summaryrefslogtreecommitdiff
path: root/drivers/dma-buf
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2022-12-13 11:59:58 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2022-12-13 11:59:58 -0800
commita594533df0f6ca391da003f43d53b336a2d23ffa (patch)
treeec984c693b0bfc208519c43134f21365797f90ee /drivers/dma-buf
parentcdb9d3537711939e4d8fd0de2889c966f88346eb (diff)
parent66efff515a6500d4b4976fbab3bee8b92a1137fb (diff)
Merge tag 'drm-next-2022-12-13' of git://anongit.freedesktop.org/drm/drm
Pull drm updates from Dave Airlie: "The biggest highlight is that the accel subsystem framework is merged. Hopefully for 6.3 we will be able to line up a driver to use it. In drivers land, i915 enables DG2 support by default now, and nouveau has a big stability refactoring and initial ampere support, AMD includes new hw IP support and should build on ARM again. There is also an ofdrm driver to take over offb on platforms it's used. Stuff outside my tree, the dma-buf patches hit a few places, the vc4 firmware changes also do, and i915 has some interactions with MEI for discrete GPUs. I think all of those should have been acked/reviewed by relevant parties. New driver: - ofdrm - replacement for offb fbdev: - add support for nomodeset fourcc: - add Vivante tiled modifier core: - atomic-helpers: CRTC primary plane test fixes, fb access hooks - connector: TV API consistency, cmdline parser improvements - send connector hotplug on cleanup - sort makefile objects tests: - sort kunit tests - improve DP-MST tests - add kunit helpers to create a device sched: - module param for scheduling policy - refcounting fix buddy: - add back random seed log ttm: - convert ttm_resource to size_t - optimize pool allocations edid: - HFVSDB parsing support fixes - logging/debug improvements - DSC quirks dma-buf: - Add unlocked vmap and attachment mapping - move drivers to common locking convention - locking improvements firmware: - new API for rPI firmware and vc4 xilinx: - zynqmp: displayport bridge support - dpsub fix bridge: - adv7533: Remove dynamic lane switching - it6505: Runtime PM support, sync improvements - ps8640: Handle AUX defer messages - tc358775: Drop soft-reset over I2C panel: - panel-edp: Add INX N116BGE-EA2 C2 and C4 support. - Jadard JD9365DA-H3 - NewVision NV3051D amdgpu: - DCN support on ARM - DCN 2.1 secure display - Sienna Cichlid mode2 reset fixes - new GC 11.x firmware versions - drop AMD specific DSC workarounds in favour of drm code - clang warning fixes - scheduler rework - SR-IOV fixes - GPUVM locking fixes - fix memory leak in CS IOCTL error path - flexible array updates - enable new GC/PSP/SMU/NBIO IP - GFX preemption support for gfx9 amdkfd: - cache size fixes - userptr fixes - enable cooperative launch on gfx 10.3 - enable GC 11.0.4 KFD support radeon: - replace kmap with kmap_local_page - ACPI ref count fix - HDA audio notifier support i915: - DG2 enabled by default - MTL enablement work - hotplug refactoring - VBT improvements - Display and watermark refactoring - ADL-P workaround - temp disable runtime_pm for discrete- - fix for A380 as a secondary GPU - Wa_18017747507 for DG2 - CS timestamp support fixes for gen5 and earlier - never purge busy TTM objects - use i915_sg_dma_sizes for all backends - demote GuC kernel contexts to normal priority - gvt: refactor for new MDEV interface - enable DC power states on eDP ports - fix gen 2/3 workarounds nouveau: - fix page fault handling - Ampere acceleration support - driver stability improvements - nva3 backlight support msm: - MSM_INFO_GET_FLAGS support - DPU: XR30 and P010 image formats - Qualcomm SM6115 support - DSI PHY support for QCM2290 - HDMI: refactored dev init