diff --git a/src/basic/missing_syscall.h b/src/basic/missing_syscall.h
index b633ea4541f..21f470d96b2 100644
--- a/src/basic/missing_syscall.h
+++ b/src/basic/missing_syscall.h
@@ -33,39 +33,47 @@ static inline int missing_pivot_root(const char *new_root, const char *put_old)
 
 /* ======================================================================= */
 
-#if !HAVE_MEMFD_CREATE
-/* may be (invalid) negative number due to libseccomp, see PR 13319 */
-#  if ! (defined __NR_memfd_create && __NR_memfd_create >= 0)
-#    if defined __NR_memfd_create
-#      undef __NR_memfd_create
-#    endif
-#    if defined __x86_64__
-#      define __NR_memfd_create 319
-#    elif defined __arm__
-#      define __NR_memfd_create 385
-#    elif defined __aarch64__
-#      define __NR_memfd_create 279
-#    elif defined __s390__
-#      define __NR_memfd_create 350
-#    elif defined _MIPS_SIM
-#      if _MIPS_SIM == _MIPS_SIM_ABI32
-#        define __NR_memfd_create 4354
-#      endif
-#      if _MIPS_SIM == _MIPS_SIM_NABI32
-#        define __NR_memfd_create 6318
-#      endif
-#      if _MIPS_SIM == _MIPS_SIM_ABI64
-#        define __NR_memfd_create 5314
-#      endif
-#    elif defined __i386__
-#      define __NR_memfd_create 356
-#    elif defined __arc__
-#      define __NR_memfd_create 279
-#    else
-#      warning "__NR_memfd_create unknown for your architecture"
-#    endif
+#if defined __x86_64__
+#  define systemd_NR_memfd_create 319
+#elif defined __arm__
+#  define systemd_NR_memfd_create 385
+#elif defined __aarch64__
+#  define systemd_NR_memfd_create 279
+#elif defined __s390__
+#  define systemd_NR_memfd_create 350
+#elif defined _MIPS_SIM
+#  if _MIPS_SIM == _MIPS_SIM_ABI32
+#    define systemd_NR_memfd_create 4354
 #  endif
+#  if _MIPS_SIM == _MIPS_SIM_NABI32
+#    define systemd_NR_memfd_create 6318
+#  endif
+#  if _MIPS_SIM == _MIPS_SIM_ABI64
+#    define systemd_NR_memfd_create 5314
+#  endif
+#elif defined __i386__
+#  define systemd_NR_memfd_create 356
+#elif defined __arc__
+#  define systemd_NR_memfd_create 279
+#else
+#  warning "memfd_create() syscall number unknown for your architecture"
+#endif
 
+/* may be (invalid) negative number due to libseccomp, see PR 13319 */
+#if defined __NR_memfd_create && __NR_memfd_create >= 0
+#  if defined systemd_NR_memfd_create
+assert_cc(__NR_memfd_create == systemd_NR_memfd_create);
+#  endif
+#else
+#  if defined __NR_memfd_create
+#    undef __NR_memfd_create
+#  endif
+#  if defined systemd_NR_memfd_create
+#    define __NR_memfd_create systemd_NR_memfd_create
+#  endif
+#endif
+
+#if !HAVE_MEMFD_CREATE
 static inline int missing_memfd_create(const char *name, unsigned int flags) {
 #  ifdef __NR_memfd_create
         return syscall(__NR_memfd_create, name, flags);
@@ -80,45 +88,53 @@ static inline int missing_memfd_create(const char *name, unsigned int flags) {
 
