On 06/29/15 12:46, Ard Biesheuvel wrote: > Hello all, > > I am running into another problem with the implementation of the UEFI > 2.5 Properties Table feature. It splits PE/COFF images into separate > but adjacent memory regions, only to be able to assign different > permissions to .text and .data sections. This is working fine at boot > time. > > However, at runtime, after calling virtual address map, this breaks > down completely. Since the virtual mapping supplied to > SetVirtualAddressMap() does not have to guarantee adjacency between > code and data regions (of which the OS does not know whether they > belong together or not), reapplying the relocations corrupts the > memory image and breaks the runtime services. > > For example, this region > > 0x00005eeb1000-0x00005eeb6fff [Runtime Code] > 0x00005eeb7000-0x00005eec0fff [Runtime Data] > > is mapped on AARCH64 as > > EFI remap 0x000000005eeb1000 => 00000000440a1000 > EFI remap 0x000000005eeb7000 => 00000000440b7000 > > which retains the relative alignment, but adds a 64 KB offset to the > second regions so that the regions can still be mapped with different > permissions when the OS is executing with a 64 KB page size. > > As far as I can tell, this is in accordance with the spec, and was > working fine until I tried to enable the properties table feature.
Where / how? Did you enable it in the guest kernel (if that question makes sense), or in the ArmVirtPkg build? In the latter, I can only see the PropertiesTableEnable PCD, but (a) it defaults to TRUE, (b) does it actually control the splitting? Thanks Laszlo > With that enabled, the two above regions could actually describe one > single PE/COFF image in memory, and the 64 KB offset results in the > relocations to be applied incorrectly. > > I looked at PeCoffLoaderRelocateImageForRuntime () but to me, it is > not very obvious how to solve this. Obviously, our PE/COFF > implementation is not complete since it assumes file offset == memory > offset for sections, but this does not hold anymore for UEFI 2.5 > > I would also like to point out again that this is another result of > the fact that this series was pushed through with any review or > testing outside of the Intel firmware team. For features of this > magnitude and complexity, more scrutiny and testing is obviously > required. > > Kind regards, > Ard. > ------------------------------------------------------------------------------ Monitor 25 network devices or servers for free with OpManager! OpManager is web-based network management software that monitors network devices and physical & virtual servers, alerts via email & sms for fault. Monitor 25 devices for free with no restriction. Download now http://ad.doubleclick.net/ddm/clk/292181274;119417398;o _______________________________________________ edk2-devel mailing list edk2-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/edk2-devel
