Lines Matching +full:protect +full:- +full:exec
4 The dma-buf subsystem provides the framework for sharing buffers for
8 This is used, for example, by drm "prime" multi-GPU support, but is of
11 The three main components of this are: (1) dma-buf, representing a
18 ------------------
20 This document serves as a guide to device-driver writers on what is the dma-buf
27 exporter, and A as buffer-user/importer.
31 - implements and manages operations in :c:type:`struct dma_buf_ops
33 - allows other users to share the buffer by using dma_buf sharing APIs,
34 - manages the details of buffer allocation, wrapped in a :c:type:`struct
36 - decides about the actual backing storage where this allocation happens,
37 - and takes care of any migration of scatterlist - for all (shared) users of
40 The buffer-user
42 - is one of (many) sharing users of the buffer.
43 - doesn't need to worry about how the buffer is allocated, or where.
44 - and needs a mechanism to get access to the scatterlist that makes up this
49 Any exporters or users of the dma-buf buffer sharing framework must have a
59 - Since kernel 3.12 the dma-buf FD supports the llseek system call, but only
62 llseek operation will report -EINVAL.
64 If llseek on dma-buf FDs isn't support the kernel will report -ESPIPE for all
65 cases. Userspace can use this to detect support for discovering the dma-buf
68 - In order to avoid fd leaks on exec, the FD_CLOEXEC flag must be set
70 potential security hole. It could give the newly exec'd application
76 multi-threaded app[3]. The issue is made worse when it is library code
81 flag be set when the dma-buf fd is created. So any API provided by
85 - Memory mapping the contents of the DMA buffer is also supported. See the
88 - The DMA buffer FD is also pollable, see `Implicit Fence Poll Support`_ below for
91 - The DMA buffer FD also supports a few dma-buf-specific ioctls, see
97 .. kernel-doc:: drivers/dma-buf/dma-buf.c
103 .. kernel-doc:: drivers/dma-buf/dma-buf.c
109 .. kernel-doc:: drivers/dma-buf/dma-buf.c
112 DMA-BUF statistics
114 .. kernel-doc:: drivers/dma-buf/dma-buf-sysfs-stats.c
120 .. kernel-doc:: include/uapi/linux/dma-buf.h
125 .. kernel-doc:: drivers/dma-buf/dma-buf.c
128 .. kernel-doc:: include/linux/dma-buf.h
134 .. kernel-doc:: include/linux/dma-buf-map.h
137 .. kernel-doc:: include/linux/dma-buf-map.h
141 -------------------
143 .. kernel-doc:: drivers/dma-buf/dma-resv.c
146 .. kernel-doc:: drivers/dma-buf/dma-resv.c
149 .. kernel-doc:: include/linux/dma-resv.h
153 ----------
155 .. kernel-doc:: drivers/dma-buf/dma-fence.c
158 DMA Fence Cross-Driver Contract
161 .. kernel-doc:: drivers/dma-buf/dma-fence.c
162 :doc: fence cross-driver contract
167 .. kernel-doc:: drivers/dma-buf/dma-fence.c
173 .. kernel-doc:: drivers/dma-buf/dma-fence.c
176 .. kernel-doc:: include/linux/dma-fence.h
182 .. kernel-doc:: include/linux/seqno-fence.h
188 .. kernel-doc:: drivers/dma-buf/dma-fence-array.c
191 .. kernel-doc:: include/linux/dma-fence-array.h
197 .. kernel-doc:: drivers/dma-buf/dma-fence-chain.c
200 .. kernel-doc:: include/linux/dma-fence-chain.h
206 .. kernel-doc:: drivers/dma-buf/sync_file.c
209 .. kernel-doc:: include/linux/sync_file.h
225 * Userspace fences or gpu futexes, fine-grained locking within a command buffer
230 * Long-running compute command buffers, while still using traditional end of
236 in-kernel DMA fences does not work, even when a fallback timeout is included to
237 protect against malicious userspace:
251 .. kernel-render:: DOT
259 kernel -> userspace [label="memory management"]
260 userspace -> kernel [label="Future fence, fence proxy, ..."]
301 on-demand fill a memory request. For now this means recoverable page
309 - The 3D workload might need to wait for the compute job to finish and release
312 - The compute workload might be stuck in a page fault, because the memory
318 - Compute workloads can always be preempted, even when a page fault is pending
321 - DMA fence workloads and workloads which need page fault handling have
326 - The reservation approach could be further refined by only reserving the
327 hardware resources for DMA fence workloads when they are in-flight. This must
331 - As a last resort, if the hardware provides no useful reservation mechanics,
339 - Only a fairly theoretical option would be to untangle these dependencies when
356 hit a page fault which holds up a userspace fence - supporting page faults on