[src/trunk]: src/sys/stand/efiboot Sanitize the memory map passed to the kernel.

[jmcneill <jmcneill%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/2bd7e45c3a9e
branches:  trunk
changeset: 834710:2bd7e45c3a9e
user:      jmcneill <jmcneill%NetBSD.org@localhost>
date:      Fri Aug 24 23:20:41 2018 +0000

description:
Sanitize the memory map passed to the kernel.

diffstat:

 sys/stand/efiboot/efifdt.c |  36 ++++++++++++++++++++++++++++--------
 1 files changed, 28 insertions(+), 8 deletions(-)

diffs (76 lines):

diff -r f560939d9230 -r 2bd7e45c3a9e sys/stand/efiboot/efifdt.c
--- a/sys/stand/efiboot/efifdt.c        Fri Aug 24 23:19:42 2018 +0000
+++ b/sys/stand/efiboot/efifdt.c        Fri Aug 24 23:20:41 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: efifdt.c,v 1.1 2018/08/24 02:01:06 jmcneill Exp $ */
+/* $NetBSD: efifdt.c,v 1.2 2018/08/24 23:20:41 jmcneill Exp $ */
 
 /*-
  * Copyright (c) 2018 Jared McNeill <jmcneill%invisible.ca@localhost>
@@ -79,8 +79,9 @@
 efi_fdt_memory_map(void)
 {
        UINTN nentries = 0, mapkey, descsize;
-       EFI_MEMORY_DESCRIPTOR *md;
+       EFI_MEMORY_DESCRIPTOR *md, *memmap;
        UINT32 descver;
+       UINT64 phys_start, phys_size;
        int n, memory;
 
        memory = fdt_path_offset(fdt_data, FDT_MEMORY_NODE_PATH);
@@ -90,30 +91,49 @@
                panic("FDT: Failed to create " FDT_MEMORY_NODE_PATH " node");
 
        fdt_delprop(fdt_data, memory, "reg");
+       while (fdt_num_mem_rsv(fdt_data) > 0) {
+               if (fdt_del_mem_rsv(fdt_data, 0) < 0)
+                       panic("FDT: Failed to remove reserved memory map entry");
+       }
 
        const int address_cells = fdt_address_cells(fdt_data, fdt_path_offset(fdt_data, "/"));
        const int size_cells = fdt_size_cells(fdt_data, fdt_path_offset(fdt_data, "/"));
 
-       md = LibMemoryMap(&nentries, &mapkey, &descsize, &descver);
-       for (n = 0; n < nentries; n++, md = NextMemoryDescriptor(md, descsize)) {
+       memmap = LibMemoryMap(&nentries, &mapkey, &descsize, &descver);
+       for (n = 0, md = memmap; n < nentries; n++, md = NextMemoryDescriptor(md, descsize)) {
                if ((md->Attribute & EFI_MEMORY_WB) == 0)
                        continue;
                if (!FDT_MEMORY_USABLE(md))
                        continue;
+               if ((address_cells == 1 || size_cells == 1) && md->PhysicalStart + (md->NumberOfPages * EFI_PAGE_SIZE) > 0xffffffff)
+                       continue;
+               if (md->NumberOfPages <= 1)
+                       continue;
+
+               phys_start = md->PhysicalStart;
+               phys_size = md->NumberOfPages * EFI_PAGE_SIZE;
+
+               if (phys_start & EFI_PAGE_MASK) {
+                       /* UEFI spec says these should be 4KB aligned, but U-Boot doesn't always.. */
+                       phys_start = (phys_start + EFI_PAGE_SIZE) & ~EFI_PAGE_MASK;
+                       phys_size -= (EFI_PAGE_SIZE * 2);
+                       if (phys_size == 0)
+                               continue;
+               }
 
                if (address_cells == 1)
                        fdt_appendprop_u32(fdt_data, fdt_path_offset(fdt_data, FDT_MEMORY_NODE_PATH),
-                           "reg", (uint32_t)md->PhysicalStart);
+                           "reg", (uint32_t)phys_start);
                else
                        fdt_appendprop_u64(fdt_data, fdt_path_offset(fdt_data, FDT_MEMORY_NODE_PATH),
-                           "reg", md->PhysicalStart);
+                           "reg", phys_start);
 
                if (size_cells == 1)
                        fdt_appendprop_u32(fdt_data, fdt_path_offset(fdt_data, FDT_MEMORY_NODE_PATH),
-                           "reg", (uint32_t)md->NumberOfPages * EFI_PAGE_SIZE);
+                           "reg", (uint32_t)phys_size);
                else
                        fdt_appendprop_u64(fdt_data, fdt_path_offset(fdt_data, FDT_MEMORY_NODE_PATH),
-                           "reg", (uint64_t)md->NumberOfPages * EFI_PAGE_SIZE);
+                           "reg", phys_size);
        }
 }