 /* ======================================================================= */
 
-#if !HAVE_GETRANDOM
-/* may be (invalid) negative number due to libseccomp, see PR 13319 */
-#  if ! (defined __NR_getrandom && __NR_getrandom >= 0)
-#    if defined __NR_getrandom
-#      undef __NR_getrandom
-#    endif
-#    if defined __x86_64__
-#      define __NR_getrandom 318
-#    elif defined(__i386__)
-#      define __NR_getrandom 355
-#    elif defined(__arm__)
-#      define __NR_getrandom 384
-#   elif defined(__aarch64__)
-#      define __NR_getrandom 278
-#    elif defined(__ia64__)
-#      define __NR_getrandom 1339
-#    elif defined(__m68k__)
-#      define __NR_getrandom 352
-#    elif defined(__s390x__)
-#      define __NR_getrandom 349
-#    elif defined(__powerpc__)
-#      define __NR_getrandom 359
-#    elif defined _MIPS_SIM
-#      if _MIPS_SIM == _MIPS_SIM_ABI32
-#        define __NR_getrandom 4353
-#      endif
-#      if _MIPS_SIM == _MIPS_SIM_NABI32
-#        define __NR_getrandom 6317
-#      endif
-#      if _MIPS_SIM == _MIPS_SIM_ABI64
-#        define __NR_getrandom 5313
-#      endif
-#    elif defined(__arc__)
-#      define __NR_getrandom 278
-#    else
-#      warning "__NR_getrandom unknown for your architecture"
-#    endif
+#if defined __x86_64__
+#  define systemd_NR_getrandom 318
+#elif defined(__i386__)
+#  define systemd_NR_getrandom 355
+#elif defined(__arm__)
+#  define systemd_NR_getrandom 384
+#elif defined(__aarch64__)
+#  define systemd_NR_getrandom 278
+#elif defined(__ia64__)
+#  define systemd_NR_getrandom 1339
+#elif defined(__m68k__)
+#  define systemd_NR_getrandom 352
+#elif defined(__s390x__)
+#  define systemd_NR_getrandom 349
+#elif defined(__powerpc__)
+#  define systemd_NR_getrandom 359
+#elif defined _MIPS_SIM
+#  if _MIPS_SIM == _MIPS_SIM_ABI32
+#    define systemd_NR_getrandom 4353
 #  endif
+#  if _MIPS_SIM == _MIPS_SIM_NABI32
+#    define systemd_NR_getrandom 6317
+#  endif
+#  if _MIPS_SIM == _MIPS_SIM_ABI64
+#    define systemd_NR_getrandom 5313
+#  endif
+#elif defined(__arc__)
+#  define systemd_NR_getrandom 278
+#else
+#  warning "getrandom() syscall number unknown for your architecture"
+#endif
 
+/* may be (invalid) negative number due to libseccomp, see PR 13319 */
+#if defined __NR_getrandom && __NR_getrandom >= 0
+#  if defined systemd_NR_getrandom
+assert_cc(__NR_getrandom == systemd_NR_getrandom);
+#  endif
+#else
+#  if defined __NR_getrandom
+#    undef __NR_getrandom
+#  endif
+#  if defined systemd_NR_getrandom
+#    define __NR_getrandom systemd_NR_getrandom
+#  endif
+#endif
+
+#if !HAVE_GETRANDOM
 static inline int missing_getrandom(void *buffer, size_t count, unsigned flags) {
 #  ifdef __NR_getrandom
         return syscall(__NR_getrandom, buffer, count, flags);
@@ -133,9 +149,14 @@ static inline int missing_getrandom(void *buffer, size_t count, unsigned flags)
 
 /* ======================================================================= */
 
+/* The syscall has been defined since forever, but the glibc wrapper was missing. */
 #if !HAVE_GETTID
 static inline pid_t missing_gettid(void) {
+#  if defined __NR_gettid && __NR_gettid >= 0
         return (pid_t) syscall(__NR_gettid);
+#  else
+#    error "__NR_gettid not defined"
+#  endif
 }
 
 #  define gettid missing_gettid
@@ -143,27 +164,35 @@ static inline pid_t missing_gettid(void) {
 
 /* ======================================================================= */
 
-#if !HAVE_NAME_TO_HANDLE_AT
-/* may be (invalid) negative number due to libseccomp, see PR 13319 */
-#  if ! (defined __NR_name_to_handle_at && __NR_name_to_handle_at >= 0)
-#    if defined __NR_name_to_handle_at
-#      undef __NR_name_to_handle_at
-#    endif
-#    if defined(__x86_64__)
-#      define __NR_name_to_handle_at 303
-#    elif defined(__i386__)
-#      define __NR_name_to_handle_at 341
-#    elif defined(__arm__)
-#      define __NR_name_to_handle_at 370
-#    elif defined(__powerpc__)
-#      define __NR_name_to_handle_at 345
-#    elif defined(__arc__)
-#      define __NR_name_to_handle_at 264
-#    else
-#      error "__NR_name_to_handle_at is not defined"
-#    endif
-#  endif
+#if defined(__x86_64__)
+#  define systemd_NR_name_to_handle_at 303
+#elif defined(__i386__)
+#  define systemd_NR_name_to_handle_at 341
+#elif defined(__arm__)
+#  define systemd_NR_name_to_handle_at 370
+#elif defined(__powerpc__)
+#  define systemd_NR_name_to_handle_at 345
+#elif defined(__arc__)
+#  define systemd_NR_name_to_handle_at 264
+#else
+#  warning "name_to_handle_at number is not defined"
+#endif
 
