On Wed, Feb 09, 2022 at 07:57:42PM +0100, Alexander Lobakin wrote: > Address places which need special care and enable > CONFIG_ARCH_SUPPORTS_ASM_FUNCTION_SECTIONS. > > Notably: > - propagate `--sectname-subst` to KBUILD_AFLAGS in > x86/boot/Makefile and x86/boot/compressed/Makefile as both > override them; > - symbols starting with a dot (like ".Lrelocated") should be > handled manually with SYM_*_START_SECT(.Lrelocated, relocated) > as "two dots" is a special (and CPP doesn't want to concatenate > two dots in general); > - some symbols explicitly need to reside in one section (like > kexec control code, hibernation page etc.); > - macros creating aliases for functions (like __memcpy() for > memcpy() etc.) should go after the main declaration (as > aliases should be declared in the same section and they > don't have SYM_PUSH_SECTION() inside); > - things like ".org", ".align" should be manually pushed to > the same section the next symbol goes to; > - expand indirect_thunk wildcards in vmlinux.lds.S to catch > symbols back into the "main" section; > - inline ASM functions like __raw_callee*() should be pushed > manually as well. > > With these changes and `-ffunction-sections` enabled, "plain" > ".text" section is empty which means that everything works > right as expected. > > Signed-off-by: Alexander Lobakin <alexandr.lobakin@xxxxxxxxx> > --- > arch/x86/Kconfig | 1 + > arch/x86/boot/Makefile | 1 + > arch/x86/boot/compressed/Makefile | 1 + > arch/x86/boot/compressed/head_32.S | 2 +- > arch/x86/boot/compressed/head_64.S | 32 ++++++++++++------- > arch/x86/boot/pmjump.S | 2 +- > arch/x86/crypto/aesni-intel_asm.S | 4 +-- > arch/x86/crypto/poly1305-x86_64-cryptogams.pl | 4 +++ > arch/x86/include/asm/paravirt.h | 2 ++ > arch/x86/include/asm/qspinlock_paravirt.h | 2 ++ > arch/x86/kernel/head_32.S | 4 +-- > arch/x86/kernel/head_64.S | 4 +-- > arch/x86/kernel/kprobes/core.c | 2 ++ > arch/x86/kernel/kvm.c | 2 ++ > arch/x86/kernel/relocate_kernel_32.S | 10 +++--- > arch/x86/kernel/relocate_kernel_64.S | 12 ++++--- > arch/x86/kernel/vmlinux.lds.S | 2 +- > arch/x86/kvm/emulate.c | 7 +++- > arch/x86/lib/copy_user_64.S | 2 +- > arch/x86/lib/error-inject.c | 2 ++ > arch/x86/lib/getuser.S | 5 ++- > arch/x86/lib/memcpy_64.S | 4 +-- > arch/x86/lib/memmove_64.S | 5 ++- > arch/x86/lib/memset_64.S | 5 +-- > arch/x86/lib/putuser.S | 2 +- > arch/x86/power/hibernate_asm_32.S | 10 +++--- > arch/x86/power/hibernate_asm_64.S | 10 +++--- > 27 files changed, 89 insertions(+), 50 deletions(-) Urgh, how much of that can you avoid by (ab)using __DISABLE_EXPORTS like: https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/commit/?h=x86/wip.ibt&id=ab74f54f2b1f6cfeaf2b3ba6999bde7cabada9ca
