tree-wide: switch dlopen hooks over to DLSYM_PROTOTYPE()/DLSYM_FUNCTION()

We have these pretty macros, let's use them everywhere (so far we mostly
used them for newer additions only).

This PR is mostly an excercise in "perl -p -i -e", but there are some
special cases:

* idn-util.c exposes a function whose prototype in the official library
  headers is marked with the "const" attribute, and this apparently does
  not propagate along typeof() correctly and then
  __builtin_types_compatible_p() fails later because it detects that
  prototype and original function don't match in prototype.

* libbpf removed some symbols in newer versions, hence we need to define
  some prototypes manually to still be able to build.

* libcryptsetup marked a symbol as deprecated we want to use (knowing it
  is deprecated). By using the macros this is detected by the compiler.
  We work around it via the usual warning off macros.

Note by using these macros we assume that all symbols are known during
build time. Which might not be the case. We might need to revert this
commit for some symbols if this trips up builds on older distros.

1 files changed, 20 insertions, 18 deletions

diff --git a/src/shared/bpf-dlopen.c b/src/shared/bpf-dlopen.c
index 15301aee60..70b1ffbf99 100644
--- a/src/shared/bpf-dlopen.c
+++ b/src/shared/bpf-dlopen.c
@@ -18,26 +18,28 @@
 #define MODERN_LIBBPF 0
 #endif
 
-struct bpf_link* (*sym_bpf_program__attach_cgroup)(const struct bpf_program *, int);
-struct bpf_link* (*sym_bpf_program__attach_lsm)(const struct bpf_program *);
-int (*sym_bpf_link__fd)(const struct bpf_link *);
-int (*sym_bpf_link__destroy)(struct bpf_link *);
-int (*sym_bpf_map__fd)(const struct bpf_map *);
-const char* (*sym_bpf_map__name)(const struct bpf_map *);
+DLSYM_FUNCTION(bpf_program__attach_cgroup);
+DLSYM_FUNCTION(bpf_program__attach_lsm);
+DLSYM_FUNCTION(bpf_link__fd);
+DLSYM_FUNCTION(bpf_link__destroy);
+DLSYM_FUNCTION(bpf_map__fd);
+DLSYM_FUNCTION(bpf_map__name);
+DLSYM_FUNCTION(bpf_map__set_max_entries);
+DLSYM_FUNCTION(bpf_map_update_elem);
+DLSYM_FUNCTION(bpf_map_delete_elem);
+DLSYM_FUNCTION(bpf_map__set_inner_map_fd);
+DLSYM_FUNCTION(bpf_object__open_skeleton);
+DLSYM_FUNCTION(bpf_object__load_skeleton);
+DLSYM_FUNCTION(bpf_object__attach_skeleton);
+DLSYM_FUNCTION(bpf_object__detach_skeleton);
+DLSYM_FUNCTION(bpf_object__destroy_skeleton);
+DLSYM_FUNCTION(bpf_program__name);
+DLSYM_FUNCTION(libbpf_set_print);
+DLSYM_FUNCTION(libbpf_get_error);
+
+/* new symbols available from libbpf 0.7.0 */
 int (*sym_bpf_map_create)(enum bpf_map_type,  const char *, __u32, __u32, __u32, const struct bpf_map_create_opts *);
-int (*sym_bpf_map__set_max_entries)(struct bpf_map *, __u32);
-int (*sym_bpf_map_update_elem)(int, const void *, const void *, __u64);
-int (*sym_bpf_map_delete_elem)(int, const void *);
-int (*sym_bpf_map__set_inner_map_fd)(struct bpf_map *, int);
-int (*sym_bpf_object__open_skeleton)(struct bpf_object_skeleton *, const struct bpf_object_open_opts *);
-int (*sym_bpf_object__load_skeleton)(struct bpf_object_skeleton *);
-int (*sym_bpf_object__attach_skeleton)(struct bpf_object_skeleton *);
-void (*sym_bpf_object__detach_skeleton)(struct bpf_object_skeleton *);
-void (*sym_bpf_object__destroy_skeleton)(struct bpf_object_skeleton *);
 int (*sym_libbpf_probe_bpf_prog_type)(enum bpf_prog_type, const void *);
-const char* (*sym_bpf_program__name)(const struct bpf_program *);
-libbpf_print_fn_t (*sym_libbpf_set_print)(libbpf_print_fn_t);
-long (*sym_libbpf_get_error)(const void *);
 
 /* compat symbols removed in libbpf 1.0 */
 int (*sym_bpf_create_map)(enum bpf_map_type,  int key_size, int value_size, int max_entries, __u32 map_flags);