malloc: add overflow checks and add aligned alloc-functions

Signed-off-by: Mattias Andrée <maandree@operamail.com>

1 files changed, 127 insertions, 2 deletions

diff --git a/include/malloc.h b/include/malloc.h
index c18f885..0e17817 100644
--- a/include/malloc.h
+++ b/include/malloc.h
@@ -97,7 +97,8 @@ void* realloc(void*, size_t)
  *              beginning of a memory allocation on the heap.
  *              However, if it is `NULL`, nothing will happen.
  */
-void free(void*) __slibc_warning("Use 'fast_free' or 'secure_free' instead.");
+void free(void*)
+  __slibc_warning("Use 'fast_free' or 'secure_free' instead.");
 
 /**
  * This function is identical to `free`.
@@ -112,7 +113,131 @@ void free(void*) __slibc_warning("Use 'fast_free' or 'secure_free' instead.");
  *              However, if it is `NULL`, nothing will happen.
  */
 #ifndef _PORTABLE_SOURCE
-void cfree(void*, ...) __deprecated("'cfree' is deprecated and not portable, use 'free' instead.");
+void cfree(void*, ...)
+  __deprecated("'cfree' is deprecated and not portable, use 'free' instead.");
+#endif
+
+
+#ifndef _PORTABLE_SOURCE
+/**
+ * Variant of `malloc` that returns an address with a
+ * specified alignment.
+ * 
+ * It is unspecified how the function works. This implemention
+ * will allocate a bit of extra memory and shift the returned
+ * pointer so that it is aligned.
+ * 
+ * As a GNU-compliant slibc extension, memory allocated
+ * with this function can be freed with `free`.
+ * 
+ * @param   boundary  The alignment.
+ * @param   size      The number of bytes to allocated.
+ * @return            Pointer to the beginning of the new allocation.
+ *                    If `size` is zero, this function will either return
+ *                    `NULL` (that is what this implement does) or return
+ *                    a unique pointer that can later be freed with `free`.
+ *                    `NULL` is returned on error, and `errno` is set to
+ *                    indicate the error.
+ * 
+ * @throws  ENOMEM  The process cannot allocate more memory.
+ * @throws  EINVAL  If `boundary` is not a power of two.
+ */
+void* memalign(size_t, size_t)
+#ifdef __C11__
+   __deprecated("'memalign' has be deprecated by 'aligned_alloc' in C11.")
+#endif
+  __GCC_ONLY(__attribute__((malloc, warn_unused_result)));
+#endif
+
+/**
+ * `posix_memalign(p, b, n)` is equivalent to
+ * `(*p = memalign(b, n), *p ? 0 : errno)`, except
+ * `boundary` must also be a multiple of `sizeof(void*)`,
+ * and `errno` is unspecified.
+ * 
+ * As a GNU-compliant slibc extension, memory allocated
+ * with this function can be freed with `free`.
+ * 
+ * @param   ptrptr    Output parameter for the allocated memory.
+ * @param   boundary  The alignment.
+ * @param   size      The number of bytes to allocated.
+ * @return            Zero on success, a value for `errno` on error.
+ * 
+ * @throws  ENOMEM  The process cannot allocate more memory.
+ * @throws  EINVAL  If `boundary` is not a power-of-two multiple of `sizeof(void*)`.
+ */
+int posix_memalign(void**, size_t, size_t)
+  __GCC_ONLY(__attribute__((nonnull)));
+
+#ifndef _PORTABLE_SOURCE
+/**
+ * `valloc(n)` is equivalent to `memalign(sysconf(_SC_PAGESIZE), n)`.
+ * 
+ * As a GNU-compliant slibc extension, memory allocated
+ * with this function can be freed with `free`.
+ * 
+ * @param   size    The number of bytes to allocated.
+ * @return          Pointer to the beginning of the new allocation.
+ *                  If `size` is zero, this function will either return
+ *                  `NULL` (that is what this implement does) or return
+ *                  a unique pointer that can later be freed with `free`.
+ *                  `NULL` is returned on error, and `errno` is set to
+ *                  indicate the error.
+ * 
+ * @throws  ENOMEM  The process cannot allocate more memory.
+ */
+void* valloc(size_t)
+  __GCC_ONLY(__attribute__((malloc, warn_unused_result)))
+  __deprecated("'valloc' is deprecated, use 'memalign' or 'posix_memalign' instead.");
+
+#ifdef _GNU_SOURCE
+/**
+ * This function works like `valloc`, except the allocation size,
+ * including auxiliary space, is rounded up to the next multiple
+ * of the page size.
+ * 
+ * @param   size    The number of bytes to allocated.
+ * @return          Pointer to the beginning of the new allocation.
+ *                  If `size` is zero, this function will either return
+ *                  `NULL` (that is what this implement does) or return
+ *                  a unique pointer that can later be freed with `free`.
+ *                  `NULL` is returned on error, and `errno` is set to
+ *                  indicate the error.
+ * 
+ * @throws  ENOMEM  The process cannot allocate more memory.
+ */
+void* pvalloc(size_t)
+  __GCC_ONLY(__attribute__((malloc, warn_unused_result)))
+  __deprecated("'pvalloc' is deprecated, use 'memalign' or 'posix_memalign' instead.");
+#endif
+#endif
+
+#ifdef __C11__
+/**
+ * This function is identical to `memalign`,
+ * except it can be freed with `free`.
+ * 
+ * Variant of `malloc` that returns an address with a
+ * specified alignment.
+ * 
+ * It is unspecified how the function works. This implemention
+ * will allocate a bit of extra memory and shift the returned
+ * pointer so that it is aligned.
+ * 
+ * @param   boundary  The alignment.
+ * @param   size      The number of bytes to allocated.
+ * @return            Pointer to the beginning of the new allocation.
+ *                    If `size` is zero, this function will either return
+ *                    `NULL` (that is what this implement does) or return
+ *                    a unique pointer that can later be freed with `free`.
+ *                    `NULL` is returned on error, and `errno` is set to
+ *                    indicate the error.
+ * 
+ * @throws  ENOMEM  The process cannot allocate more memory.
+ * @throws  EINVAL  If `boundary` is not a power of two.
+ */
+void* aligned_alloc(size_t, size_t)
+  __GCC_ONLY(__attribute__((malloc, warn_unused_result)));
 #endif