Cosmin Tanislav
c0b1da281d
Switch to u64 arithmetic and use DIV_ROUND_CLOSEST_ULL() to avoid the overflow. buffer[i] is unsigned int and is limited by the lirc core to IR_MAX_DURATION, which is 500000. idata->freq is u32, which has a max value of 0xFFFFFFFF. In the case where buffer[i] is 500000, idata->freq overflows the u32 multiplication for any values >= 8590. 0xFFFFFFFF / 500000 ~= 8589 By casting buffer[i] to u64, idata->freq can be any u32 value without overflowing the multiplication. 0xFFFFFFFFFFFFFFFF / 500000 ~= 36893488147419 (> 4294967295) The result of the final operation will fit back into the unsigned int limits without any issues. 500000 * 0xFFFFFFFF / 1000000 = 0x80000000 (< 0xFFFFFFFF) Signed-off-by: Cosmin Tanislav <demonsingur@gmail.com> Signed-off-by: Sean Young <sean@mess.org> Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
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 reStructuredText 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.