path - remove exclusive-fence hack - fix speed-bin detection - enable clamp to idle on 7c3 - improved hangcheck detection vmwgfx: - fb and cursor refactoring - convert to generic hashtable - cursor improvements etnaviv: - hw workarounds - softpin MMU fixes ast: - atomic gamma LUT support - convert to SHMEM lcdif: - support YUV planes - Increase DMA burst size - FIFO threshold tuning meson: - fix return type of cvbs mode_valid mgag200: - fix PLL setup on some revisions sun4i: - A100 and D1 support udl: - modesetting improvements - hot unplug support vc4: - support PAL-M - fix regression preventing 4K @ 60Hz - fix NULL ptr deref v3d: - switch to drm managed resources renesas: - RZ/G2L DSI support - DU Kconfig cleanup mediatek: - fixup dpi and hdmi - MT8188 dpi support - MT8195 AFBC support tegra: - NVDEC hardware on Tegra234 SoC hdlcd: - switch to drm managed resources ingenic: - fix registration error path hisilicon: - convert to drm_mode_init maildp: - use managed resources mtk: - use drm_mode_init rockchip: - use drm_mode_copy" * tag 'drm-next-2022-12-13' of git://anongit.freedesktop.org/drm/drm: (1397 commits) drm/amdgpu: fix mmhub register base coding error drm/amdgpu: add tmz support for GC IP v11.0.4 drm/amdgpu: enable GFX Clock Gating control for GC IP v11.0.4 drm/amdgpu: enable GFX Power Gating for GC IP v11.0.4 drm/amdgpu: enable GFX IP v11.0.4 CG support drm/amdgpu: Make amdgpu_ring_mux functions as static drm/amdgpu: generally allow over-commit during BO allocation drm/amd/display: fix array index out of bound error in DCN32 DML drm/amd/display: 3.2.215 drm/amd/display: set optimized required for comp buf changes drm/amd/display: Add debug option to skip PSR CRTC disable drm/amd/display: correct DML calc error of UrgentLatency drm/amd/display: correct static_screen_event_mask drm/amd/display: Ensure commit_streams returns the DC return code drm/amd/display: read invalid ddc pin status cause engine busy drm/amd/display: Bypass DET swath fill check for max clocks drm/amd/display: Disable uclk pstate for subvp pipes drm/amd/display: Fix DCN2.1 default DSC clocks drm/amd/display: Enable dp_hdmi21_pcon support drm/amd/display: prevent seamless boot on displays that don't have the preferred dig ...
Diffstat (limited to 'drivers/dma-buf')
-rw-r--r--drivers/dma-buf/dma-buf.c225
-rw-r--r--drivers/dma-buf/heaps/cma_heap.c3
-rw-r--r--drivers/dma-buf/heaps/system_heap.c3
-rw-r--r--drivers/dma-buf/udmabuf.c3
4 files changed, 201 insertions, 33 deletions
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index e6f36c014c4c..b6c36914e7c6 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -130,6 +130,7 @@ static struct file_system_type dma_buf_fs_type = {
static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma)
{
struct dma_buf *dmabuf;
+ int ret;
if (!is_dma_buf_file(file))
return -EINVAL;
@@ -145,7 +146,11 @@ static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma)
dmabuf->size >> PAGE_SHIFT)
return -EINVAL;
- return dmabuf->ops->mmap(dmabuf, vma);
+ dma_resv_lock(dmabuf->resv, NULL);
+ ret = dmabuf->ops->mmap(dmabuf, vma);
+ dma_resv_unlock(dmabuf->resv);
+
+ return ret;
}
static loff_t dma_buf_llseek(struct file *file, loff_t offset, int whence)
@@ -668,7 +673,6 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
dmabuf->file = file;
- mutex_init(&dmabuf->lock);
INIT_LIST_HEAD(&dmabuf->attachments);
mutex_lock(&db_list.lock);
@@ -807,6 +811,70 @@ static struct sg_table * __map_dma_buf(struct dma_buf_attachment *attach,
}
/**
+ * DOC: locking convention
+ *
+ * In order to avoid deadlock situations between dma-buf exports and importers,
+ * all dma-buf API users must follow the common dma-buf locking convention.
