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| author | Matt Fleming <matt@codeblueprint.co.uk> | 2015-11-27 21:09:32 +0000 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-11-29 09:15:42 +0100 |
| commit | b61a76f8850d2979550abc42d7e09154ebb8d785 (patch) | |
| tree | baeedcb458835f8a9bc61f6277e211d14d021247 /arch | |
| parent | edc3b9129cecd0f0857112136f5b8b1bc1d45918 (diff) | |
| download | linux-stable-b61a76f8850d2979550abc42d7e09154ebb8d785.tar.gz linux-stable-b61a76f8850d2979550abc42d7e09154ebb8d785.tar.bz2 linux-stable-b61a76f8850d2979550abc42d7e09154ebb8d785.zip | |
x86/efi: Map RAM into the identity page table for mixed mode
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.
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1448658575-17029-4-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/platform/efi/efi_64.c | 20 |
1 files changed, 20 insertions, 0 deletions
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"); |