target/linux/generic/patches-4.9/121-of-Add-check-to-of_scan_flat_dt-before-accessing-ini.patch

   1 From: Tobias Wolf <dev-NTEO@vplace.de>
   2 Date: Wed, 23 Nov 2016 10:40:07 +0100
   3 Subject: [PATCH] of: Add check to of_scan_flat_dt() before accessing
   4  initial_boot_params
   5
   6 An empty __dtb_start to __dtb_end section might result in initial_boot_params
   7 being null for arch/mips/ralink. This showed that the boot process hangs
   8 indefinitely in of_scan_flat_dt().
   9
  10 Signed-off-by: Tobias Wolf <dev-NTEO@vplace.de>
  11 ---
  12
  13 --- a/drivers/of/fdt.c
  14 +++ b/drivers/of/fdt.c
  15 @@ -741,9 +741,12 @@ int __init of_scan_flat_dt(int (*it)(uns
  16         const char *pathp;
  17         int offset, rc = 0, depth = -1;
  18
  19 -        for (offset = fdt_next_node(blob, -1, &depth);
  20 -             offset >= 0 && depth >= 0 && !rc;
  21 -             offset = fdt_next_node(blob, offset, &depth)) {
  22 +       if (!blob)
  23 +               return 0;
  24 +
  25 +       for (offset = fdt_next_node(blob, -1, &depth);
  26 +            offset >= 0 && depth >= 0 && !rc;
  27 +            offset = fdt_next_node(blob, offset, &depth)) {
  28
  29                 pathp = fdt_get_name(blob, offset, NULL);
  30                 if (*pathp == '/')