incoming

incoming

[Andrew Morton]

2 patches, based on d615b5416f8a1afeb82d13b238f8152c572d59c0.

Subsystems affected by this patch series:

  mm/kasan
  mm/debug

Subsystem: mm/kasan

    Zqiang <qiang1.zhang@intel.com>:
      kasan: prevent cpu_quarantine corruption when CPU offline and cache shrink occur at same time

Subsystem: mm/debug

    Akira Yokosawa <akiyks@gmail.com>:
      docs: vm/page_owner: use literal blocks for param description

 Documentation/vm/page_owner.rst |    5 +++--
 mm/kasan/quarantine.c           |    7 +++++++
 2 files changed, 10 insertions(+), 2 deletions(-)

[patch 1/2] kasan: prevent cpu_quarantine corruption when CPU offline and cache shrink occur at same time

[Andrew Morton]

From: Zqiang <qiang1.zhang@intel.com>
Subject: kasan: prevent cpu_quarantine corruption when CPU offline and cache shrink occur at same time

kasan_quarantine_remove_cache() is called in kmem_cache_shrink()/
destroy().  The kasan_quarantine_remove_cache() call is protected by
cpuslock in kmem_cache_destroy() to ensure serialization with
kasan_cpu_offline().

However the kasan_quarantine_remove_cache() call is not protected by
cpuslock in kmem_cache_shrink().  When a CPU is going offline and cache
shrink occurs at same time, the cpu_quarantine may be corrupted by
interrupt (per_cpu_remove_cache operation).

So add a cpu_quarantine offline flags check in per_cpu_remove_cache().

[akpm@linux-foundation.org: add comment, per Zqiang]
Link: https://lkml.kernel.org/r/20220414025925.2423818-1-qiang1.zhang@intel.com
Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/kasan/quarantine.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/mm/kasan/quarantine.c~kasan-prevent-cpu_quarantine-corruption-when-cpu-offline-and-cache-shrink-occur-at-same-time
+++ a/mm/kasan/quarantine.c
@@ -315,6 +315,13 @@ static void per_cpu_remove_cache(void *a
 	struct qlist_head *q;
 
 	q = this_cpu_ptr(&cpu_quarantine);
+	/*
+	 * Ensure the ordering between the writing to q->offline and
+	 * per_cpu_remove_cache.  Prevent cpu_quarantine from being corrupted
+	 * by interrupt.
+	 */
+	if (READ_ONCE(q->offline))
+		return;
 	qlist_move_cache(q, &to_free, cache);
 	qlist_free_all(&to_free, cache);
 }
_

[patch 1/2] kasan: prevent cpu_quarantine corruption when CPU offline and cache shrink occur at same time

[Andrew Morton]

From: Zqiang <qiang1.zhang@intel.com>
Subject: kasan: prevent cpu_quarantine corruption when CPU offline and cache shrink occur at same time

kasan_quarantine_remove_cache() is called in kmem_cache_shrink()/
destroy().  The kasan_quarantine_remove_cache() call is protected by
cpuslock in kmem_cache_destroy() to ensure serialization with
kasan_cpu_offline().

However the kasan_quarantine_remove_cache() call is not protected by
cpuslock in kmem_cache_shrink().  When a CPU is going offline and cache
shrink occurs at same time, the cpu_quarantine may be corrupted by
interrupt (per_cpu_remove_cache operation).

So add a cpu_quarantine offline flags check in per_cpu_remove_cache().

[akpm@linux-foundation.org: add comment, per Zqiang]
Link: https://lkml.kernel.org/r/20220414025925.2423818-1-qiang1.zhang@intel.com
Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/kasan/quarantine.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/mm/kasan/quarantine.c~kasan-prevent-cpu_quarantine-corruption-when-cpu-offline-and-cache-shrink-occur-at-same-time
+++ a/mm/kasan/quarantine.c
@@ -315,6 +315,13 @@ static void per_cpu_remove_cache(void *a
 	struct qlist_head *q;
 
 	q = this_cpu_ptr(&cpu_quarantine);
+	/*
+	 * Ensure the ordering between the writing to q->offline and
+	 * per_cpu_remove_cache.  Prevent cpu_quarantine from being corrupted
+	 * by interrupt.
+	 */
+	if (READ_ONCE(q->offline))
+		return;
 	qlist_move_cache(q, &to_free, cache);
 	qlist_free_all(&to_free, cache);
 }
_

[patch 2/2] docs: vm/page_owner: use literal blocks for param description

[Andrew Morton]

From: Akira Yokosawa <akiyks@gmail.com>
Subject: docs: vm/page_owner: use literal blocks for param description

Sphinx generates hard-to-read lists of parameters at the bottom of the
page.  Fix them by putting literal-block markers of "::" in front of them.

Link: https://lkml.kernel.org/r/cfd3bcc0-b51d-0c68-c065-ca1c4c202447@gmail.com
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Fixes: 57f2b54a9379 ("Documentation/vm/page_owner.rst: update the documentation")
Cc: Shenghong Han <hanshenghong2019@email.szu.edu.cn>
Cc: Haowen Bai <baihaowen@meizu.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Alex Shi <seakeel@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 Documentation/vm/page_owner.rst |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/Documentation/vm/page_owner.rst~docs-vm-page_owner-use-literal-blocks-for-param-description
+++ a/Documentation/vm/page_owner.rst
@@ -110,7 +110,7 @@ Usage
    If you want to sort by the page nums of buf, use the ``-m`` parameter.
    The detailed parameters are:
 
-   fundamental function:
+   fundamental function::
 
 	Sort:
 		-a		Sort by memory allocation time.
@@ -122,7 +122,7 @@ Usage
 		-s		Sort by stack trace.
 		-t		Sort by times (default).
 
-   additional function:
+   additional function::
 
 	Cull:
 		--cull <rules>
@@ -153,6 +153,7 @@ Usage
 
 STANDARD FORMAT SPECIFIERS
 ==========================
+::
 
 	KEY		LONG		DESCRIPTION
 	p		pid		process ID
_

[patch 2/2] docs: vm/page_owner: use literal blocks for param description

[Andrew Morton]

From: Akira Yokosawa <akiyks@gmail.com>
Subject: docs: vm/page_owner: use literal blocks for param description

Sphinx generates hard-to-read lists of parameters at the bottom of the
page.  Fix them by putting literal-block markers of "::" in front of them.

Link: https://lkml.kernel.org/r/cfd3bcc0-b51d-0c68-c065-ca1c4c202447@gmail.com
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Fixes: 57f2b54a9379 ("Documentation/vm/page_owner.rst: update the documentation")
Cc: Shenghong Han <hanshenghong2019@email.szu.edu.cn>
Cc: Haowen Bai <baihaowen@meizu.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Alex Shi <seakeel@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 Documentation/vm/page_owner.rst |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/Documentation/vm/page_owner.rst~docs-vm-page_owner-use-literal-blocks-for-param-description
+++ a/Documentation/vm/page_owner.rst
@@ -110,7 +110,7 @@ Usage
    If you want to sort by the page nums of buf, use the ``-m`` parameter.
    The detailed parameters are:
 
-   fundamental function:
+   fundamental function::
 
 	Sort:
 		-a		Sort by memory allocation time.
@@ -122,7 +122,7 @@ Usage
 		-s		Sort by stack trace.
 		-t		Sort by times (default).
 
-   additional function:
+   additional function::
 
 	Cull:
 		--cull <rules>
@@ -153,6 +153,7 @@ Usage
 
 STANDARD FORMAT SPECIFIERS
 ==========================
+::
 
 	KEY		LONG		DESCRIPTION
 	p		pid		process ID
_