+ *
+ * Convention for importers
+ *
+ * 1. Importers must hold the dma-buf reservation lock when calling these
+ * functions:
+ *
+ * - dma_buf_pin()
+ * - dma_buf_unpin()
+ * - dma_buf_map_attachment()
+ * - dma_buf_unmap_attachment()
+ * - dma_buf_vmap()
+ * - dma_buf_vunmap()
+ *
+ * 2. Importers must not hold the dma-buf reservation lock when calling these
+ * functions:
+ *
+ * - dma_buf_attach()
+ * - dma_buf_dynamic_attach()
+ * - dma_buf_detach()
+ * - dma_buf_export(
+ * - dma_buf_fd()
+ * - dma_buf_get()
+ * - dma_buf_put()
+ * - dma_buf_mmap()
+ * - dma_buf_begin_cpu_access()
+ * - dma_buf_end_cpu_access()
+ * - dma_buf_map_attachment_unlocked()
+ * - dma_buf_unmap_attachment_unlocked()
+ * - dma_buf_vmap_unlocked()
+ * - dma_buf_vunmap_unlocked()
+ *
+ * Convention for exporters
+ *
+ * 1. These &dma_buf_ops callbacks are invoked with unlocked dma-buf
+ * reservation and exporter can take the lock:
+ *
+ * - &dma_buf_ops.attach()
+ * - &dma_buf_ops.detach()
+ * - &dma_buf_ops.release()
+ * - &dma_buf_ops.begin_cpu_access()
+ * - &dma_buf_ops.end_cpu_access()
+ *
+ * 2. These &dma_buf_ops callbacks are invoked with locked dma-buf
+ * reservation and exporter can't take the lock:
+ *
+ * - &dma_buf_ops.pin()
+ * - &dma_buf_ops.unpin()
+ * - &dma_buf_ops.map_dma_buf()
+ * - &dma_buf_ops.unmap_dma_buf()
+ * - &dma_buf_ops.mmap()
+ * - &dma_buf_ops.vmap()
+ * - &dma_buf_ops.vunmap()
+ *
+ * 3. Exporters must hold the dma-buf reservation lock when calling these
+ * functions:
+ *
+ * - dma_buf_move_notify()
+ */
+
+/**
* dma_buf_dynamic_attach - Add the device to dma_buf's attachments list
* @dmabuf: [in] buffer to attach device to.
* @dev: [in] device to be attached.
@@ -870,8 +938,8 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
dma_buf_is_dynamic(dmabuf)) {
struct sg_table *sgt;
+ dma_resv_lock(attach->dmabuf->resv, NULL);
if (dma_buf_is_dynamic(attach->dmabuf)) {
- dma_resv_lock(attach->dmabuf->resv, NULL);
ret = dmabuf->ops->pin(attach);
if (ret)
goto err_unlock;
@@ -884,8 +952,7 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
ret = PTR_ERR(sgt);
goto err_unpin;
}
- if (dma_buf_is_dynamic(attach->dmabuf))
- dma_resv_unlock(attach->dmabuf->resv);
+ dma_resv_unlock(attach->dmabuf->resv);
attach->sgt = sgt;
attach->dir = DMA_BIDIRECTIONAL;
}
@@ -901,8 +968,7 @@ err_unpin:
dmabuf->ops->unpin(attach);
err_unlock:
- if (dma_buf_is_dynamic(attach->dmabuf))
- dma_resv_unlock(attach->dmabuf->resv);
+ dma_resv_unlock(attach->dmabuf->resv);
dma_buf_detach(dmabuf, attach);
return ERR_PTR(ret);
@@ -945,24 +1011,22 @@ static void __unmap_dma_buf(struct dma_buf_attachment *attach,
*/
void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach)
{
- if (WARN_ON(!dmabuf || !attach))
+ if (WARN_ON(!dmabuf || !attach || dmabuf != attach->dmabuf))
return;
+ dma_resv_lock(dmabuf->resv, NULL);
+
if (attach->sgt) {
- if (dma_buf_is_dynamic(attach->dmabuf))
- dma_resv_lock(attach->dmabuf->resv, NULL);
