1 files changed, 107 insertions, 36 deletions

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index edaa9e4ee4ae..77555096e4c7 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -33,7 +33,31 @@
 #include <uapi/linux/dma-buf.h>
 #include <uapi/linux/magic.h>
 
-#include "dma-buf-sysfs-stats.h"
+#define CREATE_TRACE_POINTS
+#include <trace/events/dma_buf.h>
+
+/*
+ * dmabuf->name must be accessed with holding dmabuf->name_lock.
+ * we need to take the lock around the tracepoint call itself where
+ * it is called in the code.
+ *
+ * Note: FUNC##_enabled() is a static branch that will only
+ *       be set when the trace event is enabled.
+ */
+#define DMA_BUF_TRACE(FUNC, ...)					\
+	do {								\
+		/* Always expose lock if lockdep is enabled */		\
+		if (IS_ENABLED(CONFIG_LOCKDEP) || FUNC##_enabled()) {	\
+			guard(spinlock)(&dmabuf->name_lock);		\
+			FUNC(__VA_ARGS__);				\
+		}							\
+	} while (0)
+
+/* Wrapper to hide the sg_table page link from the importer */
+struct dma_buf_sg_table_wrapper {
+	struct sg_table *original;
+	struct sg_table wrapper;
+};
 
 static inline int is_dma_buf_file(struct file *);
 
@@ -156,7 +180,6 @@ static void dma_buf_release(struct dentry *dentry)
 	 */
 	BUG_ON(dmabuf->cb_in.active || dmabuf->cb_out.active);
 
-	dma_buf_stats_teardown(dmabuf);
 	dmabuf->ops->release(dmabuf);
 
 	if (dmabuf->resv == (struct dma_resv *)&dmabuf[1])
@@ -220,6 +243,8 @@ static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma)
 	    dmabuf->size >> PAGE_SHIFT)
 		return -EINVAL;
 
+	DMA_BUF_TRACE(trace_dma_buf_mmap_internal, dmabuf);
+
 	return dmabuf->ops->mmap(dmabuf, vma);
 }
 
@@ -735,22 +760,16 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
 		dmabuf->resv = resv;
 	}
 
-	ret = dma_buf_stats_setup(dmabuf, file);
-	if (ret)
-		goto err_dmabuf;
-
 	file->private_data = dmabuf;
 	file->f_path.dentry->d_fsdata = dmabuf;
 	dmabuf->file = file;
 
 	__dma_buf_list_add(dmabuf);
 
+	DMA_BUF_TRACE(trace_dma_buf_export, dmabuf);
+
 	return dmabuf;
 
-err_dmabuf:
-	if (!resv)
-		dma_resv_fini(dmabuf->resv);
-	kfree(dmabuf);
 err_file:
 	fput(file);
 err_module:
@@ -768,10 +787,15 @@ EXPORT_SYMBOL_NS_GPL(dma_buf_export, "DMA_BUF");
  */
 int dma_buf_fd(struct dma_buf *dmabuf, int flags)
 {
+	int fd;
+
 	if (!dmabuf || !dmabuf->file)
 		return -EINVAL;
 
-	return FD_ADD(flags, dmabuf->file);
+	fd = FD_ADD(flags, dmabuf->file);
+	DMA_BUF_TRACE(trace_dma_buf_fd, dmabuf, fd);
+
+	return fd;
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_fd, "DMA_BUF");
 
@@ -786,6 +810,7 @@ EXPORT_SYMBOL_NS_GPL(dma_buf_fd, "DMA_BUF");
 struct dma_buf *dma_buf_get(int fd)
 {
 	struct file *file;
+	struct dma_buf *dmabuf;
 
 	file = fget(fd);
 
@@ -797,7 +822,11 @@ struct dma_buf *dma_buf_get(int fd)
 		return ERR_PTR(-EINVAL);
 	}
 
-	return file->private_data;
+	dmabuf = file->private_data;
+
+	DMA_BUF_TRACE(trace_dma_buf_get, dmabuf, fd);
+
+	return dmabuf;
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_get, "DMA_BUF");
 
@@ -817,24 +846,64 @@ void dma_buf_put(struct dma_buf *dmabuf)
 		return;
 
 	fput(dmabuf->file);
+
+	DMA_BUF_TRACE(trace_dma_buf_put, dmabuf);
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_put, "DMA_BUF");
 
