Messages in this thread Patch in this message | | | Date | Thu, 8 Nov 2018 11:41:41 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH v3 2/7] x86/jump_label: Use text_poke_early() during early_init |
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On Wed, Nov 07, 2018 at 07:13:03PM +0000, Nadav Amit wrote: > > diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c > > index aac0c1f7e354..ed5fe274a7d8 100644 > > --- a/arch/x86/kernel/jump_label.c > > +++ b/arch/x86/kernel/jump_label.c > > @@ -52,7 +52,12 @@ static void __ref __jump_label_transform(struct jump_entry *entry, > > jmp.offset = jump_entry_target(entry) - > > (jump_entry_code(entry) + JUMP_LABEL_NOP_SIZE); > > > > - if (early_boot_irqs_disabled) > > + /* > > + * As long as we're UP and not yet marked RO, we can use > > + * text_poke_early; SYSTEM_BOOTING guarantees both, as we switch to > > + * SYSTEM_SCHEDULING before going either. > > + */ > > + if (system_state == SYSTEM_BOOTING) > > poker = text_poke_early; > > > > if (type == JUMP_LABEL_JMP) { > > Thanks for this change, I will incorporate it. > > I wanted to point a small difference from my version. Although this version > ensures we are UP and the kernel is still RW, preemption is possible with > this version. I presume that it should not affect jump-labels, since it > switches between JMP and multi-byte NOPs.
Right, we're never running the code we're going to change on UP.
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