From: Laszlo Ersek <lersek@redhat.com>
Date: Sat, 9 Sep 2017 22:42:02 +0000 (+0200)
Subject: MdeModulePkg/PartitionDxe: remove always false comparison
X-Git-Tag: edk2-stable201903~3427
X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=commitdiff_plain;h=b4e5807d2492efd9fc453b0a09a50f4c3ae77be1;hp=b19aeeb91e3c548a7f42828f4d474e23ae6b59b8

MdeModulePkg/PartitionDxe: remove always false comparison

In the expression

  (RemainderByMediaBlockSize != 0 ||
   Media->BlockSize > UDF_LOGICAL_SECTOR_SIZE)

the second expression is only evaluated if the first expression is false.

If the first expression is false, i.e.,

  RemainderByMediaBlockSize == 0

then UDF_LOGICAL_SECTOR_SIZE is a whole multiple of "Media->BlockSize",
which implies

  UDF_LOGICAL_SECTOR_SIZE >= Media->BlockSize.

Therefore whenever

  Media->BlockSize > UDF_LOGICAL_SECTOR_SIZE

is evaluated, it is false.

The expression

  ((expression) || FALSE)

is equivalent to

  (expression).

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Paulo Alcantara <pcacjr@zytor.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Paulo Alcantara <pcacjr@zytor.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---

diff --git a/MdeModulePkg/Universal/Disk/PartitionDxe/Udf.c b/MdeModulePkg/Universal/Disk/PartitionDxe/Udf.c
index e46cf1d4f4..7856b5dfc1 100644
--- a/MdeModulePkg/Universal/Disk/PartitionDxe/Udf.c
+++ b/MdeModulePkg/Universal/Disk/PartitionDxe/Udf.c
@@ -261,8 +261,7 @@ PartitionInstallUdfChildHandles (
     Media->BlockSize,          // Divisor
     &RemainderByMediaBlockSize // Remainder
     );
-  if (RemainderByMediaBlockSize != 0 ||
-      Media->BlockSize > UDF_LOGICAL_SECTOR_SIZE) {
+  if (RemainderByMediaBlockSize != 0) {
     return EFI_NOT_FOUND;
   }