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