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authorPeter Jones <pjones@redhat.com>2016-12-13 11:12:18 -0500
committerPeter Jones <pjones@redhat.com>2016-12-13 11:12:18 -0500
commit71ec70ab2af18413e0631c497d5168a5fa4c6d1d (patch)
tree0c20b9d0a540b4dd74ab7e44f25c285318a83269 /0001-efi-prune-invalid-memory-map-entries.patch
parent1a59ad58a8f6d3fb0f572ea0b2fdb8145b2db92c (diff)
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Update UEFI memory map cleaning
Signed-off-by: Peter Jones <pjones@redhat.com>
Diffstat (limited to '0001-efi-prune-invalid-memory-map-entries.patch')
-rw-r--r--0001-efi-prune-invalid-memory-map-entries.patch141
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
+