linux/include/asm-generic/vmlinux.lds.h, branch v6.8

kunit: add KUNIT_INIT_TABLE to init linker section

2023-12-18T20:21:15Z

Add KUNIT_INIT_TABLE to the INIT_DATA linker section. Alter the KUnit macros to create init tests: kunit_test_init_section_suites Update lib/kunit/executor.c to run both the suites in KUNIT_TABLE and KUNIT_INIT_TABLE. Reviewed-by: David Gow Signed-off-by: Rae Moar Signed-off-by: Shuah Khan

kunit: move KUNIT_TABLE out of INIT_DATA

2023-12-18T20:21:15Z

Alter the linker section of KUNIT_TABLE to move it out of INIT_DATA and into DATA_DATA. Data for KUnit tests does not need to be in the init section. In order to run tests again after boot the KUnit data cannot be labeled as init data as the kernel could write over it. Add a KUNIT_INIT_TABLE in the next patch for KUnit tests that test init data/functions. Reviewed-by: David Gow Signed-off-by: Rae Moar Signed-off-by: Shuah Khan

linux/init: remove __memexit* annotations

2023-10-28T12:31:22Z

We have never used __memexit, __memexitdata, or __memexitconst. These were unneeded. Signed-off-by: Masahiro Yamada Acked-by: Arnd Bergmann

vmlinux.lds.h: remove unused CPU_KEEP and CPU_DISCARD macros

2023-10-01T05:55:23Z

Remove the left-over of commit e24f6628811e ("modpost: remove all traces of cpuinit/cpuexit sections"). Signed-off-by: Masahiro Yamada Acked-by: Paul Gortmaker

vmlinux.lds.h: Remove a reference to no longer used sections .text..refcount

2023-07-11T21:29:43Z

Sections .text..refcount were previously used to hold an error path code for fast refcount overflow protection on x86, see commit 7a46ec0e2f48 ("locking/refcounts, x86/asm: Implement fast refcount overflow protection") and commit 564c9cc84e2a ("locking/refcounts, x86/asm: Use unique .text section for refcount exceptions"). The code was replaced and removed in commit fb041bb7c0a9 ("locking/refcount: Consolidate implementations of refcount_t") and no sections .text..refcount are present since then. Remove then a relic referencing these sections from TEXT_TEXT to avoid confusing people, like me. This is a non-functional change. Signed-off-by: Petr Pavlu Link: https://lore.kernel.org/r/20230711125054.9000-1-petr.pavlu@suse.com Signed-off-by: Kees Cook

Merge tag 'riscv-for-linus-6.5-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

2023-07-07T17:07:19Z

Pull more RISC-V updates from Palmer Dabbelt: - A bunch of fixes/cleanups from the first part of the merge window, mostly related to ACPI and vector as those were large - Some documentation improvements, mostly related to the new code - The "riscv,isa" DT key is deprecated - Support for link-time dead code elimination - Support for minor fault registration in userfaultd - A handful of cleanups around CMO alternatives * tag 'riscv-for-linus-6.5-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (23 commits) riscv: mm: mark noncoherent_supported as __ro_after_init riscv: mm: mark CBO relate initialization funcs as __init riscv: errata: thead: only set cbom size & noncoherent during boot riscv: Select HAVE_ARCH_USERFAULTFD_MINOR RISC-V: Document the ISA string parsing rules for ACPI risc-v: Fix order of IPI enablement vs RCU startup mm: riscv: fix an unsafe pte read in huge_pte_alloc() dt-bindings: riscv: deprecate riscv,isa RISC-V: drop error print from riscv_hartid_to_cpuid() riscv: Discard vector state on syscalls riscv: move memblock_allow_resize() after linear mapping is ready riscv: Enable ARCH_SUSPEND_POSSIBLE for s2idle riscv: vdso: include vdso/vsyscall.h for vdso_data selftests: Test RISC-V Vector's first-use handler riscv: vector: clear V-reg in the first-use trap riscv: vector: only enable interrupts in the first-use trap RISC-V: Fix up some vector state related build failures RISC-V: Document that V registers are clobbered on syscalls riscv: disable HAVE_LD_DEAD_CODE_DATA_ELIMINATION for LLD riscv: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION ...

