fdt_check_header(__dtb_start) will always success because kernel
provided a dummy dtb, and by coincidence __dtb_start clashed with
entry of this dummy dtb. The consequence is fdt passed from
firmware will never be taken.
Fix by trying to utilise __dtb_start only when CONFIG_BUILTIN_DTB
is enabled.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 7b937cc243e5 ("of: Create of_root if no dtb provided by firmware")
Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
---
v3: Better reasoning in commit message, thanks Binbin and Huacai!
---
arch/loongarch/kernel/setup.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/loongarch/kernel/setup.c b/arch/loongarch/kernel/setup.c
index 60e0fe97f61a..ea6d5db6c878 100644
--- a/arch/loongarch/kernel/setup.c
+++ b/arch/loongarch/kernel/setup.c
@@ -275,16 +275,18 @@ static void __init arch_reserve_crashkernel(void)
static void __init fdt_setup(void)
{
#ifdef CONFIG_OF_EARLY_FLATTREE
- void *fdt_pointer;
+ void *fdt_pointer = NULL;
/* ACPI-based systems do not require parsing fdt */
if (acpi_os_get_root_pointer())
return;
+#ifdef CONFIG_BUILTIN_DTB
/* Prefer to use built-in dtb, checking its legality first. */
if (!fdt_check_header(__dtb_start))
fdt_pointer = __dtb_start;
- else
+#endif
+ if (!fdt_pointer)
fdt_pointer = efi_fdt_pointer(); /* Fallback to firmware dtb */
if (!fdt_pointer || fdt_check_header(fdt_pointer))
--
2.43.0
