| Message ID | 3042b32a13aecbf8f3c8bedee34a4ca8c7d7cb2e.1695679700.git.falcon@tinylab.org (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | DCE/DSE: Add Dead Syscalls Elimination support, part1 | expand |
On Tue, Sep 26, 2023, at 00:40, Zhangjin Wu wrote: > For HAVE_TRIM_UNUSED_SYSCALLS, the syscall tables are hacked with the > input used syscalls. > > Based on the used syscalls information, a new version of tbl file is > generated from the original tbl file and named with a 'used' suffix. > > With this new tbl file, both unistd_nr_*.h and syscall_table_*.h files > are updated to only include the used syscalls. > > $ grep _Linux_syscalls -ur arch/mips/include/generated/asm/ > arch/mips/include/generated/asm/unistd_nr_n64.h:#define > __NR_64_Linux_syscalls 165 > arch/mips/include/generated/asm/unistd_nr_n32.h:#define > __NR_N32_Linux_syscalls 165 > arch/mips/include/generated/asm/unistd_nr_o32.h:#define > __NR_O32_Linux_syscalls 89 > > $ grep -vr sys_ni_syscall > arch/mips/include/generated/asm/syscall_table_*.h > arch/mips/include/generated/asm/syscall_table_n32.h:__SYSCALL(58, > sys_exit) > arch/mips/include/generated/asm/syscall_table_n32.h:__SYSCALL(164, > sys_reboot) > arch/mips/include/generated/asm/syscall_table_n64.h:__SYSCALL(58, > sys_exit) My feeling is that instead of postprocessing the generated files, it would be much better to make the elimination part of the existing infrastructure that generates the files from syscall.tbl, and finally change the include/asm-generic/unistd.h to the same format, as we had planned for a long time. I should be able to help out with that part. Arnd
Hi, Arnd > On Tue, Sep 26, 2023, at 00:40, Zhangjin Wu wrote: > > For HAVE_TRIM_UNUSED_SYSCALLS, the syscall tables are hacked with the > > input used syscalls. > > > > Based on the used syscalls information, a new version of tbl file is > > generated from the original tbl file and named with a 'used' suffix. > > > > With this new tbl file, both unistd_nr_*.h and syscall_table_*.h files > > are updated to only include the used syscalls. > > > > $ grep _Linux_syscalls -ur arch/mips/include/generated/asm/ > > arch/mips/include/generated/asm/unistd_nr_n64.h:#define > > __NR_64_Linux_syscalls 165 > > arch/mips/include/generated/asm/unistd_nr_n32.h:#define > > __NR_N32_Linux_syscalls 165 > > arch/mips/include/generated/asm/unistd_nr_o32.h:#define > > __NR_O32_Linux_syscalls 89 > > > > $ grep -vr sys_ni_syscall > > arch/mips/include/generated/asm/syscall_table_*.h > > arch/mips/include/generated/asm/syscall_table_n32.h:__SYSCALL(58, > > sys_exit) > > arch/mips/include/generated/asm/syscall_table_n32.h:__SYSCALL(164, > > sys_reboot) > > arch/mips/include/generated/asm/syscall_table_n64.h:__SYSCALL(58, > > sys_exit) > > My feeling is that instead of postprocessing the generated files, > it would be much better to make the elimination part of the > existing infrastructure that generates the files from syscall.tbl, > and finally change the include/asm-generic/unistd.h to the > same format, as we had planned for a long time. > Agree very much, then we can simply touch the common files, no need to touch the arch specific files. > I should be able to help out with that part. > Thanks, is it enough to touch these ones? $ ls scripts/syscall* scripts/syscallhdr.sh scripts/syscallnr.sh scripts/syscalltbl.sh One question here is that is it possible or required to share the used syscalls selection code among them? Another question require your help is the compat part, the compat stuff makes things harder (include the Kconfig symbol interface definition and select logic), perhaps we can simply limit our first DSE version under !COMPAT? Best regards, Zhangjin > Arnd
