From: Balbir Singh <bsingharora@gmail.com>
To: Daniel Axtens <dja@axtens.net>
Cc: aneesh.kumar@linux.ibm.com, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, kasan-dev@googlegroups.com,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v11 1/6] kasan: allow an architecture to disable inline instrumentation
Date: Sat, 20 Mar 2021 12:46:06 +1100 [thread overview]
Message-ID: <20210320014606.GB77072@balbir-desktop> (raw)
In-Reply-To: <20210319144058.772525-2-dja@axtens.net>
On Sat, Mar 20, 2021 at 01:40:53AM +1100, Daniel Axtens wrote:
> For annoying architectural reasons, it's very difficult to support inline
> instrumentation on powerpc64.
I think we can expand here and talk about how in hash mode, the vmalloc
address space is in a region of memory different than where kernel virtual
addresses are mapped. Did I recollect the reason correctly?
>
> Add a Kconfig flag to allow an arch to disable inline. (It's a bit
> annoying to be 'backwards', but I'm not aware of any way to have
> an arch force a symbol to be 'n', rather than 'y'.)
>
> We also disable stack instrumentation in this case as it does things that
> are functionally equivalent to inline instrumentation, namely adding
> code that touches the shadow directly without going through a C helper.
>
> Signed-off-by: Daniel Axtens <dja@axtens.net>
> ---
> lib/Kconfig.kasan | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan
> index cffc2ebbf185..7e237dbb6df3 100644
> --- a/lib/Kconfig.kasan
> +++ b/lib/Kconfig.kasan
> @@ -12,6 +12,9 @@ config HAVE_ARCH_KASAN_HW_TAGS
> config HAVE_ARCH_KASAN_VMALLOC
> bool
>
> +config ARCH_DISABLE_KASAN_INLINE
> + def_bool n
> +
Some comments on what arch's want to disable kasan inline would
be helpful and why.
Balbir Singh.
next prev parent reply other threads:[~2021-03-20 1:46 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-19 14:40 [PATCH v11 0/6] KASAN for powerpc64 radix Daniel Axtens
2021-03-19 14:40 ` [PATCH v11 1/6] kasan: allow an architecture to disable inline instrumentation Daniel Axtens
2021-03-20 1:46 ` Balbir Singh [this message]
2021-03-22 0:29 ` Daniel Axtens
2021-03-22 11:08 ` Michael Ellerman
2021-03-22 8:18 ` Marco Elver
2021-03-19 14:40 ` [PATCH v11 2/6] kasan: allow architectures to provide an outline readiness check Daniel Axtens
2021-03-22 8:17 ` Marco Elver
2021-03-19 14:40 ` [PATCH v11 3/6] kasan: define and use MAX_PTRS_PER_* for early shadow tables Daniel Axtens
2021-03-19 14:40 ` [PATCH v11 4/6] kasan: Document support on 32-bit powerpc Daniel Axtens
2021-03-19 14:40 ` [PATCH v11 5/6] powerpc/mm/kasan: rename kasan_init_32.c to init_32.c Daniel Axtens
2021-03-19 14:40 ` [PATCH v11 6/6] powerpc: Book3S 64-bit outline-only KASAN support Daniel Axtens
2021-03-20 6:02 ` Balbir Singh
2021-03-22 0:55 ` Daniel Axtens
2021-03-22 2:59 ` Balbir Singh
2021-03-22 5:52 ` Daniel Axtens
2021-03-22 15:14 ` Christophe Leroy
2021-04-21 12:29 ` Christophe Leroy
2021-03-20 1:40 ` [PATCH v11 0/6] KASAN for powerpc64 radix Balbir Singh
2021-03-22 14:32 ` Christophe Leroy
2021-03-23 1:21 ` Daniel Axtens
2021-03-23 13:27 ` Christophe Leroy
2021-03-29 23:53 ` Michael Ellerman
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