tools: slabratetop fails on 5.16 kernel

[jeromemarchand]

Since commit 40f3bf0cb04c ("mm: Convert struct page to struct slab in functions used by other subsystems"), slab_def.h and slub_def.h refers to structures (slab) and functions (slab_address) defined in the internal header mm/slab.h.
It makes slabratetop tool fail with the following error:

$ slabratetop 
In file included from /virtual/main.c:13:
include/linux/slub_def.h:162:26: warning: call to undeclared function 'slab_address'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
        void *object = x - (x - slab_address(slab)) % cache->size;
                                ^
include/linux/slub_def.h:162:46: error: invalid operands to binary expression ('void *' and 'unsigned int')
        void *object = x - (x - slab_address(slab)) % cache->size;
                           ~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~
include/linux/slub_def.h:164:8: error: incomplete definition of type 'struct slab'
                (slab->objects - 1) * cache->size;
                 ~~~~^
include/linux/kasan.h:13:8: note: forward declaration of 'struct slab'
struct slab;
       ^
In file included from /virtual/main.c:13:
include/linux/slub_def.h:184:31: warning: call to undeclared function 'slab_address'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
        return __obj_to_index(cache, slab_address(slab), obj);
                                     ^
include/linux/slub_def.h:184:31: error: incompatible integer to pointer conversion passing 'int' to parameter of type 'void *' [-Wint-conversion]
        return __obj_to_index(cache, slab_address(slab), obj);
                                     ^~~~~~~~~~~~~~~~~~
include/linux/slub_def.h:173:14: note: passing argument to parameter 'addr' here
                                          void *addr, void *obj)
                                                ^
include/linux/slub_def.h:190:13: error: incomplete definition of type 'struct slab'
        return slab->objects;
               ~~~~^
include/linux/kasan.h:13:8: note: forward declaration of 'struct slab'
struct slab;
       ^
2 warnings and 4 errors generated.
Traceback (most recent call last):
  File "/usr/share/bcc/tools/slabratetop", line 111, in <module>
    b = BPF(text=bpf_text)
        ^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.11/site-packages/bcc/__init__.py", line 476, in __init__
    raise Exception("Failed to compile BPF module %s" % (src_file or "<text>"))
Exception: Failed to compile BPF module <text>

[jeromemarchand]

Looks like this has been fixed by commit a3ad36d ("tools/slabratetop: Fix error: incomplete definition of type 'struct slab'")