Merge tag 'kbuild-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2023-07-01T16:24:31Z

Pull Kbuild updates from Masahiro Yamada: - Remove the deprecated rule to build *.dtbo from *.dts - Refactor section mismatch detection in modpost - Fix bogus ARM section mismatch detections - Fix error of 'make gtags' with O= option - Add Clang's target triple to KBUILD_CPPFLAGS to fix a build error with the latest LLVM version - Rebuild the built-in initrd when KBUILD_BUILD_TIMESTAMP is changed - Ignore more compiler-generated symbols for kallsyms - Fix 'make local*config' to handle the ${CONFIG_FOO} form in Makefiles - Enable more kernel-doc warnings with W=2 - Refactor by generating KSYMTAB data by modpost - Deprecate and - Remove the EXPORT_DATA_SYMBOL macro - Move the check for static EXPORT_SYMBOL back to modpost, which makes the build faster - Re-implement CONFIG_TRIM_UNUSED_KSYMS with one-pass algorithm - Warn missing MODULE_DESCRIPTION when building modules with W=1 - Make 'make clean' robust against too long argument error - Exclude more objects from GCOV to fix CFI failures with GCOV - Allow 'make modules_install' to install modules.builtin and modules.builtin.modinfo even when CONFIG_MODULES is disabled - Include modules.builtin and modules.builtin.modinfo in the linux-image Debian package even when CONFIG_MODULES is disabled - Revive "Entering directory" logging for the latest Make version * tag 'kbuild-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (72 commits) modpost: define more R_ARM_* for old distributions kbuild: revive "Entering directory" for Make >= 4.4.1 kbuild: set correct abs_srctree and abs_objtree for package builds scripts/mksysmap: Ignore prefixed KCFI symbols kbuild: deb-pkg: remove the CONFIG_MODULES check in buildeb kbuild: builddeb: always make modules_install, to install modules.builtin* modpost: continue even with unknown relocation type modpost: factor out Elf_Sym pointer calculation to section_rel() modpost: factor out inst location calculation to section_rel() kbuild: Disable GCOV for *.mod.o kbuild: Fix CFI failures with GCOV kbuild: make clean rule robust against too long argument error script: modpost: emit a warning when the description is missing kbuild: make modules_install copy modules.builtin(.modinfo) linux/export.h: rename 'sec' argument to 'license' modpost: show offset from symbol for section mismatch warnings modpost: merge two similar section mismatch warnings kbuild: implement CONFIG_TRIM_UNUSED_KSYMS without recursion modpost: use null string instead of NULL pointer for default namespace modpost: squash sym_update_namespace() into sym_add_exported() ...

Merge patch series "riscv: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION"

2023-07-01T14:38:19Z

Jisheng Zhang says: When trying to run linux with various opensource riscv core on resource limited FPGA platforms, for example, those FPGAs with less than 16MB SDRAM, I want to save mem as much as possible. One of the major technologies is kernel size optimizations, I found that riscv does not currently support HAVE_LD_DEAD_CODE_DATA_ELIMINATION, which passes -fdata-sections, -ffunction-sections to CFLAGS and passes the --gc-sections flag to the linker. This not only benefits my case on FPGA but also benefits defconfigs. Here are some notable improvements from enabling this with defconfigs: nommu_k210_defconfig: text data bss dec hex 1112009 410288 59837 1582134 182436 before 962838 376656 51285 1390779 1538bb after rv32_defconfig: text data bss dec hex 8804455 2816544 290577 11911576 b5c198 before 8692295 2779872 288977 11761144 b375f8 after defconfig: text data bss dec hex 9438267 3391332 485333 13314932 cb2b74 before 9285914 3350052 483349 13119315 c82f53 after patch1 and patch2 are clean ups. patch3 fixes a typo. patch4 finally enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION for riscv. * b4-shazam-merge: riscv: disable HAVE_LD_DEAD_CODE_DATA_ELIMINATION for LLD riscv: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION vmlinux.lds.h: use correct .init.data.* section name riscv: vmlinux-xip.lds.S: remove .alternative section riscv: move options to keep entries sorted riscv: Fix orphan section warnings caused by kernel/pi Link: https://lore.kernel.org/r/20230523165502.2592-1-jszhang@kernel.org Signed-off-by: Palmer Dabbelt

vmlinux.lds.h: use correct .init.data.* section name

2023-06-25T23:24:04Z

If building with -fdata-sections on riscv, LD_ORPHAN_WARN will warn similar as below: riscv64-linux-gnu-ld: warning: orphan section `.init.data.efi_loglevel' from `./drivers/firmware/efi/libstub/printk.stub.o' being placed in section `.init.data.efi_loglevel' I believe this is caused by a a typo: init.data.* should be .init.data.* Signed-off-by: Jisheng Zhang Reviewed-by: Kefeng Wang Tested-by: Nick Desaulniers # build Link: https://lore.kernel.org/r/20230523165502.2592-4-jszhang@kernel.org Signed-off-by: Palmer Dabbelt

