From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Peter Jones <pjones@redhat.com>
Date: Thu, 21 Mar 2019 13:06:06 -0400
Subject: [PATCH] Fix the type of grub_efi_status_t

Currently, in some builds with some checkers, we see:

1. grub-core/disk/efi/efidisk.c:601: error[shiftTooManyBitsSigned]: Shifting signed 64-bit value by 63 bits is undefined behaviour

This is because grub_efi_status_t is defined as grub_efi_intn_t, which is
signed, and shifting into the sign bit is not defined behavior.  UEFI fixed
this in the spec in 2.3:

2.3 | Change the defined type of EFI_STATUS from INTN to UINTN | May 7, 2009

And the current EDK2 code has:
MdePkg/Include/Base.h-//
MdePkg/Include/Base.h-// Status codes common to all execution phases
MdePkg/Include/Base.h-//
MdePkg/Include/Base.h:typedef UINTN RETURN_STATUS;
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-/**
MdePkg/Include/Base.h-  Produces a RETURN_STATUS code with the highest bit set.
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-  @param  StatusCode    The status code value to convert into a warning code.
MdePkg/Include/Base.h-                        StatusCode must be in the range 0x00000000..0x7FFFFFFF.
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-  @return The value specified by StatusCode with the highest bit set.
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-**/
MdePkg/Include/Base.h-#define ENCODE_ERROR(StatusCode)     ((RETURN_STATUS)(MAX_BIT | (StatusCode)))
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-/**
MdePkg/Include/Base.h-  Produces a RETURN_STATUS code with the highest bit clear.
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-  @param  StatusCode    The status code value to convert into a warning code.
MdePkg/Include/Base.h-                        StatusCode must be in the range 0x00000000..0x7FFFFFFF.
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-  @return The value specified by StatusCode with the highest bit clear.
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-**/
MdePkg/Include/Base.h-#define ENCODE_WARNING(StatusCode)   ((RETURN_STATUS)(StatusCode))
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-/**
MdePkg/Include/Base.h-  Returns TRUE if a specified RETURN_STATUS code is an error code.
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-  This function returns TRUE if StatusCode has the high bit set.  Otherwise, FALSE is returned.
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-  @param  StatusCode    The status code value to evaluate.
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-  @retval TRUE          The high bit of StatusCode is set.
MdePkg/Include/Base.h-  @retval FALSE         The high bit of StatusCode is clear.
MdePkg/Include/Base.h-
MdePkg/Include/Base.h-**/
MdePkg/Include/Base.h-#define RETURN_ERROR(StatusCode)     (((INTN)(RETURN_STATUS)(StatusCode)) < 0)
...
Uefi/UefiBaseType.h:typedef RETURN_STATUS             EFI_STATUS;

This patch makes grub's implementation match the Edk2 declaration with regards
to the signedness of the type.

Signed-off-by: Peter Jones <pjones@redhat.com>
---
 include/grub/efi/api.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/grub/efi/api.h b/include/grub/efi/api.h
index b337e1a193d..0c15cffa23c 100644
--- a/include/grub/efi/api.h
+++ b/include/grub/efi/api.h
@@ -536,7 +536,7 @@ typedef grub_uint64_t grub_efi_uint64_t;
 typedef grub_uint8_t grub_efi_char8_t;
 typedef grub_uint16_t grub_efi_char16_t;
 
-typedef grub_efi_intn_t grub_efi_status_t;
+typedef grub_efi_uintn_t grub_efi_status_t;
 /* Make grub_efi_status_t reasonably printable. */
 #if GRUB_CPU_SIZEOF_VOID_P == 8
 #define PRIxGRUB_EFI_STATUS "lx"