Merge branch 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull EFI fixes from Ingo Molnar:
 "A number of regression fixes:

   - Fix a boot hang on machines that have somewhat unusual memory map
     entries of phys_addr=0x0 num_pages=0, which broke due to a recent
     commit. This commit got cherry-picked from the v4.11 queue because
     the bug is affecting real machines.

   - Fix a boot hang also reported by KASAN, caused by incorrect init
     ordering introduced by a recent optimization.

   - Fix a recent robustification fix to allocate_new_fdt_and_exit_boot()
     that introduced an invalid assumption. Neither bugs were seen in
     the wild AFAIK"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi/x86: Prune invalid memory map entries and fix boot regression
  x86/efi: Don't allocate memmap through memblock after mm_init()
  efi/libstub/arm*: Pass latest memory map to the kernel

1 files changed, 38 insertions, 0 deletions

diff --git a/drivers/firmware/efi/memmap.c b/drivers/firmware/efi/memmap.c
index f03ddecd232b..78686443cb37 100644
--- a/drivers/firmware/efi/memmap.c
+++ b/drivers/firmware/efi/memmap.c
@@ -9,6 +9,44 @@
 #include <linux/efi.h>
 #include <linux/io.h>
 #include <asm/early_ioremap.h>
+#include <linux/memblock.h>
+#include <linux/slab.h>
+
+static phys_addr_t __init __efi_memmap_alloc_early(unsigned long size)
+{
+	return memblock_alloc(size, 0);
+}
+
+static phys_addr_t __init __efi_memmap_alloc_late(unsigned long size)
+{
+	unsigned int order = get_order(size);
+	struct page *p = alloc_pages(GFP_KERNEL, order);
+
+	if (!p)
+		return 0;
+
+	return PFN_PHYS(page_to_pfn(p));
+}
+
+/**
+ * efi_memmap_alloc - Allocate memory for the EFI memory map
+ * @num_entries: Number of entries in the allocated map.
+ *
+ * Depending on whether mm_init() has already been invoked or not,
+ * either memblock or "normal" page allocation is used.
+ *
+ * Returns the physical address of the allocated memory map on
+ * success, zero on failure.
+ */
+phys_addr_t __init efi_memmap_alloc(unsigned int num_entries)
+{
+	unsigned long size = num_entries * efi.memmap.desc_size;
+
+	if (slab_is_available())
+		return __efi_memmap_alloc_late(size);
+
+	return __efi_memmap_alloc_early(size);
+}
 
 /**
  * __efi_memmap_init - Common code for mapping the EFI memory map