[PATCH 4.14 33/35] fdt: Update CRC check for rng-seed

From: Greg Kroah-Hartman
Date: Thu Jun 30 2022 - 09:55:24 EST


From: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>

commit dd753d961c4844a39f947be115b3d81e10376ee5 upstream.

Commit 428826f5358c ("fdt: add support for rng-seed") moves of_fdt_crc32
from early_init_dt_verify() to early_init_dt_scan() since
early_init_dt_scan_chosen() may modify fdt to erase rng-seed.

However, arm and some other arch won't call early_init_dt_scan(), they
call early_init_dt_verify() then early_init_dt_scan_nodes().

Restore of_fdt_crc32 to early_init_dt_verify() then update it in
early_init_dt_scan_chosen() if fdt if updated.

Fixes: 428826f5358c ("fdt: add support for rng-seed")
Reported-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
Tested-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/of/fdt.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -1159,6 +1159,10 @@ int __init early_init_dt_scan_chosen(uns

/* try to clear seed so it won't be found. */
fdt_nop_property(initial_boot_params, node, "rng-seed");
+
+ /* update CRC check value */
+ of_fdt_crc32 = crc32_be(~0, initial_boot_params,
+ fdt_totalsize(initial_boot_params));
}

/* break now */
@@ -1272,6 +1276,8 @@ bool __init early_init_dt_verify(void *p

/* Setup flat device-tree pointer */
initial_boot_params = params;
+ of_fdt_crc32 = crc32_be(~0, initial_boot_params,
+ fdt_totalsize(initial_boot_params));
return true;
}

@@ -1297,8 +1303,6 @@ bool __init early_init_dt_scan(void *par
return false;

early_init_dt_scan_nodes();
- of_fdt_crc32 = crc32_be(~0, initial_boot_params,
- fdt_totalsize(initial_boot_params));
return true;
}