[RFC PATCH 48/60] hyper_dmabuf: add query items for buffer private info.

From: Dongwon Kim
Date: Tue Dec 19 2017 - 14:40:51 EST


From: Mateusz Polrola <mateuszx.potrola@xxxxxxxxx>

This change adds two query items, 'HYPER_DMABUF_QUERY_PRIV_INFO_SIZE'
and 'HYPER_DMABUF_QUERY_PRIV_INFO', for retrieving buffer's private
info and its size.

'info' is an address of user-space buffer (user application provides
this) ,where private data will be copied in case query item is
'HYPER_DMABUF_QUERY_PRIV_INFO'.

Signed-off-by: Dongwon Kim <dongwon.kim@xxxxxxxxx>
---
drivers/xen/hyper_dmabuf/hyper_dmabuf_drv.c | 7 +-
drivers/xen/hyper_dmabuf/hyper_dmabuf_event.c | 6 ++
drivers/xen/hyper_dmabuf/hyper_dmabuf_ioctl.c | 12 ++--
drivers/xen/hyper_dmabuf/hyper_dmabuf_query.c | 97 +++++++++++++++++++++------
drivers/xen/hyper_dmabuf/hyper_dmabuf_query.h | 6 +-
include/uapi/xen/hyper_dmabuf.h | 4 +-
6 files changed, 100 insertions(+), 32 deletions(-)

diff --git a/drivers/xen/hyper_dmabuf/hyper_dmabuf_drv.c b/drivers/xen/hyper_dmabuf/hyper_dmabuf_drv.c
index 87ea6ca..1c35a59 100644
--- a/drivers/xen/hyper_dmabuf/hyper_dmabuf_drv.c
+++ b/drivers/xen/hyper_dmabuf/hyper_dmabuf_drv.c
@@ -168,8 +168,11 @@ ssize_t hyper_dmabuf_event_read(struct file *filp, char __user *buffer,
ret -= sizeof(struct hyper_dmabuf_event_hdr);

/* nullifying hdr of the event in user buffer */
- copy_to_user(buffer + ret, &dummy_hdr,
- sizeof(dummy_hdr));
+ if (copy_to_user(buffer + ret, &dummy_hdr,
+ sizeof(dummy_hdr))) {
+ dev_err(hyper_dmabuf_private.device,
+ "failed to nullify invalid hdr already in userspace\n");
+ }

ret = -EFAULT;

diff --git a/drivers/xen/hyper_dmabuf/hyper_dmabuf_event.c b/drivers/xen/hyper_dmabuf/hyper_dmabuf_event.c
index 8998a7d..3e1498c 100644
--- a/drivers/xen/hyper_dmabuf/hyper_dmabuf_event.c
+++ b/drivers/xen/hyper_dmabuf/hyper_dmabuf_event.c
@@ -104,6 +104,12 @@ int hyper_dmabuf_import_event(hyper_dmabuf_id_t hid)

e = kzalloc(sizeof(*e), GFP_KERNEL);

+ if (!e) {
+ dev_err(hyper_dmabuf_private.device,
+ "no space left\n");
+ return -ENOMEM;
+ }
+
e->event_data.hdr.event_type = HYPER_DMABUF_NEW_IMPORT;
e->event_data.hdr.hid = hid;
e->event_data.data = (void*)imported_sgt_info->priv;
diff --git a/drivers/xen/hyper_dmabuf/hyper_dmabuf_ioctl.c b/drivers/xen/hyper_dmabuf/hyper_dmabuf_ioctl.c
index 06f95ca..15191c2 100644
--- a/drivers/xen/hyper_dmabuf/hyper_dmabuf_ioctl.c
+++ b/drivers/xen/hyper_dmabuf/hyper_dmabuf_ioctl.c
@@ -671,9 +671,8 @@ static int hyper_dmabuf_query_ioctl(struct file *filp, void *data)
/* query for exported dmabuf */
sgt_info = hyper_dmabuf_find_exported(query_attr->hid);
if (sgt_info) {
- ret = hyper_dmabuf_query_exported(sgt_info, query_attr->item);
- if (ret != -EINVAL)
- query_attr->info = ret;
+ ret = hyper_dmabuf_query_exported(sgt_info,
+ query_attr->item, &query_attr->info);
} else {
dev_err(hyper_dmabuf_private.device,
"DMA BUF {id:%d key:%d %d %d} can't be found in the export list\n",
@@ -685,9 +684,8 @@ static int hyper_dmabuf_query_ioctl(struct file *filp, void *data)
/* query for imported dmabuf */
imported_sgt_info = hyper_dmabuf_find_imported(query_attr->hid);
if (imported_sgt_info) {
- ret = hyper_dmabuf_query_imported(imported_sgt_info, query_attr->item);
- if (ret != -EINVAL)
- query_attr->info = ret;
+ ret = hyper_dmabuf_query_imported(imported_sgt_info,
+ query_attr->item, &query_attr->info);
} else {
dev_err(hyper_dmabuf_private.device,
"DMA BUF {id:%d key:%d %d %d} can't be found in the imported list\n",
@@ -697,7 +695,7 @@ static int hyper_dmabuf_query_ioctl(struct file *filp, void *data)
}
}

