diff options
Diffstat (limited to 'arch/x86/boot/compressed/kaslr.c')
| -rw-r--r-- | arch/x86/boot/compressed/kaslr.c | 50 |
1 files changed, 49 insertions, 1 deletions
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index f03d59ea6e40..3b0948ad449f 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -760,6 +760,49 @@ static void process_e820_entries(unsigned long minimum, } } +/* + * If KHO is active, only process its scratch areas to ensure we are not + * stepping onto preserved memory. + */ +static bool process_kho_entries(unsigned long minimum, unsigned long image_size) +{ + struct kho_scratch *kho_scratch; + struct setup_data *ptr; + struct kho_data *kho; + int i, nr_areas = 0; + + if (!IS_ENABLED(CONFIG_KEXEC_HANDOVER)) + return false; + + ptr = (struct setup_data *)(unsigned long)boot_params_ptr->hdr.setup_data; + while (ptr) { + if (ptr->type == SETUP_KEXEC_KHO) { + kho = (struct kho_data *)(unsigned long)ptr->data; + kho_scratch = (void *)(unsigned long)kho->scratch_addr; + nr_areas = kho->scratch_size / sizeof(*kho_scratch); + break; + } + + ptr = (struct setup_data *)(unsigned long)ptr->next; + } + + if (!nr_areas) + return false; + + for (i = 0; i < nr_areas; i++) { + struct kho_scratch *area = &kho_scratch[i]; + struct mem_vector region = { + .start = area->addr, + .size = area->size, + }; + + if (process_mem_region(®ion, minimum, image_size)) + break; + } + + return true; +} + static unsigned long find_random_phys_addr(unsigned long minimum, unsigned long image_size) { @@ -775,7 +818,12 @@ static unsigned long find_random_phys_addr(unsigned long minimum, return 0; } - if (!process_efi_entries(minimum, image_size)) + /* + * During kexec handover only process KHO scratch areas that are known + * not to contain any data that must be preserved. + */ + if (!process_kho_entries(minimum, image_size) && + !process_efi_entries(minimum, image_size)) process_e820_entries(minimum, image_size); phys_addr = slots_fetch_random(); |