From: Daniel Axtens <dja@axtens.net>
To: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
linuxppc-dev@lists.ozlabs.org, kasan-dev@googlegroups.com,
christophe.leroy@csgroup.eu, aneesh.kumar@linux.ibm.com,
bsingharora@gmail.com
Cc: elver@google.com, Daniel Axtens <dja@axtens.net>
Subject: [PATCH v12 4/6] kasan: Document support on 32-bit powerpc
Date: Tue, 15 Jun 2021 11:47:03 +1000 [thread overview]
Message-ID: <20210615014705.2234866-5-dja@axtens.net> (raw)
In-Reply-To: <20210615014705.2234866-1-dja@axtens.net>
KASAN is supported on 32-bit powerpc and the docs should reflect this.
Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Daniel Axtens <dja@axtens.net>
---
Documentation/dev-tools/kasan.rst | 8 ++++++--
Documentation/powerpc/kasan.txt | 12 ++++++++++++
2 files changed, 18 insertions(+), 2 deletions(-)
create mode 100644 Documentation/powerpc/kasan.txt
diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst
index 83ec4a556c19..05d2d428a332 100644
--- a/Documentation/dev-tools/kasan.rst
+++ b/Documentation/dev-tools/kasan.rst
@@ -36,7 +36,8 @@ Both software KASAN modes work with SLUB and SLAB memory allocators,
while the hardware tag-based KASAN currently only supports SLUB.
Currently, generic KASAN is supported for the x86_64, arm, arm64, xtensa, s390,
-and riscv architectures, and tag-based KASAN modes are supported only for arm64.
+and riscv architectures. It is also supported on 32-bit powerpc kernels.
+Tag-based KASAN modes are supported only for arm64.
Usage
-----
@@ -343,7 +344,10 @@ CONFIG_KASAN_VMALLOC
With ``CONFIG_KASAN_VMALLOC``, KASAN can cover vmalloc space at the
cost of greater memory usage. Currently, this is supported on x86,
-riscv, s390, and powerpc.
+riscv, s390, and 32-bit powerpc.
+
+It is optional, except on 32-bit powerpc kernels with module support,
+where it is required.
This works by hooking into vmalloc and vmap and dynamically
allocating real shadow memory to back the mappings.
diff --git a/Documentation/powerpc/kasan.txt b/Documentation/powerpc/kasan.txt
new file mode 100644
index 000000000000..26bb0e8bb18c
--- /dev/null
+++ b/Documentation/powerpc/kasan.txt
@@ -0,0 +1,12 @@
+KASAN is supported on powerpc on 32-bit only.
+
+32 bit support
+==============
+
+KASAN is supported on both hash and nohash MMUs on 32-bit.
+
+The shadow area sits at the top of the kernel virtual memory space above the
+fixmap area and occupies one eighth of the total kernel virtual memory space.
+
+Instrumentation of the vmalloc area is optional, unless built with modules,
+in which case it is required.
--
2.27.0
next prev parent reply other threads:[~2021-06-15 2:44 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-15 1:46 [PATCH v12 0/6] KASAN core changes for ppc64 radix KASAN Daniel Axtens
2021-06-15 1:47 ` [PATCH v12 1/6] kasan: allow an architecture to disable inline instrumentation Daniel Axtens
2021-06-15 7:46 ` Marco Elver
2021-06-16 4:39 ` Daniel Axtens
2021-06-15 1:47 ` [PATCH v12 2/6] kasan: allow architectures to provide an outline readiness check Daniel Axtens
2021-06-15 10:08 ` Marco Elver
2021-06-16 4:41 ` Daniel Axtens
2021-06-15 1:47 ` [PATCH v12 3/6] kasan: define and use MAX_PTRS_PER_* for early shadow tables Daniel Axtens
2021-06-15 1:47 ` Daniel Axtens [this message]
2021-06-15 1:47 ` [PATCH v12 5/6] powerpc/mm/kasan: rename kasan_init_32.c to init_32.c Daniel Axtens
2021-06-15 1:47 ` [PATCH v12 6/6] [RFC] powerpc: Book3S 64-bit outline-only KASAN support Daniel Axtens
2021-06-15 10:31 ` [PATCH v12 0/6] KASAN core changes for ppc64 radix KASAN Marco Elver
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