- return 0;
+ return ret;
}

void hyper_dmabuf_emergency_release(struct hyper_dmabuf_sgt_info* sgt_info,
diff --git a/drivers/xen/hyper_dmabuf/hyper_dmabuf_query.c b/drivers/xen/hyper_dmabuf/hyper_dmabuf_query.c
index 2a5201b..39c9dee 100644
--- a/drivers/xen/hyper_dmabuf/hyper_dmabuf_query.c
+++ b/drivers/xen/hyper_dmabuf/hyper_dmabuf_query.c
@@ -27,6 +27,7 @@
*/

#include <linux/dma-buf.h>
+#include <linux/uaccess.h>
#include "hyper_dmabuf_drv.h"
#include "hyper_dmabuf_struct.h"
#include "hyper_dmabuf_id.h"
@@ -36,56 +37,91 @@ extern struct hyper_dmabuf_private hyper_dmabuf_private;
#define HYPER_DMABUF_SIZE(nents, first_offset, last_len) \
((nents)*PAGE_SIZE - (first_offset) - PAGE_SIZE + (last_len))

-int hyper_dmabuf_query_exported(struct hyper_dmabuf_sgt_info *sgt_info, int query)
+int hyper_dmabuf_query_exported(struct hyper_dmabuf_sgt_info *sgt_info,
+ int query, unsigned long* info)
{
+ int n;
+
switch (query)
{
case HYPER_DMABUF_QUERY_TYPE:
- return EXPORTED;
+ *info = EXPORTED;
+ break;

/* exporting domain of this specific dmabuf*/
case HYPER_DMABUF_QUERY_EXPORTER:
- return HYPER_DMABUF_DOM_ID(sgt_info->hid);
+ *info = HYPER_DMABUF_DOM_ID(sgt_info->hid);
+ break;

/* importing domain of this specific dmabuf */
case HYPER_DMABUF_QUERY_IMPORTER:
- return sgt_info->hyper_dmabuf_rdomain;
+ *info = sgt_info->hyper_dmabuf_rdomain;
+ break;

/* size of dmabuf in byte */
case HYPER_DMABUF_QUERY_SIZE:
- return sgt_info->dma_buf->size;
+ *info = sgt_info->dma_buf->size;
+ break;

/* whether the buffer is used by importer */
case HYPER_DMABUF_QUERY_BUSY:
- return (sgt_info->importer_exported == 0) ? false : true;
+ *info = (sgt_info->importer_exported == 0) ? false : true;
+ break;

/* whether the buffer is unexported */
case HYPER_DMABUF_QUERY_UNEXPORTED:
- return !sgt_info->valid;
+ *info = !sgt_info->valid;
+ break;

/* whether the buffer is scheduled to be unexported */
case HYPER_DMABUF_QUERY_DELAYED_UNEXPORTED:
- return !sgt_info->unexport_scheduled;
+ *info = !sgt_info->unexport_scheduled;
+ break;
+
+ /* size of private info attached to buffer */
+ case HYPER_DMABUF_QUERY_PRIV_INFO_SIZE:
+ *info = sgt_info->sz_priv;
+ break;
+
+ /* copy private info attached to buffer */
+ case HYPER_DMABUF_QUERY_PRIV_INFO:
+ if (sgt_info->sz_priv > 0) {
+ n = copy_to_user((void __user*) *info,
+ sgt_info->priv,
+ sgt_info->sz_priv);
+ if (n != 0)
+ return -EINVAL;
+ }
+ break;
+
+ default:
+ return -EINVAL;
}

- return -EINVAL;
+ return 0;
}


-int hyper_dmabuf_query_imported(struct hyper_dmabuf_imported_sgt_info *imported_sgt_info, int query)
+int hyper_dmabuf_query_imported(struct hyper_dmabuf_imported_sgt_info *imported_sgt_info,
+ int query, unsigned long *info)
{
+ int n;
+
switch (query)
{
case HYPER_DMABUF_QUERY_TYPE:
- return IMPORTED;
+ *info = IMPORTED;
+ break;

