On Mon, Oct 3, 2022, at 3:37 PM, Kees Cook wrote: > On Thu, Sep 29, 2022 at 03:29:27PM -0700, Rick Edgecombe wrote: >> From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> >> >> Applications and loaders can have logic to decide whether to enable CET. >> They usually don't report whether CET has been enabled or not, so there >> is no way to verify whether an application actually is protected by CET >> features. >> >> Add two lines in /proc/$PID/arch_status to report enabled and locked >> features. >> >> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> >> [Switched to CET, added to commit log] >> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx> >> >> --- >> >> v2: >> - New patch >> >> arch/x86/kernel/Makefile | 2 ++ >> arch/x86/kernel/fpu/xstate.c | 47 --------------------------- >> arch/x86/kernel/proc.c | 63 ++++++++++++++++++++++++++++++++++++ >> 3 files changed, 65 insertions(+), 47 deletions(-) >> create mode 100644 arch/x86/kernel/proc.c > > This is two patches: one to create proc.c, the other to add CET support. > > I found where the "arch_status" conversation was: > https://lore.kernel.org/all/CALCETrUjF9PBmkzH1J86vw4ZW785DP7FtcT+gcSrx29=BUnjoQ@xxxxxxxxxxxxxx/ > > Andy, what did you mean "make sure that everything in it is namespaced"? > Everything already has a field name. And arch_status doesn't exactly > solve having compat fields -- it still needs to be handled manually? > Anyway... we have arch_status, so I guess it's fine. I think I meant that, since it's "arch_status" not "x86_status", the fields should have names like "x86.Thread_features". Otherwise if another architecture adds a Thread_features field, then anything running under something like qemu userspace emulation could be confused. Assuming that's what I meant, I think my comment still stands :)
