1 files changed, 29 insertions, 25 deletions

diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index 3b93129a968c..58a9f9fc609a 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -156,9 +156,13 @@ static bool driver_filter(struct device *dev)
                 return true;
 
         /* driver filter on and initialized */
-        if (current_driver && dev->driver == current_driver)
+        if (current_driver && dev && dev->driver == current_driver)
                 return true;
 
+        /* driver filter on, but we can't filter on a NULL device... */
+        if (!dev)
+                return false;
+
         if (current_driver || !current_driver_name[0])
                 return false;
 
@@ -183,17 +187,17 @@ static bool driver_filter(struct device *dev)
         return ret;
 }
 
-#define err_printk(dev, entry, format, arg...) do {             \
-                error_count += 1;                               \
-                if (driver_filter(dev) &&                       \
-                    (show_all_errors || show_num_errors > 0)) { \
-                        WARN(1, "%s %s: " format,               \
-                             dev_driver_string(dev),            \
-                             dev_name(dev) , ## arg);           \
-                        dump_entry_trace(entry);                \
-                }                                               \
-                if (!show_all_errors && show_num_errors > 0)    \
-                        show_num_errors -= 1;                   \
+#define err_printk(dev, entry, format, arg...) do {                     \
+                error_count += 1;                                       \
+                if (driver_filter(dev) &&                               \
+                    (show_all_errors || show_num_errors > 0)) {         \
+                        WARN(1, "%s %s: " format,                       \
+                             dev ? dev_driver_string(dev) : "NULL",     \
+                             dev ? dev_name(dev) : "NULL", ## arg);     \
+                        dump_entry_trace(entry);                        \
+                }                                                       \
+                if (!show_all_errors && show_num_errors > 0)            \
+                        show_num_errors -= 1;                           \
         } while (0);
 
 /*
@@ -716,7 +720,7 @@ void dma_debug_init(u32 num_entries)
 
         for (i = 0; i < HASH_SIZE; ++i) {
                 INIT_LIST_HEAD(&dma_entry_hash[i].list);
-                dma_entry_hash[i].lock = SPIN_LOCK_UNLOCKED;
+                spin_lock_init(&dma_entry_hash[i].lock);
         }
 
         if (dma_debug_fs_init() != 0) {
@@ -856,22 +860,21 @@ static void check_for_stack(struct device *dev, void *addr)
                                 "stack [addr=%p]\n", addr);
 }
 
-static inline bool overlap(void *addr, u64 size, void *start, void *end)
+static inline bool overlap(void *addr, unsigned long len, void *start, void *end)
 {
-        void *addr2 = (char *)addr + size;
+        unsigned long a1 = (unsigned long)addr;
+        unsigned long b1 = a1 + len;
+        unsigned long a2 = (unsigned long)start;
+        unsigned long b2 = (unsigned long)end;
 
-        return ((addr >= start && addr < end) ||
-                (addr2 >= start && addr2 < end) ||
-                ((addr < start) && (addr2 >= end)));
+        return !(b1 <= a2 || a1 >= b2);
 }
 
-static void check_for_illegal_area(struct device *dev, void *addr, u64 size)
+static void check_for_illegal_area(struct device *dev, void *addr, unsigned long len)
 {
-        if (overlap(addr, size, _text, _etext) ||
-            overlap(addr, size, __start_rodata, __end_rodata))
-                err_printk(dev, NULL, "DMA-API: device driver maps "
-                                "memory from kernel text or rodata "
-                                "[addr=%p] [size=%llu]\n", addr, size);
+        if (overlap(addr, len, _text, _etext) ||
+            overlap(addr, len, __start_rodata, __end_rodata))
+                err_printk(dev, NULL, "DMA-API: device driver maps memory from kernel text or rodata [addr=%p] [len=%lu]\n", addr, len);
 }
 
 static void check_sync(struct device *dev,
@@ -969,7 +972,8 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
                 entry->type = dma_debug_single;
 
         if (!PageHighMem(page)) {
-                void *addr = ((char *)page_address(page)) + offset;
+                void *addr = page_address(page) + offset;
+
                 check_for_stack(dev, addr);
                 check_for_illegal_area(dev, addr, size);
         }