[Lldb-commits] [PATCH] D112824: [lldb][AArch64] Add MakeTaggedRanges to MemoryTagManager

Fri Nov 26 04:06:34 PST 2021

DavidSpickett added inline comments.

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Comment at: lldb/source/Plugins/Process/Utility/MemoryTagManagerAArch64MTE.cpp:160
+  // we must use an untagged address.
+  MemoryRegionInfo::RangeType range(RemoveNonAddressBits(addr), len);
+  range = ExpandToGranule(range);
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DavidSpickett wrote:
> omjavaid wrote:
> > RemoveNonAddressBits hard-coded but symbols may resolve to higher order bits containing PACs. For now I only came across code pointers with PACs. But if you suspect code regions can be inputs to this function then may be make accommodating changes probably in separate patch.
> The end goal here is "memory read <...> --show-tags" and that command will have to use the ABI plugin in any case so the addresses this gets will be PAC/TBI/MTE free already.
> 
> So for now this should be addressed by https://reviews.llvm.org/D103626. (once I convince myself which address should be show in the output but that's not for this issue)
> 
> I agree that there is a bit of a conflict here with the ABI plugin removing everything vs the MemoryTagManager removing only the tag. However I think that it will work fine in this case.
Speaking of conflict, `MemoryTagManagerAArch64MTE::RemoveNonAddressBits` should probably be renamed to `RemoveTagBits` but I'll do that as another change.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D112824/new/

https://reviews.llvm.org/D112824