+/* may be (invalid) negative number due to libseccomp, see PR 13319 */
+#if defined __NR_name_to_handle_at && __NR_name_to_handle_at >= 0
+#  if defined systemd_NR_name_to_handle_at
+assert_cc(__NR_name_to_handle_at == systemd_NR_name_to_handle_at);
+#  endif
+#else
+#  if defined __NR_name_to_handle_at
+#    undef __NR_name_to_handle_at
+#  endif
+#  if defined systemd_NR_name_to_handle_at
+#    define __NR_name_to_handle_at systemd_NR_name_to_handle_at
+#  endif
+#endif
+
+#if !HAVE_NAME_TO_HANDLE_AT
 struct file_handle {
         unsigned int handle_bytes;
         int handle_type;
@@ -184,23 +213,31 @@ static inline int missing_name_to_handle_at(int fd, const char *name, struct fil
 
 /* ======================================================================= */
 
-#if !HAVE_SETNS
-/* may be (invalid) negative number due to libseccomp, see PR 13319 */
-#  if ! (defined __NR_setns && __NR_setns >= 0)
-#    if defined __NR_setns
-#      undef __NR_setns
-#    endif
-#    if defined(__x86_64__)
-#      define __NR_setns 308
-#    elif defined(__i386__)
-#      define __NR_setns 346
-#    elif defined(__arc__)
-#      define __NR_setns 268
-#    else
-#      error "__NR_setns is not defined"
-#    endif
-#  endif
+#if defined(__x86_64__)
+#  define systemd_NR_setns 308
+#elif defined(__i386__)
+#  define systemd_NR_setns 346
+#elif defined(__arc__)
+#  define systemd_NR_setns 268
+#else
+#  warning "setns() syscall number unknown for your architecture"
+#endif
 
+/* may be (invalid) negative number due to libseccomp, see PR 13319 */
+#if defined __NR_setns && __NR_setns >= 0
+#  if defined systemd_NR_setns
+assert_cc(__NR_setns == systemd_NR_setns);
+#  endif
+#else
+#  if defined __NR_setns
+#    undef __NR_setns
+#  endif
+#  if defined systemd_NR_setns
+#    define __NR_setns systemd_NR_setns
+#  endif
+#endif
+
+#if !HAVE_SETNS
 static inline int missing_setns(int fd, int nstype) {
 #  ifdef __NR_setns
         return syscall(__NR_setns, fd, nstype);
@@ -225,41 +262,49 @@ static inline pid_t raw_getpid(void) {
 
