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From: Ard Biesheuvel <ardb@kernel.org>
Date: Tue, 23 Jan 2024 14:46:07 +0100
Message-ID: <CAMj1kXG3kqRy0KEvC_+f+RAgeZvcKRwHGKTbLNj34pr8rhzTdw@mail.gmail.com>
Subject: Re: [PATCH] ARM: fault: Add "cut here" line for prefetch aborts
To: Kees Cook <keescook@chromium.org>
Cc: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>, Wang Kefeng <wangkefeng.wang@huawei.com>, 
	Ben Hutchings <ben@decadent.org.uk>, linux-arm-kernel@lists.infradead.org, 
	Russell King <linux@armlinux.org.uk>, Hugh Dickins <hughd@google.com>, 
	Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org, 
	linux-hardening@vger.kernel.org
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On Tue, 23 Jan 2024 at 02:12, Kees Cook <keescook@chromium.org> wrote:
>
> The common pattern in arm is to emit a "8<--- cut here ---" line for
> faults, but it was missing for do_PrefetchAbort(). Add it.
>
> Cc: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
> Cc: Ard Biesheuvel <ardb@kernel.org>
> Cc: Wang Kefeng <wangkefeng.wang@huawei.com>
> Cc: Ben Hutchings <ben@decadent.org.uk>
> Cc: linux-arm-kernel@lists.infradead.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

Acked-by: Ard Biesheuvel <ardb@kernel.org>

> ---
>  arch/arm/mm/fault.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
> index e96fb40b9cc3..e804432e905e 100644
> --- a/arch/arm/mm/fault.c
> +++ b/arch/arm/mm/fault.c
> @@ -586,6 +586,7 @@ do_PrefetchAbort(unsigned long addr, unsigned int ifsr, struct pt_regs *regs)
>         if (!inf->fn(addr, ifsr | FSR_LNX_PF, regs))
>                 return;
>
> +       pr_alert("8<--- cut here ---\n");
>         pr_alert("Unhandled prefetch abort: %s (0x%03x) at 0x%08lx\n",
>                 inf->name, ifsr, addr);
>
> --
> 2.34.1
>