User space user can call DMA_BUF_SET_NAME to set dma_buf.name,
but until now we can't set it at kernel side, it's difficult to debug
kernel dma_buf users.
There are some kernel users of dma_heap also need it at MTK,
such as camera, it's also have a allocator for other camera part,
unlike most case in userspace, it's in kernel.
For debug buffer owner, we need add it to let it can set debug name
for each dmabuf, so that we can know dmabuf owner by dma_buf.name.
Bug: 193623372
Link: https://lore.kernel.org/patchwork/patch/1459719/
Change-Id: Iac5c6b8838b9b4d976f4525d000e17a3abab94f6
Signed-off-by: Guangming Cao <Guangming.Cao@mediatek.com>
The overhead of sysfs directory creation/teardown during
dma_buf_attach()/dma_buf_detach() is causing perf regressions for
certain drivers.
Bug: 192621117
Change-Id: I908aa3b2717bf2e183628be3446e0069ce24c68a
Fixes: 621f94a601 (BACKPORT: FROMLIST: dmabuf: Add the capability to
expose DMA-BUF stats in sysfs)
Signed-off-by: Hridya Valsaraju <hridya@google.com>
There are a lot of different structures that need to have a "frozen" abi
for the next 5+ years. Add padding to a lot of them in order to be able
to handle any future changes that might be needed due to LTS and
security fixes that might come up.
It's a best guess, based on what has happened in the past from the
5.4.0..5.4.129 release (1 1/2 years). Yes, past changes do not mean
that future changes will also be needed in the same area, but that is a
hint that those areas are both well maintained and looked after, and
there have been previous problems found in them.
Also the list of structures that are being required based on OEM usage
in the android/ symbol lists were consulted as that's a larger list than
what has been changed in the past.
Hopefully we caught everything we need to worry about, only time will
tell...
Bug: 151154716
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I880bbcda0628a7459988eeb49d18655522697664
This reverts commit 9132fbe545.
Reason for revert: mmap_count is no longer used for reporting dma-bufs
and introduces subtle bugs related to changing the vm_ops
Bug: 192459295
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Change-Id: Id07802e5a3e18918c5c46e31b73be4a594f7dc26
Add and export get_each_dmabuf function which helps in
traversing the db_list, this will be used by the minidump
module to get dmabuf info.
Bug: 181203151
Change-Id: Ie24788fcf9cf0a49316cb871dcb9191e8084ccde
Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org>
Export is_dma_buf_file function which will be used
by the minidump module to get dmabuf info.
Bug: 180978053
Change-Id: Ic8f7dd4f0a620839ab19f52841e9a6541515133c
Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org>
mmap_count can be used to efficiently calculate the
PSS for any DMA buffer that the process has mapped.
Bug: 167141117
Change-Id: I8296981f0135a5532969aca3a8baa5da61dfe39f
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
This patch allows statistics to be enabled for each DMA-BUF in
sysfs by enabling the config CONFIG_DMABUF_SYSFS_STATS.
The following stats will be exposed by the interface:
/sys/kernel/dmabuf/buffers/<inode_number>/exporter_name
/sys/kernel/dmabuf/buffers/<inode_number>/size
/sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attach_uid>/device
/sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attach_uid>/map_counter
The inode_number is unique for each DMA-BUF and was added earlier [1]
in order to allow userspace to track DMA-BUF usage across different
processes.
Currently, this information is exposed in
/sys/kernel/debug/dma_buf/bufinfo.
However, since debugfs is considered unsafe to be mounted in production,
it is being duplicated in sysfs.
This information will be used to derive DMA-BUF
per-exporter stats and per-device usage stats for Android Bug reports.
The corresponding userspace changes can be found at [2].
Telemetry tools will also capture this information(along with other
memory metrics) periodically as well as on important events like a
foreground app kill (which might have been triggered by Low Memory
Killer). It will also contribute to provide a snapshot of the system
memory usage on other events such as OOM kills and Application Not
Responding events.
A shell script that can be run on a classic Linux environment to read
out the DMA-BUF statistics can be found at [3](suggested by John
Stultz).
The patch contains the following improvements over the previous version:
1) Each attachment is represented by its own directory to allow creating
a symlink to the importing device and to also provide room for future
expansion.
2) The number of distinct mappings of each attachment is exposed in a
separate file.
3) The per-buffer statistics are now in /sys/kernel/dmabuf/buffers
inorder to make the interface expandable in future.
All of the improvements above are based on suggestions/feedback from
Daniel Vetter and Christian König.