/* exporting domain of this specific dmabuf*/
case HYPER_DMABUF_QUERY_EXPORTER:
- return HYPER_DMABUF_DOM_ID(imported_sgt_info->hid);
+ *info = HYPER_DMABUF_DOM_ID(imported_sgt_info->hid);
+ break;

/* importing domain of this specific dmabuf */
case HYPER_DMABUF_QUERY_IMPORTER:
- return hyper_dmabuf_private.domid;
+ *info = hyper_dmabuf_private.domid;
+ break;

/* size of dmabuf in byte */
case HYPER_DMABUF_QUERY_SIZE:
@@ -93,23 +129,44 @@ int hyper_dmabuf_query_imported(struct hyper_dmabuf_imported_sgt_info *imported_
/* if local dma_buf is created (if it's ever mapped),
* retrieve it directly from struct dma_buf *
*/
- return imported_sgt_info->dma_buf->size;
+ *info = imported_sgt_info->dma_buf->size;
} else {
/* calcuate it from given nents, frst_ofst and last_len */
- return HYPER_DMABUF_SIZE(imported_sgt_info->nents,
- imported_sgt_info->frst_ofst,
- imported_sgt_info->last_len);
+ *info = HYPER_DMABUF_SIZE(imported_sgt_info->nents,
+ imported_sgt_info->frst_ofst,
+ imported_sgt_info->last_len);
}
+ break;

/* whether the buffer is used or not */
case HYPER_DMABUF_QUERY_BUSY:
/* checks if it's used by importer */
- return (imported_sgt_info->num_importers > 0) ? true : false;
+ *info = (imported_sgt_info->num_importers > 0) ? true : false;
+ break;

/* whether the buffer is unexported */
case HYPER_DMABUF_QUERY_UNEXPORTED:
- return !imported_sgt_info->valid;
+ *info = !imported_sgt_info->valid;
+ break;
+ /* size of private info attached to buffer */
+ case HYPER_DMABUF_QUERY_PRIV_INFO_SIZE:
+ *info = imported_sgt_info->sz_priv;
+ break;
+
+ /* copy private info attached to buffer */
+ case HYPER_DMABUF_QUERY_PRIV_INFO:
+ if (imported_sgt_info->sz_priv > 0) {
+ n = copy_to_user((void __user*) *info,
+ imported_sgt_info->priv,
+ imported_sgt_info->sz_priv);
+ if (n != 0)
+ return -EINVAL;
+ }
+ break;
+
+ default:
+ return -EINVAL;
}

- return -EINVAL;
+ return 0;
}
diff --git a/drivers/xen/hyper_dmabuf/hyper_dmabuf_query.h b/drivers/xen/hyper_dmabuf/hyper_dmabuf_query.h
index 295e923..7bbb322 100644
--- a/drivers/xen/hyper_dmabuf/hyper_dmabuf_query.h
+++ b/drivers/xen/hyper_dmabuf/hyper_dmabuf_query.h
@@ -1,8 +1,10 @@
#ifndef __HYPER_DMABUF_QUERY_H__
#define __HYPER_DMABUF_QUERY_H__

-int hyper_dmabuf_query_imported(struct hyper_dmabuf_imported_sgt_info *imported_sgt_info, int query);
+int hyper_dmabuf_query_imported(struct hyper_dmabuf_imported_sgt_info *imported_sgt_info,
+ int query, unsigned long *info);

-int hyper_dmabuf_query_exported(struct hyper_dmabuf_sgt_info *sgt_info, int query);
+int hyper_dmabuf_query_exported(struct hyper_dmabuf_sgt_info *sgt_info,
+ int query, unsigned long *info);

#endif // __HYPER_DMABUF_QUERY_H__
diff --git a/include/uapi/xen/hyper_dmabuf.h b/include/uapi/xen/hyper_dmabuf.h
index df01b17..e18dd9b 100644
--- a/include/uapi/xen/hyper_dmabuf.h
+++ b/include/uapi/xen/hyper_dmabuf.h
@@ -109,7 +109,7 @@ struct ioctl_hyper_dmabuf_query {
int item;
/* OUT parameters */
/* Value of queried item */
- int info;
+ unsigned long info;
};

/* DMABUF query */
@@ -122,6 +122,8 @@ enum hyper_dmabuf_query {
HYPER_DMABUF_QUERY_BUSY,
HYPER_DMABUF_QUERY_UNEXPORTED,
HYPER_DMABUF_QUERY_DELAYED_UNEXPORTED,
+ HYPER_DMABUF_QUERY_PRIV_INFO_SIZE,
+ HYPER_DMABUF_QUERY_PRIV_INFO,
};

enum hyper_dmabuf_status {
--
2.7.4