The initial value of hid->collection[].parent_idx if 0. When Report descriptor doesn't contain "HID Collection", the value remains as 0. In the meanwhile, when the Report descriptor fullfill all following conditions, it will trigger hid_apply_multiplier function call. 1. Usage page is Generic Desktop Ctrls (0x01) 2. Usage is RESOLUTION_MULTIPLIER (0x48) 3. Contain any FEATURE items The while loop in hid_apply_multiplier will search the top-most collection by searching parent_idx == -1. Because all parent_idx is 0. The loop will run forever. There is a Report Descriptor triggerring the deadloop 0x05, 0x01, // Usage Page (Generic Desktop Ctrls) 0x09, 0x48, // Usage (0x48) 0x95, 0x01, // Report Count (1) 0x75, 0x08, // Report Size (8) 0xB1, 0x01, // Feature Signed-off-by: Xin Zhao <xnzhao@google.com> Link: https://lore.kernel.org/r/20230130212947.1315941-1-xnzhao@google.com Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> |
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|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.