From b798b685b42c9dbe508e59a74250d97c41bec35e Mon Sep 17 00:00:00 2001 From: Alexander Gordeev Date: Wed, 17 Jul 2024 21:43:22 +0200 Subject: [PATCH] s390/boot: Do not assume the decompressor range is reserved When allocating a random memory range for .amode31 sections the minimal randomization address is 0. That does not lead to a possible overlap with the decompressor image (which also starts from 0) since by that time the image range is already reserved. Do not assume the decompressor range is reserved and always provide the minimal randomization address for .amode31 sections beyond the decompressor. That is a prerequisite for moving the lowcore memory address from NULL elsewhere. Signed-off-by: Alexander Gordeev Signed-off-by: Sven Schnelle Signed-off-by: Vasily Gorbik --- arch/s390/boot/startup.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c index c59014945af05..cc8753c0c1216 100644 --- a/arch/s390/boot/startup.c +++ b/arch/s390/boot/startup.c @@ -478,8 +478,12 @@ void startup_kernel(void) * before the kernel started. Therefore, in case the two sections * overlap there is no risk of corrupting any data. */ - if (kaslr_enabled()) - amode31_lma = randomize_within_range(vmlinux.amode31_size, PAGE_SIZE, 0, SZ_2G); + if (kaslr_enabled()) { + unsigned long amode31_min; + + amode31_min = (unsigned long)_decompressor_end; + amode31_lma = randomize_within_range(vmlinux.amode31_size, PAGE_SIZE, amode31_min, SZ_2G); + } if (!amode31_lma) amode31_lma = __kaslr_offset_phys - vmlinux.amode31_size; physmem_reserve(RR_AMODE31, amode31_lma, vmlinux.amode31_size); -- 2.39.5