On Tue, Jan 09, 2018 at 05:03:21PM -0800, Andi Kleen wrote: > From: Andi Kleen <[email protected]> > > Remove the partial stack frame in the 64bit syscall fast path. > In the next patch we want to clear the extra registers, which requires > to always save all registers. So remove the partial stack frame > in the syscall fast path and always save everything. > > This actually simplifies the code because the ptregs stubs > are not needed anymore. > > arch/x86/entry/entry_64.S | 57 > ++++----------------------------------------------------- > arch/x86/entry/syscall_64.c | 2 +- > > Signed-off-by: Andi Kleen <[email protected]> > --- > arch/x86/entry/entry_64.S | 57 > ++++----------------------------------------- > arch/x86/entry/syscall_64.c | 2 +- > 2 files changed, 5 insertions(+), 54 deletions(-) > > diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S > index 58dbf7a12a05..bbdfbdd817d6 100644 > --- a/arch/x86/entry/entry_64.S > +++ b/arch/x86/entry/entry_64.S > @@ -234,7 +234,9 @@ GLOBAL(entry_SYSCALL_64_after_hwframe) > pushq %r9 /* pt_regs->r9 */ > pushq %r10 /* pt_regs->r10 */ > pushq %r11 /* pt_regs->r11 */ > - sub $(6*8), %rsp /* pt_regs->bp, bx, r12-15 not > saved */ > + sub $(6*8), %rsp > + SAVE_EXTRA_REGS > + > UNWIND_HINT_REGS extra=0
Now that the extra regs are being saved, the "extra=0" can be removed from the unwind hint. -- Josh
