diff options
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/kernel/efi.c | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c index 56c3327bbf79..e72f3100958f 100644 --- a/arch/arm64/kernel/efi.c +++ b/arch/arm64/kernel/efi.c @@ -414,13 +414,24 @@ static int __init arm64_enter_virtual_mode(void) for_each_efi_memory_desc(&memmap, md) { if (!(md->attribute & EFI_MEMORY_RUNTIME)) continue; - if (remap_region(md, &virt_md)) - ++count; + if (!remap_region(md, &virt_md)) + goto err_unmap; + ++count; } efi.systab = (__force void *)efi_lookup_mapped_addr(efi_system_table); - if (efi.systab) - set_bit(EFI_SYSTEM_TABLES, &efi.flags); + if (!efi.systab) { + /* + * If we have no virtual mapping for the System Table at this + * point, the memory map doesn't cover the physical offset where + * it resides. This means the System Table will be inaccessible + * to Runtime Services themselves once the virtual mapping is + * installed. + */ + pr_err("Failed to remap EFI System Table -- buggy firmware?\n"); + goto err_unmap; + } + set_bit(EFI_SYSTEM_TABLES, &efi.flags); local_irq_save(flags); cpu_switch_mm(idmap_pg_dir, &init_mm); @@ -453,5 +464,14 @@ static int __init arm64_enter_virtual_mode(void) set_bit(EFI_RUNTIME_SERVICES, &efi.flags); return 0; + +err_unmap: + /* unmap all mappings that succeeded: there are 'count' of those */ + for (virt_md = virtmap; count--; virt_md += memmap.desc_size) { + md = virt_md; + iounmap((__force void __iomem *)md->virt_addr); + } + kfree(virtmap); + return -1; } early_initcall(arm64_enter_virtual_mode); |