 /* ======================================================================= */
 
-#if !HAVE_RENAMEAT2
-/* may be (invalid) negative number due to libseccomp, see PR 13319 */
-#  if ! (defined __NR_renameat2 && __NR_renameat2 >= 0)
-#    if defined __NR_renameat2
-#      undef __NR_renameat2
-#    endif
-#    if defined __x86_64__
-#      define __NR_renameat2 316
-#    elif defined __arm__
-#      define __NR_renameat2 382
-#    elif defined __aarch64__
-#      define __NR_renameat2 276
-#    elif defined _MIPS_SIM
-#      if _MIPS_SIM == _MIPS_SIM_ABI32
-#        define __NR_renameat2 4351
-#      endif
-#      if _MIPS_SIM == _MIPS_SIM_NABI32
-#        define __NR_renameat2 6315
-#      endif
-#      if _MIPS_SIM == _MIPS_SIM_ABI64
-#        define __NR_renameat2 5311
-#      endif
-#    elif defined __i386__
-#      define __NR_renameat2 353
-#    elif defined __powerpc64__
-#      define __NR_renameat2 357
-#    elif defined __s390__ || defined __s390x__
-#      define __NR_renameat2 347
-#    elif defined __arc__
-#      define __NR_renameat2 276
-#    else
-#      warning "__NR_renameat2 unknown for your architecture"
-#    endif
+#if defined __x86_64__
+#  define systemd_NR_renameat2 316
+#elif defined __arm__
+#  define systemd_NR_renameat2 382
+#elif defined __aarch64__
+#  define systemd_NR_renameat2 276
+#elif defined _MIPS_SIM
+#  if _MIPS_SIM == _MIPS_SIM_ABI32
+#    define systemd_NR_renameat2 4351
 #  endif
+#  if _MIPS_SIM == _MIPS_SIM_NABI32
+#    define systemd_NR_renameat2 6315
+#  endif
+#  if _MIPS_SIM == _MIPS_SIM_ABI64
+#    define systemd_NR_renameat2 5311
+#  endif
+#elif defined __i386__
+#  define systemd_NR_renameat2 353
+#elif defined __powerpc64__
+#  define systemd_NR_renameat2 357
+#elif defined __s390__ || defined __s390x__
+#  define systemd_NR_renameat2 347
+#elif defined __arc__
+#  define systemd_NR_renameat2 276
+#else
+#  warning "renameat2() syscall number unknown for your architecture"
+#endif
 
+/* may be (invalid) negative number due to libseccomp, see PR 13319 */
+#if defined __NR_renameat2 && __NR_renameat2 >= 0
+#  if defined systemd_NR_renameat2
+assert_cc(__NR_renameat2 == systemd_NR_renameat2);
+#  endif
+#else
+#  if defined __NR_renameat2
+#    undef __NR_renameat2
+#  endif
+#  if defined systemd_NR_renameat2
+#    define __NR_renameat2 systemd_NR_renameat2
+#  endif
+#endif
+
+#if !HAVE_RENAMEAT2
 static inline int missing_renameat2(int oldfd, const char *oldname, int newfd, const char *newname, unsigned flags) {
 #  ifdef __NR_renameat2
         return syscall(__NR_renameat2, oldfd, oldname, newfd, newname, flags);
@@ -326,31 +371,39 @@ static inline key_serial_t missing_request_key(const char *type, const char *des
 
 /* ======================================================================= */
 
-#if !HAVE_COPY_FILE_RANGE
-/* may be (invalid) negative number due to libseccomp, see PR 13319 */
-#  if ! (defined __NR_copy_file_range && __NR_copy_file_range >= 0)
-#    if defined __NR_copy_file_range
-#      undef __NR_copy_file_range
-#    endif
-#    if defined(__x86_64__)
-#      define __NR_copy_file_range 326
-#    elif defined(__i386__)
-#      define __NR_copy_file_range 377
-#    elif defined __s390__
-#      define __NR_copy_file_range 375
-#    elif defined __arm__
-#      define __NR_copy_file_range 391
-#    elif defined __aarch64__
-#      define __NR_copy_file_range 285
-#    elif defined __powerpc__
-#      define __NR_copy_file_range 379
-#    elif defined __arc__
-#      define __NR_copy_file_range 285
-#    else
-#      warning "__NR_copy_file_range not defined for your architecture"
-#    endif
-#  endif
+#if defined(__x86_64__)
+#  define systemd_NR_copy_file_range 326
+#elif defined(__i386__)
+#  define systemd_NR_copy_file_range 377
+#elif defined __s390__
+#  define systemd_NR_copy_file_range 375
+#elif defined __arm__
+#  define systemd_NR_copy_file_range 391
+#elif defined __aarch64__
+#  define systemd_NR_copy_file_range 285
+#elif defined __powerpc__
+#  define systemd_NR_copy_file_range 379
+#elif defined __arc__
+#  define systemd_NR_copy_file_range 285
+#else
+#  warning "copy_file_range() syscall number unknown for your architecture"
+#endif
 
