From: Masahiro Yamada <masahiroy@kernel.org>
To: linux-kbuild@vger.kernel.org
Cc: linux-kernel@vger.kernel.org,
Masahiro Yamada <masahiroy@kernel.org>,
Michal Marek <michal.lkml@markovi.net>,
Nick Desaulniers <ndesaulniers@google.com>
Subject: [PATCH v2 19/26] kbuild: embed symbol versions at final link of vmlinux or modules
Date: Sun, 1 May 2022 17:40:25 +0900 [thread overview]
Message-ID: <20220501084032.1025918-20-masahiroy@kernel.org> (raw)
In-Reply-To: <20220501084032.1025918-1-masahiroy@kernel.org>
Do not update objects with version CRCs while the directory descending.
Do it at the final link stage.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
(no changes since v1)
scripts/Makefile.build | 22 +++-------------------
scripts/Makefile.modfinal | 3 ++-
scripts/link-vmlinux.sh | 4 +++-
3 files changed, 8 insertions(+), 21 deletions(-)
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index a1023868775f..cec17b28de42 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -162,15 +162,9 @@ ifdef CONFIG_MODVERSIONS
# o if <file>.o doesn't contain a __ksymtab version, i.e. does
# not export symbols, it's done.
# o otherwise, we calculate symbol versions using the good old
-# genksyms on the preprocessed source and postprocess them in a way
-# that they are usable as a linker script
-# o generate .tmp_<file>.o from <file>.o using the linker to
-# replace the unresolved symbols __crc_exported_symbol with
-# the actual value of the checksum generated by genksyms
-# o remove .tmp_<file>.o to <file>.o
-
-# Generate .o.symversions files for each .o with exported symbols, and link these
-# to the kernel and/or modules at the end.
+# genksyms on the preprocessed source and dump them into the .cmd file.
+# o modpost will extract versions from the .cmd file and create linker
+# scripts used to link the kernel and/or modules.
genksyms_format_rel_crc := [^_]*__crc_\([^ ]*\) = \.; LONG(\([^)]*\)).*
genksyms_format_normal := __crc_\(.*\) = \(.*\);
@@ -188,12 +182,6 @@ gen_symversions = \
cmd_gen_symversions_c = $(call gen_symversions,c)
-cmd_modversions = \
- if [ -r $@.symversions ]; then \
- $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ \
- -T $@.symversions; \
- mv -f $(@D)/.tmp_$(@F) $@; \
- fi
endif
ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
@@ -273,7 +261,6 @@ define rule_cc_o_c
$(call cmd,checkdoc)
$(call cmd,gen_objtooldep)
$(call cmd,gen_symversions_c)
- $(if $(CONFIG_LTO_CLANG),,$(call cmd,modversions))
$(call cmd,record_mcount)
endef
@@ -282,7 +269,6 @@ define rule_as_o_S
$(call cmd,gen_ksymdeps)
$(call cmd,gen_objtooldep)
$(call cmd,gen_symversions_S)
- $(call cmd,modversions)
endef
# Built-in and composite module parts
@@ -296,8 +282,6 @@ ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
quiet_cmd_cc_prelink_modules = LD [M] $@
cmd_cc_prelink_modules = \
$(LD) $(ld_flags) -r -o $@ \
- $(shell [ -s $(@:.prelink.o=.o.symversions) ] && \
- echo -T $(@:.prelink.o=.o.symversions)) \
--whole-archive $(filter-out FORCE,$^) \
$(cmd_objtool)
diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal
index 7f39599e9fae..d429e3f9ae1d 100644
--- a/scripts/Makefile.modfinal
+++ b/scripts/Makefile.modfinal
@@ -34,6 +34,7 @@ quiet_cmd_ld_ko_o = LD [M] $@
cmd_ld_ko_o += \
$(LD) -r $(KBUILD_LDFLAGS) \
$(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE) \
+ $(addprefix -T, $(filter %.symver.lds, $(real-prereqs)))\
-T scripts/module.lds -o $@ $(filter %.o, $^); \
$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
@@ -56,7 +57,7 @@ if_changed_except = $(if $(call newer_prereqs_except,$(2))$(cmd-check), \
# Re-generate module BTFs if either module's .ko or vmlinux changed
-$(modules): %.ko: %$(mod-prelink-ext).o %.mod.o scripts/module.lds $(if $(KBUILD_BUILTIN),vmlinux) FORCE
+$(modules): %.ko: %$(mod-prelink-ext).o %.mod.o $(if $(CONFIG_MODVERSIONS), %.symver.lds) scripts/module.lds $(if $(KBUILD_BUILTIN),vmlinux) FORCE
+$(call if_changed_except,ld_ko_o,vmlinux)
ifdef CONFIG_DEBUG_INFO_BTF_MODULES
+$(if $(newer-prereqs),$(call cmd,btf_ko))
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index eceb3ee7ec06..8da5c0182665 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -90,7 +90,6 @@ modpost_link()
if is_enabled CONFIG_MODVERSIONS; then
gen_symversions
- lds="${lds} -T .tmp_symversions.lds"
fi
# This might take a while, so indicate that we're doing
@@ -196,6 +195,9 @@ vmlinux_link()
fi
ldflags="${ldflags} ${wl}--script=${objtree}/${KBUILD_LDS}"
+ if is_enabled CONFIG_MODVERSIONS; then
+ ldflags="${ldflags} ${wl}--script=vmlinux.symver.lds"
