diff options
Diffstat (limited to 'arch/s390/boot/startup.c')
| -rw-r--r-- | arch/s390/boot/startup.c | 55 |
1 files changed, 43 insertions, 12 deletions
diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c index 44ef08518f37..3efa1f457451 100644 --- a/arch/s390/boot/startup.c +++ b/arch/s390/boot/startup.c @@ -203,7 +203,7 @@ static void kaslr_adjust_relocs(unsigned long min_addr, unsigned long max_addr, /* Adjust R_390_64 relocations */ for (reloc = vmlinux_relocs_64_start; reloc < vmlinux_relocs_64_end; reloc++) { - loc = (long)*reloc + offset; + loc = (long)*reloc + phys_offset; if (loc < min_addr || loc > max_addr) error("64-bit relocation outside of kernel!\n"); *(u64 *)loc += offset; @@ -263,8 +263,25 @@ static void setup_ident_map_size(unsigned long max_physmem_end) #endif } -static unsigned long setup_kernel_memory_layout(void) +#define FIXMAP_SIZE round_up(MEMCPY_REAL_SIZE + ABS_LOWCORE_MAP_SIZE, sizeof(struct lowcore)) + +static unsigned long get_vmem_size(unsigned long identity_size, + unsigned long vmemmap_size, + unsigned long vmalloc_size, + unsigned long rte_size) +{ + unsigned long max_mappable, vsize; + + max_mappable = max(identity_size, MAX_DCSS_ADDR); + vsize = round_up(SZ_2G + max_mappable, rte_size) + + round_up(vmemmap_size, rte_size) + + FIXMAP_SIZE + MODULES_LEN + KASLR_LEN; + return size_add(vsize, vmalloc_size); +} + +static unsigned long setup_kernel_memory_layout(unsigned long kernel_size) { + unsigned long kernel_start, kernel_end; unsigned long vmemmap_start; unsigned long asce_limit; unsigned long rte_size; @@ -277,12 +294,11 @@ static unsigned long setup_kernel_memory_layout(void) vmemmap_size = SECTION_ALIGN_UP(pages) * sizeof(struct page); /* choose kernel address space layout: 4 or 3 levels. */ - vsize = round_up(ident_map_size, _REGION3_SIZE) + vmemmap_size + - MODULES_LEN + MEMCPY_REAL_SIZE + ABS_LOWCORE_MAP_SIZE; - vsize = size_add(vsize, vmalloc_size); + vsize = get_vmem_size(ident_map_size, vmemmap_size, vmalloc_size, _REGION3_SIZE); if (IS_ENABLED(CONFIG_KASAN) || (vsize > _REGION2_SIZE)) { asce_limit = _REGION1_SIZE; rte_size = _REGION2_SIZE; + vsize = get_vmem_size(ident_map_size, vmemmap_size, vmalloc_size, _REGION2_SIZE); } else { asce_limit = _REGION2_SIZE; rte_size = _REGION3_SIZE; @@ -298,12 +314,26 @@ static unsigned long setup_kernel_memory_layout(void) /* force vmalloc and modules below kasan shadow */ vmax = min(vmax, KASAN_SHADOW_START); #endif - MODULES_END = round_down(vmax, _SEGMENT_SIZE); + kernel_end = vmax; + if (kaslr_enabled()) { + unsigned long 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_start = round_down(kernel_end - kernel_size, THREAD_SIZE); + __kaslr_offset = kernel_start; + + MODULES_END = round_down(kernel_start, _SEGMENT_SIZE); MODULES_VADDR = MODULES_END - MODULES_LEN; VMALLOC_END = MODULES_VADDR; /* allow vmalloc area to occupy up to about 1/2 of the rest virtual space left */ - vsize = (VMALLOC_END - (MEMCPY_REAL_SIZE + ABS_LOWCORE_MAP_SIZE)) / 2; + vsize = (VMALLOC_END - FIXMAP_SIZE) / 2; vsize = round_down(vsize, _SEGMENT_SIZE); vmalloc_size = min(vmalloc_size, vsize); VMALLOC_START = VMALLOC_END - vmalloc_size; @@ -330,6 +360,7 @@ static unsigned long setup_kernel_memory_layout(void) BUILD_BUG_ON(MAX_DCSS_ADDR > (1UL << MAX_PHYSMEM_BITS)); max_mappable = max(ident_map_size, MAX_DCSS_ADDR); max_mappable = min(max_mappable, vmemmap_start); + __identity_base = round_down(vmemmap_start - max_mappable, rte_size); return asce_limit; } @@ -358,7 +389,6 @@ static void setup_vmalloc_size(void) static void kaslr_adjust_vmlinux_info(unsigned long offset) { - *(unsigned long *)(&vmlinux.entry) += offset; vmlinux.bootdata_off += offset; vmlinux.bootdata_preserved_off += offset; #ifdef CONFIG_PIE_BUILD @@ -386,6 +416,7 @@ void startup_kernel(void) unsigned long max_physmem_end; unsigned long vmlinux_lma = 0; unsigned long amode31_lma = 0; + unsigned long kernel_size; unsigned long asce_limit; unsigned long safe_addr; void *img; @@ -417,7 +448,8 @@ void startup_kernel(void) max_physmem_end = detect_max_physmem_end(); setup_ident_map_size(max_physmem_end); setup_vmalloc_size(); - asce_limit = setup_kernel_memory_layout(); + kernel_size = vmlinux.default_lma + vmlinux.image_size + vmlinux.bss_size; + asce_limit = setup_kernel_memory_layout(kernel_size); /* got final ident_map_size, physmem allocations could be performed now */ physmem_set_usable_limit(ident_map_size); detect_physmem_online_ranges(max_physmem_end); @@ -432,7 +464,6 @@ void startup_kernel(void) if (vmlinux_lma) { __kaslr_offset_phys = vmlinux_lma - vmlinux.default_lma; kaslr_adjust_vmlinux_info(__kaslr_offset_phys); - __kaslr_offset = __kaslr_offset_phys; } } vmlinux_lma = vmlinux_lma ?: vmlinux.default_lma; @@ -472,7 +503,7 @@ void startup_kernel(void) __kaslr_offset, __kaslr_offset_phys); kaslr_adjust_got(__kaslr_offset); free_relocs(); - setup_vmem(asce_limit); + setup_vmem(__kaslr_offset, __kaslr_offset + kernel_size, asce_limit); copy_bootdata(); /* @@ -484,7 +515,7 @@ void startup_kernel(void) /* * Jump to the decompressed kernel entry point and switch DAT mode on. */ - psw.addr = vmlinux.entry; + psw.addr = __kaslr_offset + vmlinux.entry; psw.mask = PSW_KERNEL_BITS; __load_psw(psw); } |