From 0ce5139fd96e9d415d3faaef1c575e238f9bbd67 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Thu, 18 Sep 2025 10:05:46 +0200 Subject: kbuild: always create intermediate vmlinux.unstripped Generate the intermediate vmlinux.unstripped regardless of CONFIG_ARCH_VMLINUX_NEEDS_RELOCS. If CONFIG_ARCH_VMLINUX_NEEDS_RELOCS is unset, vmlinux.unstripped and vmlinux are identiacal. This simplifies the build rule, and allows to strip more sections by adding them to remove-section-y. Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier Link: https://patch.msgid.link/a48ca543fa2305bd17324f41606dcaed9b19f2d4.1758182101.git.legion@kernel.org Signed-off-by: Nathan Chancellor --- scripts/Makefile.vmlinux | 45 ++++++++++++++++++++++----------------------- 1 file changed, 22 insertions(+), 23 deletions(-) (limited to 'scripts/Makefile.vmlinux') diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux index b64862dc6f08..4f2d4c3fb737 100644 --- a/scripts/Makefile.vmlinux +++ b/scripts/Makefile.vmlinux @@ -9,20 +9,6 @@ include $(srctree)/scripts/Makefile.lib targets := -ifdef CONFIG_ARCH_VMLINUX_NEEDS_RELOCS -vmlinux-final := vmlinux.unstripped - -quiet_cmd_strip_relocs = RSTRIP $@ - cmd_strip_relocs = $(OBJCOPY) --remove-section='.rel*' --remove-section=!'.rel*.dyn' $< $@ - -vmlinux: $(vmlinux-final) FORCE - $(call if_changed,strip_relocs) - -targets += vmlinux -else -vmlinux-final := vmlinux -endif - %.o: %.c FORCE $(call if_changed_rule,cc_o_c) @@ -61,19 +47,19 @@ targets += .builtin-dtbs-list ifdef CONFIG_GENERIC_BUILTIN_DTB targets += .builtin-dtbs.S .builtin-dtbs.o -$(vmlinux-final): .builtin-dtbs.o +vmlinux.unstripped: .builtin-dtbs.o endif -# vmlinux +# vmlinux.unstripped # --------------------------------------------------------------------------- ifdef CONFIG_MODULES targets += .vmlinux.export.o -$(vmlinux-final): .vmlinux.export.o +vmlinux.unstripped: .vmlinux.export.o endif ifdef CONFIG_ARCH_WANTS_PRE_LINK_VMLINUX -$(vmlinux-final): arch/$(SRCARCH)/tools/vmlinux.arch.o +vmlinux.unstripped: arch/$(SRCARCH)/tools/vmlinux.arch.o arch/$(SRCARCH)/tools/vmlinux.arch.o: vmlinux.o FORCE $(Q)$(MAKE) $(build)=arch/$(SRCARCH)/tools $@ @@ -86,17 +72,30 @@ cmd_link_vmlinux = \ $< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)" "$@"; \ $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true) -targets += $(vmlinux-final) -$(vmlinux-final): scripts/link-vmlinux.sh vmlinux.o $(KBUILD_LDS) FORCE +targets += vmlinux.unstripped +vmlinux.unstripped: scripts/link-vmlinux.sh vmlinux.o $(KBUILD_LDS) FORCE +$(call if_changed_dep,link_vmlinux) ifdef CONFIG_DEBUG_INFO_BTF -$(vmlinux-final): $(RESOLVE_BTFIDS) +vmlinux.unstripped: $(RESOLVE_BTFIDS) endif ifdef CONFIG_BUILDTIME_TABLE_SORT -$(vmlinux-final): scripts/sorttable +vmlinux.unstripped: scripts/sorttable endif +# vmlinux +# --------------------------------------------------------------------------- + +remove-section-y := +remove-section-$(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS) += '.rel*' + +quiet_cmd_strip_relocs = OBJCOPY $@ + cmd_strip_relocs = $(OBJCOPY) $(addprefix --remove-section=,$(remove-section-y)) $< $@ + +targets += vmlinux +vmlinux: vmlinux.unstripped FORCE + $(call if_changed,strip_relocs) + # modules.builtin.ranges # --------------------------------------------------------------------------- ifdef CONFIG_BUILTIN_MODULE_RANGES @@ -110,7 +109,7 @@ modules.builtin.ranges: $(srctree)/scripts/generate_builtin_ranges.awk \ modules.builtin vmlinux.map vmlinux.o.map FORCE $(call if_changed,modules_builtin_ranges) -vmlinux.map: $(vmlinux-final) +vmlinux.map: