riscv/efi_stub: Fix get_boot_hartid_from_fdt() return value

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@vger.kernel.org>
Fixes: d7071743db31 ("RISC-V: Add EFI stub support.")
Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

diff --git a/drivers/firmware/efi/libstub/riscv-stub.c b/drivers/firmware/efi/libstub/riscv-stub.c
index 380e4e2..9c46084 100644 (file)
--- 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_func)(unsigned int, unsigned long);
 
 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;
        }