tyler.durden/audk
1
0
Fork 0
mirror of https://github.com/acidanthera/audk.git synced 2025-07-28 16:14:04 +02:00
Code Issues Packages Projects Releases Wiki Activity

MdeModulePkg/AtaAtapiPassThru: Fix possible out of range left shift

Browse Source 
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=699

Within function AhciModeInitialization(), left shift operations of 'BIT0'
in the following statements:
"if ((PortImplementBitMap & (BIT0 << Port)) != 0) {"

will incur possible out of range left shift when Port is 31, since
"1 << 31" is possible to exceed the range of type 'int' (signed).

According to the C11 spec, Section 6.5.7:
> 4 The result of E1 << E2 is E1 left-shifted E2 bit positions; vacated
>   bits are filled with zeros. If E1 has an unsigned type, the value
>   of the result is E1 * 2^E2 , reduced modulo one more than the
>   maximum value representable in the result type. If E1 has a signed
>   type and nonnegative value, and E1 * 2^E2 is representable in the
>   result type, then that is the resulting value; otherwise, the
>   behavior is undefined.

This commit explicitly cast 'BIT0' with UINT32 to resolve this issue.

Cc: Steven Shi <steven.shi@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
This commit is contained in:
Hao Wu 2017-09-19 16:11:29 +08:00
parent bd42d976d5
commit 27daa8658e
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
View File

@ -1,7 +1,7 @@
/** @file /** @file
The file for AHCI mode of ATA host controller. The file for AHCI mode of ATA host controller.
Copyright (c) 2010 - 2016, Intel Corporation. All rights reserved.<BR> Copyright (c) 2010 - 2017, Intel Corporation. All rights reserved.<BR>
(C) Copyright 2015 Hewlett Packard Enterprise Development LP<BR> (C) Copyright 2015 Hewlett Packard Enterprise Development LP<BR>
This program and the accompanying materials This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License are licensed and made available under the terms and conditions of the BSD License
@ -2314,7 +2314,7 @@ AhciModeInitialization (
} }
for (Port = 0; Port < EFI_AHCI_MAX_PORTS; Port ++) { for (Port = 0; Port < EFI_AHCI_MAX_PORTS; Port ++) {
if ((PortImplementBitMap & (BIT0 << Port)) != 0) { if ((PortImplementBitMap & (((UINT32)BIT0) << Port)) != 0) {
// //
// According to AHCI spec, MaxPortNumber should be equal or greater than the number of implemented ports. // According to AHCI spec, MaxPortNumber should be equal or greater than the number of implemented ports.
// //