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index bc8421859006..8a6927eff23d 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -89,6 +89,7 @@ config MIPS select HAVE_SPARSE_SYSCALL_NR select HAVE_STACKPROTECTOR select HAVE_SYSCALL_TRACEPOINTS + select HAVE_TRIM_UNUSED_SYSCALLS if HAVE_LD_DEAD_CODE_DATA_ELIMINATION select HAVE_VIRT_CPU_ACCOUNTING_GEN if 64BIT || !SMP select IRQ_FORCED_THREADING select ISA if EISA diff --git a/arch/mips/kernel/syscalls/Makefile b/arch/mips/kernel/syscalls/Makefile index e6b21de65cca..1e292a9f84a0 100644 --- a/arch/mips/kernel/syscalls/Makefile +++ b/arch/mips/kernel/syscalls/Makefile @@ -26,10 +26,29 @@ sysnr_pfx_unistd_nr_n32 := N32 sysnr_pfx_unistd_nr_n64 := 64 sysnr_pfx_unistd_nr_o32 := O32 -$(kapi)/unistd_nr_%.h: $(src)/syscall_%.tbl $(sysnr) FORCE +ifndef CONFIG_TRIM_UNUSED_SYSCALLS +tbl = $(src)/syscall_%.tbl +else + +include $(srctree)/scripts/Makefile.syscalls + +orig_tbl = $(src)/syscall_%.tbl + tbl_dir = arch/$(SRCARCH)/include/generated/tbl + tbl = $(tbl_dir)/syscall_used_%.tbl + +quiet_cmd_used = USED $@ + cmd_used = sed -E -e "/^[0-9]*[[:space:]]/{/(^($(used_syscalls))[[:space:]]|[[:space:]]($(used_syscalls))[[:space:]]|[[:space:]]($(used_syscalls))$$)/!{s/^/\#/g}}" $< > $@; + +$(tbl): $(orig_tbl) $(used_syscalls_deps) FORCE + $(Q)mkdir -p $(tbl_dir) + $(call cmd,used) + +endif + +$(kapi)/unistd_nr_%.h: $(tbl) $(sysnr) FORCE $(call if_changed,sysnr) -$(kapi)/syscall_table_%.h: $(src)/syscall_%.tbl $(systbl) FORCE +$(kapi)/syscall_table_%.h: $(tbl) $(systbl) FORCE $(call if_changed,systbl) uapisyshdr-y += unistd_n32.h \
For HAVE_TRIM_UNUSED_SYSCALLS, the syscall tables are hacked with the input used syscalls. Based on the used syscalls information, a new version of tbl file is generated from the original tbl file and named with a 'used' suffix. With this new tbl file, both unistd_nr_*.h and syscall_table_*.h files are updated to only include the used syscalls. $ grep _Linux_syscalls -ur arch/mips/include/generated/asm/ arch/mips/include/generated/asm/unistd_nr_n64.h:#define __NR_64_Linux_syscalls 165 arch/mips/include/generated/asm/unistd_nr_n32.h:#define __NR_N32_Linux_syscalls 165 arch/mips/include/generated/asm/unistd_nr_o32.h:#define __NR_O32_Linux_syscalls 89 $ grep -vr sys_ni_syscall arch/mips/include/generated/asm/syscall_table_*.h arch/mips/include/generated/asm/syscall_table_n32.h:__SYSCALL(58, sys_exit) arch/mips/include/generated/asm/syscall_table_n32.h:__SYSCALL(164, sys_reboot) arch/mips/include/generated/asm/syscall_table_n64.h:__SYSCALL(58, sys_exit) arch/mips/include/generated/asm/syscall_table_n64.h:__SYSCALL(164, sys_reboot) arch/mips/include/generated/asm/syscall_table_o32.h:__SYSCALL(1, sys_exit) arch/mips/include/generated/asm/syscall_table_o32.h:__SYSCALL(88, sys_reboot) Signed-off-by: Zhangjin Wu <falcon@tinylab.org> --- arch/mips/Kconfig | 1 + arch/mips/kernel/syscalls/Makefile | 23 +++++++++++++++++++++-- 2 files changed, 22 insertions(+), 2 deletions(-)