audk/ArmPkg
Heyi Guo 41f890164b ArmPkg/Mmu: Fix literal number left shift bug
There is a hidden bug for below code:

(1 << BaseAddressAlignment) & *BlockEntrySize

From disassembly code, we can see the literal number 1 will be treated
as INT32 by compiler by default, and we'll get 0xFFFFFFFF80000000 when
BaseAddressAlignment is equal to 31. So we will always get 31 when
alignment is larger than 31.

    if ((1 << BaseAddressAlignment) & *BlockEntrySize) {
5224: f9404be0  ldr x0, [sp,#144]
5228: 2a0003e1  mov w1, w0
522c: 52800020  mov w0, #0x1                    // #1
5230: 1ac12000  lsl w0, w0, w1
5234: 93407c01  sxtw  x1, w0

The bug can be replayed on QEMU AARCH64; by adding some debug print,
we can see lots of level 1 tables created (for block of 1GB) even
when the region is large enough to use 512GB block size.

Use LowBitSet64() in BaseLib instead to fix the bug.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Heyi Guo <heyi.guo@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18423 6f19259b-4bc3-4df7-8a09-765794883524
2015-09-09 13:37:33 +00:00
..
Application/LinuxLoader ArmPkg/Application: Add new EFI application to boot Linux 2015-07-06 16:49:40 +00:00
Drivers ArmPkg: remove ARMv6 support code 2015-08-19 10:51:59 +00:00
Filesystem/SemihostFs ArmPkg/SemihostFs: Implement SetInfo() and handle seeking past the end of a file 2014-10-27 10:42:51 +00:00
Include ArmPkg: remove ARMv6 support code 2015-08-19 10:51:59 +00:00
Library ArmPkg/Mmu: Fix literal number left shift bug 2015-09-09 13:37:33 +00:00
ArmPkg.dec ArmPkg: split off ArmGicArchLib from ArmGicLib 2015-07-28 20:44:44 +00:00
ArmPkg.dsc ArmPkg: remove ARMv6 support code 2015-08-19 10:51:59 +00:00
Contributions.txt */Contributions.txt: Update example email address 2015-02-03 17:29:14 +00:00
License.txt EDK II Packages: Added License.txt files 2012-04-12 16:40:32 +00:00