From: Joel Stanley <joel@jms.id.au>
To: Russell Currey <ruscur@russell.cc>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>,
Rashmica Gupta <rashmica.g@gmail.com>,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v2 2/2] powerpc/mm: Warn if W+X pages found on boot
Date: Fri, 3 May 2019 00:37:26 +0000 [thread overview]
Message-ID: <CACPK8XeGD85Yt1bZvuDo4LnYwn0xg15eDJoOep1JC3bg0s0uXA@mail.gmail.com> (raw)
In-Reply-To: <20190502073947.6481-2-ruscur@russell.cc>
On Thu, 2 May 2019 at 07:42, Russell Currey <ruscur@russell.cc> wrote:
>
> Implement code to walk all pages and warn if any are found to be both
> writable and executable. Depends on STRICT_KERNEL_RWX enabled, and is
> behind the DEBUG_WX config option.
>
> This only runs on boot and has no runtime performance implications.
>
> Very heavily influenced (and in some cases copied verbatim) from the
> ARM64 code written by Laura Abbott (thanks!), since our ptdump
> infrastructure is similar.
>
> Signed-off-by: Russell Currey <ruscur@russell.cc>
> ---
> v2: A myriad of fixes and cleanups thanks to Christophe Leroy
>
> arch/powerpc/Kconfig.debug | 19 ++++++++++++++
> arch/powerpc/include/asm/pgtable.h | 6 +++++
> arch/powerpc/mm/pgtable_32.c | 3 +++
> arch/powerpc/mm/pgtable_64.c | 3 +++
> arch/powerpc/mm/ptdump/ptdump.c | 41 +++++++++++++++++++++++++++++-
> 5 files changed, 71 insertions(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug
> index 4e00cb0a5464..9e8bcddd8b8f 100644
> --- a/arch/powerpc/Kconfig.debug
> +++ b/arch/powerpc/Kconfig.debug
> @@ -361,6 +361,25 @@ config PPC_PTDUMP
>
> If you are unsure, say N.
>
> +config PPC_DEBUG_WX
The other architectures call this DEBUG_WX, in case you wanted to name
it the same.
> + bool "Warn on W+X mappings at boot"
> + select PPC_PTDUMP
> + help
> + Generate a warning if any W+X mappings are found at boot.
next prev parent reply other threads:[~2019-05-03 0:40 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-02 7:39 [PATCH v2 1/2] powerpc/mm/ptdump: Wrap seq_printf() to handle NULL pointers Russell Currey
2019-05-02 7:39 ` [PATCH v2 2/2] powerpc/mm: Warn if W+X pages found on boot Russell Currey
2019-05-02 14:17 ` Michael Ellerman
2019-05-03 0:37 ` Joel Stanley [this message]
2019-05-03 0:55 ` Russell Currey
2020-01-06 10:10 ` Christophe Leroy
2019-05-03 6:59 ` [PATCH v2 1/2] powerpc/mm/ptdump: Wrap seq_printf() to handle NULL pointers Michael Ellerman
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