Peter,
I have put you as a “Co-Developed-by”, since the patch ended up as being the
single line that you wrote in the correspondence of the previous version.
I would therefore need to ask for your signed-off-by.
Regards,
Nadav
From: Nadav Amit
Sent: November 10, 2018 at 11:17:24 PM GMT
> To: Ingo Molnar <mi...@redhat.com>
> Cc: linux-kernel@vger.kernel.org>, x...@kernel.org>, H. Peter Anvin
> <h...@zytor.com>, Thomas Gleixner <t...@linutronix.de>, Borislav Petkov
> <b...@alien8.de>, Dave Hansen <dave.han...@linux.intel.com>, Nadav Amit
> <na...@vmware.com>, Andy Lutomirski <l...@kernel.org>, Kees Cook
> <keesc...@chromium.org>, Dave Hansen <dave.han...@intel.com>, Masami
> Hiramatsu <mhira...@kernel.org>
> Subject: [PATCH v4 02/10] x86/jump_label: Use text_poke_early() during early
> init
>
>
> There is no apparent reason not to use text_poke_early() while we are
> during early-init and we do not patch code that might be on the stack
> (i.e., we'll return to the middle of the patched code). This appears to
> be the case of jump-labels, so do so.
>
> This is required for the next patches that would set a temporary mm for
> patching, which is initialized after some static-keys are
> enabled/disabled.
>
> Cc: Andy Lutomirski <l...@kernel.org>
> Cc: Kees Cook <keesc...@chromium.org>
> Cc: Dave Hansen <dave.han...@intel.com>
> Cc: Masami Hiramatsu <mhira...@kernel.org>
> Co-Developed-by: Peter Zijlstra <pet...@infradead.org>
> Signed-off-by: Nadav Amit <na...@vmware.com>
> ---
> arch/x86/kernel/jump_label.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> 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) {
> --
> 2.17.1