[1]: https://lore.kernel.org/patchwork/patch/1088791/
[2]: https://android-review.googlesource.com/q/topic:%22dmabuf-sysfs%22+(status:open%20OR%20status:merged)
[3]: https://android-review.googlesource.com/c/platform/system/memory/libmeminfo/+/1549734
Bug: 167709539
Link: https://lore.kernel.org/linux-media/20210126204240.418297-1-hridya@google.com/
[hridya: minor rebase needed in include/linux/dma-buf.h for backporting]
Signed-off-by: Hridya Valsaraju <hridya@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Change-Id: I8a3342b57f2e21ff349839f5cf665980c97bf849
Steps on the way to 5.10-rc1
Fixes merge conflicts in:
drivers/gpu/drm/bridge/lontium-lt9611.c
drivers/gpu/drm/virtio/virtgpu_display.c
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I65d9d4c69ea7c79854d275462c9aca0a37d42654
There exists a sleep-while-atomic bug while accessing the dmabuf->name
under mutex in the dmabuffs_dname(). This is caused from the SELinux
permissions checks on a process where it tries to validate the inherited
files from fork() by traversing them through iterate_fd() (which
traverse files under spin_lock) and call
match_file(security/selinux/hooks.c) where the permission checks happen.
This audit information is logged using dump_common_audit_data() where it
calls d_path() to get the file path name. If the file check happen on
the dmabuf's fd, then it ends up in ->dmabuffs_dname() and use mutex to
access dmabuf->name. The flow will be like below:
flush_unauthorized_files()
iterate_fd()
spin_lock() --> Start of the atomic section.
match_file()
file_has_perm()
avc_has_perm()
avc_audit()
slow_avc_audit()
common_lsm_audit()
dump_common_audit_data()
audit_log_d_path()
d_path()
dmabuffs_dname()
mutex_lock()--> Sleep while atomic.
Call trace captured (on 4.19 kernels) is below:
___might_sleep+0x204/0x208
__might_sleep+0x50/0x88
__mutex_lock_common+0x5c/0x1068
__mutex_lock_common+0x5c/0x1068
mutex_lock_nested+0x40/0x50
dmabuffs_dname+0xa0/0x170
d_path+0x84/0x290
audit_log_d_path+0x74/0x130
common_lsm_audit+0x334/0x6e8
slow_avc_audit+0xb8/0xf8
avc_has_perm+0x154/0x218
file_has_perm+0x70/0x180
match_file+0x60/0x78
iterate_fd+0x128/0x168
selinux_bprm_committing_creds+0x178/0x248
security_bprm_committing_creds+0x30/0x48
install_exec_creds+0x1c/0x68
load_elf_binary+0x3a4/0x14e0
search_binary_handler+0xb0/0x1e0
So, use spinlock to access dmabuf->name to avoid sleep-while-atomic.
Cc: <stable@vger.kernel.org> [5.3+]
Signed-off-by: Charan Teja Kalla <charante@codeaurora.org>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Acked-by: Christian König <christian.koenig@amd.com>
[sumits: added comment to spinlock_t definition to avoid warning]
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/a83e7f0d-4e54-9848-4b58-e1acdbe06735@codeaurora.org
Tiny merge resolutions along the way to 5.8-rc1.
Change-Id: I0036e22af4e398b0bb3b9855ff90d60b9c0227ee
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This is a step along the way for the 5.7-rc1 merge, and resolves a bunch
of the DRM-specific merge conflicts in one point.
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I056c4edc603fdd3c24588c8a9305cfa67111eb5b
On the exporter side we add optional explicit pinning callbacks. Which are
called when the importer doesn't implement dynamic handling, move notification
or need the DMA-buf locked in place for its use case.
On the importer side we add an optional move_notify callback. This callback is
used by the exporter to inform the importers that their mappings should be
destroyed as soon as possible.
This allows the exporter to provide the mappings without the need to pin
the backing store.
v2: don't try to invalidate mappings when the callback is NULL,
lock the reservation obj while using the attachments,
add helper to set the callback
v3: move flag for invalidation support into the DMA-buf,
use new attach_info structure to set the callback
v4: use importer_priv field instead of mangling exporter priv.
v5: drop invalidation_supported flag
v6: squash together with pin/unpin changes
v7: pin/unpin takes an attachment now
v8: nuke dma_buf_attachment_(map|unmap)_locked,
everything is now handled backward compatible
v9: always cache when export/importer don't agree on dynamic handling
v10: minimal style cleanup
v11: drop automatically re-entry avoidance
v12: rename callback to move_notify
v13: add might_lock in appropriate places
v14: rebase on separated locking change
v15: add EXPERIMENTAL flag, some more code comments
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/353993/?series=73646&rev=1
This patch is a stripped down version of the locking changes
necessary to support dynamic DMA-buf handling.
It adds a dynamic flag for both importers as well as exporters
so that drivers can choose if they want the reservation object
locked or unlocked during mapping of attachments.
For compatibility between drivers we cache the DMA-buf mapping
during attaching an importer as soon as exporter/importer
disagree on the dynamic handling.
