On Mon, Mar 9, 2015 at 11:39 AM, Denys Vlasenko <[email protected]> wrote: > PER_CPU(old_rsp) usage is simplified - now it is used only > as temp storage, and userspace stack pointer is immediately stored > in pt_regs->sp on syscall entry, instead of being used later, > on syscall exit. > > Instead of PER_CPU(old_rsp) and task->thread.usersp, C code > uses pt_regs->sp now. > > FIXUP/RESTORE_TOP_OF_STACK are simplified. > > Signed-off-by: Denys Vlasenko <[email protected]> > CC: Linus Torvalds <[email protected]> > CC: Steven Rostedt <[email protected]> > CC: Ingo Molnar <[email protected]> > CC: Borislav Petkov <[email protected]> > CC: "H. Peter Anvin" <[email protected]> > CC: Andy Lutomirski <[email protected]> > CC: Oleg Nesterov <[email protected]> > CC: Frederic Weisbecker <[email protected]> > CC: Alexei Starovoitov <[email protected]> > CC: Will Drewry <[email protected]> > CC: Kees Cook <[email protected]> > CC: [email protected] > CC: [email protected]
Looks correct. > @@ -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? --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
