[PATCH] fix/simplify mutex debugging code

Let's switch mutex_debug_check_no_locks_freed() to take (addr, len) as
arguments instead, since all its callers were just calculating the 'to'
address for themselves anyway... (and sometimes doing so badly).

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

7 files changed, 9 insertions, 8 deletions

diff --git a/arch/i386/mm/pageattr.c b/arch/i386/mm/pageattr.c
index e8a53552b13d..d0cadb33b54c 100644
--- a/arch/i386/mm/pageattr.c
+++ b/arch/i386/mm/pageattr.c
@@ -224,7 +224,7 @@ void kernel_map_pages(struct page *page, int numpages, int enable)
                 return;
         if (!enable)
                 mutex_debug_check_no_locks_freed(page_address(page),
-                                                 page_address(page+numpages));
+                                                 numpages * PAGE_SIZE);
 
         /* the return value is ignored - the calls cannot fail,
          * large pages are disabled at boot time.
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 3f1fafc0245e..e53d2c6fd5f4 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1027,7 +1027,7 @@ kernel_map_pages(struct page *page, int numpages, int enable)
 {
         if (!PageHighMem(page) && !enable)
                 mutex_debug_check_no_locks_freed(page_address(page),
-                                                 page_address(page + numpages));
+                                                 numpages * PAGE_SIZE);
 }
 #endif
 
diff --git a/include/linux/mutex-debug.h b/include/linux/mutex-debug.h
index 8138d9eb58ec..8b5769f00467 100644
--- a/include/linux/mutex-debug.h
+++ b/include/linux/mutex-debug.h
@@ -18,6 +18,6 @@ extern void FASTCALL(mutex_destroy(struct mutex *lock));
 extern void mutex_debug_show_all_locks(void);
 extern void mutex_debug_show_held_locks(struct task_struct *filter);
 extern void mutex_debug_check_no_locks_held(struct task_struct *task);
-extern void mutex_debug_check_no_locks_freed(const void *from, const void *to);
+extern void mutex_debug_check_no_locks_freed(const void *from, unsigned long len);
 
 #endif
diff --git a/include/linux/mutex.h b/include/linux/mutex.h
index f1c84b1252f5..f1ac507fa20d 100644
--- a/include/linux/mutex.h
+++ b/include/linux/mutex.h
@@ -79,7 +79,7 @@ struct mutex_waiter {
 # define mutex_debug_show_all_locks()                   do { } while (0)
 # define mutex_debug_show_held_locks(p)                 do { } while (0)
 # define mutex_debug_check_no_locks_held(task)          do { } while (0)
-# define mutex_debug_check_no_locks_freed(from, to)     do { } while (0)
+# define mutex_debug_check_no_locks_freed(from, len)    do { } while (0)
 #endif
 
 #define __MUTEX_INITIALIZER(lockname) \
diff --git a/kernel/mutex-debug.c b/kernel/mutex-debug.c
index 6f829058ae4a..f4913c376950 100644
--- a/kernel/mutex-debug.c
+++ b/kernel/mutex-debug.c
@@ -333,9 +333,10 @@ void mutex_debug_check_no_locks_held(struct task_struct *task)
  * is destroyed or reinitialized - this code checks whether there is
  * any held lock in the memory range of <from> to <to>:
  */
-void mutex_debug_check_no_locks_freed(const void *from, const void *to)
+void mutex_debug_check_no_locks_freed(const void *from, unsigned long len)
 {
         struct list_head *curr, *next;
+        const void *to = from + len;
         unsigned long flags;
         struct mutex *lock;
         void *lock_addr;
@@ -437,7 +438,7 @@ void debug_mutex_init(struct mutex *lock, const char *name)
         /*
          * Make sure we are not reinitializing a held lock:
          */
-        mutex_debug_check_no_locks_freed((void *)lock, (void *)(lock + 1));
+        mutex_debug_check_no_locks_freed((void *)lock, sizeof(*lock));
         lock->owner = NULL;
         INIT_LIST_HEAD(&lock->held_list);
         lock->name = name;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index a5e6891f7bb6..8e363536e2da 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -417,7 +417,7 @@ static void __free_pages_ok(struct page *page, unsigned int order)
         arch_free_page(page, order);
         if (!PageHighMem(page))
                 mutex_debug_check_no_locks_freed(page_address(page),
-                        page_address(page+(1<<order)));
+                                                 PAGE_SIZE<<order);
 
 #ifndef CONFIG_MMU
         for (i = 1 ; i < (1 << order) ; ++i)
diff --git a/mm/slab.c b/mm/slab.c
index 33aab345cd4a..9374293a3012 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3071,7 +3071,7 @@ void kfree(const void *objp)
         local_irq_save(flags);
         kfree_debugcheck(objp);
         c = page_get_cache(virt_to_page(objp));
-        mutex_debug_check_no_locks_freed(objp, objp+obj_reallen(c));
+        mutex_debug_check_no_locks_freed(objp, obj_reallen(c));
         __cache_free(c, (void *)objp);
         local_irq_restore(flags);
 }