linux/arch/powerpc/kernel/prom_init_check.sh
Marco Elver 90db9dbedd kasan, powerpc: don't rename memintrinsics if compiler adds prefixes
With appropriate compiler support [1], KASAN builds use __asan prefixed
meminstrinsics, and KASAN no longer overrides memcpy/memset/memmove.

If compiler support is detected (CC_HAS_KASAN_MEMINTRINSIC_PREFIX), define
memintrinsics normally (do not prefix '__').

On powerpc, KASAN is the only user of __mem functions, which are used to
define instrumented memintrinsics.  Alias the normal versions for KASAN to
use in its implementation.

Link: https://lore.kernel.org/all/20230224085942.1791837-1-elver@google.com/ [1]
Link: https://lore.kernel.org/oe-kbuild-all/202302271348.U5lvmo0S-lkp@intel.com/
Link: https://lkml.kernel.org/r/20230227094726.3833247-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>	[powerpc]
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-03-23 17:18:33 -07:00

95 lines
2.1 KiB
Bash

#!/bin/sh
# SPDX-License-Identifier: GPL-2.0-or-later
#
# Copyright © 2008 IBM Corporation
#
# This script checks prom_init.o to see what external symbols it
# is using, if it finds symbols not in the whitelist it returns
# an error. The point of this is to discourage people from
# intentionally or accidentally adding new code to prom_init.c
# which has side effects on other parts of the kernel.
# If you really need to reference something from prom_init.o add
# it to the list below:
has_renamed_memintrinsics()
{
grep -q "^CONFIG_KASAN=y$" ${KCONFIG_CONFIG} && \
! grep -q "^CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX=y" ${KCONFIG_CONFIG}
}
if has_renamed_memintrinsics
then
MEM_FUNCS="__memcpy __memset"
else
MEM_FUNCS="memcpy memset"
fi
WHITELIST="add_reloc_offset __bss_start __bss_stop copy_and_flush
_end enter_prom $MEM_FUNCS reloc_offset __secondary_hold
__secondary_hold_acknowledge __secondary_hold_spinloop __start
logo_linux_clut224 btext_prepare_BAT
reloc_got2 kernstart_addr memstart_addr linux_banner _stext
btext_setup_display TOC. relocate"
NM="$1"
OBJ="$2"
ERROR=0
check_section()
{
file=$1
section=$2
size=$(objdump -h -j $section $file 2>/dev/null | awk "\$2 == \"$section\" {print \$3}")
size=${size:-0}
if [ $size -ne 0 ]; then
ERROR=1
echo "Error: Section $section not empty in prom_init.c" >&2
fi
}
for UNDEF in $($NM -u $OBJ | awk '{print $2}')
do
# On 64-bit nm gives us the function descriptors, which have
# a leading . on the name, so strip it off here.
UNDEF="${UNDEF#.}"
case "$KBUILD_VERBOSE" in
*1*)
echo "Checking prom_init.o symbol '$UNDEF'" ;;
esac
OK=0
for WHITE in $WHITELIST
do
if [ "$UNDEF" = "$WHITE" ]; then
OK=1
break
fi
done
# ignore register save/restore funcitons
case $UNDEF in
_restgpr_*|_restgpr0_*|_rest32gpr_*)
OK=1
;;
_savegpr_*|_savegpr0_*|_save32gpr_*)
OK=1
;;
esac
if [ $OK -eq 0 ]; then
ERROR=1
echo "Error: External symbol '$UNDEF' referenced" \
"from prom_init.c" >&2
fi
done
check_section $OBJ .data
check_section $OBJ .bss
check_section $OBJ .init.data
exit $ERROR