Due to .pushsection producing orphan sections, the kernel currently uses `KEEP()` in the linker script to address this issue. Here we purpose two methods to build reference for pushed section, SHF_LINK_ORDER method and SECTION_SHF_GROUP method. The binary files compiled using both methods turn out to be identical, and it doesn't produce any side effects. Signed-off-by: Yuan Tan <tanyuan@xxxxxxxxxxx> Signed-off-by: Zhangjin Wu <falcon@xxxxxxxxxxx> --- init/Kconfig | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) diff --git a/init/Kconfig b/init/Kconfig index 9834dbb0ddae..9599d2de44e8 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1740,6 +1740,56 @@ config USED_SYSCALLS If unsure, please disable TRIM_UNUSED_SYSCALLS. +choice + prompt "Trim methods" if EXPERT + default RESTRICTED_TRIM_UNUSED_SYSCALLS + depends on TRIM_UNUSED_SYSCALLS + help + This option selects the method to trim unused syscall wrongly kept. + + The binary files compiled using both methods are identical. + + If the trim methods is not specified, some syscalls are kept by + linker script and can not be trimmed. + +config RESTRICTED_TRIM_UNUSED_SYSCALLS + bool "Leave some kept syscalls (EXPERIMENTAL)" if EXPERT + help + Say Y here to trim 'unused' syscalls wrongly kept by __ex_table + like sections in kernel space. + + Some syscalls are kept by linker script and can not be trimmed. + + If unsure, choose this. + +config SECTION_SHF_LINK_ORDER_SUPPORT + bool "Using SHF_LINK_ORDER attribute (EXPERIMENTAL)" if EXPERT + depends on HAVE_SECTION_SHF_LINK_ORDER_SUPPORT + help + Say Y here to trim more 'unused' syscalls wrongly kept by __ex_table + like sections in kernel space. + + This option uses the SHF_LINK_ORDER attribute to build references for + orphan sections. Therefore, these sections are no longer kept in the + linker script. + + If unsure, not choose this. + +config SECTION_SHF_GROUP_SUPPORT + bool "Using SHF_GROUP attribute (EXPERIMENTAL)" if EXPERT + depends on HAVE_SECTION_SHF_GROUP_SUPPORT + help + Say Y here to trim more 'unused' syscalls wrongly kept by __ex_table + like sections in kernel space. + + This option uses the SHF_GROUP attribute to build references for + orphan sections. Therefore, these sections are no longer kept in the + linker script. + + If unsure, not choose this. + +endchoice + config KALLSYMS bool "Load all symbols for debugging/ksymoops" if EXPERT default y -- 2.34.1
