scripts: add generic syscallnr.sh

Like syscallhdr.sh and syscalltbl.sh, add a simple script to generate
the __NR_syscalls, which should not be exported to userspace.

This script is useful to replace arch/mips/kernel/syscalls/syscallnr.sh,
refactor arch/s390/kernel/syscalls/syscalltbl, and eliminate the code
surrounded by #ifdef __KERNEL__ / #endif from exported uapi/asm/unistd_*.h
files.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

diff --git a/scripts/syscallnr.sh b/scripts/syscallnr.sh
new file mode 100644 (file)
index 0000000..3aa29e0
--- /dev/null
+++ b/scripts/syscallnr.sh
@@ -0,0 +1,74 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Generate a syscall number header.
+#
+# Each line of the syscall table should have the following format:
+#
+# NR ABI NAME [NATIVE] [COMPAT]
+#
+# NR       syscall number
+# ABI      ABI name
+# NAME     syscall name
+# NATIVE   native entry point (optional)
+# COMPAT   compat entry point (optional)
+set -e
+
+usage() {
+       echo >&2 "usage: $0 [--abis ABIS] [--prefix PREFIX] INFILE OUTFILE" >&2
+       echo >&2
+       echo >&2 "  INFILE    input syscall table"
+       echo >&2 "  OUTFILE   output header file"
+       echo >&2
+       echo >&2 "options:"
+       echo >&2 "  --abis ABIS        ABI(s) to handle (By default, all lines are handled)"
+       echo >&2 "  --prefix PREFIX    The prefix to the macro like __NR_<PREFIX><NAME>"
+       exit 1
+}
+
+# default unless specified by options
+abis=
+prefix=
+
+while [ $# -gt 0 ]
+do
+       case $1 in
+       --abis)
+               abis=$(echo "($2)" | tr ',' '|')
+               shift 2;;
+       --prefix)
+               prefix=$2
+               shift 2;;
+       -*)
+               echo "$1: unknown option" >&2
+               usage;;
+       *)
+               break;;
+       esac
+done
+
+if [ $# -ne 2 ]; then
+       usage
+fi
+
+infile="$1"
+outfile="$2"
+
+guard=_ASM_$(basename "$outfile" |
+       sed -e 'y/abcdefghijklmnopqrstuvwxyz/ABCDEFGHIJKLMNOPQRSTUVWXYZ/' \
+       -e 's/[^A-Z0-9_]/_/g' -e 's/__/_/g')
+
+grep -E "^[0-9A-Fa-fXx]+[[:space:]]+$abis" "$infile" | sort -n | {
+       echo "#ifndef $guard"
+       echo "#define $guard"
+       echo
+
+       max=0
+       while read nr abi name native compat ; do
+               max=$nr
+       done
+
+       echo "#define __NR_${prefix}syscalls $(($max + 1))"
+       echo
+       echo "#endif /* $guard */"
+} > "$outfile"