[PATCH 5.4 090/155] x86/ioremap: Fix CONFIG_EFI=n build

Greg Kroah-Hartman
2020-03-31T09:20:15Z

From: Borislav Petkov <bp@suse.de>

commit 870b4333a62e45b0b2000d14b301b7b8b8cad9da upstream.

In order to use efi_mem_type(), one needs CONFIG_EFI enabled. Otherwise
that function is undefined. Use IS_ENABLED() to check and avoid the
ifdeffery as the compiler optimizes away the following unreachable code
then.

Fixes: 985e537a4082 ("x86/ioremap: Map EFI runtime services data as encrypted for SEV")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/7561e981-0d9b-d62c-0ef2-ce6007aff1ab@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/mm/ioremap.c | 3 +++
1 file changed, 3 insertions(+)

--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -115,6 +115,9 @@ static void __ioremap_check_other(resour
if (!sev_active())
return;

+ if (!IS_ENABLED(CONFIG_EFI))
+ return;
+
if (efi_mem_type(addr) == EFI_RUNTIME_SERVICES_DATA)
desc->flags |= IORES_MAP_ENCRYPTED;
}