shared: Add more dlopen() tests

Add dlopen_dw(), dlopen_elf() and dlopen_pcre2() to the dlopen test.
To enable adding dlopen_pcre2(), we move pcre2-dlopen.h/c from
src/journal to src/shared.

src/journal/meson.build

@@ -49,8 +49,6 @@ systemd_cat_sources = files('cat.c')
 
 journalctl_sources = files('''
         journalctl.c
-        pcre2-dlopen.c
-        pcre2-dlopen.h
 '''.split())
 
 if install_sysconfdir_samples

src/shared/elf-util.c

@@ -80,7 +80,7 @@ unsigned int (*sym_elf_version)(unsigned int);
 GElf_Phdr *(*sym_gelf_getphdr)(Elf *, int, GElf_Phdr *);
 size_t (*sym_gelf_getnote)(Elf_Data *, size_t, GElf_Nhdr *, size_t *, size_t *);
 
-static int dlopen_dw(void) {
+int dlopen_dw(void) {
         int r;
 
         r = dlopen_many_sym_or_warn(
@@ -123,7 +123,7 @@ static int dlopen_dw(void) {
         return 1;
 }
 
-static int dlopen_elf(void) {
+int dlopen_elf(void) {
         int r;
 
         r = dlopen_many_sym_or_warn(

src/shared/elf-util.h

@@ -4,6 +4,9 @@
 #include "json.h"
 
 #if HAVE_ELFUTILS
+int dlopen_dw(void);
+int dlopen_elf(void);
+
 /* Parse an ELF object in a forked process, so that errors while iterating over
  * untrusted and potentially malicious data do not propagate to the main caller's process.
  * If fork_disable_dump, the child process will not dump core if it crashes. */

src/shared/meson.build

@@ -243,6 +243,8 @@ shared_sources = files('''
         parse-argument.h
         parse-socket-bind-item.c
         parse-socket-bind-item.h
+        pcre2-dlopen.c
+        pcre2-dlopen.h
         pe-header.h
         pkcs11-util.c
         pkcs11-util.h

src/test/test-dlopen-so.c

@@ -5,10 +5,12 @@
 
 #include "bpf-dlopen.h"
 #include "cryptsetup-util.h"
+#include "elf-util.h"
 #include "idn-util.h"
 #include "libfido2-util.h"
 #include "macro.h"
 #include "main-func.h"
+#include "pcre2-dlopen.h"
 #include "pwquality-util.h"
 #include "qrcode-util.h"
 #include "tests.h"
@@ -49,6 +51,15 @@ static int run(int argc, char **argv) {
         assert_se(dlopen_bpf() >= 0);
 #endif
 
+#if HAVE_ELFUTILS
+        assert_se(dlopen_dw() >= 0);
+        assert_se(dlopen_elf() >= 0);
+#endif
+
+#if HAVE_PCRE2
+        assert_se(dlopen_pcre2() >= 0);
+#endif
+
         return 0;
 }