vmlinux.unstripped @: endif -- cgit v1.2.3 From 3e86e4d74c0490e5fc5a7f8de8f29e7579c9ffe5 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Thu, 18 Sep 2025 10:05:47 +0200 Subject: kbuild: keep .modinfo section in vmlinux.unstripped Keep the .modinfo section during linking, but strip it from the final vmlinux. Adjust scripts/mksysmap to exclude modinfo symbols from kallsyms. This change will allow the next commit to extract the .modinfo section from the vmlinux.unstripped intermediate. Signed-off-by: Masahiro Yamada Signed-off-by: Alexey Gladkov Reviewed-by: Nicolas Schier Link: https://patch.msgid.link/aaf67c07447215463300fccaa758904bac42f992.1758182101.git.legion@kernel.org Signed-off-by: Nathan Chancellor --- include/asm-generic/vmlinux.lds.h | 2 +- scripts/Makefile.vmlinux | 7 +++++-- scripts/mksysmap | 3 +++ 3 files changed, 9 insertions(+), 3 deletions(-) (limited to 'scripts/Makefile.vmlinux') diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index ae2d2359b79e..cfa63860dfd4 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -831,6 +831,7 @@ defined(CONFIG_AUTOFDO_CLANG) || defined(CONFIG_PROPELLER_CLANG) /* Required sections not related to debugging. */ #define ELF_DETAILS \ + .modinfo : { *(.modinfo) } \ .comment 0 : { *(.comment) } \ .symtab 0 : { *(.symtab) } \ .strtab 0 : { *(.strtab) } \ @@ -1044,7 +1045,6 @@ defined(CONFIG_AUTOFDO_CLANG) || defined(CONFIG_PROPELLER_CLANG) *(.discard.*) \ *(.export_symbol) \ *(.no_trim_symbol) \ - *(.modinfo) \ /* ld.bfd warns about .gnu.version* even when not emitted */ \ *(.gnu.version*) \ diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux index 4f2d4c3fb737..70856dab0f54 100644 --- a/scripts/Makefile.vmlinux +++ b/scripts/Makefile.vmlinux @@ -86,11 +86,14 @@ endif # vmlinux # --------------------------------------------------------------------------- -remove-section-y := +remove-section-y := .modinfo remove-section-$(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS) += '.rel*' +# To avoid warnings: "empty loadable segment detected at ..." from GNU objcopy, +# it is necessary to remove the PT_LOAD flag from the segment. quiet_cmd_strip_relocs = OBJCOPY $@ - cmd_strip_relocs = $(OBJCOPY) $(addprefix --remove-section=,$(remove-section-y)) $< $@ + cmd_strip_relocs = $(OBJCOPY) $(patsubst %,--set-section-flags %=noload,$(remove-section-y)) $< $@; \ + $(OBJCOPY) $(addprefix --remove-section=,$(remove-section-y)) $@ targets += vmlinux vmlinux: vmlinux.unstripped FORCE diff --git a/scripts/mksysmap b/scripts/mksysmap index 3accbdb269ac..a607a0059d11 100755 --- a/scripts/mksysmap +++ b/scripts/mksysmap @@ -79,6 +79,9 @@ / _SDA_BASE_$/d / _SDA2_BASE_$/d +# MODULE_INFO() +/ __UNIQUE_ID_modinfo[0-9]*$/d + # --------------------------------------------------------------------------- # Ignored patterns # (symbols that contain the pattern are ignored) -- cgit v1.2.3 From 39cfd5b12160be4f57df1c3ba60139741c827616 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Thu, 18 Sep 2025 10:05:48 +0200 Subject: kbuild: extract modules.builtin.modinfo from vmlinux.unstripped Currently, we assume all the data for modules.builtin.modinfo are available in vmlinux.o. This makes it impossible for modpost, which is invoked after vmlinux.o, to add additional module info. This commit moves the modules.builtin.modinfo rule after modpost. Signed-off-by: Masahiro Yamada Signed-off-by: Alexey Gladkov Reviewed-by: Nicolas Schier Link: https://patch.msgid.link/cdb3e5b9a739666b755cd0097dc34ab69c350e51.1758182101.git.legion@kernel.org Signed-off-by: Nathan Chancellor --- scripts/Makefile.vmlinux | 26 ++++++++++++++++++++++++++ scripts/Makefile.vmlinux_o | 26 +------------------------- 2 files changed, 27 insertions(+), 25 deletions(-) (limited to 'scripts/Makefile.vmlinux') diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux index 70856dab0f54..ce7946171497 100644 --- a/scripts/Makefile.vmlinux +++ b/scripts/Makefile.vmlinux @@ -99,6 +99,32 @@ targets += vmlinux vmlinux: vmlinux.unstripped FORCE $(call if_changed,strip_relocs) +# modules.builtin.modinfo +# --------------------------------------------------------------------------- + +OBJCOPYFLAGS_modules.builtin.modinfo := -j .modinfo -O binary + +targets += modules.builtin.modinfo +modules.builtin.modinfo: vmlinux.unstripped FORCE + $(call if_changed,objcopy) + +# modules.builtin +# --------------------------------------------------------------------------- + +__default: modules.builtin + +# The second line aids cases where multiple modules share the same object. + +quiet_cmd_modules_builtin = GEN $@ + cmd_modules_builtin = \ + tr '\0' '\n' < $< | \ + sed -n 's/^[[:alnum:]:_]*\.file=//p' | \ + tr ' ' '\n' | uniq | sed -e 's:^:kernel/:' -e 's/$$/.ko/' > $@ + +targets += modules.builtin +modules.builtin: modules.builtin.modinfo FORCE + $(call if_changed,modules_builtin) + # modules.builtin.ranges # --------------------------------------------------------------------------- ifdef CONFIG_BUILTIN_MODULE_RANGES diff --git a/scripts/Makefile.vmlinux_o b/scripts/Makefile.vmlinux_o index b024ffb3e201..23c8751285d7 100644 --- a/scripts/Makefile.vmlinux_o +++ b/scripts/Makefile.vmlinux_o @@ -1,7 +1,7 @@ # SPDX-License-Identifier: GPL-2.0-only PHONY := __default -__default: vmlinux.o modules.builtin.modinfo modules.builtin +__default: vmlinux.o include include/config/auto.conf include $(srctree)/scripts/Kbuild.include @@ -73,30 +73,6 @@ vmlinux.o: $(initcalls-lds) vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE targets += vmlinux.o -# modules.builtin.modinfo -# --------------------------------------------------------------------------- - -OBJCOPYFLAGS_modules.builtin.modinfo := -j .modinfo -O binary - -targets += modules.builtin.modinfo -modules.builtin.modinfo: vmlinux.o FORCE - $(call if_changed,objcopy) - -# modules.builtin -# --------------------------------------------------------------------------- - -# The second line aids cases where multiple modules share the same object. - -quiet_cmd_modules_builtin = GEN $@ - cmd_modules_builtin = \ - tr '\0' '\n' < $< | \ - sed -n 's/^[[:alnum:]:_]*\.file=//p' | \ - tr ' ' '\n' | uniq | sed -e 's:^:kernel/:' -e 's/$$/.ko/' > $@ - -targets += modules.builtin -modules.builtin: modules.builtin.modinfo FORCE - $(call if_changed,modules_builtin) - # Add FORCE to the prerequisites of a target to force it to be always rebuilt. # --------------------------------------------------------------------------- -- cgit v1.2.3 From 5ab23c7923a1d2ae1890026866a2d8506b010a4a Mon Sep 17 00:00:00 2001 From: Alexey Gladkov Date: Thu, 18 Sep 2025 10:05:51 +0200 Subject: modpost: Create modalias for builtin modules For some modules, modalias is generated using the modpost utility and the section is added to the module file. When a module is added inside vmlinux, modpost does not generate modalias for such modules and the information is lost. As a result kmod (which uses modules.builtin.modinfo in userspace) cannot determine that modalias is handled by a builtin kernel module. $ cat /sys/devices/pci0000:00/0000:00:14.0/modalias pci:v00008086d0000A36Dsv00001043sd00008694bc0Csc03i30 $ modinfo xhci_pci name: xhci_pci filename: (builtin) license: GPL