__unmap_dma_buf(attach, attach->sgt, attach->dir);
- if (dma_buf_is_dynamic(attach->dmabuf)) {
+ if (dma_buf_is_dynamic(attach->dmabuf))
dmabuf->ops->unpin(attach);
- dma_resv_unlock(attach->dmabuf->resv);
- }
}
-
- dma_resv_lock(dmabuf->resv, NULL);
list_del(&attach->node);
+
dma_resv_unlock(dmabuf->resv);
+
if (dmabuf->ops->detach)
dmabuf->ops->detach(dmabuf, attach);
@@ -1053,8 +1117,7 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
if (WARN_ON(!attach || !attach->dmabuf))
return ERR_PTR(-EINVAL);
- if (dma_buf_attachment_is_dynamic(attach))
- dma_resv_assert_held(attach->dmabuf->resv);
+ dma_resv_assert_held(attach->dmabuf->resv);
if (attach->sgt) {
/*
@@ -1069,7 +1132,6 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
}
if (dma_buf_is_dynamic(attach->dmabuf)) {
- dma_resv_assert_held(attach->dmabuf->resv);
if (!IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY)) {
r = attach->dmabuf->ops->pin(attach);
if (r)
@@ -1112,6 +1174,34 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
EXPORT_SYMBOL_NS_GPL(dma_buf_map_attachment, DMA_BUF);
/**
+ * dma_buf_map_attachment_unlocked - Returns the scatterlist table of the attachment;
+ * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the
+ * dma_buf_ops.
+ * @attach: [in] attachment whose scatterlist is to be returned
+ * @direction: [in] direction of DMA transfer
+ *
+ * Unlocked variant of dma_buf_map_attachment().
+ */
+struct sg_table *
+dma_buf_map_attachment_unlocked(struct dma_buf_attachment *attach,
+ enum dma_data_direction direction)
+{
+ struct sg_table *sg_table;
+
+ might_sleep();
+
+ if (WARN_ON(!attach || !attach->dmabuf))
+ return ERR_PTR(-EINVAL);
+
+ dma_resv_lock(attach->dmabuf->resv, NULL);
+ sg_table = dma_buf_map_attachment(attach, direction);
+ dma_resv_unlock(attach->dmabuf->resv);
+
+ return sg_table;
+}
+EXPORT_SYMBOL_NS_GPL(dma_buf_map_attachment_unlocked, DMA_BUF);
+
+/**
* dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might
* deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of
* dma_buf_ops.
@@ -1130,15 +1220,11 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach,
if (WARN_ON(!attach || !attach->dmabuf || !sg_table))
return;
- if (dma_buf_attachment_is_dynamic(attach))
- dma_resv_assert_held(attach->dmabuf->resv);
+ dma_resv_assert_held(attach->dmabuf->resv);
if (attach->sgt == sg_table)
return;
- if (dma_buf_is_dynamic(attach->dmabuf))
- dma_resv_assert_held(attach->dmabuf->resv);
-
__unmap_dma_buf(attach, sg_table, direction);
if (dma_buf_is_dynamic(attach->dmabuf) &&
@@ -1148,6 +1234,31 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach,
EXPORT_SYMBOL_NS_GPL(dma_buf_unmap_attachment, DMA_BUF);
/**
+ * dma_buf_unmap_attachment_unlocked - unmaps and decreases usecount of the buffer;might
+ * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of
+ * dma_buf_ops.
+ * @attach: [in] attachment to unmap buffer from
+ * @sg_table: [in] scatterlist info of the buffer to unmap
+ * @direction: [in] direction of DMA transfer
+ *
+ * Unlocked variant of dma_buf_unmap_attachment().
