diff options
Diffstat (limited to '0004-efi-efi_memmap_insert-don-t-split-regions-with-inval.patch')
| -rw-r--r-- | 0004-efi-efi_memmap_insert-don-t-split-regions-with-inval.patch | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/0004-efi-efi_memmap_insert-don-t-split-regions-with-inval.patch b/0004-efi-efi_memmap_insert-don-t-split-regions-with-inval.patch new file mode 100644 index 000000000..a69c6108c --- /dev/null +++ b/0004-efi-efi_memmap_insert-don-t-split-regions-with-inval.patch @@ -0,0 +1,45 @@ +From 1c38760731eefdbd5e9ce288009d6d19afcff004 Mon Sep 17 00:00:00 2001 +From: Peter Jones <pjones@redhat.com> +Date: Wed, 7 Dec 2016 16:34:20 -0500 +Subject: [PATCH 4/4] efi: efi_memmap_insert(): don't split regions with + invalid sizes. + +Some machines, such as the Lenovo ThinkPad W541 with firmware GNET80WW +(2.28), include memory map entries with phys_addr=0x0 and num_pages=0. + +If we're inserting a new memmap and we find a map that is either 0 +pages or all of possible memory (or more!), skip it. When a map exists +at 0 that's 0 pages, the "end" math here winds up making *every* address +within the range, and so it'll try to split that entry, and things go +poorly after that. The same would be true if num_pages were (u64)-1LL +(all bits set) or (u64)-1LL >> EFI_PAGE_SHIFT (i.e. all bits set as a +size in bytes, but then shifted to page size to fill the table in). + +Don't even try to split those entries, they're nonsense. + +Signed-off-by: Peter Jones <pjones@redhat.com> +--- + drivers/firmware/efi/memmap.c | 7 +++++++ + 1 file changed, 7 insertions(+) + +diff --git a/drivers/firmware/efi/memmap.c b/drivers/firmware/efi/memmap.c +index 5b71c717..f8c6870 100644 +--- a/drivers/firmware/efi/memmap.c ++++ b/drivers/firmware/efi/memmap.c +@@ -244,6 +244,13 @@ void __init efi_memmap_insert(struct efi_memory_map *old_memmap, void *buf, + /* copy original EFI memory descriptor */ + memcpy(new, old, old_memmap->desc_size); + md = new; ++ if (md->num_pages == 0 || ++ md->num_pages >= (((u64)-1LL) >> EFI_PAGE_SHIFT)) { ++ pr_warn("%s: Skipping absurd memory map entry for 0x%llx pages at 0x%016llx.\n", ++ __func__, md->num_pages, md->phys_addr); ++ continue; ++ } ++ + start = md->phys_addr; + end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1; + +-- +2.9.3 + |