I think this was forgotten when elf_aux_info() was added.  The _hwcap
variables are only used inside libc, so they should be declared hidden.
We can just add the declarations to hidden/sys/auxv.h.

Before:
$ readelf -s obj/libc.so.103.0| fgrep _hwcap
  4063: 00000000001051c8     4 OBJECT  LOCAL  DEFAULT   23 _hwcap_avail
  4064: 00000000001051c0     8 OBJECT  LOCAL  DEFAULT   23 _hwcap
  4065: 00000000001051d8     4 OBJECT  LOCAL  DEFAULT   23 _hwcap2_avail
  4066: 00000000001051d0     8 OBJECT  LOCAL  DEFAULT   23 _hwcap2

After:
$ readelf -s obj/libc.so.103.0| fgrep _hwcap
  1784: 0000000000100880     8 OBJECT  LOCAL  HIDDEN    23 _hwcap
  1785: 0000000000100888     4 OBJECT  LOCAL  HIDDEN    23 _hwcap_avail
  1786: 0000000000100890     8 OBJECT  LOCAL  HIDDEN    23 _hwcap2
  1787: 0000000000100898     4 OBJECT  LOCAL  HIDDEN    23 _hwcap2_avail

OK?

-----------------------------------------------
commit e030561035c15c903f1e6b0a1feacb5492867a7b (hwcap)
from: Christian Weisgerber <naddy@mips.inka.de>
date: Sat May  9 12:38:40 2026 UTC
 
 declare _hwcap and related variables as hidden
 
diff dfc436a2a7e14a48b9213e241b55d30d94477a54 e030561035c15c903f1e6b0a1feacb5492867a7b
commit - dfc436a2a7e14a48b9213e241b55d30d94477a54
commit + e030561035c15c903f1e6b0a1feacb5492867a7b
blob - dd2cd9f40451841c3fe7b8ae2dd9274b1551c959
blob + e57f9dcb277fd79922c7c82744bb5e326da436cf
--- lib/libc/dlfcn/init.c
+++ lib/libc/dlfcn/init.c
@@ -21,6 +21,7 @@
 #include <sys/types.h>
 #include <sys/syscall.h>
 #include <sys/timetc.h>		/* timekeep */
+#include <sys/auxv.h>		/* _hwcap */
 
 #ifndef PIC
 #include <sys/mman.h>
blob - a4b7667ba6fd0d1c9056e2e645d2a637e8a51790
blob + c9852bc4ca467710893631f61e11098c5ecc2b44
--- lib/libc/gen/elf_aux_info.c
+++ lib/libc/gen/elf_aux_info.c
@@ -20,11 +20,8 @@
 #include <sys/auxv.h>
 
 #include <errno.h>
+#include <unistd.h>
 
-extern int _pagesize;
-extern unsigned long _hwcap, _hwcap2;
-extern int _hwcap_avail, _hwcap2_avail;
-
 int
 elf_aux_info(int request, void *buf, int buflen)
 {
blob - cd566b7b2a21edc0421c3ef7063a8fca20fa635b
blob + 07eec4dcd49a65521acc6daefd1a127a833378b6
--- lib/libc/hidden/sys/auxv.h
+++ lib/libc/hidden/sys/auxv.h
@@ -21,6 +21,11 @@
 
 #include_next <sys/auxv.h>
 
+__BEGIN_HIDDEN_DECLS
+extern unsigned long	_hwcap, _hwcap2;
+extern int	_hwcap_avail, _hwcap2_avail;
+__END_HIDDEN_DECLS
+
 PROTO_DEPRECATED(elf_aux_info);
 
 #endif /* !_LIBC_SYS_AUXV_H_ */


-- 
Christian "naddy" Weisgerber                          naddy@mips.inka.de