diff options
Diffstat (limited to 'Documentation/userspace-api')
24 files changed, 1132 insertions, 61 deletions
diff --git a/Documentation/userspace-api/gpio/gpio-v2-get-line-ioctl.rst b/Documentation/userspace-api/gpio/gpio-v2-get-line-ioctl.rst index 56b975801b6a..6615d6ced755 100644 --- a/Documentation/userspace-api/gpio/gpio-v2-get-line-ioctl.rst +++ b/Documentation/userspace-api/gpio/gpio-v2-get-line-ioctl.rst @@ -81,7 +81,7 @@ Only one event clock flag, ``GPIO_V2_LINE_FLAG_EVENT_CLOCK_xxx``, may be set. If none are set then the event clock defaults to ``CLOCK_MONOTONIC``. The ``GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE`` flag requires supporting hardware and a kernel with ``CONFIG_HTE`` set. Requesting HTE from a device that -doesn't support it is an error (**EOPNOTSUP**). +doesn't support it is an error (**EOPNOTSUPP**). The :c:type:`debounce_period_us<gpio_v2_line_attribute>` attribute may only be applied to lines with ``GPIO_V2_LINE_FLAG_INPUT`` set. When set, debounce diff --git a/Documentation/userspace-api/index.rst b/Documentation/userspace-api/index.rst index afecfe3cc4a8..5926115ec0ed 100644 --- a/Documentation/userspace-api/index.rst +++ b/Documentation/userspace-api/index.rst @@ -20,6 +20,7 @@ System calls futex2 ebpf/index ioctl/index + mseal Security-related interfaces =========================== diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst index c472423412bf..a141e8e65c5d 100644 --- a/Documentation/userspace-api/ioctl/ioctl-number.rst +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst @@ -174,6 +174,8 @@ Code Seq# Include File Comments 'M' 00-0F drivers/video/fsl-diu-fb.h conflict! 'N' 00-1F drivers/usb/scanner.h 'N' 40-7F drivers/block/nvme.c +'N' 80-8F uapi/linux/ntsync.h NT synchronization primitives + <mailto:wine-devel@winehq.org> 'O' 00-06 mtd/ubi-user.h UBI 'P' all linux/soundcard.h conflict! 'P' 60-6F sound/sscape_ioctl.h conflict! diff --git a/Documentation/userspace-api/landlock.rst b/Documentation/userspace-api/landlock.rst index 9dd636aaa829..07b63aec56fa 100644 --- a/Documentation/userspace-api/landlock.rst +++ b/Documentation/userspace-api/landlock.rst @@ -8,7 +8,7 @@ Landlock: unprivileged access control ===================================== :Author: Mickaël Salaün -:Date: October 2023 +:Date: April 2024 The goal of Landlock is to enable to restrict ambient rights (e.g. global filesystem or network access) for a set of processes. Because Landlock @@ -76,7 +76,8 @@ to be explicit about the denied-by-default access rights. LANDLOCK_ACCESS_FS_MAKE_BLOCK | LANDLOCK_ACCESS_FS_MAKE_SYM | LANDLOCK_ACCESS_FS_REFER | - LANDLOCK_ACCESS_FS_TRUNCATE, + LANDLOCK_ACCESS_FS_TRUNCATE | + LANDLOCK_ACCESS_FS_IOCTL_DEV, .handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP | LANDLOCK_ACCESS_NET_CONNECT_TCP, @@ -85,10 +86,10 @@ to be explicit about the denied-by-default access rights. Because we may not know on which kernel version an application will be executed, it is safer to follow a best-effort security approach. Indeed, we should try to protect users as much as possible whatever the kernel they are -using. To avoid binary enforcement (i.e. either all security features or -none), we can leverage a dedicated Landlock command to get the current version -of the Landlock ABI and adapt the handled accesses. Let's check if we should -remove access rights which are only supported in higher versions of the ABI. +using. + +To be compatible with older Linux versions, we detect the available Landlock ABI +version, and only use the available subset of access rights: .. code-block:: c @@ -114,6 +115,10 @@ remove access rights which are only supported in higher versions of the ABI. ruleset_attr.handled_access_net &= ~(LANDLOCK_ACCESS_NET_BIND_TCP | LANDLOCK_ACCESS_NET_CONNECT_TCP); + __attribute__((fallthrough)); + case 4: + /* Removes LANDLOCK_ACCESS_FS_IOCTL_DEV for ABI < 5 */ + ruleset_attr.handled_access_fs &= ~LANDLOCK_ACCESS_FS_IOCTL_DEV; } This enables to create an inclusive ruleset that will contain our rules. @@ -225,6 +230,7 @@ access rights per directory enables to change the location of such directory without relying on the destination directory access rights (except those that are required for this operation, see ``LANDLOCK_ACCESS_FS_REFER`` documentation). + Having self-sufficient hierarchies also helps to tighten the required access rights to the minimal set of data. This also helps avoid sinkhole directories, i.e. directories where data can be linked to but not linked from. However, @@ -318,18 +324,26 @@ It should also be noted that truncating files does not require the system call, this can also be done through :manpage:`open(2)` with the flags ``O_RDONLY | O_TRUNC``. -When opening a file, the availability of the ``LANDLOCK_ACCESS_FS_TRUNCATE`` -right is associated with the newly created file descriptor and will be used for -subsequent truncation attempts using :manpage:`ftruncate(2)`. The behavior is -similar to opening a file for reading or writing, where permissions are checked -during :manpage:`open(2)`, but not during the subsequent :manpage:`read(2)` and +The truncate right is associated with the opened file (see below). + +Rights associated with file descriptors +--------------------------------------- + +When opening a file, the availability of the ``LANDLOCK_ACCESS_FS_TRUNCATE`` and +``LANDLOCK_ACCESS_FS_IOCTL_DEV`` rights is associated with the newly created +file descriptor and will be used for subsequent truncation and ioctl attempts +using :manpage:`ftruncate(2)` and :manpage:`ioctl(2)`. The behavior is similar +to opening a file for reading or writing, where permissions are checked during +:manpage:`open(2)`, but not during the subsequent :manpage:`read(2)` and :manpage:`write(2)` calls. -As a consequence, it is possible to have multiple open file descriptors for the -same file, where one grants the right to truncate the file and the other does -not. It is also possible to pass such file descriptors between processes, -keeping their Landlock properties, even when these processes do not have an -enforced Landlock ruleset. +As a consequence, it is possible that a process has multiple open file +descriptors referring to the same file, but Landlock enforces different things +when operating with these file descriptors. This can happen when a Landlock +ruleset gets enforced and the process keeps file descriptors which were opened +both before and after the enforcement. It is also possible to pass such file +descriptors between processes, keeping their Landlock properties, even when some +of the involved processes do not have an enforced Landlock ruleset. Compatibility ============= @@ -458,6 +472,28 @@ Memory usage Kernel memory allocated to create rulesets is accounted and can be restricted by the