Remove bp-thunks code

["Joseph S. Myers" <joseph at codesourcery dot com>]

As was discussed about a year ago, the bounded-pointers code in glibc
is thoroughly bitrotten, relates to a feature removed from GCC in 2002
and is no longer useful; if any similar feature were added in future,
the version control history could be used to indicate the sorts of
places in glibc that would need changing to add support, but large
amounts of glibc would need auditing for any new such feature in any
case.  So the bitrotten code should be removed as not useful to have
in current mainline glibc.

This patch starts that removal by removing the bp-thunks code for
system calls; I expect subsequent patches will remove various other
bits of bounded-pointers code.  This patch does not do anything about
the large variety of letters used in syscalls.list to describe
properties of syscall arguments that were only used in generating
these thunks; maybe many such letters should be removed, or maybe some
would be useful for other things such as debug info for syscall
arguments.  In any case, the letters used could be simplified in a
separate patch.

Tested x86_64.

2013-01-25  Joseph Myers  <joseph@codesourcery.com>

	[BZ #13550]
	* Makerules (elide-bp-thunks): Remove variable.
	(elide-routines.oS): Don't use $(elide-bp-thunks).
	(elide-routines.os): Likewise.
	(elide-routines.o): Likewise.
	(elide-routines.op): Likewise.
	(elide-routines.og): Likewise.
	(objects): Don't use $(bp-thunks).
	* sysdeps/unix/Makefile ($(common-objpfx)s-proto-bp.d): Do not
	include.
	(common-generated): Do not add s-proto-bp.d.
	* sysdeps/unix/make-syscalls.sh (ptr): Remove variable.
	(int): Likewise.
	(typ): Likewise.
	Do not generate makefile rules for bounded-pointer thunks.
	* sysdeps/generic/bp-thunks.h: Remove file.
	* sysdeps/unix/sysv/linux/i386/bp-thunks.h: Likewise.
	* sysdeps/unix/s-proto-bp.S: Likewise.

diff --git a/Makerules b/Makerules
index ce86d50..5e7d205 100644
--- a/Makerules
+++ b/Makerules
@@ -409,19 +409,15 @@ static-only-routines =
 endif
 endif
 
-# Bounded pointer thunks are only built for *.ob
-elide-bp-thunks = $(addprefix $(bppfx),$(bp-thunks))
-
 elide-routines.oS += $(filter-out $(static-only-routines),\
-				  $(routines) $(aux) $(sysdep_routines)) \
-		     $(elide-bp-thunks)
-elide-routines.os += $(static-only-routines) $(elide-bp-thunks)
+				  $(routines) $(aux) $(sysdep_routines))
+elide-routines.os += $(static-only-routines)
 
 # If we have versioned code we don't need the old versions in any of the
 # static libraries.
-elide-routines.o  += $(shared-only-routines) $(elide-bp-thunks)
-elide-routines.op += $(shared-only-routines) $(elide-bp-thunks)
-elide-routines.og += $(shared-only-routines) $(elide-bp-thunks)
+elide-routines.o  += $(shared-only-routines)
+elide-routines.op += $(shared-only-routines)
+elide-routines.og += $(shared-only-routines)
 elide-routines.ob += $(shared-only-routines)
 
 # Shared library building.
@@ -601,11 +597,7 @@ headers := $(headers) $(sysdep_headers)
 
 # This is the list of all object files, gotten by
 # replacing every ".c" in `sources' with a ".o".
-# We also add bounded-pointer thunks, which are later
-# elided for all suffixes except for `.ob'.
-override objects := $(addprefix $(objpfx),$(sources:.c=.o) \
-		      $(patsubst %,$(bppfx)%.o,\
-			$(filter $(routines) $(sysdep_routines),$(bp-thunks))))
+override objects := $(addprefix $(objpfx),$(sources:.c=.o))
 
