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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@c-s.fr, aneesh.kumar@linux.ibm.com,
	bsingharora@gmail.com
Cc: Daniel Axtens <dja@axtens.net>
Subject: [PATCH v6 2/4] kasan: Document support on 32-bit powerpc
Date: Wed, 12 Feb 2020 16:47:22 +1100	[thread overview]
Message-ID: <20200212054724.7708-3-dja@axtens.net> (raw)
In-Reply-To: <20200212054724.7708-1-dja@axtens.net>

KASAN is supported on 32-bit powerpc and the docs should reflect this.

Document s390 support while we're at it.

Suggested-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Daniel Axtens <dja@axtens.net>

---

Changes since v5:
 - rebase - riscv has now got support.
 - document s390 support while we're at it
 - clarify when kasan_vmalloc support is required
---
 Documentation/dev-tools/kasan.rst |  7 +++++--
 Documentation/powerpc/kasan.txt   | 12 ++++++++++++
 2 files changed, 17 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 c652d740735d..012ef3d91d1f 100644
--- a/Documentation/dev-tools/kasan.rst
+++ b/Documentation/dev-tools/kasan.rst
@@ -22,7 +22,8 @@ global variables yet.
 Tag-based KASAN is only supported in Clang and requires version 7.0.0 or later.
 
 Currently generic KASAN is supported for the x86_64, arm64, xtensa, s390 and
-riscv architectures, and tag-based KASAN is supported only for arm64.
+riscv architectures. It is also supported on 32-bit powerpc kernels. Tag-based 
+KASAN is supported only on arm64.
 
 Usage
 -----
@@ -255,7 +256,9 @@ CONFIG_KASAN_VMALLOC
 ~~~~~~~~~~~~~~~~~~~~
 
 With ``CONFIG_KASAN_VMALLOC``, KASAN can cover vmalloc space at the
-cost of greater memory usage. Currently this is only supported on x86.
+cost of greater memory usage. Currently this supported on x86, 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.
-- 
2.20.1


  parent reply	other threads:[~2020-02-12  5:47 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-12  5:47 [PATCH v6 0/4] KASAN for powerpc64 radix Daniel Axtens
2020-02-12  5:47 ` [PATCH v6 1/4] kasan: define and use MAX_PTRS_PER_* for early shadow tables Daniel Axtens
2020-02-12  5:47 ` Daniel Axtens [this message]
2020-02-12  5:47 ` [PATCH v6 3/4] powerpc/mm/kasan: rename kasan_init_32.c to init_32.c Daniel Axtens
2020-02-12  5:47 ` [PATCH v6 4/4] powerpc: Book3S 64-bit "heavyweight" KASAN support Daniel Axtens
2020-02-12  6:35   ` Christophe Leroy
2020-02-12 10:12     ` Daniel Axtens
2020-02-12 10:35       ` Christophe Leroy
2020-02-12 12:16         ` Daniel Axtens

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