file: drivers/usb/host/xhci-pci description: xHCI PCI Host Controller Driver Missing modalias "pci:v*d*sv*sd*bc0Csc03i30*" which will be generated by modpost if the module is built separately. To fix this it is necessary to generate the same modalias for vmlinux as for the individual modules. Fortunately '.vmlinux.export.o' is already generated from which '.modinfo' can be extracted in the same way as for vmlinux.o. Signed-off-by: Masahiro Yamada Signed-off-by: Alexey Gladkov Tested-by: Stephen Rothwell Reviewed-by: Nicolas Schier Link: https://patch.msgid.link/28d4da3b0e3fc8474142746bcf469e03752c3208.1758182101.git.legion@kernel.org Signed-off-by: Nathan Chancellor --- include/linux/module.h | 4 ---- scripts/Makefile.vmlinux | 4 +++- scripts/mksysmap | 3 +++ scripts/mod/file2alias.c | 19 ++++++++++++++++++- scripts/mod/modpost.c | 15 +++++++++++++++ scripts/mod/modpost.h | 2 ++ 6 files changed, 41 insertions(+), 6 deletions(-) (limited to 'scripts/Makefile.vmlinux') diff --git a/include/linux/module.h b/include/linux/module.h index e31ee29fac6b..e135cc79acee 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -256,14 +256,10 @@ struct module_kobject *lookup_or_create_module_kobject(const char *name); __PASTE(type, \ __PASTE(__, name))))) -#ifdef MODULE /* Creates an alias so file2alias.c can find device table. */ #define MODULE_DEVICE_TABLE(type, name) \ static typeof(name) __mod_device_table(type, name) \ __attribute__ ((used, alias(__stringify(name)))) -#else /* !MODULE */ -#define MODULE_DEVICE_TABLE(type, name) -#endif /* Version of form [:][-]. * Or for CVS/RCS ID version, everything but the number is stripped. diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux index ce7946171497..1e5e37aadcd0 100644 --- a/scripts/Makefile.vmlinux +++ b/scripts/Makefile.vmlinux @@ -89,11 +89,13 @@ endif remove-section-y := .modinfo remove-section-$(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS) += '.rel*' +remove-symbols := -w --strip-symbol='__mod_device_table__*' + # To avoid warnings: "empty loadable segment detected at ..." from GNU objcopy, # it is necessary to remove the PT_LOAD flag from the segment. quiet_cmd_strip_relocs = OBJCOPY $@ cmd_strip_relocs = $(OBJCOPY) $(patsubst %,--set-section-flags %=noload,$(remove-section-y)) $< $@; \ - $(OBJCOPY) $(addprefix --remove-section=,$(remove-section-y)) $@ + $(OBJCOPY) $(addprefix --remove-section=,$(remove-section-y)) $(remove-symbols) $@ targets += vmlinux vmlinux: vmlinux.unstripped FORCE diff --git a/scripts/mksysmap b/scripts/mksysmap index a607a0059d11..c4531eacde20 100755 --- a/scripts/mksysmap +++ b/scripts/mksysmap @@ -59,6 +59,9 @@ # EXPORT_SYMBOL (namespace) / __kstrtabns_/d +# MODULE_DEVICE_TABLE (symbol name) +/ __mod_device_table__/d + # --------------------------------------------------------------------------- # Ignored suffixes # (do not forget '$' after each pattern) diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c index 1260bc2287fb..7da9735e7ab3 100644 --- a/scripts/mod/file2alias.c +++ b/scripts/mod/file2alias.c @@ -1477,7 +1477,7 @@ void handle_moddevtable(struct module *mod, struct elf_info *info, void *symval; char *zeros = NULL; const char *type, *name, *modname; - size_t typelen; + size_t typelen, modnamelen; static const char *prefix = "__mod_device_table__"; /* We're looking for a section relative symbol */ @@ -1500,6 +1500,7 @@ void handle_moddevtable(struct module *mod, struct elf_info *info, type = strstr(modname, "__"); if (!type) return; + modnamelen = type - modname; type += strlen("__"); name = strstr(type, "__"); @@ -1526,5 +1527,21 @@ void handle_moddevtable(struct module *mod, struct elf_info *info, } } + if (mod->is_vmlinux) { + struct module_alias *alias; + + /* + * If this is vmlinux, record the name of the builtin module. + * Traverse the linked list in the reverse order, and set the + * builtin_modname unless it has already been set in the + * previous call. + */ + list_for_each_entry_reverse(alias, &mod->aliases, node) { + if (alias->builtin_modname) + break; + alias->builtin_modname = xstrndup(modname, modnamelen); + } + } + free(zeros); } diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 5ca7c268294e..47c8aa2a6939 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -2067,11 +2067,26 @@ static void write_if_changed(struct buffer *b, const char *fname) static void write_vmlinux_export_c_file(struct module *mod) { struct buffer buf = { }; + struct module_alias *alias, *next; buf_printf(&buf, "#include \n"); add_exported_symbols(&buf, mod); + + buf_printf(&buf, + "#include \n" + "#undef __MODULE_INFO_PREFIX\n" + "#define __MODULE_INFO_PREFIX\n"); + + list_for_each_entry_safe(alias, next, &mod->aliases, node) { + buf_printf(&buf, "MODULE_INFO(%s.alias, \"%s\");\n", + alias->builtin_modname, alias->str); + list_del(&alias->node); + free(alias->builtin_modname); + free(alias); + } + write_if_changed(&buf, ".vmlinux.export.c"); free(buf.p); } diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h index 9133e4c3803f..2aecb8f25c87 100644 --- a/scripts/mod/modpost.h +++ b/scripts/mod/modpost.h @@ -99,10 +99,12 @@ buf_write(struct buffer *buf, const char *s, int len); * struct module_alias - auto-generated MODULE_ALIAS() * * @node: linked to module::aliases + * @modname: name of the builtin module (only for vmlinux) * @str: a string for MODULE_ALIAS() */ struct module_alias { struct list_head node; + char *builtin_modname; char str[]; }; -- cgit v1.2.3 From 3328d39a8dca2d6ed27197a0025df7540b99adf2 Mon Sep 17 00:00:00 2001 From: Alexey Gladkov Date: Thu, 18 Sep 2025 10:05:52 +0200 Subject: kbuild: vmlinux.unstripped should always depend on .vmlinux.export.o Since .vmlinux.export.c is used to add generated by modpost modaliases for builtin modules the .vmlinux.export.o is no longer optional and should always be created. The generation of this file is not dependent on CONFIG_MODULES. Signed-off-by: Alexey Gladkov Reviewed-by: Nicolas Schier Link: https://patch.msgid.link/0e63a9c7741fe8217e4fd7c60afcf057ffa2ef5a.1758182101.git.legion@kernel.org Signed-off-by: Nathan Chancellor --- scripts/Makefile.vmlinux | 9 ++------- scripts/link-vmlinux.sh | 5 +---- 2 files changed, 3 insertions(+), 11 deletions(-) (limited to 'scripts/Makefile.vmlinux') diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux index 1e5e37aadcd0..7c6ae9886f8f 100644 --- a/scripts/Makefile.vmlinux +++ b/scripts/Makefile.vmlinux @@ -53,11 +53,6 @@ endif # vmlinux.unstripped # --------------------------------------------------------------------------- -ifdef CONFIG_MODULES -targets += .vmlinux.export.o -vmlinux.unstripped: .vmlinux.export.o -endif - ifdef CONFIG_ARCH_WANTS_PRE_LINK_VMLINUX vmlinux.unstripped: arch/$(SRCARCH)/tools/vmlinux.arch.o @@ -72,8 +67,8 @@ cmd_link_vmlinux = \ $< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)" "$@"; \ $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true) -targets += vmlinux.unstripped -vmlinux.unstripped: scripts/link-vmlinux.sh vmlinux.o $(KBUILD_LDS) FORCE +targets += vmlinux.unstripped .vmlinux.export.o +vmlinux.unstripped: scripts/link-vmlinux.sh vmlinux.o .vmlinux.export.o $(KBUILD_LDS) FORCE +$(call