+/* may be (invalid) negative number due to libseccomp, see PR 13319 */
+#if defined __NR_copy_file_range && __NR_copy_file_range >= 0
+#  if defined systemd_NR_copy_file_range
+assert_cc(__NR_copy_file_range == systemd_NR_copy_file_range);
+#  endif
+#else
+#  if defined __NR_copy_file_range
+#    undef __NR_copy_file_range
+#  endif
+#  if defined systemd_NR_copy_file_range
+#    define __NR_copy_file_range systemd_NR_copy_file_range
+#  endif
+#endif
+
+#if !HAVE_COPY_FILE_RANGE
 static inline ssize_t missing_copy_file_range(int fd_in, loff_t *off_in,
                                               int fd_out, loff_t *off_out,
                                               size_t len,
@@ -368,31 +421,39 @@ static inline ssize_t missing_copy_file_range(int fd_in, loff_t *off_in,
 
 /* ======================================================================= */
 
-#if !HAVE_BPF
-/* may be (invalid) negative number due to libseccomp, see PR 13319 */
-#  if ! (defined __NR_bpf && __NR_bpf >= 0)
-#    if defined __NR_bpf
-#      undef __NR_bpf
-#    endif
-#    if defined __i386__
-#      define __NR_bpf 357
-#    elif defined __x86_64__
-#      define __NR_bpf 321
-#    elif defined __aarch64__
-#      define __NR_bpf 280
-#    elif defined __arm__
-#      define __NR_bpf 386
-#    elif defined __sparc__
-#      define __NR_bpf 349
-#    elif defined __s390__
-#      define __NR_bpf 351
-#    elif defined __tilegx__
-#      define __NR_bpf 280
-#    else
-#      warning "__NR_bpf not defined for your architecture"
-#    endif
-#  endif
+#if defined __i386__
+#  define systemd_NR_bpf 357
+#elif defined __x86_64__
+#  define systemd_NR_bpf 321
+#elif defined __aarch64__
+#  define systemd_NR_bpf 280
+#elif defined __arm__
+#  define systemd_NR_bpf 386
+#elif defined __sparc__
+#  define systemd_NR_bpf 349
+#elif defined __s390__
+#  define systemd_NR_bpf 351
+#elif defined __tilegx__
+#  define systemd_NR_bpf 280
+#else
+#  warning "bpf() syscall number unknown for your architecture"
+#endif
 
+/* may be (invalid) negative number due to libseccomp, see PR 13319 */
+#if defined __NR_bpf && __NR_bpf >= 0
+#  if defined systemd_NR_bpf
+assert_cc(__NR_bpf == systemd_NR_bpf);
+#  endif
+#else
+#  if defined __NR_bpf
+#    undef __NR_bpf
+#  endif
+#  if defined systemd_NR_bpf
+#    define __NR_bpf systemd_NR_bpf
+#  endif
+#endif
+
+#if !HAVE_BPF
 union bpf_attr;
 
 static inline int missing_bpf(int cmd, union bpf_attr *attr, size_t size) {
@@ -410,69 +471,80 @@ static inline int missing_bpf(int cmd, union bpf_attr *attr, size_t size) {
 /* ======================================================================= */
 
 #ifndef __IGNORE_pkey_mprotect
+#  if defined __i386__
+#    define systemd_NR_pkey_mprotect 380
+#  elif defined __x86_64__
+#    define systemd_NR_pkey_mprotect 329
+#  elif defined __arm__
+#    define systemd_NR_pkey_mprotect 394
+#  elif defined __aarch64__
+#    define systemd_NR_pkey_mprotect 394
+#  elif defined __powerpc__
+#    define systemd_NR_pkey_mprotect 386
+#  elif defined __s390__
+#    define systemd_NR_pkey_mprotect 384
+#  elif defined _MIPS_SIM
+#    if _MIPS_SIM == _MIPS_SIM_ABI32
+#      define systemd_NR_pkey_mprotect 4363
+#    endif
+#    if _MIPS_SIM == _MIPS_SIM_NABI32
+#      define systemd_NR_pkey_mprotect 6327
+#    endif
+#    if _MIPS_SIM == _MIPS_SIM_ABI64
+#      define systemd_NR_pkey_mprotect 5323
+#    endif
+#  else
+#    warning "pkey_mprotect() syscall number unknown for your architecture"
+#  endif
+
 /* may be (invalid) negative number due to libseccomp, see PR 13319 */
-#  if ! (defined __NR_pkey_mprotect && __NR_pkey_mprotect >= 0)
+#  if defined __NR_pkey_mprotect && __NR_pkey_mprotect >= 0
+#    if defined systemd_NR_pkey_mprotect
+assert_cc(__NR_pkey_mprotect == systemd_NR_pkey_mprotect);
+#    endif
+#  else
 #    if defined __NR_pkey_mprotect
 #      undef __NR_pkey_mprotect
 #    endif
-#    if defined __i386__
-#      define __NR_pkey_mprotect 380
-#    elif defined __x86_64__
-#      define __NR_pkey_mprotect 329
-#    elif defined __arm__
-#      define __NR_pkey_mprotect 394
-#    elif defined __aarch64__
-#      define __NR_pkey_mprotect 394
-#    elif defined __powerpc__
-#      define __NR_pkey_mprotect 386
-#    elif defined __s390__
-#      define __NR_pkey_mprotect 384
-#    elif defined _MIPS_SIM
-#      if _MIPS_SIM == _MIPS_SIM_ABI32
-#        define __NR_pkey_mprotect 4363
-#      endif
-#      if _MIPS_SIM == _MIPS_SIM_NABI32
-#        define __NR_pkey_mprotect 6327
-#      endif
-#      if _MIPS_SIM == _MIPS_SIM_ABI64
-#        define __NR_pkey_mprotect 5323
-#      endif
-#    else
-#      warning "__NR_pkey_mprotect not defined for your architecture"
+#    if defined systemd_NR_pkey_mprotect
+#      define __NR_pkey_mprotect systemd_NR_pkey_mprotect
 #    endif
 #  endif
 #endif
 
