Segher Boessenkool's on February 26, 2020 7:20 am: > Hi! > > On Wed, Feb 26, 2020 at 03:35:35AM +1000, Nicholas Piggin wrote: >> Kernel addresses and potentially other sensitive data could be leaked >> in volatile registers after a syscall. > >> cmpdi r3,0 >> bne .Lsyscall_restore_regs >> + li r0,0 >> + li r4,0 >> + li r5,0 >> + li r6,0 >> + li r7,0 >> + li r8,0 >> + li r9,0 >> + li r10,0 >> + li r11,0 >> + li r12,0 >> + mtctr r0 >> + mtspr SPRN_XER,r0 >> .Lsyscall_restore_regs_cont: > > What about LR? Is that taken care of later?
LR is preserved by sc as per ABI. > This also deserves a big fat comment imo, it is very important after > all, and not so obvious. Sure I can add something. Thanks, Nick
