From c2dea0bc53397166a77811d9b66928643a83d6f3 Mon Sep 17 00:00:00 2001 From: Alexandre Ghiti Date: Wed, 29 Mar 2023 06:53:28 +0200 Subject: riscv: Check relocations at compile time Relocating kernel at runtime is done very early in the boot process, so it is not convenient to check for relocations there and react in case a relocation was not expected. There exists a script in scripts/ that extracts the relocations from vmlinux that is then used at postlink to check the relocations. Signed-off-by: Alexandre Ghiti Reviewed-by: Anup Patel Link: https://lore.kernel.org/r/20230329045329.64565-6-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt --- arch/riscv/Makefile.postlink | 36 ++++++++++++++++++++++++++++++++++++ arch/riscv/tools/relocs_check.sh | 26 ++++++++++++++++++++++++++ 2 files changed, 62 insertions(+) create mode 100644 arch/riscv/Makefile.postlink create mode 100755 arch/riscv/tools/relocs_check.sh diff --git a/arch/riscv/Makefile.postlink b/arch/riscv/Makefile.postlink new file mode 100644 index 000000000000..d5de8d520d3e --- /dev/null +++ b/arch/riscv/Makefile.postlink @@ -0,0 +1,36 @@ +# SPDX-License-Identifier: GPL-2.0 +# =========================================================================== +# Post-link riscv pass +# =========================================================================== +# +# Check that vmlinux relocations look sane + +PHONY := __archpost +__archpost: + +-include include/config/auto.conf +include $(srctree)/scripts/Kbuild.include + +quiet_cmd_relocs_check = CHKREL $@ +cmd_relocs_check = \ + $(CONFIG_SHELL) $(srctree)/arch/riscv/tools/relocs_check.sh "$(OBJDUMP)" "$(NM)" "$@" + +# `@true` prevents complaint when there is nothing to be done + +vmlinux: FORCE + @true +ifdef CONFIG_RELOCATABLE + $(call if_changed,relocs_check) +endif + +%.ko: FORCE + @true + +clean: + @true + +PHONY += FORCE clean + +FORCE: + +.PHONY: $(PHONY) diff --git a/arch/riscv/tools/relocs_check.sh b/arch/riscv/tools/relocs_check.sh new file mode 100755 index 000000000000..baeb2e7b2290 --- /dev/null +++ b/arch/riscv/tools/relocs_check.sh @@ -0,0 +1,26 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0-or-later +# Based on powerpc relocs_check.sh + +# This script checks the relocations of a vmlinux for "suspicious" +# relocations. + +if [ $# -lt 3 ]; then + echo "$0 [path to objdump] [path to nm] [path to vmlinux]" 1>&2 + exit 1 +fi + +bad_relocs=$( +${srctree}/scripts/relocs_check.sh "$@" | + # These relocations are okay + # R_RISCV_RELATIVE + grep -F -w -v 'R_RISCV_RELATIVE' +) + +if [ -z "$bad_relocs" ]; then + exit 0 +fi + +num_bad=$(echo "$bad_relocs" | wc -l) +echo "WARNING: $num_bad bad relocations" +echo "$bad_relocs" -- cgit v1.2.3