 
 # The makefile may define $(extra-libs) with `libfoo libbar'
diff --git a/sysdeps/generic/bp-thunks.h b/sysdeps/generic/bp-thunks.h
deleted file mode 100644
index 8e4e11d..0000000
--- a/sysdeps/generic/bp-thunks.h
+++ /dev/null
@@ -1,69 +0,0 @@
-/* Bounded-pointer syscall thunk support.
-   Copyright (C) 2000-2013 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Greg McGary <greg@mcgary.org>
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <http://www.gnu.org/licenses/>.  */
-
-#ifndef _bpthunks_h_
-#define _bpthunks_h_
-
-#ifndef __ASSEMBLER__
-
-/* This header is included by the syscall BP thunks defined in
-   sysd-syscalls, as created by sysdeps/unix/make-syscalls.sh.  It
-   includes all headers that contain prototype declarations for system
-   call functions.  */
-
-#include <libc-symbols.h>
-#include <bp-sym.h>
-#include <bp-checks.h>
-
-/* Get `struct timeval' definition for select.  */
-#define __need_timeval
-#include <bits/time.h>
-
-#include <stddef.h>
-#include <unistd.h>
-#include <sched.h>
-#include <signal.h>
-#include <fcntl.h>
-#include <time.h>
-#include <utime.h>
-#include <stdio.h>
-
-#include <sys/types.h>
-#include <sys/ioctl.h>
-#include <sys/klog.h>
-#include <sys/mman.h>
-#include <sys/mount.h>
-#include <sys/quota.h>
-#include <sys/resource.h>
-#include <sys/select.h>
-#include <io/sys/sendfile.h>
-#include <sys/socket.h>
-#include <sys/stat.h>
-#include <sys/statfs.h>
-#include <sys/swap.h>
-#include <sys/sysinfo.h>
-#include <sys/time.h>
-#include <sys/times.h>
-#include <sys/timex.h>
-#include <sys/utsname.h>
-#include <sys/wait.h>
-
-#endif /* Not __ASSEMBLER__.  */
-
-#endif /* _bpthunks_h_ */
diff --git a/sysdeps/unix/Makefile b/sysdeps/unix/Makefile
index 7fd0003..375561f 100644
--- a/sysdeps/unix/Makefile
+++ b/sysdeps/unix/Makefile
@@ -88,21 +88,10 @@ $(common-objpfx)sysd-syscalls: $(..)sysdeps/unix/make-syscalls.sh \
 	mv -f $@T $@
 endif
 
-# The $(bppfx)syscall.ob objects depend on s-proto-bp.d, which are
-# generated to specify dependencies generated BP stubs have on headers.
-# These deps use file names relative to a subdir, so don't
-# include them in the parent directory.
-ifneq (,$(filter $(unix-syscalls),$(routines) $(sysdep_routines) $(aux)))
-ifndef no_deps
--include $(common-objpfx)s-proto-bp.d
-endif
-endif
-
 $(common-objpfx)s-%.d: $(..)sysdeps/unix/s-%.S \
 		       $(wildcard $(+sysdep_dirs:%=%/syscalls.list))
 	$(+make-deps)
 
-common-generated += s-proto-bp.d
 postclean-generated += sysd-syscalls
 
 endif
diff --git a/sysdeps/unix/make-syscalls.sh b/sysdeps/unix/make-syscalls.sh
index f7162e2..f04f2ab 100644
--- a/sysdeps/unix/make-syscalls.sh
+++ b/sysdeps/unix/make-syscalls.sh
@@ -36,10 +36,6 @@
 # W: wait status, optionally-NULL pointer to int (e.g., 2nd arg of wait4)
 #
 
-ptr='[abBfFINpPsSWV]'	# all pointer keyletters
-int='[inv]'		# all scalar keyletters
-typ='[ifnNpP]'		# typed-arg keyletters: we capture type for use in thunk
-
 ##############################################################################
 
 thisdir=$1; shift
@@ -313,114 +309,4 @@ while read file srcfile caller syscall args strong weak; do
  ;;
  esac
 
