On Wed, 1 Apr 2015 16:50:57 +0200 Denys Vlasenko <dvlas...@redhat.com> wrote:
> - /* runs on exception stack */ > +/* Runs on exception stack */ > ENTRY(nmi) > INTR_FRAME > PARAVIRT_ADJUST_EXCEPTION_FRAME > @@ -1428,8 +1416,18 @@ ENTRY(nmi) > * We check the variable because the first NMI could be in a > * breakpoint routine using a breakpoint stack. > */ > - lea 6*8(%rsp), %rdx > - test_in_nmi rdx, 4*8(%rsp), nested_nmi, first_nmi > + lea 6*8(%rsp), %rdx > + /* Compare the NMI stack (rdx) with the stack we came from (4*8(%rsp)) > */ > + cmpq %rdx, 4*8(%rsp) > + /* If the stack pointer is above the NMI stack, this is a normal NMI */ > + ja first_nmi > + subq $EXCEPTION_STKSZ, %rdx > + cmpq %rdx, 4*8(%rsp) > + /* If it is below the NMI stack, it is a normal NMI */ > + jb first_nmi > + /* Ah, it is within the NMI stack, treat it as nested */ > + jmp nested_nmi I guess we can get rid of the jmp nested_nmi, as it just jumps to the next instruction. Although, I would keep the comment. -- Steve > + > CFI_REMEMBER_STATE > > nested_nmi: -- 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/
