(type) and \p count. This is necessary for security. + * + * \param ctx The context to use for new allocation. If \p ptr != NULL, + * it must be the same as ralloc_parent(\p ptr). + * \param ptr Pointer to the array to be resized. May be NULL. + * \param size The size of an individual element. + * \param old_count The number of elements in the previous allocation. + * \param new_count The number of elements to allocate. + * + * \return True unless allocation failed. + */ +void *rerzalloc_array_size(const void *ctx, void *ptr, size_t size, + unsigned old_count, unsigned new_count); /// @} /** |