 /* ======================================================================= */
 
-#if !HAVE_STATX
-/* may be (invalid) negative number due to libseccomp, see PR 13319 */
-#  if ! (defined __NR_statx && __NR_statx >= 0)
-#    if defined __NR_statx
-#      undef __NR_statx
-#    endif
-#    if defined __aarch64__ || defined __arm__
-#      define __NR_statx 397
-#    elif defined __alpha__
-#      define __NR_statx 522
-#    elif defined __i386__ || defined __powerpc64__
-#      define __NR_statx 383
-#    elif defined __sparc__
-#      define __NR_statx 360
-#    elif defined __x86_64__
-#      define __NR_statx 332
-#    else
-#      warning "__NR_statx not defined for your architecture"
-#    endif
-#  endif
-
-struct statx;
+#if defined __aarch64__ || defined __arm__
+#  define systemd_NR_statx 397
+#elif defined __alpha__
+#  define systemd_NR_statx 522
+#elif defined __i386__ || defined __powerpc64__
+#  define systemd_NR_statx 383
+#elif defined __sparc__
+#  define systemd_NR_statx 360
+#elif defined __x86_64__
+#  define systemd_NR_statx 332
+#else
+#  warning "statx() syscall number unknown for your architecture"
 #endif
 
-/* This typedef is supposed to be always defined. */
-typedef struct statx struct_statx;
+/* may be (invalid) negative number due to libseccomp, see PR 13319 */
+#if defined __NR_statx && __NR_statx >= 0
+#  if defined systemd_NR_statx
+assert_cc(__NR_statx == systemd_NR_statx);
+#  endif
+#else
+#  if defined __NR_statx
+#    undef __NR_statx
+#  endif
+#  if defined systemd_NR_statx
+#    define __NR_statx systemd_NR_statx
+#  endif
+#endif
 
 #if !HAVE_STATX
+struct statx;
+
 static inline ssize_t missing_statx(int dfd, const char *filename, unsigned flags, unsigned int mask, struct statx *buffer) {
 #  ifdef __NR_statx
         return syscall(__NR_statx, dfd, filename, flags, mask, buffer);
@@ -481,12 +553,18 @@ static inline ssize_t missing_statx(int dfd, const char *filename, unsigned flag
         return -1;
 #  endif
 }
+#endif
 
+/* This typedef is supposed to be always defined. */
+typedef struct statx struct_statx;
+
+#if !HAVE_STATX
 #  define statx(dfd, filename, flags, mask, buffer) missing_statx(dfd, filename, flags, mask, buffer)
 #endif
 
-#if !HAVE_SET_MEMPOLICY
+/* ======================================================================= */
 
+#if !HAVE_SET_MEMPOLICY
 enum {
         MPOL_DEFAULT,
         MPOL_PREFERRED,
@@ -527,19 +605,28 @@ static inline long missing_get_mempolicy(int *mode, unsigned long *nodemask,
 #  define get_mempolicy missing_get_mempolicy
 #endif
 
