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charset=utf-8 Content-Disposition: inline In-Reply-To: <20251006004741.GA29231@pendragon.ideasonboard.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251005_180815_695427_EDFE2466 X-CRM114-Status: GOOD ( 57.29 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Oct 06, 2025 at 03:47:43AM +0300, Laurent Pinchart wrote: > Hi Jacopo, > > Thank you for the patch. > > On Mon, Sep 15, 2025 at 07:18:14PM +0200, Jacopo Mondi wrote: > > Add to the v4l2 framework helper functions to support drivers > > s/v4l2/V4L2/ > > > when validating a buffer of extensible ISP parameters. > > > > Introduce new types in include/media/v4l2-isp.h that drivers shall use > > in order to comply with the generic ISP parameters validation procedure, > > and add helper functionss to v4l2-isp.c to perform blocks and buffer > > validation. > > > > Reviewed-by: Daniel Scally > > Signed-off-by: Jacopo Mondi > > --- > > MAINTAINERS | 2 + > > drivers/media/v4l2-core/Kconfig | 4 ++ > > drivers/media/v4l2-core/Makefile | 1 + > > drivers/media/v4l2-core/v4l2-isp.c | 108 +++++++++++++++++++++++++++++++++++++ > > include/media/v4l2-isp.h | 100 ++++++++++++++++++++++++++++++++++ > > 5 files changed, 215 insertions(+) > > > > diff --git a/MAINTAINERS b/MAINTAINERS > > index abba872cb63f1430a49a2afbace4b9f9958c3991..5e0e4208ebe6c58a9ea0834e1ebb36abd2de06e1 100644 > > --- a/MAINTAINERS > > +++ b/MAINTAINERS > > @@ -26415,6 +26415,8 @@ M: Jacopo Mondi > > L: linux-media@vger.kernel.org > > S: Maintained > > F: Documentation/userspace-api/media/v4l/extensible-parameters.rst > > +F: drivers/media/v4l2-core/v4l2-isp.c > > +F: include/media/v4l2-isp.h > > F: include/uapi/linux/media/v4l2-isp.h > > > > VF610 NAND DRIVER > > diff --git a/drivers/media/v4l2-core/Kconfig b/drivers/media/v4l2-core/Kconfig > > index 331b8e535e5bbf33f22638b2ae8bc764ad5fc407..d50ccac9733cc39a43426ae7e7996dd0b5b45186 100644 > > --- a/drivers/media/v4l2-core/Kconfig > > +++ b/drivers/media/v4l2-core/Kconfig > > @@ -82,3 +82,7 @@ config V4L2_CCI_I2C > > depends on I2C > > select REGMAP_I2C > > select V4L2_CCI > > + > > +config V4L2_ISP > > + tristate > > + depends on VIDEOBUF2_CORE > > diff --git a/drivers/media/v4l2-core/Makefile b/drivers/media/v4l2-core/Makefile > > index 2177b9d63a8ffc1127c5a70118249a2ff63cd759..329f0eadce994cc1c8580beb435f68fa7e2a7aeb 100644 > > --- a/drivers/media/v4l2-core/Makefile > > +++ b/drivers/media/v4l2-core/Makefile > > @@ -29,6 +29,7 @@ obj-$(CONFIG_V4L2_CCI) += v4l2-cci.o > > obj-$(CONFIG_V4L2_FLASH_LED_CLASS) += v4l2-flash-led-class.o > > obj-$(CONFIG_V4L2_FWNODE) += v4l2-fwnode.o > > obj-$(CONFIG_V4L2_H264) += v4l2-h264.o > > +obj-$(CONFIG_V4L2_ISP) += v4l2-isp.o > > obj-$(CONFIG_V4L2_JPEG_HELPER) += v4l2-jpeg.o > > obj-$(CONFIG_V4L2_MEM2MEM_DEV) += v4l2-mem2mem.o > > obj-$(CONFIG_V4L2_VP9) += v4l2-vp9.o > > diff --git a/drivers/media/v4l2-core/v4l2-isp.c b/drivers/media/v4l2-core/v4l2-isp.c > > new file mode 100644 > > index 0000000000000000000000000000000000000000..e350bdaf53b5502e1ec2a4989c20df1100ab2d2a > > --- /dev/null > > +++ b/drivers/media/v4l2-core/v4l2-isp.c > > @@ -0,0 +1,108 @@ > > +// SPDX-License-Identifier: GPL-2.0-or-later > > +/* > > + * Video4Linux2 generic ISP parameters and statistics support > > + * > > + * Copyright (C) 2025 Ideas On Board Oy > > + * Author: Jacopo Mondi > > + */ > > + > > +#include > > +#include > > + > > +#include > > +#include > > v4l2-isp goes first. > > > + > > +int v4l2_params_buffer_validate(struct device *dev, struct vb2_buffer *vb, > > + size_t max_size) > > +{ > > + size_t header_size = offsetof(struct v4l2_params_buffer, data); > > + struct v4l2_params_buffer *buffer = vb2_plane_vaddr(vb, 0); > > + size_t payload_size = vb2_get_plane_payload(vb, 0); > > + size_t buffer_size; > > + > > + /* Payload size can't be greater than the destination buffer size */ > > + if (payload_size > max_size) { > > + dev_dbg(dev, "Payload size is too large: %zu\n", payload_size); > > + return -EINVAL; > > + } > > + > > + /* Payload size can't be smaller than the header size */ > > + if (payload_size < header_size) { > > + dev_dbg(dev, "Payload size is too small: %zu\n", payload_size); > > + return -EINVAL; > > + } > > + > > + /* Validate the size reported in the parameter buffer header */ > > + buffer_size = header_size + buffer->data_size; > > + if (buffer_size != payload_size) { > > + dev_dbg(dev, "Data size %zu and payload size %zu are different\n", > > + buffer_size, payload_size); > > + return -EINVAL; > > + } > > This check needs to go to v4l2_params_blocks_validate() as it has to be > performed on the data after copying. > > > + > > + return 0; > > +} > > +EXPORT_SYMBOL_GPL(v4l2_params_buffer_validate); > > + > > +int v4l2_params_blocks_validate(struct device *dev, > > + const struct v4l2_params_buffer *buffer, > > + const struct v4l2_params_handler *handlers, > > + size_t num_handlers) > > +{ > > + size_t block_offset = 0; > > + size_t buffer_size; > > + > > + /* Walk the list of parameter blocks and validate them. */ > > + buffer_size = buffer->data_size; > > + while (buffer_size >= sizeof(struct v4l2_params_block_header)) { > > + const struct v4l2_params_handler *handler; > > + const struct v4l2_params_block_header *block; > > + > > + /* Validate block sizes and types against the handlers. */ > > + block = (const struct v4l2_params_block_header *) > > + (buffer->data + block_offset); > > + > > + if (block->type >= num_handlers) { > > + dev_dbg(dev, "Invalid parameters block type\n"); > > I'd print the type and offset in the message to ease debugging. > > > + return -EINVAL; > > + } > > + > > + if (block->size > buffer_size) { > > + dev_dbg(dev, "Premature end of parameters data\n"); > > + return -EINVAL; > > + } > > + > > + /* It's invalid to specify both ENABLE and DISABLE. */ > > + if ((block->flags & (V4L2_PARAMS_FL_BLOCK_ENABLE | > > + V4L2_PARAMS_FL_BLOCK_DISABLE)) == > > + (V4L2_PARAMS_FL_BLOCK_ENABLE | > > + V4L2_PARAMS_FL_BLOCK_DISABLE)) { > > + dev_dbg(dev, "Invalid parameters block flags\n"); > > Same here (print the flags and offset). > > > + return -EINVAL; > > + } > > + > > + /* > > + * Match the block reported size against the handler's expected > > + * one, but allow the block to only contain the header in > > + * case it is going to be disabled. > > + */ > > + handler = &handlers[block->type]; > > + if (block->size != handler->size && > > + (!(block->flags & V4L2_PARAMS_FL_BLOCK_DISABLE) || > > + block->size != sizeof(*block))) { > > + dev_dbg(dev, "Invalid parameters block size\n"); > > And here too (print the size and offset). > > > + return -EINVAL; > > + } > > + > > + block_offset += block->size; > > + buffer_size -= block->size; > > + } > > + > > + if (buffer_size) { > > + dev_dbg(dev, "Unexpected data after the parameters buffer end\n"); > > + return -EINVAL; > > + } > > + > > + return 0; > > +} > > +EXPORT_SYMBOL_GPL(v4l2_params_blocks_validate); > > diff --git a/include/media/v4l2-isp.h b/include/media/v4l2-isp.h > > new file mode 100644 > > index 0000000000000000000000000000000000000000..2ad62c6169eef3d0fb8d245de56cc6bd7e6227e4 > > --- /dev/null > > +++ b/include/media/v4l2-isp.h > > @@ -0,0 +1,100 @@ > > +/* SPDX-License-Identifier: GPL-2.0-or-later */ > > +/* > > + * Video4Linux2 generic ISP parameters and statistics support > > + * > > + * Copyright (C) 2025 Ideas On Board Oy > > + * Author: Jacopo Mondi > > + */ > > + > > +#ifndef V4L2_PARAMS_H_ > > +#define V4L2_PARAMS_H_ > > V4L2_ISP_H_ > > > + > > +#include > > + > > +struct device; > > +struct vb2_buffer; > > + > > +/** > > + * typedef v4l2_params_block_handler - V4L2 extensible format block handler > > As commented on 1/8, let's use the v4l2_isp_ prefix. > > > + * @arg: pointer the driver-specific argument > > + * @block: the ISP configuration block to handle > > + * > > + * Defines the function signature of the functions that handle an ISP block > > + * configuration. > > + */ > > +typedef void (*v4l2_params_block_handler)(void *arg, > > + const struct v4l2_params_block_header *block); > > + > > +/** > > + * struct v4l2_params_handler - V4L2 extensible format handler > > + * @size: the block expected size > > + * @handler: the block handler function > > + * > > + * The v4l2_params_handler defines the type that driver making use of the > > + * V4L2 extensible parameters shall use to define their own ISP block > > + * handlers. > > + * > > + * Drivers shall prepare a list of