On Mon, Mar 9, 2015 at 1:32 PM, Denys Vlasenko <vda.li...@googlemail.com> wrote: > On Mon, Mar 9, 2015 at 9:11 PM, Andy Lutomirski <l...@amacapital.net> wrote: >>> @@ -253,11 +247,13 @@ GLOBAL(system_call_after_swapgs) >>> */ >>> ENABLE_INTERRUPTS(CLBR_NONE) >>> ALLOC_PT_GPREGS_ON_STACK 8 /* +8: space for orig_ax */ >>> + movq %rcx,RIP(%rsp) >>> + movq PER_CPU_VAR(old_rsp),%rcx >>> + movq %r11,EFLAGS(%rsp) >>> + movq %rcx,RSP(%rsp) >>> + movq_cfi rax,ORIG_RAX >>> SAVE_C_REGS_EXCEPT_RAX_RCX_R11 >>> movq $-ENOSYS,RAX(%rsp) >>> - movq_cfi rax,ORIG_RAX >>> - movq %r11,EFLAGS(%rsp) >>> - movq %rcx,RIP(%rsp) >> >> Why the reordering? > > No strong reason. > > iret stack is "above" the rest of pt_regs. > > This does not matter now, but when/if we convert to PUSHes > for register saving, pushes which build iret frame > will have to be before "save C-clobbered registers" part, > exactly as in this patch.
Fair enough. Acked-by: Andy Lutomirski <l...@amacapital.net> -- Andy Lutomirski AMA Capital Management, LLC -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
