1#!/bin/bash 2# SPDX-License-Identifier: GPL-2.0-or-later 3# 4# This script checks vmlinux to ensure that all functions can call ftrace_caller() either directly, 5# or through the stub, ftrace_tramp_text, at the end of kernel text. 6 7# Error out if any command fails 8set -e 9 10# Allow for verbose output 11if [ "$V" = "1" ]; then 12 set -x 13fi 14 15if [ $# -lt 2 ]; then 16 echo "$0 [path to nm] [path to vmlinux]" 1>&2 17 exit 1 18fi 19 20# Have Kbuild supply the path to nm so we handle cross compilation. 21nm="$1" 22vmlinux="$2" 23 24stext_addr=$($nm "$vmlinux" | grep -e " [TA] _stext$" | \ 25 cut -d' ' -f1 | tr '[:lower:]' '[:upper:]') 26ftrace_caller_addr=$($nm "$vmlinux" | grep -e " T ftrace_caller$" | \ 27 cut -d' ' -f1 | tr '[:lower:]' '[:upper:]') 28ftrace_tramp_addr=$($nm "$vmlinux" | grep -e " T ftrace_tramp_text$" | \ 29 cut -d' ' -f1 | tr '[:lower:]' '[:upper:]') 30 31ftrace_caller_offset=$(echo "ibase=16;$ftrace_caller_addr - $stext_addr" | bc) 32ftrace_tramp_offset=$(echo "ibase=16;$ftrace_tramp_addr - $ftrace_caller_addr" | bc) 33sz_32m=$(printf "%d" 0x2000000) 34sz_64m=$(printf "%d" 0x4000000) 35 36# ftrace_caller - _stext < 32M 37if [ "$ftrace_caller_offset" -ge "$sz_32m" ]; then 38 echo "ERROR: ftrace_caller (0x$ftrace_caller_addr) is beyond 32MiB of _stext" 1>&2 39 echo "ERROR: consider disabling CONFIG_FUNCTION_TRACER, or reducing the size \ 40 of kernel text" 1>&2 41 exit 1 42fi 43 44# ftrace_tramp_text - ftrace_caller < 64M 45if [ "$ftrace_tramp_offset" -ge "$sz_64m" ]; then 46 echo "ERROR: kernel text extends beyond 64MiB from ftrace_caller" 1>&2 47 echo "ERROR: consider disabling CONFIG_FUNCTION_TRACER, or reducing the size \ 48 of kernel text" 1>&2 49 exit 1 50fi 51