From dfec072ecd35ba6ecad2d51dde325253ac9a2936 Mon Sep 17 00:00:00 2001
From: Vegard Nossum <vegard.nossum@gmail.com>
Date: Fri, 4 Apr 2008 00:51:41 +0200
Subject: kmemcheck: add the kmemcheck core
General description: kmemcheck is a patch to the linux kernel that
detects use of uninitialized memory. It does this by trapping every
read and write to memory that was allocated dynamically (e.g. using
kmalloc()). If a memory address is read that has not previously been
written to, a message is printed to the kernel log.
Thanks to Andi Kleen for the set_memory_4k() solution.
Andrew Morton suggested documenting the shadow member of struct page.
Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
[export kmemcheck_mark_initialized]
[build fix for setup_max_cpus]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no>
---
include/linux/kmemcheck.h | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
create mode 100644 include/linux/kmemcheck.h
(limited to 'include/linux/kmemcheck.h')
diff --git a/include/linux/kmemcheck.h b/include/linux/kmemcheck.h
new file mode 100644
index 000000000000..39480c91b2f9
--- /dev/null
+++ b/include/linux/kmemcheck.h
@@ -0,0 +1,17 @@
+#ifndef LINUX_KMEMCHECK_H
+#define LINUX_KMEMCHECK_H
+
+#include <linux/mm_types.h>
+#include <linux/types.h>
+
+#ifdef CONFIG_KMEMCHECK
+extern int kmemcheck_enabled;
+
+int kmemcheck_show_addr(unsigned long address);
+int kmemcheck_hide_addr(unsigned long address);
+#else
+#define kmemcheck_enabled 0
+
+#endif /* CONFIG_KMEMCHECK */
+
+#endif /* LINUX_KMEMCHECK_H */
--
cgit v1.2.2
From 2dff440525f8faba8836e9f05297b76f23b4af30 Mon Sep 17 00:00:00 2001
From: Vegard Nossum <vegard.nossum@gmail.com>
Date: Sat, 31 May 2008 15:56:17 +0200
Subject: kmemcheck: add mm functions
With kmemcheck enabled, the slab allocator needs to do this:
1. Tell kmemcheck to allocate the shadow memory which stores the status of
each byte in the allocation proper, e.g. whether it is initialized or
uninitialized.
2. Tell kmemcheck which parts of memory that should be marked uninitialized.
There are actually a few more states, such as "not yet allocated" and
"recently freed".
If a slab cache is set up using the SLAB_NOTRACK flag, it will never return
memory that can take page faults because of kmemcheck.
If a slab cache is NOT set up using the SLAB_NOTRACK flag, callers can still
request memory with the __GFP_NOTRACK flag. This does not prevent the page
faults from occuring, however, but marks the object in question as being
initialized so that no warnings will ever be produced for this object.
In addition to (and in contrast to) __GFP_NOTRACK, the
__GFP_NOTRACK_FALSE_POSITIVE flag indicates that the allocation should
not be tracked _because_ it would produce a false positive. Their values
are identical, but need not be so in the future (for example, we could now
enable/disable false positives with a config option).
Parts of this patch were contributed by Pekka Enberg but merged for
atomicity.
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
---
include/linux/kmemcheck.h | 47 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)
(limited to 'include/linux/kmemcheck.h')
diff --git a/include/linux/kmemcheck.h b/include/linux/kmemcheck.h
index 39480c91b2f9..5b65f4ebeadf 100644
--- a/include/linux/kmemcheck.h
+++ b/include/linux/kmemcheck.h
@@ -7,11 +7,58 @@
#ifdef CONFIG_KMEMCHECK
extern int kmemcheck_enabled;
+/* The slab-related functions. */
+void kmemcheck_alloc_shadow(struct kmem_cache *s, gfp_t flags, int node,
+ struct page *page, int order);
+void kmemcheck_free_shadow(struct kmem_cache *s, struct page *page, int order);
+void kmemcheck_slab_alloc(struct kmem_cache *s, gfp_t gfpflags, void *object,
+ size_t size);
+void kmemcheck_slab_free(struct kmem_cache *s, void *object, size_t size);
+
+void kmemcheck_show_pages(struct page *p, unsigned int n);
+void kmemcheck_hide_pages(struct page *p, unsigned int n);
+
+bool kmemcheck_page_is_tracked(struct page *p);
+
+void kmemcheck_mark_unallocated(void *address, unsigned int n);
+void kmemcheck_mark_uninitialized(void *address, unsigned int n);
+void kmemcheck_mark_initialized(void *address, unsigned int n);
+void kmemcheck_mark_freed(void *address, unsigned int n);
+
+void kmemcheck_mark_unallocated_pages(struct page *p, unsigned int n);
+void kmemcheck_mark_uninitialized_pages(struct page *p, unsigned int n);
+
int kmemcheck_show_addr(unsigned long address);
int kmemcheck_hide_addr(unsigned long address);
#else
#define kmemcheck_enabled 0
+static inline void
+kmemcheck_alloc_shadow(struct kmem_cache *s, gfp_t flags, int node,
+ struct page *page, int order)
+{
+}
+
+static inline void
+kmemcheck_free_shadow(struct kmem_cache *s, struct page *page, int order)
+{
+}
+
+static inline void
+kmemcheck_slab_alloc(struct kmem_cache *s, gfp_t gfpflags, void *object,
+ size_t size)
+{
+}
+
+static inline void kmemcheck_slab_free(struct kmem_cache *s, void *object,
+ size_t size)
+{
+}
+
+static inline bool kmemcheck_page_is_tracked(struct page *p)
+{
+ return false;
+}
#endif /* CONFIG_KMEMCHECK */
#endif /* LINUX_KMEMCHECK_H */
--
cgit v1.2.2
From d7002857dee6e9a3ce1f78d23f37caba106b29c5 Mon Sep 17 00:00:00 2001
From: Vegard Nossum <vegard.nossum@gmail.com>
Date: Sun, 20 Jul 2008 10:44:54 +0200
Subject: kmemcheck: add DMA hooks
This patch hooks into the DMA API to prevent the reporting of the
false positives that would otherwise be reported when memory is
accessed that is also used directly by devices.