Documentation/admin-guide/cgroup-v1/memory.rst. +IOCTL support +------------- + +The ``LANDLOCK_ACCESS_FS_IOCTL_DEV`` right restricts the use of +:manpage:`ioctl(2)`, but it only applies to *newly opened* device files. This +means specifically that pre-existing file descriptors like stdin, stdout and +stderr are unaffected. + +Users should be aware that TTY devices have traditionally permitted to control +other processes on the same TTY through the ``TIOCSTI`` and ``TIOCLINUX`` IOCTL +commands. Both of these require ``CAP_SYS_ADMIN`` on modern Linux systems, but +the behavior is configurable for ``TIOCSTI``. + +On older systems, it is therefore recommended to close inherited TTY file +descriptors, or to reopen them from ``/proc/self/fd/*`` without the +``LANDLOCK_ACCESS_FS_IOCTL_DEV`` right, if possible. + +Landlock's IOCTL support is coarse-grained at the moment, but may become more +fine-grained in the future. Until then, users are advised to establish the +guarantees that they need through the file hierarchy, by only allowing the +``LANDLOCK_ACCESS_FS_IOCTL_DEV`` right on files where it is really required. + Previous limitations ==================== @@ -495,6 +531,16 @@ bind and connect actions to only a set of allowed ports thanks to the new ``LANDLOCK_ACCESS_NET_BIND_TCP`` and ``LANDLOCK_ACCESS_NET_CONNECT_TCP`` access rights. +IOCTL (ABI < 5) +--------------- + +IOCTL operations could not be denied before the fifth Landlock ABI, so +:manpage:`ioctl(2)` is always allowed when using a kernel that only supports an +earlier ABI. + +Starting with the Landlock ABI version 5, it is possible to restrict the use of +:manpage:`ioctl(2)` using the new ``LANDLOCK_ACCESS_FS_IOCTL_DEV`` right. + .. _kernel_support: Kernel support diff --git a/Documentation/userspace-api/media/cec/cec-func-open.rst b/Documentation/userspace-api/media/cec/cec-func-open.rst index d86563a34b9e..125c8ac6680b 100644 --- a/Documentation/userspace-api/media/cec/cec-func-open.rst +++ b/Documentation/userspace-api/media/cec/cec-func-open.rst @@ -70,5 +70,5 @@ include: ``ENOMEM`` Insufficient kernel memory was available. -``ENXIO`` - No device corresponding to this device special file exists. +``ENODEV`` + Device not found or was removed. diff --git a/Documentation/userspace-api/media/dvb/frontend_f_open.rst b/Documentation/userspace-api/media/dvb/frontend_f_open.rst index bb37eded0870..70e169b8f601 100644 --- a/Documentation/userspace-api/media/dvb/frontend_f_open.rst +++ b/Documentation/userspace-api/media/dvb/frontend_f_open.rst @@ -91,7 +91,7 @@ appropriately. - The caller has no permission to access the device. - - ``EBUSY`` - - The the device driver is already in use. + - The device driver is already in use. - - ``EMFILE`` - The process already has the maximum number of files open. diff --git a/Documentation/userspace-api/media/glossary.rst b/Documentation/userspace-api/media/glossary.rst index 96a360edbf3b..55a9c37130ba 100644 --- a/Documentation/userspace-api/media/glossary.rst +++ b/Documentation/userspace-api/media/glossary.rst @@ -25,6 +25,13 @@ Glossary See :ref:`cec`. + Data Unit + + Unit of data transported by a bus. On parallel buses, the data unit + consists of one or more related samples while on serial buses the data + unit is logical. If the data unit is image data, it may also be called a + pixel. + Device Driver Part of the Linux Kernel that implements support for a hardware component. @@ -173,6 +180,11 @@ Glossary An integrated circuit that integrates all components of a computer or other electronic systems. + Stream + A distinct flow of data (image data or metadata) from an initial source + to a final sink. The initial source may be e.g. an image sensor and the + final sink e.g. a memory buffer. + V4L2 API **V4L2 userspace API** diff --git a/Documentation/userspace-api/media/v4l/dev-meta.rst b/Documentation/userspace-api/media/v4l/dev-meta.rst index 0e7e1ee1471a..5eee9ab60395 100644 --- a/Documentation/userspace-api/media/v4l/dev-meta.rst +++ b/Documentation/userspace-api/media/v4l/dev-meta.rst @@ -47,6 +47,12 @@ member of the ``fmt`` union as needed per the desired operation. Both drivers and applications must set the remainder of the :c:type:`v4l2_format` structure to 0. +Devices that capture metadata by line have the struct v4l2_fmtdesc +``V4L2_FMT_FLAG_META_LINE_BASED`` flag set for :c:func:`VIDIOC_ENUM_FMT`. Such +devices can typically also :ref:`capture image data <capture>`. This primarily +involves devices that receive the data from a different devices such as a camera +sensor. + .. c:type:: v4l2_meta_format .. tabularcolumns:: |p{1.4cm}|p{2.4cm}|p{13.5cm}| @@ -65,3 +71,18 @@ to 0. - ``buffersize`` - Maximum buffer size in bytes required for data. The value is set by the driver. + * - __u32 + - ``width`` + - Width of a line of metadata in Data Units. Valid when + :c:type`v4l2_fmtdesc` flag ``V4L2_FMT_FLAG_META_LINE_BASED`` is set, + otherwise zero. See :c:func:`VIDIOC_ENUM_FMT`. + * - __u32 + - ``height`` + - Number of rows of metadata. Valid when :c:type`v4l2_fmtdesc` flag + ``V4L2_FMT_FLAG_META_LINE_BASED`` is set, otherwise zero. See + :c:func:`VIDIOC_ENUM_FMT`. + * - __u32 + - ``bytesperline`` + - Offset in bytes between the beginning of two consecutive lines. Valid + when :c:type`v4l2_fmtdesc` flag ``V4L2_FMT_FLAG_META_LINE_BASED`` is + set, otherwise zero. See :c:func:`VIDIOC_ENUM_FMT`. diff --git a/Documentation/userspace-api/media/v4l/dev-subdev.rst b/Documentation/userspace-api/media/v4l/dev-subdev.rst index 43988516acdd..0f9eda3187f3 100644 --- a/Documentation/userspace-api/media/v4l/dev-subdev.rst +++ b/Documentation/userspace-api/media/v4l/dev-subdev.rst @@ -506,6 +506,8 @@ source pads. subdev-formats +.. _subdev-routing: + Streams, multiplexed media pads and internal routing ---------------------------------------------------- @@ -527,9 +529,9 @@ the its sink pad and allows to route them individually to one of its source pads. Subdevice drivers that support multiplexed streams are compatible with -non-multiplexed subdev drivers, but, of course, require a routing configuration -where the link between those two types of drivers contains only a single -stream. +non-multiplexed subdev drivers. However, if the driver at the sink end of a link +does not support streams, then only stream 0 of source end may be captured. +There may be additional limitations specific to the sink device. Understanding streams ^^^^^^^^^^^^^^^^^^^^^ @@ -570,6 +572,29 @@ Any configurations of a stream within a pad, such as format or selections, are independent of similar configurations on other streams. This is subject to change in the future. +Device types and routing setup +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Different kinds of sub-devices have differing behaviour for route activation, +depending on the hardware. In all