powerpc/prom_init: Undo relocation before entering secure mode
The ultravisor will do an integrity check of the kernel image but we
relocated it so the check will fail. Restore the original image by
relocating it back to the kernel virtual base address.
This works because during build vmlinux is linked with an expected
virtual runtime address of KERNELBASE.
Fixes: 6a9c930bd775 ("powerpc/prom_init: Add the ESM call to prom_init")
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Tested-by: Michael Anderson <andmike@linux.ibm.com>
[mpe: Add IS_ENABLED() to fix the CONFIG_RELOCATABLE=n build]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190911163433.12822-1-bauerman@linux.ibm.com
diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index a4e7762..100f1b5 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -3249,7 +3249,20 @@ static void setup_secure_guest(unsigned long kbase, unsigned long fdt)
/* Switch to secure mode. */
prom_printf("Switching to secure mode.\n");
+ /*
+ * The ultravisor will do an integrity check of the kernel image but we
+ * relocated it so the check will fail. Restore the original image by
+ * relocating it back to the kernel virtual base address.
+ */
+ if (IS_ENABLED(CONFIG_RELOCATABLE))
+ relocate(KERNELBASE);
+
ret = enter_secure_mode(kbase, fdt);
+
+ /* Relocate the kernel again. */
+ if (IS_ENABLED(CONFIG_RELOCATABLE))
+ relocate(kbase);
+
if (ret != U_SUCCESS) {
prom_printf("Returned %d from switching to secure mode.\n", ret);
prom_rtas_os_term("Switch to secure mode failed.\n");