diff options
Diffstat (limited to 'arch/riscv/mm/init.c')
| -rw-r--r-- | arch/riscv/mm/init.c | 36 |
1 files changed, 35 insertions, 1 deletions
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 943c18d6ef4d..0798bd861dcb 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -1014,11 +1014,45 @@ static void __init pt_ops_set_late(void) #endif } +#ifdef CONFIG_RANDOMIZE_BASE +extern bool __init __pi_set_nokaslr_from_cmdline(uintptr_t dtb_pa); +extern u64 __init __pi_get_kaslr_seed(uintptr_t dtb_pa); + +static int __init print_nokaslr(char *p) +{ + pr_info("Disabled KASLR"); + return 0; +} +early_param("nokaslr", print_nokaslr); + +unsigned long kaslr_offset(void) +{ + return kernel_map.virt_offset; +} +#endif + asmlinkage void __init setup_vm(uintptr_t dtb_pa) { pmd_t __maybe_unused fix_bmap_spmd, fix_bmap_epmd; - kernel_map.virt_addr = KERNEL_LINK_ADDR; +#ifdef CONFIG_RANDOMIZE_BASE + if (!__pi_set_nokaslr_from_cmdline(dtb_pa)) { + u64 kaslr_seed = __pi_get_kaslr_seed(dtb_pa); + u32 kernel_size = (uintptr_t)(&_end) - (uintptr_t)(&_start); + u32 nr_pos; + + /* + * Compute the number of positions available: we are limited + * by the early page table that only has one PUD and we must + * be aligned on PMD_SIZE. + */ + nr_pos = (PUD_SIZE - kernel_size) / PMD_SIZE; + + kernel_map.virt_offset = (kaslr_seed % nr_pos) * PMD_SIZE; + } +#endif + + kernel_map.virt_addr = KERNEL_LINK_ADDR + kernel_map.virt_offset; kernel_map.page_offset = _AC(CONFIG_PAGE_OFFSET, UL); #ifdef CONFIG_XIP_KERNEL |