From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Nicholas Miehlbradt <nicholas@linux.ibm.com>,
"glider@google.com" <glider@google.com>,
"elver@google.com" <elver@google.com>,
"dvyukov@google.com" <dvyukov@google.com>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"mpe@ellerman.id.au" <mpe@ellerman.id.au>,
"npiggin@gmail.com" <npiggin@gmail.com>
Cc: "linux-mm@kvack.org" <linux-mm@kvack.org>,
"kasan-dev@googlegroups.com" <kasan-dev@googlegroups.com>,
"iii@linux.ibm.com" <iii@linux.ibm.com>,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 04/13] powerpc: Disable CONFIG_DCACHE_WORD_ACCESS when KMSAN is enabled
Date: Thu, 14 Dec 2023 08:42:06 +0000 [thread overview]
Message-ID: <1f3b22d4-00b3-4ff9-b29b-a901c03988e3@csgroup.eu> (raw)
In-Reply-To: <20231214055539.9420-5-nicholas@linux.ibm.com>
Le 14/12/2023 à 06:55, Nicholas Miehlbradt a écrit :
> Word sized accesses may read uninitialized data when optimizing loads.
> Disable this optimization when KMSAN is enabled to prevent false
> positives.
>
> Signed-off-by: Nicholas Miehlbradt <nicholas@linux.ibm.com>
> ---
> arch/powerpc/Kconfig | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 6f105ee4f3cf..e33e3250c478 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -182,7 +182,7 @@ config PPC
> select BUILDTIME_TABLE_SORT
> select CLONE_BACKWARDS
> select CPUMASK_OFFSTACK if NR_CPUS >= 8192
> - select DCACHE_WORD_ACCESS if PPC64 && CPU_LITTLE_ENDIAN
> + select DCACHE_WORD_ACCESS if PPC64 && CPU_LITTLE_ENDIAN && !KMSAN
> select DMA_OPS_BYPASS if PPC64
> select DMA_OPS if PPC64
> select DYNAMIC_FTRACE if FUNCTION_TRACER
Seems like all archs do this. Maybe a better approach would be to define
a HAVE_DCACHE_WORD_ACCESS that is selected by arches, and then the core
part select DCACHE_WORD_ACCESS when HAVE_DCACHE_WORD_ACCESS && !KMSAN
Christophe
next prev parent reply other threads:[~2023-12-14 8:42 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-14 5:55 [PATCH 00/13] kmsan: Enable on powerpc Nicholas Miehlbradt
2023-12-14 5:55 ` [PATCH 05/13] powerpc: Unpoison buffers populated by hcalls Nicholas Miehlbradt
2023-12-14 5:55 ` [PATCH 07/13] powerpc/kprobes: Unpoison instruction in kprobe struct Nicholas Miehlbradt
2023-12-15 7:51 ` Naveen N Rao
2023-12-14 5:55 ` [PATCH 08/13] powerpc: Unpoison pt_regs Nicholas Miehlbradt
2023-12-14 5:55 ` [PATCH 09/13] powerpc: Disable KMSAN checks on functions which walk the stack Nicholas Miehlbradt
2023-12-14 9:00 ` Christophe Leroy
2024-01-10 4:16 ` Nicholas Miehlbradt
2023-12-15 9:02 ` Aneesh Kumar K.V
2023-12-14 5:55 ` [PATCH 10/13] powerpc: Define KMSAN metadata address ranges for vmalloc and ioremap Nicholas Miehlbradt
2023-12-14 9:17 ` Christophe Leroy
2024-01-10 3:54 ` Nicholas Miehlbradt
2023-12-15 9:27 ` Aneesh Kumar K.V
2023-12-14 5:55 ` [PATCH 11/13] powerpc: Implement architecture specific KMSAN interface Nicholas Miehlbradt
2023-12-14 9:20 ` Christophe Leroy
2023-12-14 5:55 ` [PATCH 12/13] powerpc/string: Add KMSAN support Nicholas Miehlbradt
2023-12-14 9:25 ` Christophe Leroy
2024-01-10 4:09 ` Nicholas Miehlbradt
2023-12-14 5:55 ` [PATCH 13/13] powerpc: Enable KMSAN on powerpc Nicholas Miehlbradt
2023-12-14 9:27 ` Christophe Leroy
[not found] ` <20231214055539.9420-3-nicholas@linux.ibm.com>
2023-12-14 8:36 ` [PATCH 02/13] hvc: Fix use of uninitialized array in udbg_hvc_putc Christophe Leroy
2023-12-21 12:09 ` Michael Ellerman
[not found] ` <20231214055539.9420-5-nicholas@linux.ibm.com>
2023-12-14 8:42 ` Christophe Leroy [this message]
[not found] ` <20231214055539.9420-2-nicholas@linux.ibm.com>
2024-02-19 19:37 ` [PATCH 01/13] kmsan: Export kmsan_handle_dma Christophe Leroy
2024-02-20 6:39 ` [PATCH 00/13] kmsan: Enable on powerpc Christophe Leroy
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