Skip to content

Commit

Permalink
should data-trace record load data before or after ACPERM updates? (#463
Browse files Browse the repository at this point in the history
  • Loading branch information
tariqkurd-repo authored Dec 9, 2024
1 parent 7cc80fd commit e7e6922
Showing 1 changed file with 3 additions and 1 deletion.
4 changes: 3 additions & 1 deletion src/insns/load_tag_perms.adoc
Original file line number Diff line number Diff line change
Expand Up @@ -13,4 +13,6 @@ Similarly, sealed capabilities are not modified as they are not directly derefer
NOTE: Missing <<el_perm>> also affects the level of sealed capabilities since notionally the <<section_cap_level>> of a capability is not a permission but rather a data flow label attached to the loaded value.
However, untagged values are not affected by <<el_perm>>.

NOTE: While the implicit <<ACPERM>> introduces a dependency on the loaded data, microarchitectures can avoid this by deferring the actual masking of permissions until the loaded capability is dereferenced or the metadata bits are inspected using <<GCPERM>> or <<GCHI>>.
NOTE: While the implicit <<ACPERM>> introduces a dependency on the loaded data, implementations can avoid this by deferring the actual masking of permissions until the loaded capability is dereferenced or the metadata bits are inspected using <<GCPERM>> or <<GCHI>>.

NOTE: When sending load data to a trace interface implementations can choose whether to trace the value before or after <<ACPERM>> has modified the data. The recommendation is to trace the value after <<ACPERM>>.

0 comments on commit e7e6922

Please sign in to comment.