[PATCH] add poison.h and patch primary users

Localize poison values into one header file for better documentation and
easier/quicker debugging and so that the same values won't be used for
multiple purposes.

Use these constants in core arch., mm, driver, and fs code.

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Matt Mackall <mpm@selenic.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 45 insertions, 0 deletions

diff --git a/include/linux/poison.h b/include/linux/poison.h
new file mode 100644
index 000000000000..d536de7dd825
--- /dev/null
+++ b/include/linux/poison.h
@@ -0,0 +1,45 @@
+#ifndef _LINUX_POISON_H
+#define _LINUX_POISON_H
+
+/********** include/linux/list.h **********/
+/*
+ * These are non-NULL pointers that will result in page faults
+ * under normal circumstances, used to verify that nobody uses
+ * non-initialized list entries.
+ */
+#define LIST_POISON1  ((void *) 0x00100100)
+#define LIST_POISON2  ((void *) 0x00200200)
+
+/********** mm/slab.c **********/
+/*
+ * Magic nums for obj red zoning.
+ * Placed in the first word before and the first word after an obj.
+ */
+#define RED_INACTIVE    0x5A2CF071UL    /* when obj is inactive */
+#define RED_ACTIVE      0x170FC2A5UL    /* when obj is active */
+
+/* ...and for poisoning */
+#define POISON_INUSE    0x5a    /* for use-uninitialised poisoning */
+#define POISON_FREE     0x6b    /* for use-after-free poisoning */
+#define POISON_END      0xa5    /* end-byte of poisoning */
+
+/********** arch/$ARCH/mm/init.c **********/
+#define POISON_FREE_INITMEM     0xcc
+
+/********** arch/x86_64/mm/init.c **********/
+#define POISON_FREE_INITDATA    0xba
+
+/********** arch/ia64/hp/common/sba_iommu.c **********/
+/*
+ * arch/ia64/hp/common/sba_iommu.c uses a 16-byte poison string with a
+ * value of "SBAIOMMU POISON\0" for spill-over poisoning.
+ */
+
+/********** fs/jbd/journal.c **********/
+#define JBD_POISON_FREE 0x5b
+
+/********** drivers/base/dmapool.c **********/
+#define POOL_POISON_FREED       0xa7    /* !inuse */
+#define POOL_POISON_ALLOCATED   0xa9    /* !initted */
+
+#endif