[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
---
include/linux/kmemcheck.h | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
(limited to 'include/linux/kmemcheck.h')
diff --git a/include/linux/kmemcheck.h b/include/linux/kmemcheck.h
index 5b65f4ebeadf..71f21ae33d1d 100644
--- a/include/linux/kmemcheck.h
+++ b/include/linux/kmemcheck.h
@@ -59,6 +59,22 @@ static inline bool kmemcheck_page_is_tracked(struct page *p)
{
return false;
}
+
+static inline void kmemcheck_mark_unallocated(void *address, unsigned int n)
+{
+}
+
+static inline void kmemcheck_mark_uninitialized(void *address, unsigned int n)
+{
+}
+
+static inline void kmemcheck_mark_initialized(void *address, unsigned int n)
+{
+}
+
+static inline void kmemcheck_mark_freed(void *address, unsigned int n)
+{
+}
#endif /* CONFIG_KMEMCHECK */
#endif /* LINUX_KMEMCHECK_H */
--
cgit v1.2.2
From b1eeab67682a5e397aecf172046b3a8bd4808ae4 Mon Sep 17 00:00:00 2001
From: Vegard Nossum <vegard.nossum@gmail.com>
Date: Tue, 25 Nov 2008 16:55:53 +0100
Subject: kmemcheck: add hooks for the page allocator
This adds support for tracking the initializedness of memory that
was allocated with the page allocator. Highmem requests are not
tracked.
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
[build fix for !CONFIG_KMEMCHECK]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
---
include/linux/kmemcheck.h | 35 +++++++++++++++++++++++++++++------
1 file changed, 29 insertions(+), 6 deletions(-)
(limited to 'include/linux/kmemcheck.h')
diff --git a/include/linux/kmemcheck.h b/include/linux/kmemcheck.h
index 71f21ae33d1d..093d23969b1b 100644
--- a/include/linux/kmemcheck.h
+++ b/include/linux/kmemcheck.h
@@ -8,13 +8,15 @@
extern int kmemcheck_enabled;
/* The slab-related functions. */
-void kmemcheck_alloc_shadow(struct kmem_cache *s, gfp_t flags, int node,
- struct page *page, int order);
-void kmemcheck_free_shadow(struct kmem_cache *s, struct page *page, int order);
+void kmemcheck_alloc_shadow(struct page *page, int order, gfp_t flags, int node);
+void kmemcheck_free_shadow(struct page *page, int order);
void kmemcheck_slab_alloc(struct kmem_cache *s, gfp_t gfpflags, void *object,
size_t size);
void kmemcheck_slab_free(struct kmem_cache *s, void *object, size_t size);
+void kmemcheck_pagealloc_alloc(struct page *p, unsigned int order,
+ gfp_t gfpflags);
+
void kmemcheck_show_pages(struct page *p, unsigned int n);
void kmemcheck_hide_pages(struct page *p, unsigned int n);
@@ -27,6 +29,7 @@ void kmemcheck_mark_freed(void *address, unsigned int n);
void kmemcheck_mark_unallocated_pages(struct page *p, unsigned int n);
void kmemcheck_mark_uninitialized_pages(struct page *p, unsigned int n);
+void kmemcheck_mark_initialized_pages(struct page *p, unsigned int n);
int kmemcheck_show_addr(unsigned long address);
int kmemcheck_hide_addr(unsigned long address);
@@ -34,13 +37,12 @@ int kmemcheck_hide_addr(unsigned long address);
#define kmemcheck_enabled 0
static inline void
-kmemcheck_alloc_shadow(struct kmem_cache *s, gfp_t flags, int node,
- struct page *page, int order)
+kmemcheck_alloc_shadow(struct page *page, int order, gfp_t flags, int node)
{
}
static inline void
-kmemcheck_free_shadow(struct kmem_cache *s, struct page *page, int order)
+kmemcheck_free_shadow(struct page *page, int order)
{
}
@@ -55,6 +57,11 @@ static inline void kmemcheck_slab_free(struct kmem_cache *s, void *object,
