diff options
Diffstat (limited to 'arch/s390/boot/startup.c')
| -rw-r--r-- | arch/s390/boot/startup.c | 33 |
1 files changed, 24 insertions, 9 deletions
diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c index 3efa1f457451..fc9c1d51ef8d 100644 --- a/arch/s390/boot/startup.c +++ b/arch/s390/boot/startup.c @@ -281,8 +281,8 @@ static unsigned long get_vmem_size(unsigned long identity_size, static unsigned long setup_kernel_memory_layout(unsigned long kernel_size) { - unsigned long kernel_start, kernel_end; unsigned long vmemmap_start; + unsigned long kernel_start; unsigned long asce_limit; unsigned long rte_size; unsigned long pages; @@ -294,11 +294,18 @@ static unsigned long setup_kernel_memory_layout(unsigned long kernel_size) vmemmap_size = SECTION_ALIGN_UP(pages) * sizeof(struct page); /* choose kernel address space layout: 4 or 3 levels. */ + BUILD_BUG_ON(!IS_ALIGNED(__NO_KASLR_START_KERNEL, THREAD_SIZE)); + BUILD_BUG_ON(__NO_KASLR_END_KERNEL > _REGION1_SIZE); vsize = get_vmem_size(ident_map_size, vmemmap_size, vmalloc_size, _REGION3_SIZE); - if (IS_ENABLED(CONFIG_KASAN) || (vsize > _REGION2_SIZE)) { + if (IS_ENABLED(CONFIG_KASAN) || __NO_KASLR_END_KERNEL > _REGION2_SIZE || + (vsize > _REGION2_SIZE && kaslr_enabled())) { asce_limit = _REGION1_SIZE; - rte_size = _REGION2_SIZE; - vsize = get_vmem_size(ident_map_size, vmemmap_size, vmalloc_size, _REGION2_SIZE); + if (__NO_KASLR_END_KERNEL > _REGION2_SIZE) { + rte_size = _REGION2_SIZE; + vsize = get_vmem_size(ident_map_size, vmemmap_size, vmalloc_size, _REGION2_SIZE); + } else { + rte_size = _REGION3_SIZE; + } } else { asce_limit = _REGION2_SIZE; rte_size = _REGION3_SIZE; @@ -308,24 +315,32 @@ static unsigned long setup_kernel_memory_layout(unsigned long kernel_size) * Forcing modules and vmalloc area under the ultravisor * secure storage limit, so that any vmalloc allocation * we do could be used to back secure guest storage. + * + * Assume the secure storage limit always exceeds _REGION2_SIZE, + * otherwise asce_limit and rte_size would have been adjusted. */ vmax = adjust_to_uv_max(asce_limit); #ifdef CONFIG_KASAN + BUILD_BUG_ON(__NO_KASLR_END_KERNEL > KASAN_SHADOW_START); /* force vmalloc and modules below kasan shadow */ vmax = min(vmax, KASAN_SHADOW_START); #endif - kernel_end = vmax; + vsize = min(vsize, vmax); if (kaslr_enabled()) { - unsigned long kaslr_len, slots, pos; + unsigned long kernel_end, kaslr_len, slots, pos; - vsize = min(vsize, vmax); kaslr_len = max(KASLR_LEN, vmax - vsize); slots = DIV_ROUND_UP(kaslr_len - kernel_size, THREAD_SIZE); if (get_random(slots, &pos)) pos = 0; - kernel_end -= pos * THREAD_SIZE; + kernel_end = vmax - pos * THREAD_SIZE; + kernel_start = round_down(kernel_end - kernel_size, THREAD_SIZE); + } else if (vmax < __NO_KASLR_END_KERNEL || vsize > __NO_KASLR_END_KERNEL) { + kernel_start = round_down(vmax - kernel_size, THREAD_SIZE); + decompressor_printk("The kernel base address is forced to %lx\n", kernel_start); + } else { + kernel_start = __NO_KASLR_START_KERNEL; } - kernel_start = round_down(kernel_end - kernel_size, THREAD_SIZE); __kaslr_offset = kernel_start; MODULES_END = round_down(kernel_start, _SEGMENT_SIZE); |