From e493f472752000968f5b30aac10391288cfbf5b1 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Thu, 5 May 2022 16:22:34 +0900 Subject: kbuild: generate a list of objects in vmlinux A *.mod file lists the member objects of a module, but vmlinux does not have such a file. Generate this list to allow modpost to know all the member objects. Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier Tested-by: Nathan Chancellor --- scripts/link-vmlinux.sh | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'scripts/link-vmlinux.sh') diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index 20f44504a644..eceb3ee7ec06 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -311,6 +311,7 @@ cleanup() rm -f vmlinux.map rm -f vmlinux.o rm -f .vmlinux.d + rm -f .vmlinux.objs } # Use "make V=1" to debug this script @@ -342,6 +343,16 @@ ${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init need-builtin=1 modpost_link vmlinux.o objtool_link vmlinux.o +# Generate the list of objects in vmlinux +for f in ${KBUILD_VMLINUX_OBJS} ${KBUILD_VMLINUX_LIBS}; do + case ${f} in + *.a) + ${AR} t ${f} ;; + *) + echo ${f} ;; + esac +done > .vmlinux.objs + # modpost vmlinux.o to check for section mismatches ${MAKE} -f "${srctree}/scripts/Makefile.modpost" MODPOST_VMLINUX=1 -- cgit v1.2.3 From 7b4537199a4a8480b8c3ba37a2d44765ce76cd9b Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Fri, 13 May 2022 20:39:22 +0900 Subject: kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS include/{linux,asm-generic}/export.h defines a weak symbol, __crc_* as a placeholder. Genksyms writes the version CRCs into the linker script, which will be used for filling the __crc_* symbols. The linker script format depends on CONFIG_MODULE_REL_CRCS. If it is enabled, __crc_* holds the offset to the reference of CRC. It is time to get rid of this complexity. Now that modpost parses text files (.*.cmd) to collect all the CRCs, it can generate C code that will be linked to the vmlinux or modules. Generate a new C file, .vmlinux.export.c, which contains the CRCs of symbols exported by vmlinux. It is compiled and linked to vmlinux in scripts/link-vmlinux.sh. Put the CRCs of symbols exported by modules into the existing *.mod.c files. No additional build step is needed for modules. As before, *.mod.c are compiled and linked to *.ko in scripts/Makefile.modfinal. No linker magic is used here. The new C implementation works in the same way, whether CONFIG_RELOCATABLE is enabled or not. CONFIG_MODULE_REL_CRCS is no longer needed. Previously, Kbuild invoked additional $(LD) to update the CRCs in objects, but this step is unneeded too. Signed-off-by: Masahiro Yamada Tested-by: Nathan Chancellor Tested-by: Nicolas Schier Reviewed-by: Nicolas Schier Tested-by: Sedat Dilek # LLVM-14 (x86-64) --- scripts/link-vmlinux.sh | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'scripts/link-vmlinux.sh') diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index eceb3ee7ec06..db34dc3163ae 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -90,7 +90,6 @@ modpost_link() if is_enabled CONFIG_MODVERSIONS; then gen_symversions - lds="${lds} -T .tmp_symversions.lds" fi # This might take a while, so indicate that we're doing @@ -183,6 +182,10 @@ vmlinux_link() libs="${KBUILD_VMLINUX_LIBS}" fi + if is_enabled CONFIG_MODULES; then + objs="${objs} .vmlinux.export.o" + fi + if [ "${SRCARCH}" = "um" ]; then wl=-Wl, ld="${CC}" @@ -312,6 +315,7 @@ cleanup() rm -f vmlinux.o rm -f .vmlinux.d rm -f .vmlinux.objs + rm -f .vmlinux.export.c } # Use "make V=1" to debug this script @@ -363,6 +367,10 @@ info GEN modules.builtin tr '\0' '\n' < modules.builtin.modinfo | sed -n 's/^[[:alnum:]:_]*\.file=//p' | tr ' ' '\n' | uniq | sed -e 's:^:kernel/:' -e 's/$/.ko/' > modules.builtin +if is_enabled CONFIG_MODULES; then + ${MAKE} -f "${srctree}/scripts/Makefile.vmlinux" .vmlinux.export.o +fi + btf_vmlinux_bin_o="" if is_enabled CONFIG_DEBUG_INFO_BTF; then btf_vmlinux_bin_o=.btf.vmlinux.bin.o -- cgit v1.2.3 From 7375cbcf2343a9337b19846e76dfd94c3af98a27 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Fri, 13 May 2022 20:39:23 +0900 Subject: kbuild: stop merging *.symversions Now modpost reads symbol versions from .*.cmd files. The merged *.symversions are no longer needed. Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier Tested-by: Nathan Chancellor Tested-by: Sedat Dilek # LLVM-14 (x86-64) --- scripts/link-vmlinux.sh | 19 ------------------- 1 file changed, 19 deletions(-) (limited to 'scripts/link-vmlinux.sh') diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index db34dc3163ae..eb6721e2fc47 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -56,20 +56,6 @@ gen_initcalls() > .tmp_initcalls.lds } -# If CONFIG_LTO_CLANG is selected, collect generated symbol versions into -# .tmp_symversions.lds -gen_symversions() -{ - info GEN .tmp_symversions.lds - rm -f .tmp_symversions.lds - - for o in ${KBUILD_VMLINUX_OBJS} ${KBUILD_VMLINUX_LIBS}; do - if [ -f ${o}.symversions ]; then - cat ${o}.symversions >> .tmp_symversions.lds - fi - done -} - # Link of vmlinux.o used for section mismatch analysis # ${1} output file modpost_link() @@ -88,10 +74,6 @@ modpost_link() gen_initcalls lds="-T .tmp_initcalls.lds" - if is_enabled CONFIG_MODVERSIONS; then - gen_symversions - fi - # This might take a while, so indicate that we're doing # an LTO link info LTO ${1} @@ -307,7 +289,6 @@ cleanup() rm -f .btf.* rm -f .tmp_System.map rm -f .tmp_initcalls.lds - rm -f .tmp_symversions.lds rm -f .tmp_vmlinux* rm -f System.map rm -f vmlinux -- cgit v1.2.3 From 0aa24a79ee3b603f6e6cd470c364edc2d746f613 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sun, 29 May 2022 13:23:18 +0900 Subject: kbuild: do not try to parse *.cmd files for objects provided by compiler Guenter Roeck reported the build breakage for parisc and csky. I confirmed nios2 and openrisc are broken as well. The reason is that they borrow libgcc.a from the toolchains. For example, see this line in arch/parisc/Makefile: LIBGCC := $(shell $(CC) -print-libgcc-file-name) Some objects in libgcc.a are linked to vmlinux.o, but they do not have .*.cmd files. Obviously, there is no EXPORT_SYMBOL in external objects. Ignore them. (Most of the architectures import library code into the kernel tree. Perhaps those 4 architectures can do similar, but I do not know how challenging it is.) Fixes: f292d875d0dc ("modpost: extract symbol versions from *.cmd files") Link: https://lore.kernel.org/linux-kbuild/20220528224745.GA2501857@roeck-us.net/T/#mac65c20c71c3e272db0350ecfba53fcd8905b0a0 Reported-by: Guenter Roeck Signed-off-by: Masahiro Yamada Tested-by: Guenter Roeck --- scripts/link-vmlinux.sh | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'scripts/link-vmlinux.sh') diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index a7f6196c7e41..68e4be463a76 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -344,9 +344,16 @@ ${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init need-builtin=1 modpost_link vmlinux.o objtool_link vmlinux.o -# Generate the list of objects in vmlinux +# Generate the list of in-tree objects in vmlinux +# +# This is used to retrieve symbol versions generated by genksyms. for f in ${KBUILD_VMLINUX_OBJS} ${KBUILD_VMLINUX_LIBS}; do case ${f} in + *libgcc.a) + # Some architectures do '$(CC) --print-libgcc-file-name' to + # borrow libgcc.a from the toolchain. + # There is no EXPORT_SYMBOL in external objects. Ignore this. + ;; *.a) ${AR} t ${f} ;; *) -- cgit v1.2.3 From a78b6afa9913890e92aede1c17e72dec7e528549 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sun, 29 May 2022 00:47:01 +0900 Subject: kbuild: remove redundant cleanups in scripts/link-vmlinux.sh These are cleaned by the top Makefile. vmlinux.o and .vmlinux.d matches the '*.[aios]' and '.*.d' patterns respectively. Signed-off-by: Masahiro Yamada Tested-by: Sedat Dilek # LLVM-14 (x86-64) --- scripts/link-vmlinux.sh | 2 -- 1 file changed, 2 deletions(-) (limited to 'scripts/link-vmlinux.sh') diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index 68e4be463a76..1c0af7288b79 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -309,8 +309,6 @@ cleanup() rm -f System.map rm -f vmlinux rm -f vmlinux.map - rm -f vmlinux.o - rm -f .vmlinux.d rm -f .vmlinux.objs rm -f .vmlinux.export.c } -- cgit v1.2.3 From b0d6207bad2cb5a6f2099ac4a6ea4e76864dd596 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sun, 29 May 2022 00:47:02 +0900 Subject: kbuild: clean .tmp_* pattern by make clean Change the "make clean" rule to remove all the .tmp_* files. .tmp_objdiff is the only exception, which should be removed by "make mrproper". Rename the record directory of objdiff, .tmp_objdiff to .objdiff to avoid the removal by "make clean". Signed-off-by: Masahiro Yamada Tested-by: Sedat Dilek # LLVM-14 (x86-64) --- scripts/link-vmlinux.sh | 3 --- 1 file changed, 3 deletions(-) (limited to 'scripts/link-vmlinux.sh') diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index 1c0af7288b79..3f51b08cc203 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -303,9 +303,6 @@ sorttable() cleanup() { rm -f .btf.* - rm -f .tmp_System.map - rm -f .tmp_initcalls.lds - rm -f .tmp_vmlinux* rm -f System.map rm -f vmlinux rm -f vmlinux.map -- cgit v1.2.3 From 5d45950dfbb1540bba3e3762a3497de8b4a715d3 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sun, 29 May 2022 00:47:03 +0900 Subject: kbuild: move vmlinux.o link to scripts/Makefile.vmlinux_o This is a preparation for moving the objtool rule in the next commit. Signed-off-by: Masahiro Yamada Tested-by: Sedat Dilek # LLVM-14 (x86-64) --- scripts/link-vmlinux.sh | 41 +---------------------------------------- 1 file changed, 1 insertion(+), 40 deletions(-) (limited to 'scripts/link-vmlinux.sh') diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index 3f51b08cc203..bf685d4547c1 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -45,45 +45,6 @@ info() printf " %-7s %s\n" "${1}" "${2}" } -# Generate a linker script to ensure correct ordering of initcalls. -gen_initcalls() -{ - info GEN .tmp_initcalls.lds - - ${PYTHON3} ${srctree}/scripts/jobserver-exec \ - ${PERL} ${srctree}/scripts/generate_initcall_order.pl \ - ${KBUILD_VMLINUX_OBJS} ${KBUILD_VMLINUX_LIBS} \ - > .tmp_initcalls.lds -} - -# Link of vmlinux.o used for section mismatch analysis -# ${1} output file -modpost_link() -{ - local objects - local lds="" - - objects="--whole-archive \ - ${KBUILD_VMLINUX_OBJS} \ - --no-whole-archive \ - --start-group \ - ${KBUILD_VMLINUX_LIBS} \ - --end-group" - - if is_enabled