-#if !HAVE_PIDFD_SEND_SIGNAL
-/* may be (invalid) negative number due to libseccomp, see PR 13319 */
-#  if ! (defined __NR_pidfd_send_signal && __NR_pidfd_send_signal >= 0)
-#    if defined __NR_pidfd_send_signal
-#      undef __NR_pidfd_send_signal
-#    endif
+/* ======================================================================= */
+
 /* should be always defined, see kernel 39036cd2727395c3369b1051005da74059a85317 */
-#    if defined(__alpha__)
-#      define __NR_pidfd_send_signal 534
-#    else
-#      define __NR_pidfd_send_signal 424
-#    endif
+#if defined(__alpha__)
+#  define systemd_NR_pidfd_send_signal 534
+#else
+#  define systemd_NR_pidfd_send_signal 424
+#endif
+
+/* may be (invalid) negative number due to libseccomp, see PR 13319 */
+#if defined __NR_pidfd_send_signal && __NR_pidfd_send_signal >= 0
+#  if defined systemd_NR_pidfd_send_signal
+assert_cc(__NR_pidfd_send_signal == systemd_NR_pidfd_send_signal);
 #  endif
+#else
+#  if defined __NR_pidfd_send_signal
+#    undef __NR_pidfd_send_signal
+#  endif
+#  define __NR_pidfd_send_signal systemd_NR_pidfd_send_signal
+#endif
+
+#if !HAVE_PIDFD_SEND_SIGNAL
 static inline int missing_pidfd_send_signal(int fd, int sig, siginfo_t *info, unsigned flags) {
 #  ifdef __NR_pidfd_open
         return syscall(__NR_pidfd_send_signal, fd, sig, info, flags);
@@ -552,19 +639,26 @@ static inline int missing_pidfd_send_signal(int fd, int sig, siginfo_t *info, un
 #  define pidfd_send_signal missing_pidfd_send_signal
 #endif
 
-#if !HAVE_PIDFD_OPEN
-/* may be (invalid) negative number due to libseccomp, see PR 13319 */
-#  if ! (defined __NR_pidfd_open && __NR_pidfd_open >= 0)
-#    if defined __NR_pidfd_open
-#      undef __NR_pidfd_open
-#    endif
 /* should be always defined, see kernel 7615d9e1780e26e0178c93c55b73309a5dc093d7 */
-#    if defined(__alpha__)
-#      define __NR_pidfd_open 544
-#    else
-#      define __NR_pidfd_open 434
-#    endif
+#if defined(__alpha__)
+#  define systemd_NR_pidfd_open 544
+#else
+#  define systemd_NR_pidfd_open 434
+#endif
+
+/* may be (invalid) negative number due to libseccomp, see PR 13319 */
+#if defined __NR_pidfd_open && __NR_pidfd_open >= 0
+#  if defined systemd_NR_pidfd_open
+assert_cc(__NR_pidfd_open == systemd_NR_pidfd_open);
 #  endif
+#else
+#  if defined __NR_pidfd_open
+#    undef __NR_pidfd_open
+#  endif
+#  define __NR_pidfd_open systemd_NR_pidfd_open
+#endif
+
+#if !HAVE_PIDFD_OPEN
 static inline int missing_pidfd_open(pid_t pid, unsigned flags) {
 #  ifdef __NR_pidfd_open
         return syscall(__NR_pidfd_open, pid, flags);
@@ -577,9 +671,15 @@ static inline int missing_pidfd_open(pid_t pid, unsigned flags) {
 #  define pidfd_open missing_pidfd_open
 #endif
 
+/* ======================================================================= */
+
 #if !HAVE_RT_SIGQUEUEINFO
 static inline int missing_rt_sigqueueinfo(pid_t tgid, int sig, siginfo_t *info) {
+#  if defined __NR_rt_sigqueueinfo && __NR_rt_sigqueueinfo >= 0
         return syscall(__NR_rt_sigqueueinfo, tgid, sig, info);
+#  else
+#    error "__NR_rt_sigqueueinfo not defined"
+#  endif
 }
 
 #  define rt_sigqueueinfo missing_rt_sigqueueinfo