GCC 11.x added support for arguments to __attribute__ (malloc):

* https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;f=gcc/doc/extend.texi;h=dce6c58db87ebf7f4477bd3126228e73e4eeee97#patch6

For example:

$ cat test.c
typedef struct my_s {} my;
void myclose (my*);
__attribute__ ((malloc, malloc (myclose))) my* myopen(void);


$ gcc-11 -c test.c
(works)

$ clang-13 -c test.c
test.c:3:25: error: 'malloc' attribute takes no arguments
__attribute__ ((malloc, malloc (myclose))) my* myopen(void);
                        ^