1 files changed, 43 insertions, 0 deletions

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 3b4a695051b6..82499a5bdcb7 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -552,6 +552,41 @@ int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
 }
 EXPORT_SYMBOL_GPL(blk_trace_setup);
 
+#if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
+static int compat_blk_trace_setup(struct request_queue *q, char *name,
+                                  dev_t dev, struct block_device *bdev,
+                                  char __user *arg)
+{
+        struct blk_user_trace_setup buts;
+        struct compat_blk_user_trace_setup cbuts;
+        int ret;
+
+        if (copy_from_user(&cbuts, arg, sizeof(cbuts)))
+                return -EFAULT;
+
+        buts = (struct blk_user_trace_setup) {
+                .act_mask = cbuts.act_mask,
+                .buf_size = cbuts.buf_size,
+                .buf_nr = cbuts.buf_nr,
+                .start_lba = cbuts.start_lba,
+                .end_lba = cbuts.end_lba,
+                .pid = cbuts.pid,
+        };
+        memcpy(&buts.name, &cbuts.name, 32);
+
+        ret = do_blk_trace_setup(q, name, dev, bdev, &buts);
+        if (ret)
+                return ret;
+
+        if (copy_to_user(arg, &buts.name, 32)) {
+                blk_trace_remove(q);
+                return -EFAULT;
+        }
+
+        return 0;
+}
+#endif
+
 int blk_trace_startstop(struct request_queue *q, int start)
 {
         int ret;
@@ -604,6 +639,7 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
         if (!q)
                 return -ENXIO;
 
+        lock_kernel();
         mutex_lock(&bdev->bd_mutex);
 
         switch (cmd) {
@@ -611,6 +647,12 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
                 bdevname(bdev, b);
                 ret = blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
                 break;
+#if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
+        case BLKTRACESETUP32:
+                bdevname(bdev, b);
+                ret = compat_blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
+                break;
+#endif
         case BLKTRACESTART:
                 start = 1;
         case BLKTRACESTOP:
@@ -625,6 +667,7 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
         }
 
         mutex_unlock(&bdev->bd_mutex);
+        unlock_kernel();
         return ret;
 }