On Fri, Oct 18, 2019 at 9:11 AM Sami Tolvanen <samitolva...@google.com> wrote: > > Don't lose the current task's shadow stack when the CPU is suspended. > > Signed-off-by: Sami Tolvanen <samitolva...@google.com> > --- > arch/arm64/mm/proc.S | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S > index fdabf40a83c8..9a8bd4bc8549 100644 > --- a/arch/arm64/mm/proc.S > +++ b/arch/arm64/mm/proc.S > @@ -73,6 +73,9 @@ alternative_endif > stp x8, x9, [x0, #48] > stp x10, x11, [x0, #64] > stp x12, x13, [x0, #80] > +#ifdef CONFIG_SHADOW_CALL_STACK > + stp x18, xzr, [x0, #96]
Could this be a str/ldr of just x18 rather than stp/ldp of x18 + garbage? Maybe there's no real cost difference, or some kind of alignment invariant? > +#endif > ret > ENDPROC(cpu_do_suspend) > > @@ -89,6 +92,9 @@ ENTRY(cpu_do_resume) > ldp x9, x10, [x0, #48] > ldp x11, x12, [x0, #64] > ldp x13, x14, [x0, #80] > +#ifdef CONFIG_SHADOW_CALL_STACK > + ldp x18, x19, [x0, #96] > +#endif > msr tpidr_el0, x2 > msr tpidrro_el0, x3 > msr contextidr_el1, x4 > -- > 2.23.0.866.gb869b98d4c-goog > -- Thanks, ~Nick Desaulniers
