[PATCH 4.9 36/83] x86/boot: Fix boot regression caused by bootparam sanitizing

[Greg Kroah-Hartman]

From: John Hubbard <jhubbard@xxxxxxxxxx>

commit 7846f58fba964af7cb8cf77d4d13c33254725211 upstream.

commit a90118c445cc ("x86/boot: Save fields explicitly, zero out everything
else") had two errors:

    * It preserved boot_params.acpi_rsdp_addr, and
    * It failed to preserve boot_params.hdr

Therefore, zero out acpi_rsdp_addr, and preserve hdr.

Fixes: a90118c445cc ("x86/boot: Save fields explicitly, zero out everything else")
Reported-by: Neil MacLeod <neil@xxxxxxxxxxxx>
Suggested-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Tested-by: Neil MacLeod <neil@xxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/20190821192513.20126-1-jhubbard@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/x86/include/asm/bootparam_utils.h |    1 +
 1 file changed, 1 insertion(+)

--- a/arch/x86/include/asm/bootparam_utils.h
+++ b/arch/x86/include/asm/bootparam_utils.h
@@ -70,6 +70,7 @@ static void sanitize_boot_params(struct
 			BOOT_PARAM_PRESERVE(eddbuf_entries),
 			BOOT_PARAM_PRESERVE(edd_mbr_sig_buf_entries),
 			BOOT_PARAM_PRESERVE(edd_mbr_sig_buffer),
+			BOOT_PARAM_PRESERVE(hdr),
 			BOOT_PARAM_PRESERVE(eddbuf),
 		};