cases, however, only routes that have the +``V4L2_SUBDEV_STREAM_FL_ACTIVE`` flag set are active. + +Devices generating the streams may allow enabling and disabling some of the +routes or have a fixed routing configuration. If the routes can be disabled, not +declaring the routes (or declaring them without +``VIDIOC_SUBDEV_STREAM_FL_ACTIVE`` flag set) in ``VIDIOC_SUBDEV_S_ROUTING`` will +disable the routes. ``VIDIOC_SUBDEV_S_ROUTING`` will still return such routes +back to the user in the routes array, with the ``V4L2_SUBDEV_STREAM_FL_ACTIVE`` +flag unset. + +Devices transporting the streams almost always have more configurability with +respect to routing. Typically any route between the sub-device's sink and source +pads is possible, and multiple routes (usually up to certain limited number) may +be active simultaneously. For such devices, no routes are created by the driver +and user-created routes are fully replaced when ``VIDIOC_SUBDEV_S_ROUTING`` is +called on the sub-device. Such newly created routes have the device's default +configuration for format and selection rectangles. + Configuring streams ^^^^^^^^^^^^^^^^^^^ diff --git a/Documentation/userspace-api/media/v4l/func-open.rst b/Documentation/userspace-api/media/v4l/func-open.rst index ba23ff1e45dd..be3808cbf876 100644 --- a/Documentation/userspace-api/media/v4l/func-open.rst +++ b/Documentation/userspace-api/media/v4l/func-open.rst @@ -65,8 +65,8 @@ EBUSY The driver does not support multiple opens and the device is already in use. -ENXIO - No device corresponding to this device special file exists. +ENODEV + Device not found or was removed. ENOMEM Not enough kernel memory was available to complete the request. diff --git a/Documentation/userspace-api/media/v4l/meta-formats.rst b/Documentation/userspace-api/media/v4l/meta-formats.rst index 0bb61fc5bc00..c23aac823d2c 100644 --- a/Documentation/userspace-api/media/v4l/meta-formats.rst +++ b/Documentation/userspace-api/media/v4l/meta-formats.rst @@ -13,9 +13,10 @@ These formats are used for the :ref:`metadata` interface only. :maxdepth: 1 metafmt-d4xx + metafmt-generic metafmt-intel-ipu3 metafmt-rkisp1 metafmt-uvc + metafmt-vivid metafmt-vsp1-hgo metafmt-vsp1-hgt - metafmt-vivid diff --git a/Documentation/userspace-api/media/v4l/metafmt-generic.rst b/Documentation/userspace-api/media/v4l/metafmt-generic.rst new file mode 100644 index 000000000000..78ab56b21682 --- /dev/null +++ b/Documentation/userspace-api/media/v4l/metafmt-generic.rst @@ -0,0 +1,340 @@ +.. SPDX-License-Identifier: GPL-2.0 OR GFDL-1.1-no-invariants-or-later + +******************************************************************************************************************************************************************************************************************************************************************************** +V4L2_META_FMT_GENERIC_8 ('MET8'), V4L2_META_FMT_GENERIC_CSI2_10 ('MC1A'), V4L2_META_FMT_GENERIC_CSI2_12 ('MC1C'), V4L2_META_FMT_GENERIC_CSI2_14 ('MC1E'), V4L2_META_FMT_GENERIC_CSI2_16 ('MC1G'), V4L2_META_FMT_GENERIC_CSI2_20 ('MC1K'), V4L2_META_FMT_GENERIC_CSI2_24 ('MC1O') +******************************************************************************************************************************************************************************************************************************************************************************** + + +Generic line-based metadata formats + + +Description +=========== + +These generic line-based metadata formats define the memory layout of the data +without defining the format or meaning of the metadata itself. + +.. _v4l2-meta-fmt-generic-8: + +V4L2_META_FMT_GENERIC_8 +----------------------- + +The V4L2_META_FMT_GENERIC_8 format is a plain 8-bit metadata format. This format +is used on CSI-2 for 8 bits per :term:`Data Unit`. + +Additionally it is used for 16 bits per Data Unit when two bytes of metadata are +packed into one 16-bit Data Unit. Otherwise the 16 bits per pixel dataformat is +:ref:`V4L2_META_FMT_GENERIC_CSI2_16 <v4l2-meta-fmt-generic-csi2-16>`. + +**Byte Order Of V4L2_META_FMT_GENERIC_8.** +Each cell is one byte. "M" denotes a byte of metadata. + +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}| + +.. flat-table:: Sample 4x2 Metadata Frame + :header-rows: 0 + :stub-columns: 0 + :widths: 12 8 8 8 8 + + * - start + 0: + - M\ :sub:`00` + - M\ :sub:`10` + - M\ :sub:`20` + - M\ :sub:`30` + * - start + 4: + - M\ :sub:`01` + - M\ :sub:`11` + - M\ :sub:`21` + - M\ :sub:`31` + +.. _v4l2-meta-fmt-generic-csi2-10: + +V4L2_META_FMT_GENERIC_CSI2_10 +----------------------------- + +V4L2_META_FMT_GENERIC_CSI2_10 contains 8-bit generic metadata packed in 10-bit +Data Units, with one padding byte after every four bytes of metadata. This +format is typically used by CSI-2 receivers with a source that transmits +MEDIA_BUS_FMT_META_10 and the CSI-2 receiver writes the received data to memory +as-is. + +The packing of the data follows the MIPI CSI-2 specification and the padding of +the data is defined in the MIPI CCS specification. + +This format is also used in conjunction with 20 bits per :term:`Data Unit` +formats that pack two bytes of metadata into one Data Unit. Otherwise the +20 bits per pixel dataformat is :ref:`V4L2_META_FMT_GENERIC_CSI2_20 +<v4l2-meta-fmt-generic-csi2-20>`. + +This format is little endian. + +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_10.** +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding. + +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{.8cm}| + +.. flat-table:: Sample 4x2 Metadata Frame + :header-rows: 0 + :stub-columns: 0 + :widths: 12 8 8 8 8 8 + + * - start + 0: + - M\ :sub:`00` + - M\ :sub:`10` + - M\ :sub:`20` + - M\ :sub:`30` + - x + * - start + 5: + - M\ :sub:`01` + - M\ :sub:`11` + - M\ :sub:`21` + - M\ :sub:`31` + - x + +.. _v4l2-meta-fmt-generic-csi2-12: + +V4L2_META_FMT_GENERIC_CSI2_12 +----------------------------- + +V4L2_META_FMT_GENERIC_CSI2_12 contains 8-bit generic metadata packed in 12-bit +Data Units, with one padding byte after every two bytes of metadata. This format +is typically used by CSI-2 receivers with a source that transmits +MEDIA_BUS_FMT_META_12 and the CSI-2 receiver writes the received data to memory +as-is. + +The packing of the data follows the MIPI CSI-2 specification and the padding of +the data is defined in the MIPI CCS specification. + +This format is also used in conjunction with 24 bits per :term:`Data Unit` +formats that pack two bytes of metadata into one Data Unit. Otherwise the +24 bits per pixel dataformat is :ref:`V4L2_META_FMT_GENERIC_CSI2_24 +<v4l2-meta-fmt-generic-csi2-24>`. + +This format is little endian. + +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_12.