handlers, one for each supported ISP block > > + * and correctly populate the structure's field with the expected block @size > > + * (used for validation) and a pointer to each block @handler function. > > + */ > > +struct v4l2_params_handler { > > + size_t size; > > + v4l2_params_block_handler handler; > > +}; > > + > > +/** > > + * v4l2_params_buffer_validate - Validate a V4L2 extensible parameters buffer > > As this is the pre-copy validation, what would you think of calling the > function v4l2_isp_params_pre_validate_buffer() ? The next function would > be called v4l2_isp_params_validate_buffer(), as they're both about > buffer validation. I'm also OK to keep the current names (with a > v4l2_isp_ prefix). > > I'm also thinking that the copy could be moved to the helper, but it can > be done later. > > > + * @dev: the driver's device pointer > > + * @vb: the videobuf2 buffer > > + * @max_size: the maximum allowed buffer size > > + * @buffer_validate: callback to the driver-specific buffer validation > > You forgot to drop the documentation for this argument. > > > + * > > + * Helper function that performs validation of an extensible parameters buffer. > > + * > > + * The helper is meant to be used by drivers to perform validation of the > > + * extensible parameters buffer size correctness. > > + * > > + * The @vb buffer as received from the vb2 .buf_prepare() operation is checked > > + * against @max_size and its validated to be large enough to accommodate at > > + * least one ISP configuration block. The effective buffer size is compared > > + * with the reported data size to make sure they match. > > + * > > + * Drivers should use this function to validate the buffer size correctness > > + * before performing a copy of the user-provided videobuf2 buffer content into a > > + * kernel-only memory buffer to prevent userspace from modifying the buffer > > + * content after it has been submitted to the driver. > > + */ > > +int v4l2_params_buffer_validate(struct device *dev, struct vb2_buffer *vb, > > + size_t max_size); > > + > > +/** > > + * v4l2_params_blocks_validate - Validate V4L2 extensible parameters ISP > > + * configuration blocks > > + * @dev: the driver's device pointer > > + * @buffer: the extensible parameters configuration buffer > > + * @handlers: the list of block handlers > > array of block handlers > > > + * @num_handlers: the number of block handlers > > + * > > + * Helper function that performs validation of the ISP configuration blocks in > > + * an extensible parameters buffer. > > + * > > + * The helper is meant to be used by drivers to perform validation of the > > + * ISP configuration data blocks. For each block in the extensible parameters > > + * buffer, its size and correctness are validated against its associated handler > > + * in the @handlers list. > > You need to explain somewhere that the handlers array is indexed by > block type. > > > + * > > + * Drivers should use this function to validate the ISP configuration blocks > > + * after having validated the correctness of the vb2 buffer sizes by using the > > + * v4l2_params_buffer_validate() helper first. Once the buffer size has been > > + * validated, drivers should perform a copy of the user-provided buffer into a > > + * kernel-only memory buffer to prevent userspace from modifying the buffer > > + * content after it has been submitted to the driver, and then call this > > + * function to perform per-block validation. > > There's room for improvement in the documentation. I think it would be > clearer if you explained the big picture in > Documentation/userspace-api/media/v4l/extensible-parameters.rst My bad, that should be Documentation/driver-api/media/v4l2-isp.rst. > (pre-validation, copy and post-validation), and only focussed on what > those two functions do in their kerneldoc. That can be done later, > nothing that you say here is incorrect. > > With the other comments addressed, > > Reviewed-by: Laurent Pinchart > > > + */ > > +int v4l2_params_blocks_validate(struct device *dev, > > + const struct v4l2_params_buffer *buffer, > > + const struct v4l2_params_handler *handlers, > > + size_t num_handlers); > > + > > +#endif /* V4L2_PARAMS_H_ */ -- Regards, Laurent Pinchart