{
}
+static inline void kmemcheck_pagealloc_alloc(struct page *p,
+ unsigned int order, gfp_t gfpflags)
+{
+}
+
static inline bool kmemcheck_page_is_tracked(struct page *p)
{
return false;
@@ -75,6 +82,22 @@ static inline void kmemcheck_mark_initialized(void *address, unsigned int n)
static inline void kmemcheck_mark_freed(void *address, unsigned int n)
{
}
+
+static inline void kmemcheck_mark_unallocated_pages(struct page *p,
+ unsigned int n)
+{
+}
+
+static inline void kmemcheck_mark_uninitialized_pages(struct page *p,
+ unsigned int n)
+{
+}
+
+static inline void kmemcheck_mark_initialized_pages(struct page *p,
+ unsigned int n)
+{
+}
+
#endif /* CONFIG_KMEMCHECK */
#endif /* LINUX_KMEMCHECK_H */
--
cgit v1.2.2
From fc7d0c9f2122e8bf58deaf1252b0e750df5b0e91 Mon Sep 17 00:00:00 2001
From: Vegard Nossum <vegard.nossum@gmail.com>
Date: Sat, 30 Aug 2008 12:16:05 +0200
Subject: kmemcheck: introduce bitfield API
Add the bitfield API which can be used to annotate bitfields in structs
and get rid of false positive reports.
According to Al Viro, the syntax we were using (putting #ifdef inside
macro arguments) was not valid C. He also suggested using begin/end
markers instead, which is what we do now.
[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
---
include/linux/kmemcheck.h | 50 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 50 insertions(+)
(limited to 'include/linux/kmemcheck.h')
diff --git a/include/linux/kmemcheck.h b/include/linux/kmemcheck.h
index 093d23969b1b..47b39b7c7e84 100644
--- a/include/linux/kmemcheck.h
+++ b/include/linux/kmemcheck.h
@@ -33,6 +33,7 @@ void kmemcheck_mark_initialized_pages(struct page *p, unsigned int n);
int kmemcheck_show_addr(unsigned long address);
int kmemcheck_hide_addr(unsigned long address);
+
#else
#define kmemcheck_enabled 0
@@ -100,4 +101,53 @@ static inline void kmemcheck_mark_initialized_pages(struct page *p,
#endif /* CONFIG_KMEMCHECK */
+/*
+ * Bitfield annotations
+ *
+ * How to use: If you have a struct using bitfields, for example
+ *
+ * struct a {
+ * int x:8, y:8;
+ * };
+ *
+ * then this should be rewritten as
+ *
+ * struct a {
+ * kmemcheck_bitfield_begin(flags);
+ * int x:8, y:8;
+ * kmemcheck_bitfield_end(flags);
+ * };
+ *
+ * Now the "flags_begin" and "flags_end" members may be used to refer to the
+ * beginning and end, respectively, of the bitfield (and things like
+ * &x.flags_begin is allowed). As soon as the struct is allocated, the bit-
+ * fields should be annotated:
+ *
+ * struct a *a = kmalloc(sizeof(struct a), GFP_KERNEL);
+ * kmemcheck_annotate_bitfield(a, flags);
+ *
+ * Note: We provide the same definitions for both kmemcheck and non-
+ * kmemcheck kernels. This makes it harder to introduce accidental errors. It
+ * is also allowed to pass NULL pointers to kmemcheck_annotate_bitfield().
+ */
+#define kmemcheck_bitfield_begin(name) \
+ int name##_begin[0];
+
+#define kmemcheck_bitfield_end(name) \
+ int name##_end[0];
+
+#define kmemcheck_annotate_bitfield(ptr, name) \
+ do if (ptr) { \
+ int _n = (long) &((ptr)->name##_end) \
+ - (long) &((ptr)->name##_begin); \
+ BUILD_BUG_ON(_n < 0); \
+ \
+ kmemcheck_mark_initialized(&((ptr)->name##_begin), _n); \
+ } while (0)
+
+#define kmemcheck_annotate_variable(var) \
+ do { \
+ kmemcheck_mark_initialized(&(var), sizeof(var)); \
+ } while (0) \
+
#endif /* LINUX_KMEMCHECK_H */
--
cgit v1.2.2