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| author | Nicholas Piggin <npiggin@gmail.com> | 2018-05-09 23:00:00 +1000 |
|---|---|---|
| committer | Masahiro Yamada <yamada.masahiro@socionext.com> | 2018-05-17 22:45:01 +0900 |
| commit | 5d20ee3192a58750ef8cc24b21aad23a82689be0 (patch) | |
| tree | 7a91f8a8ee8ab7126f6d36bad1b0b121746a60c3 | |
| parent | 6ca8d9433d7712d4c3c6102816b685470504dc3d (diff) | |
| download | linux-5d20ee3192a58750ef8cc24b21aad23a82689be0.tar.bz2 | |
kbuild: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selectable if enabled
Architectures that are capable can select
HAVE_LD_DEAD_CODE_DATA_ELIMINATION to enable selection of that
option (as an EXPERT kernel option).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| -rw-r--r-- | arch/Kconfig | 15 | ||||
| -rw-r--r-- | init/Kconfig | 27 |
2 files changed, 27 insertions, 15 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index 706dec4d295a..c88fa0eb49df 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -596,21 +596,6 @@ config CC_STACKPROTECTOR_AUTO endchoice -config LD_DEAD_CODE_DATA_ELIMINATION - bool - help - Select this if the architecture wants to do dead code and - data elimination with the linker by compiling with - -ffunction-sections -fdata-sections and linking with - --gc-sections. - - This requires that the arch annotates or otherwise protects - its external entry points from being discarded. Linker scripts - must also merge .text.*, .data.*, and .bss.* correctly into - output sections. Care must be taken not to pull in unrelated - sections (e.g., '.text.init'). Typically '.' in section names - is used to distinguish them from label names / C identifiers. - config HAVE_ARCH_WITHIN_STACK_FRAMES bool help diff --git a/init/Kconfig b/init/Kconfig index f013afc74b11..1706d963766b 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1038,6 +1038,33 @@ config CC_OPTIMIZE_FOR_SIZE endchoice +config HAVE_LD_DEAD_CODE_DATA_ELIMINATION + bool + help + This requires that the arch annotates or otherwise protects + its external entry points from being discarded. Linker scripts + must also merge .text.*, .data.*, and .bss.* correctly into + output sections. Care must be taken not to pull in unrelated + sections (e.g., '.text.init'). Typically '.' in section names + is used to distinguish them from label names / C identifiers. + +config LD_DEAD_CODE_DATA_ELIMINATION + bool "Dead code and data elimination (EXPERIMENTAL)" + depends on HAVE_LD_DEAD_CODE_DATA_ELIMINATION + depends on EXPERT + help + Select this if the architecture wants to do dead code and + data elimination with the linker by compiling with + -ffunction-sections -fdata-sections, and linking with + --gc-sections. + + This can reduce on disk and in-memory size of the kernel + code and static data, particularly for small configs and + on small systems. This has the possibility of introducing + silently broken kernel if the required annotations are not + present. This option is not well tested yet, so use at your + own risk. + config SYSCTL bool |