chill added a comment. In D80791#2210124 <https://reviews.llvm.org/D80791#2210124>, @danielkiss wrote:
>>> it is not useful to have a bti annotated function unless everything else is >>> bti compatible too: it is all or nothing per elf module. >> >> This is false. Some functions in an elf module could be in a guarded region, >> some in a non-guarded region. Some function may always >> be called in a "BTI-safe" way, which may be unknown to the compiler. > > Right now the elf and all of the `text` sections considered BTI enabled or > not. The dynamic linkers/loaders can't support this > use case without additional information to be encoded somewhere (and > specified). To support such we need to consider grouping/align to page > boundaries these functions in the linker because BTI could be controlled by > flags in PTE. > With the current spec this usecase is not supported in this way. The user > have to link the BTI protected code into another elf. > Side note: The `force-bti` linker option can't work with half BTI enabled > objects. I suppose this is valid for typical Linux-based systems today. Is it valid in general, across the whole spectre of operating systems or for bare-metal targets? Guess not. CHANGES SINCE LAST ACTION https://reviews.llvm.org/D80791/new/ https://reviews.llvm.org/D80791 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
