public inbox for linuxppc-dev@ozlabs.org 
 help / color / mirror / Atom feed
From: Michael Ellerman <mpe@ellerman•id.au>
To: Balbir Singh <bsingharora@gmail•com>,
	benh@kernel•crashing.org, paulus@samba•org
Cc: Michael Neuling <mikey@neuling•org>,
	linuxppc-dev@lists•ozlabs.org,
	"Aneesh Kumar K.V" <aneesh.kumar@linux•vnet.ibm.com>
Subject: Re: [2/2] Detect instruction fetch denied and report
Date: Tue, 20 Sep 2016 16:35:42 +1000 (AEST)	[thread overview]
Message-ID: <3sdY0t2gfYz9svs@ozlabs.org> (raw)
In-Reply-To: <1471831017-18167-2-git-send-email-bsingharora@gmail.com>

On Mon, 2016-22-08 at 01:56:57 UTC, Balbir Singh wrote:
> diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
> index a4db22f..f162e77 100644
> --- a/arch/powerpc/mm/fault.c
> +++ b/arch/powerpc/mm/fault.c
> @@ -404,6 +404,10 @@ good_area:
>  		    (cpu_has_feature(CPU_FTR_NOEXECUTE) ||
>  		     !(vma->vm_flags & (VM_READ | VM_WRITE))))
>  			goto bad_area;
> +#ifdef CONFIG_PPC_RADIX_MMU

We shouldn't need the #ifdef, radix_enabled() will be false.

> +		if (radix_enabled() && regs->msr & PPC_BIT(35))
> +			goto bad_area;

Is it really architected as radix only?

Personally I dislike PPC_BIT(), I'd rather you just used 0x10000000. That way
when I'm staring at a register dump I have some chance of spotting that mask.

Also brackets around the bitwise & would make me feel more comfortable.

cheers

  parent reply	other threads:[~2016-09-20  6:35 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-22  1:56 [PATCH 1/2] Enable storage keys for radix - user mode execution Balbir Singh
2016-08-22  1:56 ` [PATCH 2/2] Detect instruction fetch denied and report Balbir Singh
2016-08-22  6:05   ` Aneesh Kumar K.V
2016-08-22  7:55     ` Balbir Singh
2016-09-20  6:35   ` Michael Ellerman [this message]
2016-09-20  7:44     ` [2/2] " Balbir Singh
2016-08-22  6:02 ` [PATCH 1/2] Enable storage keys for radix - user mode execution Aneesh Kumar K.V
2016-08-22  8:07   ` Balbir Singh

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=3sdY0t2gfYz9svs@ozlabs.org \
    --to=mpe@ellerman$(echo .)id.au \
    --cc=aneesh.kumar@linux$(echo .)vnet.ibm.com \
    --cc=benh@kernel$(echo .)crashing.org \
    --cc=bsingharora@gmail$(echo .)com \
    --cc=linuxppc-dev@lists$(echo .)ozlabs.org \
    --cc=mikey@neuling$(echo .)org \
    --cc=paulus@samba$(echo .)org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox