Masahiro Yamada 7c8f5662c5 modpost: avoid false-positive file open error
One problem of grab_file() is that it cannot distinguish the following
two cases:

 - It cannot read the file (the file does not exist, or read permission
   is not set)

 - It can read the file, but the file size is zero

This is because grab_file() calls mmap(), which requires the mapped
length is greater than 0. Hence, grab_file() fails for both cases.

If an empty header file were included for checksum calculation, the
following warning would be printed:

  WARNING: modpost: could not open ...: Invalid argument

An empty file is a valid source file, so it should not fail.

Use read_text_file() instead. It can read a zero-length file.
Then, parse_file() will succeed with doing nothing.

Going forward, the first case (it cannot read the file) is a fatal
error. If the source file from which an object was compiled is missing,
something went wrong.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06 23:38:13 +09:00
..
2020-02-04 03:05:24 +00:00
2017-03-28 16:16:52 +02:00
2020-04-03 13:12:26 -07:00