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: Daniel Axtens <dja@axtens.net>
Subject: [PATCH v11 4/6] kasan: Document support on 32-bit powerpc
Date: Sat, 20 Mar 2021 01:40:56 +1100 [thread overview]
Message-ID: <20210319144058.772525-5-dja@axtens.net> (raw)
In-Reply-To: <20210319144058.772525-1-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 a8c3e0cff88d..2cfd5d9068c0 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
-----
@@ -334,7 +335,10 @@ 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:[~2021-03-19 14:41 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
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 ` Daniel Axtens [this message]
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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