+ */
+void dma_buf_unmap_attachment_unlocked(struct dma_buf_attachment *attach,
+ struct sg_table *sg_table,
+ enum dma_data_direction direction)
+{
+ might_sleep();
+
+ if (WARN_ON(!attach || !attach->dmabuf || !sg_table))
+ return;
+
+ dma_resv_lock(attach->dmabuf->resv, NULL);
+ dma_buf_unmap_attachment(attach, sg_table, direction);
+ dma_resv_unlock(attach->dmabuf->resv);
+}
+EXPORT_SYMBOL_NS_GPL(dma_buf_unmap_attachment_unlocked, DMA_BUF);
+
+/**
* dma_buf_move_notify - notify attachments that DMA-buf is moving
*
* @dmabuf: [in] buffer which is moving
@@ -1358,6 +1469,8 @@ EXPORT_SYMBOL_NS_GPL(dma_buf_end_cpu_access, DMA_BUF);
int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
unsigned long pgoff)
{
+ int ret;
+
if (WARN_ON(!dmabuf || !vma))
return -EINVAL;
@@ -1378,7 +1491,11 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
vma_set_file(vma, dmabuf->file);
vma->vm_pgoff = pgoff;
- return dmabuf->ops->mmap(dmabuf, vma);
+ dma_resv_lock(dmabuf->resv, NULL);
+ ret = dmabuf->ops->mmap(dmabuf, vma);
+ dma_resv_unlock(dmabuf->resv);
+
+ return ret;
}
EXPORT_SYMBOL_NS_GPL(dma_buf_mmap, DMA_BUF);
@@ -1401,42 +1518,68 @@ EXPORT_SYMBOL_NS_GPL(dma_buf_mmap, DMA_BUF);
int dma_buf_vmap(struct dma_buf *dmabuf, struct iosys_map *map)
{
struct iosys_map ptr;
- int ret = 0;
+ int ret;
iosys_map_clear(map);
if (WARN_ON(!dmabuf))
return -EINVAL;
+ dma_resv_assert_held(dmabuf->resv);
+
if (!dmabuf->ops->vmap)
return -EINVAL;
- mutex_lock(&dmabuf->lock);
if (dmabuf->vmapping_counter) {
dmabuf->vmapping_counter++;
BUG_ON(iosys_map_is_null(&dmabuf->vmap_ptr));
*map = dmabuf->vmap_ptr;
- goto out_unlock;
+ return 0;
}
BUG_ON(iosys_map_is_set(&dmabuf->vmap_ptr));
ret = dmabuf->ops->vmap(dmabuf, &ptr);
if (WARN_ON_ONCE(ret))
- goto out_unlock;
+ return ret;
dmabuf->vmap_ptr = ptr;
dmabuf->vmapping_counter = 1;
*map = dmabuf->vmap_ptr;
-out_unlock:
- mutex_unlock(&dmabuf->lock);
- return ret;
+ return 0;
}
EXPORT_SYMBOL_NS_GPL(dma_buf_vmap, DMA_BUF);
/**
+ * dma_buf_vmap_unlocked - Create virtual mapping for the buffer object into kernel
+ * address space. Same restrictions as for vmap and friends apply.
+ * @dmabuf: [in] buffer to vmap
+ * @map: [out] returns the vmap pointer
+ *
+ * Unlocked version of dma_buf_vmap()
+ *
+ * Returns 0 on success, or a negative errno code otherwise.
+ */
+int dma_buf_vmap_unlocked(struct dma_buf *dmabuf, struct iosys_map *map)
+{
+ int ret;
+
+ iosys_map_clear(map);
+
+ if (WARN_ON(!dmabuf))
+ return -EINVAL;
+
+ dma_resv_lock(dmabuf->resv, NULL);
+ ret = dma_buf_vmap(dmabuf, map);
+ dma_resv_unlock(dmabuf->resv);
+
+ return ret;
+}
+EXPORT_SYMBOL_NS_GPL(dma_buf_vmap_unlocked, DMA_BUF);
+
+/**
* dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap.
