We are relying on the pre-existing mappings in 'trampoline_pgd' when accessing function arguments in the EFI mixed mode thunking code. Instead let's map memory explicitly so that things will continue to work when we move to a separate page table in the future. Reviewed-by: Borislav Petkov <bp@xxxxxxx> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@xxxxxxxxx> Signed-off-by: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx> --- arch/x86/platform/efi/efi_64.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index 5aa186db59e3..102976dda8c4 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -144,6 +144,7 @@ void efi_sync_low_kernel_mappings(void) int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) { unsigned long pfn, text; + efi_memory_desc_t *md; struct page *page; unsigned npages; pgd_t *pgd; @@ -177,6 +178,25 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) if (!IS_ENABLED(CONFIG_EFI_MIXED)) return 0; + /* + * Map all of RAM so that we can access arguments in the 1:1 + * mapping when making EFI runtime calls. + */ + for_each_efi_memory_desc(&memmap, md) { + if (md->type != EFI_CONVENTIONAL_MEMORY && + md->type != EFI_LOADER_DATA && + md->type != EFI_LOADER_CODE) + continue; + + pfn = md->phys_addr >> PAGE_SHIFT; + npages = md->num_pages; + + if (kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, npages, 0)) { + pr_err("Failed to map 1:1 memory\n"); + return 1; + } + } + page = alloc_page(GFP_KERNEL|__GFP_DMA32); if (!page) panic("Unable to allocate EFI runtime stack < 4GB\n"); -- 2.6.2 -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html