From d8e94af60b56d86bdb59acc93d8396fb4e3ce770 Mon Sep 17 00:00:00 2001
From: Roland McGrath <roland@gnu.org>
Date: Wed, 26 Mar 2003 22:49:15 +0000
Subject: [PATCH] 2003-03-26  Roland McGrath  <roland@redhat.com>

	* sysdeps/unix/make-syscalls.sh: When an undefined syscall has
	SOURCE=-, append its symbol names to make variable unix-stub-syscalls.
	* sysdeps/unix/Makefile [$(subdir) = misc] [unix-stub-syscalls]
	(sysdep_routines): Add stub-syscalls.
	($(objpfx)stub-syscalls.c): New target.
	(generated): Add stub-syscalls.c.
---
 sysdeps/unix/Makefile         | 30 ++++++++++++++++++++++++++++++
 sysdeps/unix/make-syscalls.sh | 10 ++++++++++
 2 files changed, 40 insertions(+)

diff --git a/sysdeps/unix/Makefile b/sysdeps/unix/Makefile
index 18de414341..f3600136f3 100644
--- a/sysdeps/unix/Makefile
+++ b/sysdeps/unix/Makefile
@@ -282,6 +282,36 @@ omit-deps += $(unix-syscalls)
 
 ifeq (misc,$(subdir))
 sysdep_routines += $(unix-extra-syscalls)
+
+ifdef unix-stub-syscalls
+# The system call entry points in this list are supposed to be additional
+# functions not overriding any other sysdeps/.../call.c implementation, but
+# their system call numbers are unavailable in the kernel headers we're
+# using.  Instead of a system call stub, these get a function that fails
+# with ENOSYS.  We just generate a single module defining one function and
+# making all these entry point names aliases for it.
+sysdep_routines += stub-syscalls
+$(objpfx)stub-syscalls.c: $(common-objpfx)sysd-syscalls \
+			  $(..)sysdeps/unix/Makefile
+	(echo '#include <errno.h>'; \
+	 echo 'long int _no_syscall (void)'; \
+	 echo '{ __set_errno (ENOSYS); return -1L; }'; \
+	 for call in $(unix-stub-syscalls); do \
+	   case $$call in \
+	   *@@*) ver=$${call##*@}; call=$${call%%*@}; \
+		 echo "strong_alias (_no_syscall, $${call}_$${ver})"; \
+		 echo "default_symbol_version \
+		         ($${call}_$${ver}, $$call, $$ver);" ;; \
+	   *@@*) ver=$${call##*@}; call=$${call%%*@}; \
+		 echo "strong_alias (_no_syscall, $${call}_$${ver})"; \
+		 echo "symbol_version ($${call}_$${ver}, $$call, $$ver);" ;; \
+	   *) echo "weak_alias (_no_syscall, $$call)"; \
+	      echo "weak_alias (_no_syscall, __GI_$$call)" ;; \
+	   esac; \
+	 done) > $@T
+	mv -f $@T $@
+generated += stub-syscalls.c
+endif
 endif
 
 export sysdirs
diff --git a/sysdeps/unix/make-syscalls.sh b/sysdeps/unix/make-syscalls.sh
index 275875e793..0c7eab64c9 100644
--- a/sysdeps/unix/make-syscalls.sh
+++ b/sysdeps/unix/make-syscalls.sh
@@ -111,6 +111,16 @@ while read file srcfile caller syscall args strong weak; do
   echo "#### CALL=$file NUMBER=$callnum ARGS=$args SOURCE=$srcfile"
 
  case x$srcfile"$callnum" in
+ x--)
+  # Undefined callnum for an extra syscall.
+  if [ x$caller != x- ]; then
+    if [ x$noerrno != x ]; then
+      echo >&2 "$0: no number for $fileno, no-error syscall ($strong $weak)"
+      exit 2
+    fi
+    echo "unix-stub-syscalls += $strong $weak"
+  fi
+  ;;
  x*-) ;; ### Do nothing for undefined callnum
  x-*)
   echo "ifeq (,\$(filter $file,\$(unix-syscalls)))"