** +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding. + +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|p{.8cm}| + +.. flat-table:: Sample 4x2 Metadata Frame + :header-rows: 0 + :stub-columns: 0 + :widths: 12 8 8 8 8 8 8 + + * - start + 0: + - M\ :sub:`00` + - M\ :sub:`10` + - x + - M\ :sub:`20` + - M\ :sub:`30` + - x + * - start + 6: + - M\ :sub:`01` + - M\ :sub:`11` + - x + - M\ :sub:`21` + - M\ :sub:`31` + - x + +.. _v4l2-meta-fmt-generic-csi2-14: + +V4L2_META_FMT_GENERIC_CSI2_14 +----------------------------- + +V4L2_META_FMT_GENERIC_CSI2_14 contains 8-bit generic metadata packed in 14-bit +Data Units, with three padding bytes after every four bytes of metadata. This +format is typically used by CSI-2 receivers with a source that transmits +MEDIA_BUS_FMT_META_14 and the CSI-2 receiver writes the received data to memory +as-is. + +The packing of the data follows the MIPI CSI-2 specification and the padding of +the data is defined in the MIPI CCS specification. + +This format is little endian. + +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_14.** +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding. + +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{.8cm}| + +.. flat-table:: Sample 4x2 Metadata Frame + :header-rows: 0 + :stub-columns: 0 + :widths: 12 8 8 8 8 8 8 8 + + * - start + 0: + - M\ :sub:`00` + - M\ :sub:`10` + - M\ :sub:`20` + - M\ :sub:`30` + - x + - x + - x + * - start + 7: + - M\ :sub:`01` + - M\ :sub:`11` + - M\ :sub:`21` + - M\ :sub:`31` + - x + - x + - x + +.. _v4l2-meta-fmt-generic-csi2-16: + +V4L2_META_FMT_GENERIC_CSI2_16 +----------------------------- + +V4L2_META_FMT_GENERIC_CSI2_16 contains 8-bit generic metadata packed in 16-bit +Data Units, with one padding byte after every byte of metadata. This format is +typically used by CSI-2 receivers with a source that transmits +MEDIA_BUS_FMT_META_16 and the CSI-2 receiver writes the received data to memory +as-is. + +The packing of the data follows the MIPI CSI-2 specification and the padding of +the data is defined in the MIPI CCS specification. + +Some devices support more efficient packing of metadata in conjunction with +16-bit image data. In that case the dataformat is +:ref:`V4L2_META_FMT_GENERIC_8 <v4l2-meta-fmt-generic-8>`. + +This format is little endian. + +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_16.** +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding. + +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}| + +.. flat-table:: Sample 4x2 Metadata Frame + :header-rows: 0 + :stub-columns: 0 + :widths: 12 8 8 8 8 8 8 8 8 + + * - start + 0: + - M\ :sub:`00` + - x + - M\ :sub:`10` + - x + - M\ :sub:`20` + - x + - M\ :sub:`30` + - x + * - start + 8: + - M\ :sub:`01` + - x + - M\ :sub:`11` + - x + - M\ :sub:`21` + - x + - M\ :sub:`31` + - x + +.. _v4l2-meta-fmt-generic-csi2-20: + +V4L2_META_FMT_GENERIC_CSI2_20 +----------------------------- + +V4L2_META_FMT_GENERIC_CSI2_20 contains 8-bit generic metadata packed in 20-bit +Data Units, with alternating one or two padding bytes after every byte of +metadata. This format is typically used by CSI-2 receivers with a source that +transmits MEDIA_BUS_FMT_META_20 and the CSI-2 receiver writes the received data +to memory as-is. + +The packing of the data follows the MIPI CSI-2 specification and the padding of +the data is defined in the MIPI CCS specification. + +Some devices support more efficient packing of metadata in conjunction with +16-bit image data. In that case the dataformat is +:ref:`V4L2_META_FMT_GENERIC_CSI2_10 <v4l2-meta-fmt-generic-csi2-10>`. + +This format is little endian. + +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_20.** +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding. + +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}| + +.. flat-table:: Sample 4x2 Metadata Frame + :header-rows: 0 + :stub-columns: 0 + :widths: 12 8 8 8 8 8 8 8 8 8 8 + + * - start + 0: + - M\ :sub:`00` + - x + - M\ :sub:`10` + - x + - x + - M\ :sub:`20` + - x + - M\ :sub:`30` + - x + - x + * - start + 10: + - M\ :sub:`01` + - x + - M\ :sub:`11` + - x + - x + - M\ :sub:`21` + - x + - M\ :sub:`31` + - x + - x + +.. _v4l2-meta-fmt-generic-csi2-24: + +V4L2_META_FMT_GENERIC_CSI2_24 +----------------------------- + +V4L2_META_FMT_GENERIC_CSI2_24 contains 8-bit generic metadata packed in 24-bit +Data Units, with two padding bytes after every byte of metadata. This format is +typically used by CSI-2 receivers with a source that transmits +MEDIA_BUS_FMT_META_24 and the CSI-2 receiver writes the received data to memory +as-is. + +The packing of the data follows the MIPI CSI-2 specification and the padding of +the data is defined in the MIPI CCS specification. + +Some devices support more efficient packing of metadata in conjunction with +16-bit image data. In that case the dataformat is +:ref:`V4L2_META_FMT_GENERIC_CSI2_12 <v4l2-meta-fmt-generic-csi2-12>`. + +This format is little endian. + +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_24.** +Each cell is one byte. "M" denotes a byte of metadata and "x" a byte of padding. + +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}| + +.. flat-table:: Sample 4x2 Metadata Frame + :header-rows: 0 + :stub-columns: 0 + :widths: 12 8 8 8 8 8 8 8 8 8 8 8 8 + + * - start + 0: + - M\ :sub:`00` + - x + - x + - M\ :sub:`10` + - x + - x + - M\ :sub:`20` + - x + - x + - M\ :sub:`30` + - x + - x + * - start + 12: + - M\ :sub:`01` + - x + - x + - M\ :sub:`11` + - x + - x + - M\ :sub:`21` + - x + - x + - M\ :sub:`31` + - x + - x diff --git a/Documentation/userspace-api/media/v4l/mmap.rst b/Documentation/userspace-api/media/v4l/mmap.rst index a5672573dd6f..1a48c3cbda17 100644 --- a/Documentation/userspace-api/media/v4l/mmap.rst +++ b/Documentation/userspace-api/media/v4l/mmap.rst @@ -188,7 +188,7 @@ Example: Mapping buffers in the multi-planar API buffers[i].start[j] = mmap(NULL, buffer.m.planes[j].length, PROT_READ | PROT_WRITE, /* recommended */ MAP_SHARED, /* recommended */ - fd, buffer.m.planes[j].m.offset); + fd, buffer.m.planes[j].m.mem_offset); if (MAP_FAILED == buffers[i].start[j]) { /* If you do not exit here you should unmap() and free() diff --git a/Documentation/userspace-api/media/v4l/pixfmt-yuv-luma.rst b/Documentation/userspace-api/media/v4l/pixfmt-yuv-luma.rst index cf8e4dfbfbd4..b3c5779521d8 100644 --- a/Documentation/userspace-api/media/v4l/pixfmt-yuv-luma.rst +++ b/Documentation/userspace-api/media/v4l/pixfmt-yuv-luma.rst @@ -36,6 +36,8 @@ are often referred to as greyscale formats. - Byte 2 - Byte 3 - Byte 4 + - Byte 5 + - Byte 6 * .. _V4L2-PIX-FMT-GREY: @@ -47,6 +49,8 @@ are often referred to as greyscale formats. - ... - ... - ... + - ... + - ... * .. _V4L2-PIX-FMT-IPU3-Y10: @@ -58,6 +62,8 @@ are often referred to as greyscale formats. - Y'\ :sub:`2`\ [3:0] Y'\ :sub:`1`\ [9:6] - Y'\ :sub:`3`\ [1:0] Y'\ :sub:`2`\ [9:4] - Y'\ :sub:`3`\ [9:2] + - ... + - ... * .. _V4L2-PIX-FMT-Y10: @@ -69,6 +75,8 @@ are often referred to as greyscale formats. - ... - ... - ... + - ... + - ... * .. _V4L2-PIX-FMT-Y10BPACK: @@ -80,6 +88,8 @@ are often referred to as greyscale formats. - Y'\ :sub:`1`\ [3:0] Y'\ :sub:`2`\ [9:6] - Y'\ :sub:`2`\ [5:0] Y'\ :sub:`3`\ [9:8] - Y'\ :sub:`3`\ [7:0] + - ... + - ... * .. _V4L2-PIX-FMT-Y10P: @@ -91,6 +101,8 @@ are often referred to as greyscale formats. - Y'\ :sub:`2`\ [9:2] - Y'\ :sub:`3`\ [9:2] - Y'\ :sub:`3`\ [1:0] Y'\ :sub:`2`\ [1:0] Y'\ :sub:`1`\ [1:0] Y'\ :sub:`0`\ [1:0] + - ... + - ... * .. _V4L2-PIX-FMT-Y12: @@ -102,6 +114,8 @@ are often referred to as greyscale formats. - ... - ... - ... + - ... + - ... * .. _V4L2-PIX-FMT-Y012: @@ -113,6 +127,21 @@ are often referred to as greyscale formats. - ... - ... - ... + - ... + - ... + + * .. _V4L2-PIX-FMT-Y12P: + + - ``V4L2_PIX_FMT_Y12P`` + - 'Y12P' + + - Y'\ :sub:`0`\ [11:4] + - Y'\ :sub:`1`\ [11:4] + - Y'\ :sub:`1`\ [3:0] Y'\ :sub:`0`\ [3:0] + - ... + - ... + - ... + - ... * .. _V4L2-PIX-FMT-Y14: @@ -124,6 +153,21 @@ are often referred to as greyscale formats. - ... - ... - ... + - ... + - ... + + * .. _V4L2-PIX-FMT-Y14P: + + - ``V4L2_PIX_FMT_Y14P`` + - 'Y14P' + + - Y'\ :sub:`0`\ [13:6] + - Y'\ :sub:`1`\ [13:6] + - Y'\ :sub:`2`\ [13:6] + - Y'\ :sub:`3`\ [13:6] + - Y'\ :sub:`1`\ [1:0] Y'\ :sub:`0`\ [5:0] + - Y'\ :sub:`2`\ [3:0] Y'\ :sub:`1`\ [5:2] + - Y'\ :sub:`3`\ [5:0] Y'\ :sub:`2`\ [5:4] * .. _V4L2-PIX-FMT-Y16: @@ -135,6 +179,8 @@ are often referred to as greyscale formats. - ... - ... - ... + - ... + - ... * .. _V4L2-PIX-FMT-Y16-BE: @@ -146,6 +192,8 @@ are often referred to as greyscale formats. - ... - ... - ... + - ... + - ... .. raw:: latex diff --git a/Documentation/userspace-api/media/v4l/subdev-formats.rst b/Documentation/userspace-api/media/v4l/subdev-formats.rst index eb3cd20b0cf2..d2a6cd2e1eb2 100644 --- a/Documentation/userspace-api/media/v4l/subdev-formats.rst +++ b/Documentation/userspace-api/media/v4l/subdev-formats.rst @@ -33,7 +33,7 @@ Media Bus Formats * - __u32 - ``field`` - Field order, from enum :c:type:`v4l2_field`. See - :ref:`field-order` for details. + :ref:`field-order` for details. Zero for metadata mbus codes. * - __u32 - ``colorspace`` - Image colorspace, from enum :c:type:`v4l2_colorspace`. @@ -45,7 +45,7 @@ Media Bus Formats conversion is supported by setting the flag V4L2_SUBDEV_MBUS_CODE_CSC_COLORSPACE in the corresponding struct :c:type:`v4l2_subdev_mbus_code_enum` during enumeration. - See :ref:`v4l2-subdev-mbus-code-flags`. + See :ref:`v4l2-subdev-mbus-code-flags`. Zero for metadata mbus codes. * - union { - (anonymous) * - __u16 @@ -61,7 +61,7 @@ Media Bus Formats that ycbcr_enc conversion is supported by setting the flag V4L2_SUBDEV_MBUS_CODE_CSC_YCBCR_ENC in the corresponding struct :c:type:`v4l2_subdev_mbus_code_enum` during enumeration. - See :ref:`v4l2-subdev-mbus-code-flags`. + See :ref:`v4l2-subdev-mbus-code-flags`. Zero for metadata mbus codes. * - __u16 - ``hsv_enc`` - HSV encoding, from enum :c:type:`v4l2_hsv_encoding`. @@ -75,7 +75,7 @@ Media Bus Formats that hsv_enc conversion is supported by setting the flag V4L2_SUBDEV_MBUS_CODE_CSC_HSV_ENC in the corresponding struct :c:type:`v4l2_subdev_mbus_code_enum` during enumeration. - See :ref:`v4l2-subdev-mbus-code-flags` + See :ref:`v4l2-subdev-mbus-code-flags`. Zero for metadata mbus codes. * - } - * - __u16 @@ -90,8 +90,8 @@ Media Bus Formats The driver indicates that quantization conversion is supported by setting the flag V4L2_SUBDEV_MBUS_CODE_CSC_QUANTIZATION in the corresponding struct :c:type:`v4l2_subdev_mbus_code_enum` - during enumeration. See :ref:`v4l2-subdev-mbus-code-flags`. - + during enumeration. See :ref:`v4l2-subdev-mbus-code-flags`. Zero for + metadata mbus codes. * - __u16 - ``xfer_func`` - Transfer function, from enum :c:type:`v4l2_xfer_func`. @@ -104,7 +104,8 @@ Media Bus Formats The driver indicates that the transfer function conversion is supported by setting the flag V4L2_SUBDEV_MBUS_CODE_CSC_XFER_FUNC in the corresponding struct :c:type:`v4l2_subdev_mbus_code_enum` - during enumeration. See :ref:`v4l2-subdev-mbus-code-flags`. + during enumeration. See :ref:`v4l2-subdev-mbus-code-flags`. Zero for + metadata mbus codes. * - __u16 - ``flags`` - flags See: :ref:v4l2-mbus-framefmt-flags @@ -8306,3 +8307,257 @@ The following table lists the existing metadata formats. both sides of the link and the bus format is a fixed metadata format that is not configurable from userspace. Width and height will be set to 0 for this format. + +Generic Serial Metadata Formats +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Generic serial metadata formats are used on serial buses where the actual data +content is more or less device specific but the data is transmitted and received +by multiple devices that do not process the data in any way, simply writing +it to system memory for processing in software at the end of the pipeline. + +"b" in an array cell signifies a byte of data, followed by the number of the bit +and finally the bit number in subscript. "x" indicates a padding bit. + +.. _media-bus-format-generic-meta: + +.. cssclass: longtable + +.. flat-table:: Generic Serial Metadata Formats + :header-rows: 2 + :stub-columns: 0 + + * - Identifier + - Code + - + - :cspan:`23` Data organization within bus :term:`Data Unit` + * - + - + - Bit + - 23 + - 22 + - 21 + - 20 + - 19 + - 18 + - 17 + - 16 + - 15 + - 14 + - 13 + - 12 + - 11 + - 10 + - 9 + - 8 + - 7 + - 6 + - 5 + - 4 + - 3 + - 2 + - 1 + - 0 + * .. _MEDIA-BUS-FMT-META-8: + + - MEDIA_BUS_FMT_META_8 + - 0x8001 + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - b0\ :sub:`7` + - b0\ :sub:`6` + - b0\ :sub:`5` + - b0\ :sub:`4` + - b0\ :sub:`3` + - b0\ :sub:`2` + - b0\ :sub:`1` + - b0\ :sub:`0` + * .. _MEDIA-BUS-FMT-META-10: + + - MEDIA_BUS_FMT_META_10 + - 0x8002 + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - b0\ :sub:`7` + - b0\ :sub:`6` + - b0\ :sub:`5` + - b0\ :sub:`4` + - b0\ :sub:`3` + - b0\ :sub:`2` + - b0\ :sub:`1` + - b0\ :sub:`0` + - x + - x + * .. _MEDIA-BUS-FMT-META-12: + + - MEDIA_BUS_FMT_META_12 + - 0x8003 + - + - + - + - + - + - + - + - + - + - + - + - + - + - b0\ :sub:`7` + - b0\ :sub:`6` + - b0\ :sub:`5` + - b0\ :sub:`4` + - b0\ :sub:`3` + - b0\ :sub:`2` + - b0\ :sub:`1` + - b0\ :sub:`0` + - x + - x + - x + - x + * .. _MEDIA-BUS-FMT-META-14: + + - MEDIA_BUS_FMT_META_14 + - 0x8004 + - + - + - + - + - + - + - + - + - + - + - + - b0\ :sub:`7` + - b0\ :sub:`6` + - b0\ :sub:`5` + - b0\ :sub:`4` + - b0\ :sub:`3` + - b0\ :sub:`2` + - b0\ :sub:`1` + - b0\ :sub:`0` + - x + - x + - x + - x + - x + - x + * .. _MEDIA-BUS-FMT-META-16: + + - MEDIA_BUS_FMT_META_16 + - 0x8005 + - + - + - + - + - + - + - + - + - + - b0\ :sub:`7` + - b0\ :sub:`6` + - b0\ :sub:`5` + - b0\ :sub:`4` + - b0\ :sub:`3` + - b0\ :sub:`2` + - b0\ :sub:`1` + - b0\ :sub:`0` + - x + - x + - x + - x + - x + - x + - x + - x + * .. _MEDIA-BUS-FMT-META-20: + + - MEDIA_BUS_FMT_META_20 + - 0x8006 + - + - + - + - + - + - b0\ :sub:`7` + - b0\ :sub:`6` + - b0\ :sub:`5` + - b0\ :sub:`4` + - b0\ :sub:`3` + - b0\ :sub:`2` + - b0\ :sub:`1` + - b0\ :sub:`0` + - x + - x + - x + - x + - x + - x + - x + - x + - x + - x + - x + - x + * .. _MEDIA-BUS-FMT-META-24: + + - MEDIA_BUS_FMT_META_24 + - 0x8007 + - + - b0\ :sub:`7` + - b0\ :sub:`6` + - b0\ :sub:`5` + - b0\ :sub:`4` + - b0\ :sub:`3` + - b0\ :sub:`2` + - b0\ :sub:`1` + - b0\ :sub:`0` + - x + - x + - x + - x + - x + - x + - x + - x + - x + - x + - x + - x + - x + - x + - x + - x diff --git a/Documentation/userspace-api/media/v4l/user-func.rst b/Documentation/userspace-api/media/v4l/user-func.rst index 15ff0bf7bbe6..6f661138801c 100644 --- a/Documentation/userspace-api/media/v4l/user-func.rst +++ b/Documentation/userspace-api/media/v4l/user-func.rst @@ -62,6 +62,7 @@ Function Reference vidioc-query-dv-timings vidioc-querystd vidioc-reqbufs + vidioc-remove-bufs vidioc-s-hw-freq-seek vidioc-streamon vidioc-subdev-enum-frame-interval diff --git a/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst b/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst index 000c154b0f98..3adb3d205531 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst @@ -227,6 +227,13 @@ the ``mbus_code`` field is handled differently: The application can ask to configure the quantization of the capture device when calling the :ref:`VIDIOC_S_FMT <VIDIOC_G_FMT>` ioctl with :ref:`V4L2_PIX_FMT_FLAG_SET_CSC <v4l2-pix-fmt-flag-set-csc>` set. + * - ``V4L2_FMT_FLAG_META_LINE_BASED`` + - 0x0200 + - The metadata format is line-based. In this case the ``width``, + ``height`` and ``bytesperline`` fields of :c:type:`v4l2_meta_format` are + valid. The buffer consists of ``height`` lines, each having ``width`` + Data Units of data and the offset (in bytes) between the beginning of + each two consecutive lines is ``bytesperline``. Return Value ============ diff --git a/Documentation/userspace-api/media/v4l/vidioc-remove-bufs.rst b/Documentation/userspace-api/media/v4l/vidioc-remove-bufs.rst new file mode 100644 index 000000000000..1995b39af9ba --- /dev/null +++ b/Documentation/userspace-api/media/v4l/vidioc-remove-bufs.rst @@ -0,0 +1,86 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: V4L + +.. _VIDIOC_REMOVE_BUFS: + +************************ +ioctl VIDIOC_REMOVE_BUFS +************************ + +Name +==== + +VIDIOC_REMOVE_BUFS - Removes buffers from a queue + +Synopsis +======== + +.. c:macro:: VIDIOC_REMOVE_BUFS + +``int ioctl(int fd, VIDIOC_REMOVE_BUFS, struct v4l2_remove_buffers *argp)`` + +Arguments +========= + +``fd`` + File descriptor returned by :c:func:`open()`. + +``argp`` + Pointer to struct :c:type:`v4l2_remove_buffers`. + +Description +=========== + +Applications can optionally call the :ref:`VIDIOC_REMOVE_BUFS` ioctl to +remove buffers from a queue. +:ref:`VIDIOC_CREATE_BUFS` ioctl support is mandatory to enable :ref:`VIDIOC_REMOVE_BUFS`. +This ioctl is available if the ``V4L2_BUF_CAP_SUPPORTS_REMOVE_BUFS`` capability +is set on the queue when :c:func:`VIDIOC_REQBUFS` or :c:func:`VIDIOC_CREATE_BUFS` +are invoked. + +.. c:type:: v4l2_remove_buffers + +.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm}| + +.. flat-table:: struct v4l2_remove_buffers + :header-rows: 0 + :stub-columns: 0 + :widths: 1 1 2 + + * - __u32 + - ``index`` + - The starting buffer index to remove. This field is ignored if count == 0. + * - __u32 + - ``count`` + - The number of buffers to be removed with indices 'index' until 'index + count - 1'. + All buffers in this range must be valid and in DEQUEUED state. + :ref:`VIDIOC_REMOVE_BUFS` will always check the validity of ``type`, if it is + invalid it returns ``EINVAL`` error code. + If count is set to 0 :ref:`VIDIOC_REMOVE_BUFS` will do nothing and return 0. + * - __u32 + - ``type`` + - Type of the stream or buffers, this is the same as the struct + :c:type:`v4l2_format` ``type`` field. See + :c:type:`v4l2_buf_type` for valid values. + * - __u32 + - ``reserved``\ [13] + - A place holder for future extensions. Drivers and applications + must set the array to zero. + +Return Value +============ + +On success 0 is returned, on error -1 and the ``errno`` variable is set +appropriately. The generic error codes are described at the +:ref:`Generic Error Codes <gen-errors>` chapter. If an error occurs, no +buffers will be freed and one of the error codes below will be returned: + +EBUSY + File I/O is in progress. + One or more of the buffers in the range ``index`` to ``index + count - 1`` are not + in DEQUEUED state. + +EINVAL + One or more of the buffers in the range ``index`` to ``index + count - 1`` do not + exist in the queue. + The buffer type (``type`` field) is not valid. diff --git a/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst b/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst index 0b3a41a45d05..bbc22dd76032 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst @@ -121,6 +121,7 @@ aborting or finishing any DMA in progress, an implicit .. _V4L2-BUF-CAP-SUPPORTS-M2M-HOLD-CAPTURE-BUF: .. _V4L2-BUF-CAP-SUPPORTS-MMAP-CACHE-HINTS: .. _V4L2-BUF-CAP-SUPPORTS-MAX-NUM-BUFFERS: +.. _V4L2-BUF-CAP-SUPPORTS-REMOVE-BUFS: .. raw:: latex diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-crop.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-crop.rst index 92d933631fda..88a748103a71 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-crop.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-crop.rst @@ -37,9 +37,9 @@ Description .. note:: - This is an :ref:`obsolete` interface and may be removed - in the future. It is superseded by - :ref:`the selection API <VIDIOC_SUBDEV_G_SELECTION>`. + This is an :ref:`obsolete` interface and may be removed in the future. It is + superseded by :ref:`the selection API <VIDIOC_SUBDEV_G_SELECTION>`. No new + extensions to the :c:type:`v4l2_subdev_crop` structure will be accepted. To retrieve the current crop rectangle applications set the ``pad`` field of a struct :c:type:`v4l2_subdev_crop` to the diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst index 26b5004bfe6d..1cf795480602 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst @@ -43,23 +43,39 @@ The routing configuration determines the flows of data inside an entity. Drivers report their current routing tables using the ``VIDIOC_SUBDEV_G_ROUTING`` ioctl and application may enable or disable routes with the ``VIDIOC_SUBDEV_S_ROUTING`` ioctl, by adding or removing routes and -setting or clearing flags of the ``flags`` field of a -struct :c:type:`v4l2_subdev_route`. +setting or clearing flags of the ``flags`` field of a struct +:c:type:`v4l2_subdev_route`. Similarly