kbuild: generate KSYMTAB entries by modpost

2023-06-22T12:17:10Z

Commit 7b4537199a4a ("kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS") made modpost output CRCs in the same way whether the EXPORT_SYMBOL() is placed in *.c or *.S. For further cleanups, this commit applies a similar approach to the entire data structure of EXPORT_SYMBOL(). The EXPORT_SYMBOL() compilation is split into two stages. When a source file is compiled, EXPORT_SYMBOL() will be converted into a dummy symbol in the .export_symbol section. For example, EXPORT_SYMBOL(foo); EXPORT_SYMBOL_NS_GPL(bar, BAR_NAMESPACE); will be encoded into the following assembly code: .section ".export_symbol","a" __export_symbol_foo: .asciz "" /* license */ .asciz "" /* name space */ .balign 8 .quad foo /* symbol reference */ .previous .section ".export_symbol","a" __export_symbol_bar: .asciz "GPL" /* license */ .asciz "BAR_NAMESPACE" /* name space */ .balign 8 .quad bar /* symbol reference */ .previous They are mere markers to tell modpost the name, license, and namespace of the symbols. They will be dropped from the final vmlinux and modules because the *(.export_symbol) will go into /DISCARD/ in the linker script. Then, modpost extracts all the information about EXPORT_SYMBOL() from the .export_symbol section, and generates the final C code: KSYMTAB_FUNC(foo, "", ""); KSYMTAB_FUNC(bar, "_gpl", "BAR_NAMESPACE"); KSYMTAB_FUNC() (or KSYMTAB_DATA() if it is data) is expanded to struct kernel_symbol that will be linked to the vmlinux or a module. With this change, EXPORT_SYMBOL() works in the same way for *.c and *.S files, providing the following benefits. [1] Deprecate EXPORT_DATA_SYMBOL() In the old days, EXPORT_SYMBOL() was only available in C files. To export a symbol in *.S, EXPORT_SYMBOL() was placed in a separate *.c file. arch/arm/kernel/armksyms.c is one example written in the classic manner. Commit 22823ab419d8 ("EXPORT_SYMBOL() for asm") removed this limitation. Since then, EXPORT_SYMBOL() can be placed close to the symbol definition in *.S files. It was a nice improvement. However, as that commit mentioned, you need to use EXPORT_DATA_SYMBOL() for data objects on some architectures. In the new approach, modpost checks symbol's type (STT_FUNC or not), and outputs KSYMTAB_FUNC() or KSYMTAB_DATA() accordingly. There are only two users of EXPORT_DATA_SYMBOL: EXPORT_DATA_SYMBOL_GPL(empty_zero_page) (arch/ia64/kernel/head.S) EXPORT_DATA_SYMBOL(ia64_ivt) (arch/ia64/kernel/ivt.S) They are transformed as follows and output into .vmlinux.export.c KSYMTAB_DATA(empty_zero_page, "_gpl", ""); KSYMTAB_DATA(ia64_ivt, "", ""); The other EXPORT_SYMBOL users in ia64 assembly are output as KSYMTAB_FUNC(). EXPORT_DATA_SYMBOL() is now deprecated. [2] merge and There are two similar header implementations: include/linux/export.h for .c files include/asm-generic/export.h for .S files Ideally, the functionality should be consistent between them, but they tend to diverge. Commit 8651ec01daed ("module: add support for symbol namespaces.") did not support the namespace for *.S files. This commit shifts the essential implementation part to C, which supports EXPORT_SYMBOL_NS() for *.S files. and will remain as a wrapper of for a while. They will be removed after #include directives are all replaced with #include . [3] Implement CONFIG_TRIM_UNUSED_KSYMS in one-pass algorithm (by a later commit) When CONFIG_TRIM_UNUSED_KSYMS is enabled, Kbuild recursively traverses the directory tree to determine which EXPORT_SYMBOL to trim. If an EXPORT_SYMBOL turns out to be unused by anyone, Kbuild begins the second traverse, where some source files are recompiled with their EXPORT_SYMBOL() tuned into a no-op. We can do this better now; modpost can selectively emit KSYMTAB entries that are really used by modules. Signed-off-by: Masahiro Yamada Reviewed-by: Nick Desaulniers