Re: [PATCH] ARM: fix alignement of __bug_table section entries

From: Russell King - ARM Linux
Date: Sun Sep 06 2015 - 19:54:36 EST


On Sun, Sep 06, 2015 at 11:31:34PM +0200, Robert Jarzmik wrote:
> Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> writes:
>
> >> [1] Approach 1 : translation table sync
> >> =======================================
> ...
> > The important place is in arch/arm/include/asm/domain.h, which is where
> > we manipulate the DACR within probe_kernel_address().
>
> Gah, silly me. But even with [1], I still get an error [2]. I have a
> confirmation that I have a "Page Permission" fault on the
> probe_kernel_address().

Hmm, that's not right. If it's the DACR, then it should be a page domain
fault, not a page permission fault.

> [2] Oops
> ========
> # insmod /tmp/unalign.ko
> RJK1: fsr=23 far=e1c23643 dacr=51
> RJK2: fsr=23 far=e1c23643 dacr=51
> RJK3: fsr=2f far=bf00202c dacr=51
> RJK: fault=4 instr=0x00000000 instrptr=bf00202c

Can you add a show_pte(current->mm, instrptr) to dump those page
table entries please?

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