to ``VIDIOC_SUBDEV_G_ROUTING``, also +``VIDIOC_SUBDEV_S_ROUTING`` returns the routes back to the user. -All stream configurations are reset when ``VIDIOC_SUBDEV_S_ROUTING`` is called. This -means that the userspace must reconfigure all streams after calling the ioctl -with e.g. ``VIDIOC_SUBDEV_S_FMT``. +All stream configurations are reset when ``VIDIOC_SUBDEV_S_ROUTING`` is called. +This means that the userspace must reconfigure all stream formats and selections +after calling the ioctl with e.g. ``VIDIOC_SUBDEV_S_FMT``. Only subdevices which have both sink and source pads can support routing. -When inspecting routes through ``VIDIOC_SUBDEV_G_ROUTING`` and the application -provided ``num_routes`` is not big enough to contain all the available routes -the subdevice exposes, drivers return the ENOSPC error code and adjust the -value of the ``num_routes`` field. Application should then reserve enough memory -for all the route entries and call ``VIDIOC_SUBDEV_G_ROUTING`` again. - -On a successful ``VIDIOC_SUBDEV_G_ROUTING`` call the driver updates the -``num_routes`` field to reflect the actual number of routes returned. +The ``len_routes`` field indicates the number of routes that can fit in the +``routes`` array allocated by userspace. It is set by applications for both +ioctls to indicate how many routes the kernel can return, and is never modified +by the kernel. + +The ``num_routes`` field indicates the number of routes in the routing +table. For ``VIDIOC_SUBDEV_S_ROUTING``, it is set by userspace to the number of +routes that the application stored in the ``routes`` array. For both ioctls, it +is returned by the kernel and indicates how many routes are stored in the +subdevice routing table. This may be smaller or larger than the value of +``num_routes`` set by the application for ``VIDIOC_SUBDEV_S_ROUTING``, as +drivers may adjust the requested routing table. + +The kernel can return a ``num_routes`` value larger than ``len_routes`` from +both ioctls. This indicates thare are more routes in the routing table than fits +the ``routes`` array. In this case, the ``routes`` array is filled by the kernel +with the first ``len_routes`` entries of the subdevice routing table. This is +not considered to be an error, and the ioctl call succeeds. If the applications +wants to retrieve the missing routes, it can issue a new +``VIDIOC_SUBDEV_G_ROUTING`` call with a large enough ``routes`` array. + +``VIDIOC_SUBDEV_S_ROUTING`` may return more routes than the user provided in +``num_routes`` field due to e.g. hardware properties. .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| @@ -74,6 +90,9 @@ On a successful ``VIDIOC_SUBDEV_G_ROUTING`` call the driver updates the - ``which`` - Routing table to be accessed, from enum :ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`. + * - __u32 + - ``len_routes`` + - The length of the array (as in memory reserved for the array) * - struct :c:type:`v4l2_subdev_route` - ``routes[]`` - Array of struct :c:type:`v4l2_subdev_route` entries @@ -81,7 +100,7 @@ On a successful ``VIDIOC_SUBDEV_G_ROUTING`` call the driver updates the - ``num_routes`` - Number of entries of the routes array * - __u32 - - ``reserved``\ [5] + - ``reserved``\ [11] - Reserved for future extensions. Applications and drivers must set the array to zero. @@ -135,10 +154,6 @@ On success 0 is returned, on error -1 and the ``errno`` variable is set appropriately. The generic error codes are described at the :ref:`Generic Error Codes <gen-errors>` chapter. -ENOSPC - The application provided ``num_routes`` is not big enough to contain - all the available routes the subdevice exposes. - EINVAL The sink or source pad identifiers reference a non-existing pad or reference pads of different types (ie. the sink_pad identifiers refers to a source diff --git a/Documentation/userspace-api/media/videodev2.h.rst.exceptions b/Documentation/userspace-api/media/videodev2.h.rst.exceptions index 3e58aac4ef0b..bdc628e8c1d6 100644 --- a/Documentation/userspace-api/media/videodev2.h.rst.exceptions +++ b/Documentation/userspace-api/media/videodev2.h.rst.exceptions @@ -215,6 +215,7 @@ replace define V4L2_FMT_FLAG_CSC_XFER_FUNC fmtdesc-flags replace define V4L2_FMT_FLAG_CSC_YCBCR_ENC fmtdesc-flags replace define V4L2_FMT_FLAG_CSC_HSV_ENC fmtdesc-flags replace define V4L2_FMT_FLAG_CSC_QUANTIZATION fmtdesc-flags +replace define V4L2_FMT_FLAG_META_LINE_BASED fmtdesc-flags # V4L2 timecode types replace define V4L2_TC_TYPE_24FPS timecode-type diff --git a/Documentation/userspace-api/mseal.rst b/Documentation/userspace-api/mseal.rst new file mode 100644 index 000000000000..4132eec995a3 --- /dev/null +++ b/Documentation/userspace-api/mseal.rst @@ -0,0 +1,199 @@ +.. SPDX-License-Identifier: GPL-2.0 + +===================== +Introduction of mseal +===================== + +:Author: Jeff Xu <jeffxu@chromium.org> + +Modern CPUs support memory permissions such as RW and NX bits. The memory +permission feature improves security stance on memory corruption bugs, i.e. +the attacker can’t just write to arbitrary memory and point the code to it, +the memory has to be marked with X bit, or else an exception will happen. + +Memory sealing additionally protects the mapping itself against +modifications. This is useful to mitigate memory corruption issues where a +corrupted pointer is passed to a memory management system. For example, +such an attacker primitive can break control-flow integrity guarantees +since read-only memory that is supposed to be trusted can become writable +or .text pages can get remapped. Memory sealing can automatically be +applied by the runtime loader to seal .text and .rodata pages and +applications can additionally seal security critical data at runtime. + +A similar feature already exists in the XNU kernel with the +VM_FLAGS_PERMANENT flag [1] and on OpenBSD with the mimmutable syscall [2]. + +User API +======== +mseal() +----------- +The mseal() syscall has the following signature: + +``int mseal(void addr, size_t len, unsigned long flags)`` + +**addr/len**: virtual memory address range. + +The address range set by ``addr``/``len`` must meet: + - The start address must be in an allocated VMA. + - The start address must be page aligned. + - The end address (``addr`` + ``len``) must be in an allocated VMA. + - no gap (unallocated memory) between start and end address. + +The ``len`` will be paged aligned implicitly by the kernel. + +**flags**: reserved for future use. + +**return values**: + +- ``0``: Success. + +- ``-EINVAL``: + - Invalid input ``flags``. + - The start address (``addr``) is not page aligned. + - Address range (``addr`` + ``len``) overflow. + +- ``-ENOMEM``: + - The start address (``addr``) is not allocated. + - The end address (``addr`` + ``len``) is not allocated. + - A gap (unallocated