tree d8aa0cf8801b143f6f67eb9f83ca66fb940056b2
parent aae4e7a8bc44722fe70d58920a36916b1043195e
author Nicholas Piggin <npiggin@gmail.com> 1501073187 +1000
committer Masahiro Yamada <yamada.masahiro@socionext.com> 1502294262 +0900

kbuild: linker script do not match C names unless LD_DEAD_CODE_DATA_ELIMINATION is configured

The .data and .bss sections were modified in the generic linker script to
pull in sections named .data.<C identifier>, which are generated by gcc with
-ffunction-sections and -fdata-sections options.

The problem with this pattern is it can also match section names that Linux
defines explicitly, e.g., .data.unlikely. This can cause Linux sections to
get moved into the wrong place.

The way to avoid this is to use ".." separators for explicit section names
(the dot character is valid in a section name but not a C identifier).
However currently there are sections which don't follow this rule, so for
now just disable the wild card by default.

Example: http://marc.info/?l=linux-arm-kernel&m=150106824024221&w=2

Cc: <stable@vger.kernel.org> # 4.9
Fixes: b67067f1176df ("kbuild: allow archs to select link dead code/data elimination")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>