if_changed_dep,link_vmlinux) ifdef CONFIG_DEBUG_INFO_BTF vmlinux.unstripped: $(RESOLVE_BTFIDS) diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index 51367c2bfc21..433849ff7529 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -73,10 +73,7 @@ vmlinux_link() objs="${objs} .builtin-dtbs.o" fi - if is_enabled CONFIG_MODULES; then - objs="${objs} .vmlinux.export.o" - fi - + objs="${objs} .vmlinux.export.o" objs="${objs} init/version-timestamp.o" if [ "${SRCARCH}" = "um" ]; then -- cgit v1.2.3 From 4b47a3aefb29c523ca66f0d28de8db15a10f9352 Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Wed, 8 Oct 2025 15:46:44 -0700 Subject: kbuild: Restore pattern to avoid stripping .rela.dyn from vmlinux Commit 0ce5139fd96e ("kbuild: always create intermediate vmlinux.unstripped") removed the pattern to avoid stripping .rela.dyn sections added by commit e9d86b8e17e7 ("scripts: Do not strip .rela.dyn section"). Restore it so that .rela.dyn sections remain in the final vmlinux. Fixes: 0ce5139fd96e ("kbuild: always create intermediate vmlinux.unstripped") Acked-by: Ard Biesheuvel Acked-by: Alexey Gladkov Acked-by: Nicolas Schier Link: https://patch.msgid.link/20251008-kbuild-fix-modinfo-regressions-v1-1-9fc776c5887c@kernel.org Signed-off-by: Nathan Chancellor --- scripts/Makefile.vmlinux | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'scripts/Makefile.vmlinux') diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux index 7c6ae9886f8f..a62639982be5 100644 --- a/scripts/Makefile.vmlinux +++ b/scripts/Makefile.vmlinux @@ -82,7 +82,7 @@ endif # --------------------------------------------------------------------------- remove-section-y := .modinfo -remove-section-$(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS) += '.rel*' +remove-section-$(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS) += '.rel*' '!.rel*.dyn' remove-symbols := -w --strip-symbol='__mod_device_table__*' -- cgit v1.2.3 From 8ec3af916fe3954381cf3555ea03dc5adf4d0e8e Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Wed, 8 Oct 2025 15:46:45 -0700 Subject: kbuild: Add '.rel.*' strip pattern for vmlinux Prior to binutils commit c12d9fa2afe ("Support objcopy --remove-section=.relaFOO") [1] in 2.32, stripping relocation sections required the trailing period (i.e., '.rel.*') to work properly. After commit 3e86e4d74c04 ("kbuild: keep .modinfo section in vmlinux.unstripped"), there is an error with binutils 2.31.1 or earlier because these sections are not properly removed: s390-linux-objcopy: st6tO8Ev: symbol `.modinfo' required but not present s390-linux-objcopy:st6tO8Ev: no symbols Add the old pattern to resolve this issue (along with a comment to allow cleaning this when binutils 2.32 or newer is the minimum supported version). While the aforementioned kbuild change exposes this, the pattern was originally changed by commit 71d815bf5dfd ("kbuild: Strip runtime const RELA sections correctly"), where it would still be incorrect with binutils older than 2.32. Fixes: 71d815bf5dfd ("kbuild: Strip runtime const RELA sections correctly") Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=c12d9fa2afe7abcbe407a00e15719e1a1350c2a7 [1] Reported-by: Linux Kernel Functional Testing Closes: https://lore.kernel.org/CA+G9fYvVktRhFtZXdNgVOL8j+ArsJDpvMLgCitaQvQmCx=hwOQ@mail.gmail.com/ Acked-by: Ard Biesheuvel Acked-by: Alexey Gladkov Acked-by: Nicolas Schier Link: https://patch.msgid.link/20251008-kbuild-fix-modinfo-regressions-v1-2-9fc776c5887c@kernel.org Signed-off-by: Nathan Chancellor --- scripts/Makefile.vmlinux | 3 +++ 1 file changed, 3 insertions(+) (limited to 'scripts/Makefile.vmlinux') diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux index a62639982be5..c02f85c2e241 100644 --- a/scripts/Makefile.vmlinux +++ b/scripts/Makefile.vmlinux @@ -83,6 +83,9 @@ endif remove-section-y := .modinfo remove-section-$(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS) += '.rel*' '!.rel*.dyn' +# for compatibility with binutils < 2.32 +# https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=c12d9fa2afe7abcbe407a00e15719e1a1350c2a7 +remove-section-$(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS) += '.rel.*' remove-symbols := -w --strip-symbol='__mod_device_table__*' -- cgit v1.2.3 From b0f2942a16017f88395d768afedd7373860968ce Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Fri, 10 Oct 2025 14:49:27 -0700 Subject: kbuild: Use '--strip-unneeded-symbol' for removing module device table symbols After commit 5ab23c7923a1 ("modpost: Create modalias for builtin modules"), relocatable RISC-V kernels with CONFIG_KASAN=y start failing when attempting to strip the module device table symbols: riscv64-linux-objcopy: not stripping symbol `__mod_device_table__kmod_irq_starfive_jh8100_intc__of__starfive_intc_irqchip_match_table' because it is named in a relocation make[4]: *** [scripts/Makefile.vmlinux:97: vmlinux] Error 1 The relocation appears to come from .LASANLOC5 in .data.rel.local: $ llvm-objdump --disassemble-symbols=.LASANLOC5 --disassemble-all -r drivers/irqchip/irq-starfive-jh8100-intc.o drivers/irqchip/irq-starfive-jh8100-intc.o: file format elf64-littleriscv Disassembly of section .data.rel.local: 0000000000000180 <.LASANLOC5>: ... 1d0: 0000 unimp 00000000000001d0: R_RISCV_64 __mod_device_table__kmod_irq_starfive_jh8100_intc__of__starfive_intc_irqchip_match_table ... This section appears to come from GCC for including additional information about global variables that may be protected by KASAN. There appears to be no way to opt out of the generation of these symbols through either a flag or attribute. Attempting to remove '.LASANLOC*' with '--strip-symbol' results in the same error as above because these symbols may refer to (thus have relocation between) each other. Avoid this build breakage by switching to '--strip-unneeded-symbol' for removing __mod_device_table__ symbols, as it will only remove the symbol when there is no relocation pointing to it. While this may result in a little more bloat in the symbol table in certain configurations, it is not as bad as outright build failures. Fixes: 5ab23c7923a1 ("modpost: Create modalias for builtin modules") Reported-by: Charles Mirabile Closes: https://lore.kernel.org/20251007011637.2512413-1-cmirabil@redhat.com/ Suggested-by: Alexey Gladkov Tested-by: Nicolas Schier Signed-off-by: Nathan Chancellor --- scripts/Makefile.vmlinux | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'scripts/Makefile.vmlinux') diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux index c02f85c2e241..ced4379550d7 100644 --- a/scripts/Makefile.vmlinux +++ b/scripts/Makefile.vmlinux @@ -87,7 +87,7 @@ remove-section-$(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS) += '.rel*' '!.rel*.dyn' # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=c12d9fa2afe7abcbe407a00e15719e1a1350c2a7 remove-section-$(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS) += '.rel.*' -remove-symbols := -w --strip-symbol='__mod_device_table__*' +remove-symbols := -w --strip-unneeded-symbol='__mod_device_table__*' # To avoid warnings: "empty loadable segment detected at ..." from GNU objcopy, # it is necessary to remove the PT_LOAD flag from the segment. -- cgit v1.2.3