diff options
Diffstat (limited to '0001-efi-prune-invalid-memory-map-entries.patch')
| -rw-r--r-- | 0001-efi-prune-invalid-memory-map-entries.patch | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/0001-efi-prune-invalid-memory-map-entries.patch b/0001-efi-prune-invalid-memory-map-entries.patch new file mode 100644 index 000000000..4b65ef504 --- /dev/null +++ b/0001-efi-prune-invalid-memory-map-entries.patch @@ -0,0 +1,141 @@ +From c7c7030a020405d5826c03839e38986e0f78f2ea Mon Sep 17 00:00:00 2001 +From: Peter Jones <pjones@redhat.com> +Date: Tue, 13 Dec 2016 10:25:10 +0000 +Subject: [PATCH] efi: prune invalid memory map entries + +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. + +Currently the log output for this case (with efi=debug) looks like: + +[ 0.000000] efi: mem45: [Reserved | | | | | | | | | | | | ] range=[0x0000000000000000-0xffffffffffffffff] (0MB) + +This is clearly wrong, and also not as informative as it could be. This +patch changes it so that if we find obviously invalid memory map +entries, we print an error and those entries. It also detects the +display of the address range calculation overflow, so the new output is: + +[ 0.000000] efi: [Firmware Bug]: Invalid EFI memory map entries: +[ 0.000000] efi: mem45: [Reserved | | | | | | | | | | | | ] range=[0x0000000000000000-0x0000000000000000] (invalid) + +It also detects memory map sizes that would overflow the physical +address, for example phys_addr=0xfffffffffffff000 and +num_pages=0x0200000000000001, and prints: + +[ 0.000000] efi: [Firmware Bug]: Invalid EFI memory map entries: +[ 0.000000] efi: mem45: [Reserved | | | | | | | | | | | | ] range=[phys_addr=0xfffffffffffff000-0x20ffffffffffffffff] (invalid) + +It then removes these entries from the memory map. + +Cc: Matt Fleming <matt@codeblueprint.co.uk> +Signed-off-by: Peter Jones <pjones@redhat.com> +[ardb: refactor for clarity with no functional changes, avoid PAGE_SHIFT] +Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> +--- + arch/x86/platform/efi/efi.c | 70 +++++++++++++++++++++++++++++++++++++++++++++ + include/linux/efi.h | 1 + + 2 files changed, 71 insertions(+) + +diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c +index bf99aa7..0a1550b 100644 +--- a/arch/x86/platform/efi/efi.c ++++ b/arch/x86/platform/efi/efi.c +@@ -210,6 +210,74 @@ int __init efi_memblock_x86_reserve_range(void) + return 0; + } + ++#define OVERFLOW_ADDR_SHIFT (64 - EFI_PAGE_SHIFT) ++#define OVERFLOW_ADDR_MASK (U64_MAX << OVERFLOW_ADDR_SHIFT) ++#define U64_HIGH_BIT (~(U64_MAX >> 1)) ++ ++static bool __init efi_memmap_entry_valid(const efi_memory_desc_t *md, int i) ++{ ++ static __initdata bool once = true; ++ u64 end = (md->num_pages << EFI_PAGE_SHIFT) + md->phys_addr - 1; ++ u64 end_hi = 0; ++ char buf[64]; ++ ++ if (md->num_pages == 0) { ++ end = 0; ++ } else if (md->num_pages > EFI_PAGES_MAX || ++ EFI_PAGES_MAX - md->num_pages < ++ (md->phys_addr >> EFI_PAGE_SHIFT)) { ++ end_hi = (md->num_pages & OVERFLOW_ADDR_MASK) ++ >> OVERFLOW_ADDR_SHIFT; ++ ++ if ((md->phys_addr & U64_HIGH_BIT) && !(end & U64_HIGH_BIT)) ++ end_hi += 1; ++ } else { ++ return true; ++ } ++ ++ if (once) { ++ pr_warn(FW_BUG "Invalid EFI memory map entries:\n"); ++ once = false; ++ } ++ ++ if (end_hi) { ++ pr_warn("mem%02u: %s range=[0x%016llx-0x%llx%016llx] (invalid)\n", ++ i, efi_md_typeattr_format(buf, sizeof(buf), md), ++ md->phys_addr, end_hi, end); ++ } else { ++ pr_warn("mem%02u: %s range=[0x%016llx-0x%016llx] (invalid)\n", ++ i, efi_md_typeattr_format(buf, sizeof(buf), md), ++ md->phys_addr, end); ++ } ++ return false; ++} ++ ++static void __init efi_clean_memmap(void) ++{ ++ efi_memory_desc_t *out = efi.memmap.map; ++ const efi_memory_desc_t *in = out; ++ const efi_memory_desc_t *end = efi.memmap.map_end; ++ int i, n_removal; ++ ++ for (i = n_removal = 0; in < end; i++) { ++ if (efi_memmap_entry_valid(in, i)) { ++ if (out != in) ++ memcpy(out, in, efi.memmap.desc_size); ++ out = (void *)out + efi.memmap.desc_size; ++ } else { ++ n_removal++; ++ } ++ in = (void *)in + efi.memmap.desc_size; ++ } ++ ++ if (n_removal > 0) { ++ u64 size = efi.memmap.nr_map - n_removal; ++ ++ pr_warn("Removing %d invalid memory map entries.\n", n_removal); ++ efi_memmap_install(efi.memmap.phys_map, size); ++ } ++} ++ + void __init efi_print_memmap(void) + { + efi_memory_desc_t *md; +@@ -472,6 +540,8 @@ void __init efi_init(void) + } + } + ++ efi_clean_memmap(); ++ + if (efi_enabled(EFI_DBG)) + efi_print_memmap(); + } +diff --git a/include/linux/efi.h b/include/linux/efi.h +index 4c1b3ea..712a3aa 100644 +--- a/include/linux/efi.h ++++ b/include/linux/efi.h +@@ -103,6 +103,7 @@ typedef struct { + + #define EFI_PAGE_SHIFT 12 + #define EFI_PAGE_SIZE (1UL << EFI_PAGE_SHIFT) ++#define EFI_PAGES_MAX (U64_MAX >> EFI_PAGE_SHIFT) + + typedef struct { + u32 type; +-- +2.9.3 + |