mainlining shenanigans
e78fdbad1e
The device-managed allocation API doesn't work well with the life-cycle of device objects. Since ports have device objects allocated within, it can lead to situations where these devices need to stay around until after their parent pad controller has been unbound from its driver. The device-managed memory allocated for the port objects will, however, get freed when the pad controller unbinds from the driver. This can cause use-after-free errors down the road. Note that the device is deleted as part of the driver unbind operation, so there isn't much that can be done with it after that point, but the memory still needs to stay around to ensure none of the references are invalidated. One situation where this arises is when a VBUS supply is associated with a USB 2 or 3 port. When that supply is released using regulator_put() an SRCU call will queue the release of the device link connecting the port and the regulator after a grace period. This means that the regulator is going to keep on to the last reference of the port device even after the pad controller driver was unbound (which is when the memory backing the port device is freed). Fix this by allocating port objects using non-device-managed memory. Add release callbacks for these objects so that their memory gets freed when the last reference goes away. This decouples the port devices' lifetime from the "active" lifetime of the pad controller (i.e. the time during which the pad controller driver owns the device). Signed-off-by: Thierry Reding <treding@nvidia.com> |
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| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| 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.