-  case x"$callnum",$srcfile,$args in
-  x[_-],-,* | x*,*.[sS],*V*) ;;
-  x*,-,*$ptr* | x*,*.[sS],*$ptr*)
-
-    nv_weak=`for name in $weak; do
-		case $name in
-		*@*) ;;
-		*) echo $name;;
-	        esac; done`
-
-    # choose the name with the fewest leading underscores, preferably none
-    set `echo $strong $nv_weak |tr '@ \t' ' \n\n' |sort -r`
-    callname=$1
-
-    # convert signature string to individual numbered arg names
-    # e.g., i:ipbN -> i0 i1 p2 b3 N4
-    set `echo $args |
-	sed -e 's/^\(.\):\(.*\)/\2 <\10>/' \
-	    -e 's/^\([^ ]\)\(.*\)/\2 <\11>/' \
-	    -e 's/^\([^ ]\)\(.*\)/\2 <\12>/' \
-	    -e 's/^\([^ ]\)\(.*\)/\2 <\13>/' \
-	    -e 's/^\([^ ]\)\(.*\)/\2 <\14>/' \
-	    -e 's/^\([^ ]\)\(.*\)/\2 <\15>/' \
-	    -e 's/^\([^ ]\)\(.*\)/\2 <\16>/' \
-	    -e 's/^\([^ ]\)\(.*\)/\2 <\17>/' \
-	    -e 's/^\([^ ]\)\(.*\)/\2 <\18>/' \
-	    -e 's/^\([^ ]\)\(.*\)/\2 <\19>/'`
-    rtn=$1; shift
-    args=$*
-    arglist=`echo $* |sed 's/ /, /g'`
-
-    # The best way to understand what's going on here is to examine
-    # the output in BUILDDIR/sysd-syscalls.
-
-    # generate makefile envelope & rule head
-    echo "ifeq (,\$(filter $file,\$(bp-thunks)))"
-    echo "bp-thunks += $file"
-    echo "\$(objpfx)\$(bppfx)$file.ob: \$(common-objpfx)s-proto-bp.d"
-
-    # generate macro head
-    echo "	(echo '#define $callname(`echo $arglist | \
-	    sed -e 's/[<>]//g'`) `echo $rtn | \
-	    sed -e 's/<\('$typ'0\)>/\1v;/g' \
-		-e 's/<\(b0\)>/x0; extern char \1v;/g'` \\'; \\"
-
-    # generate extern decls of dummy variables for each arg
-    echo "	 echo '`echo $args | \
-	    sed -e 's/<\('$typ'[1-9]\)>/extern \1, \1v;/g' \
-		-e 's/<\([abBFIsSV][1-9]\)>/extern char \1v;/g' \
-		-e 's/<\([Wv][1-9]\)>/extern int \1v;/g'` \\'; \\"
-
-    # generate bounded-pointer thunk declarator
-    echo "	 echo '`echo $rtn | \
-	    sed -e 's/<\('$ptr'0\)>/__typeof (\1v) *__bounded/g' \
-		-e 's/<\('$int'0\)>/__typeof (\1v)/g'` BP_SYM ($strong) (`echo $arglist | \
-	    sed -e 's/<\('$ptr'[1-9]\)>/__typeof (\1v) *__bounded \1a/g' \
-		-e 's/<\('$int'[1-9]\)>/__typeof (\1v) \1a/g'`) { \\'; \\"
-
-    # generate extern primitive syscall declaration
-    echo "	 echo '  extern `echo $rtn | \
-	    sed -e 's/<\('$ptr'0\)>/__typeof (\1v) *__unbounded/g' \
-		-e 's/<\('$int'0\)>/__typeof (\1v)/g'` ($callname) (`echo $arglist | \
-	    sed -e 's/<\('$ptr'[1-9]\)>/__typeof (\1v) *__unbounded/g' \
-		-e 's/<\('$int'[1-9]\)>/__typeof (\1v)/g'`); \\'; \\"
-
-    # generate call the primtive system call, optionally wrapping bounds
