f08cae2f28
The file offset argument to the arm64 sys_mmap() implementation is scaled from bytes to pages by shifting right by PAGE_SHIFT. Unfortunately, the offset is passed in as a signed 'off_t' type and therefore large offsets (i.e. with the top bit set) are incorrectly sign-extended by the shift. This has been observed to cause false mmap() failures when mapping GPU doorbells on an arm64 server part. Change the type of the file offset argument to sys_mmap() from 'off_t' to 'unsigned long' so that the shifting scales the value as expected. Cc: <stable@vger.kernel.org> Signed-off-by: Boyang Zhou <zhouby_cn@126.com> [will: rewrote commit message] Signed-off-by: Will Deacon <will.deacon@arm.com>
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.