memory) between start and end address. + +- ``-EPERM``: + - sealing is supported only on 64-bit CPUs, 32-bit is not supported. + +- For above error cases, users can expect the given memory range is + unmodified, i.e. no partial update. + +- There might be other internal errors/cases not listed here, e.g. + error during merging/splitting VMAs, or the process reaching the max + number of supported VMAs. In those cases, partial updates to the given + memory range could happen. However, those cases should be rare. + +**Blocked operations after sealing**: + Unmapping, moving to another location, and shrinking the size, + via munmap() and mremap(), can leave an empty space, therefore + can be replaced with a VMA with a new set of attributes. + + Moving or expanding a different VMA into the current location, + via mremap(). + + Modifying a VMA via mmap(MAP_FIXED). + + Size expansion, via mremap(), does not appear to pose any + specific risks to sealed VMAs. It is included anyway because + the use case is unclear. In any case, users can rely on + merging to expand a sealed VMA. + + mprotect() and pkey_mprotect(). + + Some destructive madvice() behaviors (e.g. MADV_DONTNEED) + for anonymous memory, when users don't have write permission to the + memory. Those behaviors can alter region contents by discarding pages, + effectively a memset(0) for anonymous memory. + + Kernel will return -EPERM for blocked operations. + + For blocked operations, one can expect the given address is unmodified, + i.e. no partial update. Note, this is different from existing mm + system call behaviors, where partial updates are made till an error is + found and returned to userspace. To give an example: + + Assume following code sequence: + + - ptr = mmap(null, 8192, PROT_NONE); + - munmap(ptr + 4096, 4096); + - ret1 = mprotect(ptr, 8192, PROT_READ); + - mseal(ptr, 4096); + - ret2 = mprotect(ptr, 8192, PROT_NONE); + + ret1 will be -ENOMEM, the page from ptr is updated to PROT_READ. + + ret2 will be -EPERM, the page remains to be PROT_READ. + +**Note**: + +- mseal() only works on 64-bit CPUs, not 32-bit CPU. + +- users can call mseal() multiple times, mseal() on an already sealed memory + is a no-action (not error). + +- munseal() is not supported. + +Use cases: +========== +- glibc: + The dynamic linker, during loading ELF executables, can apply sealing to + non-writable memory segments. + +- Chrome browser: protect some security sensitive data-structures. + +Notes on which memory to seal: +============================== + +It might be important to note that sealing changes the lifetime of a mapping, +i.e. the sealed mapping won’t be unmapped till the process terminates or the +exec system call is invoked. Applications can apply sealing to any virtual +memory region from userspace, but it is crucial to thoroughly analyze the +mapping's lifetime prior to apply the sealing. + +For example: + +- aio/shm + + aio/shm can call mmap()/munmap() on behalf of userspace, e.g. ksys_shmdt() in + shm.c. The lifetime of those mapping are not tied to the lifetime of the + process. If those memories are sealed from userspace, then munmap() will fail, + causing leaks in VMA address space during the lifetime of the process. + +- Brk (heap) + + Currently, userspace applications can seal parts of the heap by calling + malloc() and mseal(). + let's assume following calls from user space: + + - ptr = malloc(size); + - mprotect(ptr, size, RO); + - mseal(ptr, size); + - free(ptr); + + Technically, before mseal() is added, the user can change the protection of + the heap by calling mprotect(RO). As long as the user changes the protection + back to RW before free(), the memory range can be reused. + + Adding mseal() into the picture, however, the heap is then sealed partially, + the user can still free it, but the memory remains to be RO. If the address + is re-used by the heap manager for another malloc, the process might crash + soon after. Therefore, it is important not to apply sealing to any memory + that might get recycled. + + Furthermore, even if the application never calls the free() for the ptr, + the heap manager may invoke the brk system call to shrink the size of the + heap. In the kernel, the brk-shrink will call munmap(). Consequently, + depending on the location of the ptr, the outcome of brk-shrink is + nondeterministic. + + +Additional notes: +================= +As Jann Horn pointed out in [3], there are still a few ways to write +to RO memory, which is, in a way, by design. Those cases are not covered +by mseal(). If applications want to block such cases, sandbox tools (such as +seccomp, LSM, etc) might be considered. + +Those cases are: + +- Write to read-only memory through /proc/self/mem interface. +- Write to read-only memory through ptrace (such as PTRACE_POKETEXT). +- userfaultfd. + +The idea that inspired this patch comes from Stephen Röttger’s work in V8 +CFI [4]. Chrome browser in ChromeOS will be the first user of this API. + +Reference: +========== +[1] https://github.com/apple-oss-distributions/xnu/blob/1031c584a5e37aff177559b9f69dbd3c8c3fd30a/osfmk/mach/vm_statistics.h#L274 + +[2] https://man.openbsd.org/mimmutable.2 + +[3] https://lore.kernel.org/lkml/CAG48ez3ShUYey+ZAFsU2i1RpQn0a5eOs2hzQ426FkcgnfUGLvA@mail.gmail.com + +[4] https://docs.google.com/document/d/1O2jwK4dxI3nRcOJuPYkonhTkNQfbmwdvxQMyXgeaRHo/edit#heading=h.bvaojj9fu6hc diff --git a/Documentation/userspace-api/netlink/genetlink-legacy.rst b/Documentation/userspace-api/netlink/genetlink-legacy.rst index 70a77387f6c4..fa005989193a 100644 --- a/Documentation/userspace-api/netlink/genetlink-legacy.rst +++ b/Documentation/userspace-api/netlink/genetlink-legacy.rst @@ -46,10 +46,16 @@ For reference the ``multi-attr`` array may look like this:: where ``ARRAY-ATTR`` is the array entry type. -array-nest -~~~~~~~~~~ +indexed-array +~~~~~~~~~~~~~ + +``indexed-array`` wraps the entire array in an extra attribute (hence +limiting its size to 64kB). The ``ENTRY`` nests are special and have the +index of the entry as their type instead of normal attribute type. -``array-nest`` creates the following structure:: +A ``sub-type`` is needed to describe what type in the ``ENTRY``. A ``nest`` +``sub-type`` means there are nest arrays in the ``ENTRY``, with the structure +looks like:: [SOME-OTHER-ATTR] [ARRAY-ATTR] @@ -60,9 +66,13 @@ array-nest [MEMBER1] [MEMBER2] -It wraps the entire array in an extra attribute (hence limiting its size -to 64kB). The ``ENTRY`` nests are special and have the index of the entry -as their type instead of normal attribute type. +Other ``sub-type`` like ``u32`` means there is only one member as described +in ``sub-type`` in the ``ENTRY``. The structure looks like:: + + [SOME-OTHER-ATTR] + [ARRAY-ATTR] + [ENTRY u32] + [ENTRY u32] type-value ~~~~~~~~~~ |