hurd: Fix ld.so __getcwd override from libc

ld.so symbols to be overriden by libc need to be extern to really get
overriden. __getcwd happens to have never been exposed, putting it to
GLIBC_PRIVATE.

include/unistd.h

@@ -75,7 +75,8 @@ extern int __lchown (const char *__file, __uid_t __owner,
 		     __gid_t __group);
 extern int __chdir (const char *__path) attribute_hidden;
 extern int __fchdir (int __fd) attribute_hidden;
-extern char *__getcwd (char *__buf, size_t __size) attribute_hidden;
+extern char *__getcwd (char *__buf, size_t __size);
+libc_hidden_proto (__getcwd)
 extern int __rmdir (const char *__path) attribute_hidden;
 extern int __execvpe (const char *file, char *const argv[],
 		      char *const envp[]) attribute_hidden;

io/getcwd.c

@@ -32,6 +32,7 @@ __getcwd (char *buf, size_t size)
   __set_errno (ENOSYS);
   return NULL;
 }
+libc_hidden_def (__getcwd)
 weak_alias (__getcwd, getcwd)
 
 stub_warning (__getcwd)

sysdeps/mach/hurd/Versions

@@ -1,7 +1,7 @@
 libc {
   GLIBC_2.0 {
     # functions with a weak definition in the dynamic linker
-    __access; __getcwd; __mmap;
+    __access; __mmap;
   }
   GLIBC_2.2.6 {
     # functions with a weak definition in the dynamic linker
@@ -10,7 +10,7 @@ libc {
   GLIBC_PRIVATE {
     # Functions shared with the dynamic linker
     __access_noerrno; __libc_read; __libc_write; __libc_lseek64;
-    __libc_lock_self0; __sigprocmask;
+    __libc_lock_self0; __sigprocmask; __getcwd;
 
     _dl_init_first;
   }
@@ -22,7 +22,7 @@ ld {
     __hurd_threadvar_stack_mask;  __hurd_threadvar_stack_offset;
 
     # functions that must be shared with libc
-    __access; __close; __getcwd; __getpid;
+    __access; __close; __getpid;
     __mmap; __open; __read; __sbrk; __strtoul_internal;
     __write; __writev; __xstat64; __fxstat64;
     _exit; _hurd_intr_rpc_mach_msg;
@@ -41,6 +41,6 @@ ld {
 
     # functions that must be shared with libc
     __access_noerrno; __libc_read; __libc_write; __libc_lseek64;
-    __libc_lock_self0; __sigprocmask;
+    __libc_lock_self0; __sigprocmask; __getcwd;
   }
 }

sysdeps/mach/hurd/getcwd.c

@@ -306,4 +306,5 @@ __getcwd (char *buf, size_t size)
 							    buf, size));
   return cwd;
 }
+libc_hidden_def (__getcwd)
 weak_alias (__getcwd, getcwd)

sysdeps/mach/hurd/i386/localplt.data

@@ -35,7 +35,7 @@ ld.so: __xstat64
 #ld.so: __access
 ld.so: __access_noerrno
 ld.so: __getpid
-#ld.so: __getcwd
+ld.so: __getcwd
 ld.so: __sbrk
 ld.so: __strtoul_internal
 #ld.so: _exit

sysdeps/posix/getcwd.c

@@ -531,5 +531,6 @@ __getcwd (char *buf, size_t size)
 }
 
 #if defined _LIBC && !defined __getcwd
+libc_hidden_def (__getcwd)
 weak_alias (__getcwd, getcwd)
 #endif

sysdeps/unix/sysv/linux/getcwd.c

@@ -127,6 +127,7 @@ __getcwd (char *buf, size_t size)
 
   return NULL;
 }
+libc_hidden_def (__getcwd)
 weak_alias (__getcwd, getcwd)
 
 /* Get the code for the generic version.  */