[PATCH 5.16 051/186] riscv/efi_stub: Fix get_boot_hartid_from_fdt() return value

[Greg Kroah-Hartman]

From: Sunil V L <sunilvl@xxxxxxxxxxxxxxxx>

commit dcf0c838854c86e1f41fb1934aea906845d69782 upstream.

The get_boot_hartid_from_fdt() function currently returns U32_MAX
for failure case which is not correct because U32_MAX is a valid
hartid value. This patch fixes the issue by returning error code.

Cc: <stable@xxxxxxxxxxxxxxx>
Fixes: d7071743db31 ("RISC-V: Add EFI stub support.")
Signed-off-by: Sunil V L <sunilvl@xxxxxxxxxxxxxxxx>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@xxxxxxxxxxxxx>
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/firmware/efi/libstub/riscv-stub.c |   17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

--- a/drivers/firmware/efi/libstub/riscv-stub.c
+++ b/drivers/firmware/efi/libstub/riscv-stub.c
@@ -25,7 +25,7 @@ typedef void __noreturn (*jump_kernel_fu
 
 static u32 hartid;
 
-static u32 get_boot_hartid_from_fdt(void)
+static int get_boot_hartid_from_fdt(void)
 {
 	const void *fdt;
 	int chosen_node, len;
@@ -33,23 +33,26 @@ static u32 get_boot_hartid_from_fdt(void
 
 	fdt = get_efi_config_table(DEVICE_TREE_GUID);
 	if (!fdt)
-		return U32_MAX;
+		return -EINVAL;
 
 	chosen_node = fdt_path_offset(fdt, "/chosen");
 	if (chosen_node < 0)
-		return U32_MAX;
+		return -EINVAL;
 
 	prop = fdt_getprop((void *)fdt, chosen_node, "boot-hartid", &len);
 	if (!prop || len != sizeof(u32))
-		return U32_MAX;
+		return -EINVAL;
 
-	return fdt32_to_cpu(*prop);
+	hartid = fdt32_to_cpu(*prop);
+	return 0;
 }
 
 efi_status_t check_platform_features(void)
 {
-	hartid = get_boot_hartid_from_fdt();
-	if (hartid == U32_MAX) {
+	int ret;
+
+	ret = get_boot_hartid_from_fdt();
+	if (ret) {
 		efi_err("/chosen/boot-hartid missing or invalid!\n");
 		return EFI_UNSUPPORTED;
 	}