CONFIG_LTO_CLANG; then - gen_initcalls - lds="-T .tmp_initcalls.lds" - - # This might take a while, so indicate that we're doing - # an LTO link - info LTO ${1} - else - info LD ${1} - fi - - ${LD} ${KBUILD_LDFLAGS} -r -o ${1} ${lds} ${objects} -} - objtool_link() { local objtoolcmd; @@ -336,7 +297,7 @@ fi; ${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init need-builtin=1 #link vmlinux.o -modpost_link vmlinux.o +${MAKE} -f "${srctree}/scripts/Makefile.vmlinux_o" objtool_link vmlinux.o # Generate the list of in-tree objects in vmlinux -- cgit v1.2.3 From b42d2306502419688190aa6dd4dab4a6def24b3d Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sun, 29 May 2022 00:47:04 +0900 Subject: kbuild: factor out the common objtool arguments scripts/Makefile.build and scripts/link-vmlinux.sh have similar setups for the objtool arguments. It was difficult to factor out them because all the vmlinux build rules were written in a shell script. It is somewhat tedious to touch the two files every time a new objtool option is supported. To reduce the code duplication, move the objtool for vmlinux.o into scripts/Makefile.vmlinux_o. Then, move the common macros to Makefile.lib so they are shared between Makefile.build and Makefile.vmlinux_o. Signed-off-by: Masahiro Yamada Tested-by: Sedat Dilek # LLVM-14 (x86-64) --- scripts/link-vmlinux.sh | 71 ------------------------------------------------- 1 file changed, 71 deletions(-) (limited to 'scripts/link-vmlinux.sh') diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index bf685d4547c1..eecc1863e556 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -45,76 +45,6 @@ info() printf " %-7s %s\n" "${1}" "${2}" } -objtool_link() -{ - local objtoolcmd; - local objtoolopt; - - if ! is_enabled CONFIG_OBJTOOL; then - return; - fi - - if is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT; then - - # For LTO and IBT, objtool doesn't run on individual - # translation units. Run everything on vmlinux instead. - - if is_enabled CONFIG_HAVE_JUMP_LABEL_HACK; then - objtoolopt="${objtoolopt} --hacks=jump_label" - fi - - if is_enabled CONFIG_HAVE_NOINSTR_HACK; then - objtoolopt="${objtoolopt} --hacks=noinstr" - fi - - if is_enabled CONFIG_X86_KERNEL_IBT; then - objtoolopt="${objtoolopt} --ibt" - fi - - if is_enabled CONFIG_FTRACE_MCOUNT_USE_OBJTOOL; then - objtoolopt="${objtoolopt} --mcount" - fi - - if is_enabled CONFIG_UNWINDER_ORC; then - objtoolopt="${objtoolopt} --orc" - fi - - if is_enabled CONFIG_RETPOLINE; then - objtoolopt="${objtoolopt} --retpoline" - fi - - if is_enabled CONFIG_SLS; then - objtoolopt="${objtoolopt} --sls" - fi - - if is_enabled CONFIG_STACK_VALIDATION; then - objtoolopt="${objtoolopt} --stackval" - fi - - if is_enabled CONFIG_HAVE_STATIC_CALL_INLINE; then - objtoolopt="${objtoolopt} --static-call" - fi - - objtoolopt="${objtoolopt} --uaccess" - fi - - if is_enabled CONFIG_NOINSTR_VALIDATION; then - objtoolopt="${objtoolopt} --noinstr" - fi - - if [ -n "${objtoolopt}" ]; then - - if is_enabled CONFIG_GCOV_KERNEL; then - objtoolopt="${objtoolopt} --no-unreachable" - fi - - objtoolopt="${objtoolopt} --link" - - info OBJTOOL ${1} - tools/objtool/objtool ${objtoolopt} ${1} - fi -} - # Link of vmlinux # ${1} - output file # ${2}, ${3}, ... - optional extra .o files @@ -298,7 +228,6 @@ ${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init need-builtin=1 #link vmlinux.o ${MAKE} -f "${srctree}/scripts/Makefile.vmlinux_o" -objtool_link vmlinux.o # Generate the list of in-tree objects in vmlinux # -- cgit v1.2.3