Re: [edk2-devel] ovmf build fail with gcc 4.8.5

["Chen, Farrah" <farrah.chen@intel.com>]

Thanks, we use the latest commit and it works well now.


Thanks,
Fan



-----Original Message-----
From: Laszlo Ersek [mailto:lersek@redhat.com] 
Sent: Tuesday, August 13, 2019 8:23 PM
To: devel@edk2.groups.io; Chen, Farrah <farrah.chen@intel.com>
Cc: Hao, Xudong <xudong.hao@intel.com>
Subject: Re: [edk2-devel] ovmf build fail with gcc 4.8.5

On 08/13/19 03:13, Chen, Farrah wrote:
> Hi,
> 
> When build ovmf with the latest two commits of master branch, we meet error on Red Hat 7.6 with gcc version 4.8.5, but succeed on Red Hat 8.0 with gcc version 8.2.1.
> 
> Steps:
> git clone https://github.com/tianocore/edk2.git
> cd edk2
> git submodule init
> git submodule update -recursive
> OvmfPkg/build.sh -a X64 -n 64
> 
> Error log:
> .......
> /home/build/kvm_build/nightly/kvm_qemu/kvm-next-20190813010558-a738b5e7-5e7bcdcf/edk2/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c:641:50: error: 'PageMapLevel5Entry' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>    PAGE_MAP_AND_DIRECTORY_POINTER                *PageMapLevel5Entry;
>                                                   ^
> cc1: all warnings being treated as errors "objcopy"  
> /home/build/kvm_build/nightly/kvm_qemu/kvm-next-20190813010558-a738b5e
> 7-5e7bcdcf/edk2/Build/OvmfX64/DEBUG_GCC48/X64/MdeModulePkg/Bus/Pci/Pci
> HostBridgeDxe/PciHostBridgeDxe/DEBUG/PciHostBridgeDxe.dll
> "GenFw" -e UEFI_DRIVER -o 
> /home/build/kvm_build/nightly/kvm_qemu/kvm-next-20190813010558-a738b5e
> 7-5e7bcdcf/edk2/Build/OvmfX64/DEBUG_GCC48/X64/OvmfPkg/XenBusDxe/XenBus
> Dxe/OUTPUT/XenBusDxe.efi 
> /home/build/kvm_build/nightly/kvm_qemu/kvm-next-20190813010558-a738b5e
> 7-5e7bcdcf/edk2/Build/OvmfX64/DEBUG_GCC48/X64/OvmfPkg/XenBusDxe/XenBus
> Dxe/DEBUG/XenBusDxe.dll
> make: *** 
> [/home/build/kvm_build/nightly/kvm_qemu/kvm-next-20190813010558-a738b5
> e7-5e7bcdcf/edk2/Build/OvmfX64/DEBUG_GCC48/X64/MdeModulePkg/Core/DxeIp
> lPeim/DxeIpl/OUTPUT/X64/VirtualMemory.obj] Error 1 cp -f 
> /home/build/kvm_build/nightly/kvm_qemu/kvm-next-20190813010558-a738b5e
> 7-5e7bcdcf/edk2/Build/OvmfX64/DEBUG_GCC48/X64/OvmfPkg/XenBusDxe/XenBus
> Dxe/OUTPUT/XenBusDxe.efi 
> /home/build/kvm_build/nightly/kvm_qemu/kvm-next-20190813010558-a738b5e
> 7-5e7bcdcf/edk2/Build/OvmfX64/DEBUG_GCC48/X64/OvmfPkg/XenBusDxe/XenBus
> Dxe/DEBUG
> 
> 
> build.py...
> : error 7000: Failed to execute command
>         make tbuild 
> [/home/build/kvm_build/nightly/kvm_qemu/kvm-next-20190813010558-a738b5
> e7-5e7bcdcf/edk2/Build/OvmfX64/DEBUG_GCC48/X64/MdeModulePkg/Core/DxeIp
> lPeim/DxeIpl]
> 
> 
> 
> 
> build.py...
> : error F002: Failed to build module
>         
> /home/build/kvm_build/nightly/kvm_qemu/kvm-next-20190813010558-a738b5e
> 7-5e7bcdcf/edk2/MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf [X64, GCC48, 
> DEBUG]
> 
> - Failed -
> Build end time: 08:46:33, Aug.13 2019
> Build total time: 00:01:15
> 
> GCC:
> gcc --version
> gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-36) Copyright (C) 2015 Free 
> Software Foundation, Inc.
> This is free software; see the source for copying conditions.  There 
> is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

This bug was introduced in commit b3527dedc395 ("MdeModulePkg/DxeIpl:
Create 5-level page table for long mode", 2019-08-09).

It's being addressed in the following (pending) patch:

[edk2-devel] [PATCH 1/1] MdeModulePkg/DxeIplPeim: Relocate the operation of PageMapLevel5Entry++

(I'm calling the issue a bug and not an invalid compiler warning because the patch looks like an actual fix.)

Thanks
Laszlo