If a spinlock is scribbled on with 0x6b then it becomes "unlocked". I'd
prefer that a scribbed-on lock be treated as locked, so things get stuck
earlier.
So make sure that all the slab poisoning values are negative.
include/linux/sched.h | 2 +-
mm/slab.c | 12 ++++++------
2 files changed, 7 insertions(+), 7 deletions(-)
diff -puN mm/slab.c~slab-scribble-negative mm/slab.c
--- 25/mm/slab.c~slab-scribble-negative 2003-05-26 23:03:18.000000000 -0700
+++ 25-akpm/mm/slab.c 2003-05-26 23:08:27.000000000 -0700
@@ -344,8 +344,8 @@ struct kmem_cache_s {
#define RED_ACTIVE 0x170FC2A5UL /* when obj is active */
/* ...and for poisoning */
-#define POISON_BEFORE 0x5a /* for use-uninitialised poisoning */
-#define POISON_AFTER 0x6b /* for use-after-free poisoning */
+#define POISON_BEFORE 0x8a /* for use-uninitialised poisoning */
+#define POISON_AFTER 0x9b /* for use-after-free poisoning */
#define POISON_END 0xa5 /* end-byte of poisoning */
#endif
@@ -871,9 +871,9 @@ static void check_poison_obj(kmem_cache_
}
printk(KERN_ERR "Data: ");
for (s = 0; s < size; s++) {
- if (((char*)addr)[s] == POISON_BEFORE)
+ if (((unsigned char*)addr)[s] == POISON_BEFORE)
printk(".");
- else if (((char*)addr)[s] == POISON_AFTER)
+ else if (((unsigned char*)addr)[s] == POISON_AFTER)
printk("*");
else
printk("%02X ", ((unsigned char*)addr)[s]);
@@ -881,9 +881,9 @@ static void check_poison_obj(kmem_cache_
printk("\n");
printk(KERN_ERR "Next: ");
for (; s < size + 32; s++) {
- if (((char*)addr)[s] == POISON_BEFORE)
+ if (((unsigned char*)addr)[s] == POISON_BEFORE)
printk(".");
- else if (((char*)addr)[s] == POISON_AFTER)
+ else if (((unsigned char*)addr)[s] == POISON_AFTER)
printk("*");
else
printk("%02X ", ((unsigned char*)addr)[s]);
diff -puN include/linux/sched.h~slab-scribble-negative include/linux/sched.h
--- 25/include/linux/sched.h~slab-scribble-negative 2003-05-26 23:03:18.000000000 -0700
+++ 25-akpm/include/linux/sched.h 2003-05-26 23:07:47.000000000 -0700
@@ -463,7 +463,7 @@ extern void __put_task_struct(struct tas
#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
#define put_task_struct(tsk) \
do { \
- BUG_ON((tsk)->debug == 0x6b6b6b6b); \
+ BUG_ON((tsk)->debug == 0x9b9b9b9b); \
if (atomic_dec_and_test(&(tsk)->usage)) \
__put_task_struct(tsk); \
} while (0)
_