Various dlopen/linking cleanups from #42100 (#42166)

- **bpf-util: rename from bpf-dlopen, unify version-specific symbol
handling**
- **cryptsetup: dlopen libcryptsetup in tokens**
- **tree-wide: dlopen libpam in pam plugins**
- **test-bus-marshal: dlopen() glib and libdbus instead of linking
directly**
- **lock-util: Simplify timeout for lock_generic_with_timeout()**
- **color-util: simplify hsv_to_rgb, fix rgb_to_hsv negative-hue wrap**
- **tree-wide: Use our own macros instead of fabs()/fmax()/fmin()**
- **locale-util: dlopen() libintl instead of linking against it**
- **home: Use log2u64() over log2()**
- **meson: drop libdl, threads, and librt dependencies**
- **libc: Use dlsym() from a constructor instead of weak symbols**
- **libc: Make sure C23 versions of strtol(), sscanf() are not used**

src/core/bpf-bind-iface.c

@@ -12,7 +12,7 @@
 
 #if BPF_FRAMEWORK
 /* libbpf, clang, llvm and bpftool compile time dependencies are satisfied */
-#include "bpf-dlopen.h"
+#include "bpf-util.h"
 #include "bpf-link.h"
 #include "bind-iface-skel.h"
 

src/core/bpf-restrict-fs.c

@@ -15,7 +15,7 @@
 
 #if BPF_FRAMEWORK
 /* libbpf, clang and llc compile time dependencies are satisfied */
-#include "bpf-dlopen.h"
+#include "bpf-util.h"
 #include "bpf-link.h"
 #include "restrict-fs-skel.h"
 

src/core/bpf-restrict-fsaccess.c

@@ -37,7 +37,7 @@ const char* const restrict_fsaccess_link_names[_RESTRICT_FILESYSTEM_ACCESS_LINK_
 };
 
 #if BPF_FRAMEWORK && HAVE_LSM_INTEGRITY_TYPE
-#include "bpf-dlopen.h"
+#include "bpf-util.h"
 #include "bpf-link.h"
 #include "restrict-fsaccess-skel.h"
 

src/core/bpf-restrict-ifaces.c

@@ -14,7 +14,7 @@
 #if BPF_FRAMEWORK
 /* libbpf, clang and llc compile time dependencies are satisfied */
 
-#include "bpf-dlopen.h"
+#include "bpf-util.h"
 #include "bpf-link.h"
 #include "restrict-ifaces-skel.h"
 

src/core/bpf-socket-bind.c

@@ -9,7 +9,7 @@
 
 #if BPF_FRAMEWORK
 /* libbpf, clang, llvm and bpftool compile time dependencies are satisfied */
-#include "bpf-dlopen.h"
+#include "bpf-util.h"
 #include "bpf-link.h"
 #include "socket-bind-api.bpf.h"
 #include "socket-bind-skel.h"

src/core/exec-invoke.c

@@ -21,7 +21,7 @@
 #include "ask-password-api.h"
 #include "barrier.h"
 #include "bitfield.h"
-#include "bpf-dlopen.h"
+#include "bpf-util.h"
 #include "bpf-restrict-fs.h"
 #include "btrfs-util.h"
 #include "capability-util.h"

src/core/meson.build

@@ -148,13 +148,10 @@ libcore_static = static_library(
         dependencies : [libaudit_cflags,
                         libbpf_cflags,
                         libcryptsetup_cflags,
-                        libdl,
                         libm,
                         libmount_cflags,
-                        librt,
                         libseccomp_cflags,
                         libselinux_cflags,
-                        threads,
                         userspace],
         build_by_default : false)