lib/: Use [[gnu::alloc_size(...)]] on allocation functions

Suggested-by: Martin Uecker <uecker@tugraz.at>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

lib/alloc/malloc.h

@@ -19,6 +19,7 @@
 )
 
 
+ATTR_ALLOC_SIZE(1, 2)
 ATTR_MALLOC(free)
 inline void *mallocarray(size_t nmemb, size_t size);
 

lib/alloc/reallocf.h

@@ -20,6 +20,7 @@
 )
 
 
+ATTR_ALLOC_SIZE(2, 3)
 ATTR_MALLOC(free)
 inline void *reallocarrayf(void *p, size_t nmemb, size_t size);
 

lib/alloc/x/xcalloc.h

@@ -20,6 +20,7 @@
 )
 
 
+ATTR_ALLOC_SIZE(1, 2)
 ATTR_MALLOC(free)
 void *xcalloc(size_t nmemb, size_t size);
 

lib/alloc/x/xmalloc.h

@@ -20,6 +20,7 @@
 )
 
 
+ATTR_ALLOC_SIZE(1, 2)
 ATTR_MALLOC(free)
 inline void *xmallocarray(size_t nmemb, size_t size);
 

lib/alloc/x/xrealloc.h

@@ -23,6 +23,7 @@
 )
 
 
+ATTR_ALLOC_SIZE(2, 3)
 ATTR_MALLOC(free)
 void *xreallocarray(void *p, size_t nmemb, size_t size);
 

lib/attr.h

@@ -10,11 +10,13 @@
 # define NORETURN                    __attribute__((__noreturn__))
 # define format_attr(type, fmt, va)  __attribute__((format(type, fmt, va)))
 # define ATTR_ACCESS(...)            __attribute__((access(__VA_ARGS__)))
+# define ATTR_ALLOC_SIZE(...)        __attribute__((alloc_size(__VA_ARGS__)))
 #else
 # define MAYBE_UNUSED
 # define NORETURN
 # define format_attr(type, fmt, va)
 # define ATTR_ACCESS(...)
+# define ATTR_ALLOC_SIZE(...)
 #endif
 
 #if (__GNUC__ >= 11) && !defined(__clang__)