On Fri, Jul 13, 2018 at 10:19 AM, Andy Lutomirski <l...@kernel.org> wrote: > On Fri, Jul 13, 2018 at 2:48 AM, Joerg Roedel <j...@8bytes.org> wrote: >> On Thu, Jul 12, 2018 at 01:49:13PM -0700, Andy Lutomirski wrote: >>> > On Jul 11, 2018, at 4:29 AM, Joerg Roedel <j...@8bytes.org> wrote: >>> > /* Offset from the sysenter stack to tss.sp0 */ >>> > - DEFINE(TSS_entry_stack, offsetof(struct cpu_entry_area, >>> > tss.x86_tss.sp0) - >>> > + DEFINE(TSS_entry_stack, offsetof(struct cpu_entry_area, >>> > tss.x86_tss.sp1) - >>> > offsetofend(struct cpu_entry_area, entry_stack_page.stack)); >>> > >>> >>> The code reads differently. Did you perhaps mean TSS_task_stack? >> >> Well, the offset name came from TSS_sysenter_sp0, which was the offset >> from the sysenter_sp0 (==sysenter-stack) to the task stack in TSS, now >> sysenter_sp0 became entry_stack, because its used for all entry points >> and not only sysenter. So with the old convention the naming makes still >> sense, no? >> > > Trying to parse it certainly makes my brain hurt a bit. This is the > offset from the entry stack to sp1, where sp1 is the location of the > pointer to the task stack. > > Maybe all the arithmetic could go in entry_32.S and the asm-offset > name could just be TSS_sp1, just like on 64-bit? >
I re-read it again. How about keeping TSS_entry_stack but making it be the offset from the TSS to the entry stack. Then do the arithmetic in asm.
