================ @@ -255,33 +260,160 @@ signing schema breaks down even more simply: It is important that the signing schema be independently derived at all signing and authentication sites. Preferably, the schema should be hard-coded everywhere it is needed, but at the very least, it must not be derived by -inspecting information stored along with the pointer. +inspecting information stored along with the pointer. See the section on +`Attacks on pointer authentication`_ for more information. + -Language Features +Language features ----------------- -There is currently one main pointer authentication language feature: +There are three levels of the pointer authentication language feature: + +- The language implementation automatically signs and authenticates function + pointers (and certain data pointers) across a variety of standard situations, + including return addresses, function pointers, and C++ virtual functions. The + intent is for all pointers to code in program memory to be signed in some way + and for all branches to code in program text to authenticate those + signatures. ---------------- ojhunt wrote:
We already do sign v-table pointers, and a bunch of other data pointers (mostly objc and pending review block metadata, but also "data" pointers that are equivalent to code pointers like obj-c's SEL type). Longer term we want to implicitly sign a bunch of data pointers in things like lambdas, coroutines, etc but they don't have the same ABI constraints so have been lower priority. https://github.com/llvm/llvm-project/pull/152596 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