-static void mangle_sg_table(struct sg_table *sg_table)
+static int dma_buf_wrap_sg_table(struct sg_table **sg_table)
 {
-#ifdef CONFIG_DMABUF_DEBUG
-	int i;
-	struct scatterlist *sg;
-
-	/* To catch abuse of the underlying struct page by importers mix
-	 * up the bits, but take care to preserve the low SG_ bits to
-	 * not corrupt the sgt. The mixing is undone on unmap
-	 * before passing the sgt back to the exporter.
+	struct scatterlist *to_sg, *from_sg;
+	struct sg_table *from = *sg_table;
+	struct dma_buf_sg_table_wrapper *to;
+	int i, ret;
+
+	if (!IS_ENABLED(CONFIG_DMABUF_DEBUG))
+		return 0;
+
+	/*
+	 * To catch abuse of the underlying struct page by importers copy the
+	 * sg_table without copying the page_link and give only the copy back to
+	 * the importer.
 	 */
-	for_each_sgtable_sg(sg_table, sg, i)
-		sg->page_link ^= ~0xffUL;
-#endif
+	to = kzalloc(sizeof(*to), GFP_KERNEL);
+	if (!to)
+		return -ENOMEM;
+
+	ret = sg_alloc_table(&to->wrapper, from->nents, GFP_KERNEL);
+	if (ret)
+		goto free_to;
+
+	to_sg = to->wrapper.sgl;
+	for_each_sgtable_dma_sg(from, from_sg, i) {
+		to_sg->offset = 0;
+		to_sg->length = 0;
+		sg_assign_page(to_sg, NULL);
+		sg_dma_address(to_sg) = sg_dma_address(from_sg);
+		sg_dma_len(to_sg) = sg_dma_len(from_sg);
+		to_sg = sg_next(to_sg);
+	}
+
+	to->original = from;
+	*sg_table = &to->wrapper;
+	return 0;
 
+free_to:
+	kfree(to);
+	return ret;
+}
+
+static void dma_buf_unwrap_sg_table(struct sg_table **sg_table)
+{
+	struct dma_buf_sg_table_wrapper *copy;
+
+	if (!IS_ENABLED(CONFIG_DMABUF_DEBUG))
+		return;
+
+	copy = container_of(*sg_table, typeof(*copy), wrapper);
+	*sg_table = copy->original;
+	sg_free_table(&copy->wrapper);
+	kfree(copy);
 }
 
 static inline bool
@@ -971,6 +1040,9 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
 	list_add(&attach->node, &dmabuf->attachments);
 	dma_resv_unlock(dmabuf->resv);
 
+	DMA_BUF_TRACE(trace_dma_buf_dynamic_attach, dmabuf, attach,
+		dma_buf_attachment_is_dynamic(attach), dev);
+
 	return attach;
 
 err_attach:
@@ -1015,6 +1087,9 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach)
 	if (dmabuf->ops->detach)
 		dmabuf->ops->detach(dmabuf, attach);
 
+	DMA_BUF_TRACE(trace_dma_buf_detach, dmabuf, attach,
+		dma_buf_attachment_is_dynamic(attach), attach->dev);
+
 	kfree(attach);
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_detach, "DMA_BUF");
@@ -1131,10 +1206,11 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
 		if (ret < 0)
 			goto error_unmap;
 	}
-	mangle_sg_table(sg_table);
+	ret = dma_buf_wrap_sg_table(&sg_table);
+	if (ret)
+		goto error_unmap;
 
-#ifdef CONFIG_DMA_API_DEBUG
-	{
+	if (IS_ENABLED(CONFIG_DMA_API_DEBUG)) {
 		struct scatterlist *sg;
 		u64 addr;
 		int len;
@@ -1146,10 +1222,10 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
 			if (!PAGE_ALIGNED(addr) || !PAGE_ALIGNED(len)) {
 				pr_debug("%s: addr %llx or len %x is not page aligned!\n",
 					 __func__, addr, len);
+				break;
 			}
 		}
 	}
-#endif /* CONFIG_DMA_API_DEBUG */
 	return sg_table;
 
 error_unmap:
@@ -1213,7 +1289,7 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach,
 
 	dma_resv_assert_held(attach->dmabuf->resv);
 
-	mangle_sg_table(sg_table);
+	dma_buf_unwrap_sg_table(&sg_table);
 	attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, direction);
 
 	if (dma_buf_pin_on_map(attach))
@@ -1480,6 +1556,8 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
 	vma_set_file(vma, dmabuf->file);
 	vma->vm_pgoff = pgoff;
 
+	DMA_BUF_TRACE(trace_dma_buf_mmap, dmabuf);
+
 	return dmabuf->ops->mmap(dmabuf, vma);
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_mmap, "DMA_BUF");
@@ -1710,12 +1788,6 @@ static inline void dma_buf_uninit_debugfs(void)
 
 static int __init dma_buf_init(void)
 {
-	int ret;
-
-	ret = dma_buf_init_sysfs_statistics();
-	if (ret)
-		return ret;
-
 	dma_buf_mnt = kern_mount(&dma_buf_fs_type);
 	if (IS_ERR(dma_buf_mnt))
 		return PTR_ERR(dma_buf_mnt);
@@ -1729,6 +1801,5 @@ static void __exit dma_buf_deinit(void)
 {
 	dma_buf_uninit_debugfs();
 	kern_unmount(dma_buf_mnt);
-	dma_buf_uninit_sysfs_statistics();
 }
 __exitcall(dma_buf_deinit);