https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102768
nsz at gcc dot gnu.org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |nsz at gcc dot gnu.org
--- Comment #1 from nsz at gcc dot gnu.org ---
note that this at least
- requires runtime support (to manage the shadow stack),
- needs a reserved register (x18),
- affects unwinding (shadow stack must be unwound too),
- affects longjmp and jmp_buf abi.
i guess these are taken care of in the linux context and in
that case i think it makes sense to have the gcc support
upstream instead of in a plugin.
however the general support in user-space is not trivial
(the required libc changes may not be possible in a backward
compatible way such as changing jmp_buf, or reliably such as
allocating the size of shadow stack and dealing with related
failures, or with good ui e.g. opt-in mechanism for binaries
that require shadow stack so there is no regression for
non-shadow-stack binaries, etc.) and there are existing stack
protection mechanisms implemented.
i just wanted to note here that the linux kernel use-case
can be treated separately from user-space applications and
likely less effort and less controversial if you scope the
feature right.
