dma-buf: Release module reference on creation failure

[cascardo/linux.git] / drivers / dma-buf / dma-buf.c

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 4a2c07e..ddaee60 100644 (file)
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -33,6 +33,7 @@
 #include <linux/seq_file.h>
 #include <linux/poll.h>
 #include <linux/reservation.h>
+#include <linux/mm.h>
 
 #include <uapi/linux/dma-buf.h>
 
@@ -90,7 +91,7 @@ static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma)
        dmabuf = file->private_data;
 
        /* check for overflowing the buffer's size */
-       if (vma->vm_pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) >
+       if (vma->vm_pgoff + vma_pages(vma) >
            dmabuf->size >> PAGE_SHIFT)
                return -EINVAL;
 
@@ -333,6 +334,7 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
        struct reservation_object *resv = exp_info->resv;
        struct file *file;
        size_t alloc_size = sizeof(struct dma_buf);
+       int ret;
 
        if (!exp_info->resv)
                alloc_size += sizeof(struct reservation_object);
@@ -356,8 +358,8 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
 
        dmabuf = kzalloc(alloc_size, GFP_KERNEL);
        if (!dmabuf) {
-               module_put(exp_info->owner);
-               return ERR_PTR(-ENOMEM);
+               ret = -ENOMEM;
+               goto err_module;
        }
 
        dmabuf->priv = exp_info->priv;
@@ -378,8 +380,8 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
        file = anon_inode_getfile("dmabuf", &dma_buf_fops, dmabuf,
                                        exp_info->flags);
        if (IS_ERR(file)) {
-               kfree(dmabuf);
-               return ERR_CAST(file);
+               ret = PTR_ERR(file);
+               goto err_dmabuf;
        }
 
        file->f_mode |= FMODE_LSEEK;
@@ -393,6 +395,12 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
        mutex_unlock(&db_list.lock);
 
        return dmabuf;
+
+err_dmabuf:
+       kfree(dmabuf);
+err_module:
+       module_put(exp_info->owner);
+       return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(dma_buf_export);
 
@@ -723,11 +731,11 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
                return -EINVAL;
 
        /* check for offset overflow */
-       if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) < pgoff)
+       if (pgoff + vma_pages(vma) < pgoff)
                return -EOVERFLOW;
 
        /* check for overflowing the buffer's size */
-       if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) >
+       if (pgoff + vma_pages(vma) >
            dmabuf->size >> PAGE_SHIFT)
                return -EINVAL;
 
@@ -823,7 +831,7 @@ void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr)
 EXPORT_SYMBOL_GPL(dma_buf_vunmap);
 
 #ifdef CONFIG_DEBUG_FS
-static int dma_buf_describe(struct seq_file *s)
+static int dma_buf_debug_show(struct seq_file *s, void *unused)
 {
        int ret;
        struct dma_buf *buf_obj;
@@ -878,17 +886,9 @@ static int dma_buf_describe(struct seq_file *s)
        return 0;
 }
 
-static int dma_buf_show(struct seq_file *s, void *unused)
-{
-       void (*func)(struct seq_file *) = s->private;
-
-       func(s);
-       return 0;
-}
-
 static int dma_buf_debug_open(struct inode *inode, struct file *file)
 {
-       return single_open(file, dma_buf_show, inode->i_private);
+       return single_open(file, dma_buf_debug_show, NULL);
 }
 
 static const struct file_operations dma_buf_debug_fops = {
@@ -902,20 +902,23 @@ static struct dentry *dma_buf_debugfs_dir;
 
 static int dma_buf_init_debugfs(void)
 {
+       struct dentry *d;
        int err = 0;
 
-       dma_buf_debugfs_dir = debugfs_create_dir("dma_buf", NULL);
+       d = debugfs_create_dir("dma_buf", NULL);
+       if (IS_ERR(d))
+               return PTR_ERR(d);
 
-       if (IS_ERR(dma_buf_debugfs_dir)) {
-               err = PTR_ERR(dma_buf_debugfs_dir);
-               dma_buf_debugfs_dir = NULL;
-               return err;
-       }
-
-       err = dma_buf_debugfs_create_file("bufinfo", dma_buf_describe);
+       dma_buf_debugfs_dir = d;
 
-       if (err)
+       d = debugfs_create_file("bufinfo", S_IRUGO, dma_buf_debugfs_dir,
+                               NULL, &dma_buf_debug_fops);
+       if (IS_ERR(d)) {
                pr_debug("dma_buf: debugfs: failed to create node bufinfo\n");
+               debugfs_remove_recursive(dma_buf_debugfs_dir);
+               dma_buf_debugfs_dir = NULL;
+               err = PTR_ERR(d);
+       }
 
        return err;
 }
@@ -925,17 +928,6 @@ static void dma_buf_uninit_debugfs(void)
        if (dma_buf_debugfs_dir)
                debugfs_remove_recursive(dma_buf_debugfs_dir);
 }
-
-int dma_buf_debugfs_create_file(const char *name,
-                               int (*write)(struct seq_file *))
-{
-       struct dentry *d;
-
-       d = debugfs_create_file(name, S_IRUGO, dma_buf_debugfs_dir,
-                       write, &dma_buf_debug_fops);
-
-       return PTR_ERR_OR_ZERO(d);
-}
 #else
 static inline int dma_buf_init_debugfs(void)
 {