+ fi
# The kallsyms linking does not need debug symbols included.
if [ "$output" != "${output#.tmp_vmlinux.kallsyms}" ] ; then
--
2.32.0
next prev parent reply other threads:[~2022-05-01 8:43 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-01 8:40 [PATCH v2 00/26] kbuild: yet another series of cleanups (modpost and LTO) Masahiro Yamada
2022-05-01 8:40 ` [PATCH v2 01/26] modpost: use bool type where appropriate Masahiro Yamada
2022-05-03 21:43 ` Nick Desaulniers
2022-05-04 5:47 ` Masahiro Yamada
2022-05-01 8:40 ` [PATCH v2 02/26] modpost: change mod->gpl_compatible to bool type Masahiro Yamada
2022-05-03 21:45 ` Nick Desaulniers
2022-05-01 8:40 ` [PATCH v2 03/26] modpost: import include/linux/list.h Masahiro Yamada
2022-05-01 8:40 ` [PATCH v2 04/26] modpost: traverse modules in order Masahiro Yamada
2022-05-01 8:40 ` [PATCH v2 05/26] modpost: add sym_add_unresolved() helper Masahiro Yamada
2022-05-01 8:40 ` [PATCH v2 06/26] modpost: traverse unresolved symbols in order Masahiro Yamada
2022-05-03 21:49 ` Nick Desaulniers
2022-05-01 8:40 ` [PATCH v2 07/26] modpost: use doubly linked list for dump_lists Masahiro Yamada
2022-05-01 8:40 ` [PATCH v2 08/26] modpost: traverse the namespace_list in order Masahiro Yamada
2022-05-01 8:40 ` [PATCH v2 09/26] modpost: dump Module.symvers in the same order of modules.order Masahiro Yamada
2022-05-01 8:40 ` [PATCH v2 10/26] modpost: move static EXPORT_SYMBOL check to check_exports() Masahiro Yamada
2022-05-03 21:54 ` Nick Desaulniers
2022-05-01 8:40 ` [PATCH v2 11/26] modpost: make multiple export error Masahiro Yamada
2022-05-01 8:40 ` [PATCH v2 12/26] modpost: make sym_add_exported() always allocate a new symbol Masahiro Yamada
2022-05-03 21:56 ` Nick Desaulniers
2022-05-01 8:40 ` [PATCH v2 13/26] modpost: split new_symbol() to symbol allocation and hash table addition Masahiro Yamada
2022-05-03 22:00 ` Nick Desaulniers
2022-05-01 8:40 ` [PATCH v2 14/26] modpost: mitigate false-negatives for static EXPORT_SYMBOL checks Masahiro Yamada
2022-05-01 8:40 ` [PATCH v2 15/26] kbuild: record symbol versions in *.cmd files Masahiro Yamada
2022-05-01 8:40 ` [PATCH v2 16/26] kbuild: generate a list of objects in vmlinux Masahiro Yamada
2022-05-01 8:40 ` [PATCH v2 17/26] modpost: extract symbol versions from *.cmd files Masahiro Yamada
2022-05-01 8:40 ` [PATCH v2 18/26] modpost: generate linker script to collect symbol versions Masahiro Yamada
2022-05-01 8:40 ` Masahiro Yamada [this message]
2022-05-03 2:55 ` [PATCH v2 19/26] kbuild: embed symbol versions at final link of vmlinux or modules Masahiro Yamada
2022-05-01 8:40 ` [PATCH v2 20/26] kbuild: stop merging *.symversions Masahiro Yamada
2022-05-01 8:40 ` [PATCH v2 21/26] genksyms: adjust the output format for .cmd files Masahiro Yamada
2022-05-04 20:22 ` Nicolas Schier
2022-05-05 13:47 ` Masahiro Yamada
2022-05-01 8:40 ` [PATCH v2 22/26] kbuild: do not create *.prelink.o for Clang LTO or IBT Masahiro Yamada
2022-05-01 8:40 ` [PATCH v2 23/26] kbuild: make built-in.a rule robust against too long argument error Masahiro Yamada
2022-05-01 8:40 ` [PATCH v2 24/26] kbuild: make *.mod " Masahiro Yamada
2022-05-01 8:40 ` [PATCH v2 25/26] modpost: simplify the ->is_static initialization Masahiro Yamada
2022-05-01 8:40 ` [PATCH v2 26/26] modpost: use hlist for hash table implementation Masahiro Yamada
2022-05-01 12:23 ` [PATCH v2 00/26] kbuild: yet another series of cleanups (modpost and LTO) Masahiro Yamada
2022-05-05 6:55 ` Masahiro Yamada
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