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authorVegard Nossum <vegard.nossum@gmail.com>2008-05-31 15:56:17 +0200
committerVegard Nossum <vegard.nossum@gmail.com>2009-06-15 12:40:03 +0200
commit2dff440525f8faba8836e9f05297b76f23b4af30 (patch)
tree9f15e1dc2da06dba97cd939e41f34342caf05097 /include/linux/slab.h
parentf85612967c93b67b10dd240e3e8bf8a0eee9def7 (diff)
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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>
Diffstat (limited to 'include/linux/slab.h')
-rw-r--r--include/linux/slab.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 4880306..e339fcf 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -64,6 +64,13 @@
#define SLAB_NOLEAKTRACE 0x00800000UL /* Avoid kmemleak tracing */
+/* Don't track use of uninitialized memory */
+#ifdef CONFIG_KMEMCHECK
+# define SLAB_NOTRACK 0x01000000UL
+#else
+# define SLAB_NOTRACK 0x00000000UL
+#endif
+
/* The following flags affect the page allocator grouping pages by mobility */
#define SLAB_RECLAIM_ACCOUNT 0x00020000UL /* Objects are reclaimable */
#define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */