[SRU Bionic/Focal/Hirsute/Impish 0/1] LP: #1950644 - LTP finit_module02 failure

[Thadeu Lima de Souza Cascardo]

BugLink: https://bugs.launchpad.net/bugs/1950644

[Impact]
Some uses of kernel_read_file_from_fd may lead to a WARN when the file is
not opened for reading.

The WARNING, however, is not present on earlier kernels, which will return
a different error code. The fix, however, has been applied to upstream stable
and may be worth so tests can PASS without much change.

[Fix/Backport]
The fix is trivial, but the backport for Focal and Bionic was picked up
from 5.4.y upstream stable tree, because the function was moved to a
different file.

[Test case]
The finit_module02 test case from LTP covers this.

[Potential regression]
kernel_read_file_from_fd is used for module loading and kexec, so there is
where regressions might show up.

-- 
2.32.0