-    # around the result if the signature's return keyletter is `b'.
-    echo "	 echo '  return `echo $rtn |
-	    sed -e 's/<b0>/BOUNDED_N (/' \
-		-e 's/<.0>//'`($callname) (`echo $arglist | \
-	    sed -e 's/<\(a[1-9]\)>/__ptrvalue (\1a)/g' \
-		-e 's/<\(n[1-9]\)>, <\(V[1-9]\)>/\1a, CHECK_N_PAGES (\2a, \1a)/g' \
-		-e 's/<\(b[1-9]\)>, <\(n[1-9]\)>/CHECK_N (\1a, \2a), \2a/g' \
-		-e 's/<\(b[1-9]\)>, <\(N[1-9]\)>/CHECK_N (\1a, *CHECK_1 (\2a)), __ptrvalue (\2a)/g' \
-		-e 's/<\(B[1-9]\)>, <\(n[1-9]\)>/CHECK_N_NULL_OK (\1a, \2a), \2a/g' \
-		-e 's/<\(B[1-9]\)>, <\(N[1-9]\)>/CHECK_N_NULL_OK (\1a, *CHECK_1 (\2a)), __ptrvalue (\2a)/g' \
-		-e 's/<\(f[1-9]\)>/CHECK_N (\1a, 2)/g' \
-		-e 's/<\(i[1-9]\)>, <\(F[1-9]\)>/\1a, CHECK_FCNTL (\2a, \1a)/g' \
-		-e 's/<\(i[1-9]\)>, <\(I[1-9]\)>/\1a, CHECK_IOCTL (\2a, \1a)/g' \
-		-e 's/<\(p[1-9]\)>/CHECK_1 (\1a)/g' \
-		-e 's/<\([PW][1-9]\)>/CHECK_1_NULL_OK (\1a)/g' \
-		-e 's/<\(s[1-9]\)>/CHECK_STRING (\1a)/g' \
-		-e 's/<\(S[1-9]\)>/CHECK_STRING_NULL_OK (\1a)/g' \
-		-e 's/<\([ivn][1-9]\)>/\1a/g'`)`echo $rtn $args |
-	    sed -e 's/<b0>.*<\(n[1-9]\)>.*/, \1a)/' \
-		-e 's/<.0>.*//'`; \\'; \\"
-
-    echo "	 echo '} \\'; \\"
-
-    echo "	 echo 'libc_hidden_def (BP_SYM ($strong)) \\'; \\"
-
-    # generate thunk aliases
-    for name in $nv_weak; do
-      echo "	 echo 'weak_alias (BP_SYM ($strong), BP_SYM ($name)) \\'; \\"
-      echo "	 echo 'libc_hidden_weak (BP_SYM ($name)) \\'; \\"
-    done
-
-    # wrap up
-    echo "\
-	 echo ''; \\
-	 echo '#include <bp-thunks.h>'; \\
-	) | \$(COMPILE.c) -x c -o \$@ -"
-### Use this for debugging intermediate output:
-### 	) >\$(@:.ob=.c)
-### 	\$(subst -c,-E,\$(COMPILE.c)) -o \$(@:.ob=.ib) \$(@:.ob=.c)
-### 	\$(COMPILE.c) -x cpp-output -o \$@ \$(@:.ob=.ib)"
-    echo endif
-    ;;
-  esac
-
 done
diff --git a/sysdeps/unix/s-proto-bp.S b/sysdeps/unix/s-proto-bp.S
deleted file mode 100644
index ba0363e..0000000
--- a/sysdeps/unix/s-proto-bp.S
+++ /dev/null
@@ -1,4 +0,0 @@
-/* This file exists just to have its dependencies determined.
-   Those dependencies are then used for the bp thunk objects.  */
-
-#include <bp-thunks.h>
diff --git a/sysdeps/unix/sysv/linux/i386/bp-thunks.h b/sysdeps/unix/sysv/linux/i386/bp-thunks.h
deleted file mode 100644
index 59a42dd..0000000
--- a/sysdeps/unix/sysv/linux/i386/bp-thunks.h
+++ /dev/null
@@ -1,4 +0,0 @@
-#ifndef __ASSEMBLER__
-# include <sysdeps/generic/bp-thunks.h>
-# include <sys/vm86.h>
-#endif

-- 
Joseph S. Myers
joseph@codesourcery.com