From 2c51d97ee88da897db8405f659d1735ffe86ad7c Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Mon, 15 Oct 2018 13:49:59 +1100 Subject: [PATCH] powerpc: Check prom_init for disallowed sections prom_init.c must not modify the kernel image outside of the .bss.prominit section. Thus make sure that prom_init.o doesn't have anything in any of these: .data .bss .init.data Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/prom_init_check.sh | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/arch/powerpc/kernel/prom_init_check.sh b/arch/powerpc/kernel/prom_init_check.sh index acb6b92..667df97 100644 --- a/arch/powerpc/kernel/prom_init_check.sh +++ b/arch/powerpc/kernel/prom_init_check.sh @@ -28,6 +28,18 @@ OBJ="$2" ERROR=0 +function 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 @@ -66,4 +78,8 @@ do fi done +check_section $OBJ .data +check_section $OBJ .bss +check_section $OBJ .init.data + exit $ERROR -- 2.7.4