diff options
Diffstat (limited to 'drivers/firmware/efi/libstub/randomalloc.c')
| -rw-r--r-- | drivers/firmware/efi/libstub/randomalloc.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/firmware/efi/libstub/randomalloc.c b/drivers/firmware/efi/libstub/randomalloc.c index 724155b9e10d..715f37479154 100644 --- a/drivers/firmware/efi/libstub/randomalloc.c +++ b/drivers/firmware/efi/libstub/randomalloc.c @@ -56,6 +56,7 @@ efi_status_t efi_random_alloc(unsigned long size, unsigned long random_seed) { unsigned long map_size, desc_size, total_slots = 0, target_slot; + unsigned long total_mirrored_slots = 0; unsigned long buff_size; efi_status_t status; efi_memory_desc_t *memory_map; @@ -86,8 +87,14 @@ efi_status_t efi_random_alloc(unsigned long size, slots = get_entry_num_slots(md, size, ilog2(align)); MD_NUM_SLOTS(md) = slots; total_slots += slots; + if (md->attribute & EFI_MEMORY_MORE_RELIABLE) + total_mirrored_slots += slots; } + /* consider only mirrored slots for randomization if any exist */ + if (total_mirrored_slots > 0) + total_slots = total_mirrored_slots; + /* find a random number between 0 and total_slots */ target_slot = (total_slots * (u64)(random_seed & U32_MAX)) >> 32; @@ -107,6 +114,10 @@ efi_status_t efi_random_alloc(unsigned long size, efi_physical_addr_t target; unsigned long pages; + if (total_mirrored_slots > 0 && + !(md->attribute & EFI_MEMORY_MORE_RELIABLE)) + continue; + if (target_slot >= MD_NUM_SLOTS(md)) { target_slot -= MD_NUM_SLOTS(md); continue; |