Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
In-Reply-To: <20180816102219.GF31093@arm.com>
References: <462f8ae6-9948-a8e5-7504-623d40344336@iki.fi> <20180816102219.GF31093@arm.com>
From:   John Stultz <john.stultz@linaro.org>
Date:   Thu, 16 Aug 2018 10:57:51 -0700
Message-ID: <CALAqxLWJzpV2Mqkz_ed_5zYX3SFyMZTBgTzyRAden7ab3VNm-Q@mail.gmail.com>
Subject: Re: AArch64 boot failure on Hikey960 on latest master after "arm64:
 insn: Don't fallback on nosync path for general insn patching"
To:     Will Deacon <will.deacon@arm.com>
Cc:     Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>,
        Catalin Marinas <catalin.marinas@arm.com>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        lkml <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Thu, Aug 16, 2018 at 3:22 AM, Will Deacon <will.deacon@arm.com> wrote:
> Hi Tuomas, [+John]
>
> On Thu, Aug 16, 2018 at 02:38:51AM +0300, Tuomas Tynkkynen wrote:
>> Booting Linus's master of today with the usual arm64 defconfig fails for
>> me on the Hikey960 board. I've bisected it down to:
>>
>> commit 693350a7998018391852c48f68956cf0f855b2b9 (HEAD, refs/bisect/bad)
>> Author: Will Deacon <will.deacon@arm.com>
>> Date:   Tue Jun 19 17:55:28 2018 +0100
>>
>>     arm64: insn: Don't fallback on nosync path for general insn patching
>>
>> Here's the boot log with earlycon enabled after which the boot hangs:
>
> Thanks for the boot log, that's really helpful. Please can you try the diff
> below?
>
> Out of interest -- do you know if Hikey960 is used by any boot-testing
> farms? The patch above has been in linux-next for ages, but we didn't see
> any complaints until it hit mainline :(

Unfortunately not yet. HiKey960 upstreaming is ongoing, and the UFS
support patches should land in the 4.19 merge window.
After which, it will enable more mainline testing as folks won't have
to carry patches just to get the system to boot.

> diff --git a/arch/arm64/kernel/jump_label.c b/arch/arm64/kernel/jump_label.c
> index c2dd1ad3e648..e0756416e567 100644
> --- a/arch/arm64/kernel/jump_label.c
> +++ b/arch/arm64/kernel/jump_label.c
> @@ -36,7 +36,7 @@ void arch_jump_label_transform(struct jump_entry *entry,
>                 insn = aarch64_insn_gen_nop();
>         }
>
> -       aarch64_insn_patch_text(&addr, &insn, 1);
> +       aarch64_insn_patch_text_nosync(addr, insn);
>  }
>
>  void arch_jump_label_transform_static(struct jump_entry *entry,

Yes, this works for me as well.

Tested-by: John Stultz <john.stultz@linaro.org>

thanks so much!
-john