Issues and solutions we considered:
- We can't change all existing drivers, and existing improters have
strong opinions about which locks they're holding while calling
dma_buf_attachment_map/unmap. Exporters also have strong opinions about
which locks they can acquire in their ->map/unmap callbacks, levaing no
room for change. The solution to avoid this was to move the
actual map/unmap out from this call, into the attach/detach callbacks,
and cache the mapping. This works because drivers don't call
attach/detach from deep within their code callchains (like deep in
memory management code called from cs/execbuf ioctl), but directly from
the fd2handle implementation.
- The caching has some troubles on some soc drivers, which set other modes
than DMA_BIDIRECTIONAL. We can't have 2 incompatible mappings, and we
can't re-create the mapping at _map time due to the above locking fun.
We very carefuly step around that by only caching at attach time if the
dynamic mode between importer/expoert mismatches.
- There's been quite some discussion on dma-buf mappings which need active
cache management, which would all break down when caching, plus we don't
have explicit flush operations on the attachment side. The solution to
this was to shrug and keep the current discrepancy between what the
dma-buf docs claim and what implementations do, with the hope that the
begin/end_cpu_access hooks are good enough and that all necessary
flushing to keep device mappings consistent will be done there.
v2: cleanup set_name merge, improve kerneldoc
v3: update commit message, kerneldoc and cleanup _debug_show()
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/336788/
To make the 5.4-rc1 merge easier, merge at a prerelease point in time
before the final release happens.
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I29b683c837ed1a3324644dbf9bf863f30740cd0b
Allow kernel clients to get the flags associated with a buffer
that is wrapped by a dma-buf. This information can be used to
communicate the type of memory associated with the
buffer(e.g. uncached vs cached memory).
Bug: 133508579
Test: ion-unit-tests
Change-Id: I82eab8beb738b258616c22a01080615d7ffb6ad5
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>
Signed-off-by: Sandeep Patil <sspatil@google.com>
When mapping the memory represented by a dma-buf into a device's
address space, it might be desireable to map the memory with
certain DMA attributes. Thus, introduce the dma_mapping_attrs
field in the dma_buf_attachment structure so that when
the memory is mapped with dma_buf_map_attachment, it is mapped
with the desired DMA attributes.
Bug: 133508579
Test: ion-unit-tests
Change-Id: Ib2e5bafdc02ae31a58ce96a82d77cc508dd71bd4
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>
Signed-off-by: Sandeep Patil <sspatil@google.com>
In order to improve performance, allow dma-buf clients to
apply cache maintenance to only a subset of a dma-buf.
Kernel clients will be able to use the dma_buf_begin_cpu_access_partial
and dma_buf_end_cpu_access_partial functions to only apply cache
maintenance to a range within the dma-buf.
Bug: 133508579
Test: ion-unit-tests
Change-Id: Icce61fc21b1542f5248daea34f713184449a62c3
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>
Signed-off-by: Sandeep Patil <sspatil@google.com>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not see http www gnu org
licenses
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 503 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Enrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds complimentary DMA_BUF_SET_NAME ioctls, which lets
userspace processes attach a free-form name to each buffer.
This information can be extremely helpful for tracking and accounting
shared buffers. For example, on Android, we know what each buffer will
be used for at allocation time: GL, multimedia, camera, etc. The
userspace allocator can use DMA_BUF_SET_NAME to associate that
information with the buffer, so we can later give developers a
breakdown of how much memory they're allocating for graphics, camera,
etc.
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Chenbo Feng <fengc@google.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190613223408.139221-3-fengc@google.com
- Again move the information relevant for driver writers next to the
callbacks.
- Put the overview and userspace interface documentation into a DOC:
section within the code.
- Remove the text that mmap needs to be coherent - since the
DMA_BUF_IOCTL_SYNC landed that's no longer the case. But keep the text
that for pte zapping exporters need to adjust the address space.
- Add a FIXME that kmap and the new begin/end stuff used by the SYNC
ioctl don't really mix correctly. That's something I just realized
while doing this doc rework.
- Augment function and structure docs like usual.
Cc: linux-doc@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
[sumits: fix cosmetic issues]
Link: http://patchwork.freedesktop.org/patch/msgid/20161209185309.1682-5-daniel.vetter@ffwll.ch
- Put the initial overview for dma-buf into dma-buf.rst.
- Put all the comments about detailed semantics into the right
kernel-doc comment for functions or ops structure member.
- To allow that detail, switch the reworked kerneldoc to inline style
for dma_buf_ops.
- Tie everything together into a much more streamlined overview
comment, relying on the hyperlinks for all the details.
- Also sprinkle some links into the kerneldoc for dma_buf and
dma_buf_attachment to tie it all together.
Cc: linux-doc@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20161209185309.1682-4-daniel.vetter@ffwll.ch
Apparently nobody noticed that dma-buf.h wasn't actually pulled into
docbook build. And as a result the headerdoc comments bitrot a bit.
Add missing params/fields.
Signed-off-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