* @dmabuf: [in] buffer to vunmap
* @map: [in] vmap pointer to vunmap
@@ -1446,20 +1589,36 @@ void dma_buf_vunmap(struct dma_buf *dmabuf, struct iosys_map *map)
if (WARN_ON(!dmabuf))
return;
+ dma_resv_assert_held(dmabuf->resv);
+
BUG_ON(iosys_map_is_null(&dmabuf->vmap_ptr));
BUG_ON(dmabuf->vmapping_counter == 0);
BUG_ON(!iosys_map_is_equal(&dmabuf->vmap_ptr, map));
- mutex_lock(&dmabuf->lock);
if (--dmabuf->vmapping_counter == 0) {
if (dmabuf->ops->vunmap)
dmabuf->ops->vunmap(dmabuf, map);
iosys_map_clear(&dmabuf->vmap_ptr);
}
- mutex_unlock(&dmabuf->lock);
}
EXPORT_SYMBOL_NS_GPL(dma_buf_vunmap, DMA_BUF);
+/**
+ * dma_buf_vunmap_unlocked - Unmap a vmap obtained by dma_buf_vmap.
+ * @dmabuf: [in] buffer to vunmap
+ * @map: [in] vmap pointer to vunmap
+ */
+void dma_buf_vunmap_unlocked(struct dma_buf *dmabuf, struct iosys_map *map)
+{
+ if (WARN_ON(!dmabuf))
+ return;
+
+ dma_resv_lock(dmabuf->resv, NULL);
+ dma_buf_vunmap(dmabuf, map);
+ dma_resv_unlock(dmabuf->resv);
+}
+EXPORT_SYMBOL_NS_GPL(dma_buf_vunmap_unlocked, DMA_BUF);
+
#ifdef CONFIG_DEBUG_FS
static int dma_buf_debug_show(struct seq_file *s, void *unused)
{
diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
index 28fb04eccdd0..1131fb943992 100644
--- a/drivers/dma-buf/heaps/cma_heap.c
+++ b/drivers/dma-buf/heaps/cma_heap.c
@@ -13,6 +13,7 @@
#include <linux/dma-buf.h>
#include <linux/dma-heap.h>
#include <linux/dma-map-ops.h>
+#include <linux/dma-resv.h>
#include <linux/err.h>
#include <linux/highmem.h>
#include <linux/io.h>
@@ -182,6 +183,8 @@ static int cma_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
{
struct cma_heap_buffer *buffer = dmabuf->priv;
+ dma_resv_assert_held(dmabuf->resv);
+
if ((vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) == 0)
return -EINVAL;
diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c
index fcf836ba9c1f..e8bd10e60998 100644
--- a/drivers/dma-buf/heaps/system_heap.c
+++ b/drivers/dma-buf/heaps/system_heap.c
@@ -13,6 +13,7 @@
#include <linux/dma-buf.h>
#include <linux/dma-mapping.h>
#include <linux/dma-heap.h>
+#include <linux/dma-resv.h>
#include <linux/err.h>
#include <linux/highmem.h>
#include <linux/mm.h>
@@ -201,6 +202,8 @@ static int system_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
struct sg_page_iter piter;
int ret;
+ dma_resv_assert_held(dmabuf->resv);
+
for_each_sgtable_page(table, &piter, vma->vm_pgoff) {
struct page *page = sg_page_iter_page(&piter);
diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
index 2bcdb935a3ac..283816fbd72f 100644
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -2,6 +2,7 @@
#include <linux/cred.h>
#include <linux/device.h>
#include <linux/dma-buf.h>
+#include <linux/dma-resv.h>
#include <linux/highmem.h>
#include <linux/init.h>
#include <linux/kernel.h>
@@ -49,6 +50,8 @@ static int mmap_udmabuf(struct dma_buf *buf, struct vm_area_struct *vma)
{
struct udmabuf *ubuf = buf->priv;
+ dma_resv_assert_held(buf->resv);
+
if ((vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) == 0)
return -EINVAL;