user/sven/linux.git/scripts/link-vmlinux.sh, branch v5.9.8

Merge tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2020-08-09T21:10:26Z

Pull Kbuild updates from Masahiro Yamada: - run the checker (e.g. sparse) after the compiler - remove unneeded cc-option tests for old compiler flags - fix tar-pkg to install dtbs - introduce ccflags-remove-y and asflags-remove-y syntax - allow to trace functions in sub-directories of lib/ - introduce hostprogs-always-y and userprogs-always-y syntax - various Makefile cleanups * tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: stop filtering out $(GCC_PLUGINS_CFLAGS) from cc-option base kbuild: include scripts/Makefile.* only when relevant CONFIG is enabled kbuild: introduce hostprogs-always-y and userprogs-always-y kbuild: sort hostprogs before passing it to ifneq kbuild: move host .so build rules to scripts/gcc-plugins/Makefile kbuild: Replace HTTP links with HTTPS ones kbuild: trace functions in subdirectories of lib/ kbuild: introduce ccflags-remove-y and asflags-remove-y kbuild: do not export LDFLAGS_vmlinux kbuild: always create directories of targets powerpc/boot: add DTB to 'targets' kbuild: buildtar: add dtbs support kbuild: remove cc-option test of -ffreestanding kbuild: remove cc-option test of -fno-stack-protector Revert "kbuild: Create directory for target DTB" kbuild: run the checker after the compiler

kbuild: do not export LDFLAGS_vmlinux

2020-08-09T16:32:58Z

When you clean the build tree for ARCH=arm, you may see the following error message from 'nm' command: $ make -j24 ARCH=arm clean CLEAN arch/arm/crypto CLEAN arch/arm/kernel CLEAN arch/arm/mach-at91 CLEAN arch/arm/mach-omap2 CLEAN arch/arm/vdso CLEAN certs CLEAN lib CLEAN usr CLEAN net/wireless CLEAN drivers/firmware/efi/libstub nm: 'arch/arm/boot/compressed/../../../../vmlinux': No such file /bin/sh: 1: arithmetic expression: expecting primary: " " CLEAN arch/arm/boot/compressed CLEAN drivers/scsi CLEAN drivers/tty/vt CLEAN arch/arm/boot CLEAN vmlinux.symvers modules.builtin modules.builtin.modinfo Even if you rerun the same command, the error message will not be shown despite vmlinux is already gone. To reproduce it, the parallel option -j is needed. Single thread cleaning always executes 'archclean', 'vmlinuxclean' in this order, so vmlinux still exists when arch/arm/boot/compressed/ is cleaned. Looking at arch/arm/boot/compressed/Makefile does not help understand the reason of the error message. Both KBSS_SZ and LDFLAGS_vmlinux are assigned with '=' operator, hence, they are not expanded unless used. Obviously, 'make clean' does not use them. In fact, the root cause exists in the top Makefile: export LDFLAGS_vmlinux Since LDFLAGS_vmlinux is an exported variable, LDFLAGS_vmlinux in arch/arm/boot/compressed/Makefile is expanded when scripts/Makefile.clean has a command to execute. This is why the error message shows up only when there exist build artifacts in arch/arm/boot/compressed/. Adding 'unexport LDFLAGS_vmlinux' to arch/arm/boot/compressed/Makefile will fix it as far as ARCH=arm is concerned, but I think the proper fix is to get rid of 'export LDFLAGS_vmlinux' from the top Makefile. LDFLAGS_vmlinux in the top Makefile contains linker flags for the top vmlinux. LDFLAGS_vmlinux in arch/arm/boot/compressed/Makefile is for arch/arm/boot/compressed/vmlinux. They just happen to have the same variable name, but are used for different purposes. Stop shadowing LDFLAGS_vmlinux. This commit passes LDFLAGS_vmlinux to scripts/link-vmlinux.sh via a command line parameter instead of via an environment variable. LD and KBUILD_LDFLAGS are exported, but I did the same for consistency. Anyway, they must be included in cmd_link-vmlinux to allow if_changed to detect the changes in LD or KBUILD_LDFLAGS. The following Makefiles are not affected: arch/arm/boot/compressed/Makefile arch/h8300/boot/compressed/Makefile arch/nios2/boot/compressed/Makefile arch/parisc/boot/compressed/Makefile arch/s390/boot/compressed/Makefile arch/sh/boot/compressed/Makefile arch/sh/boot/romimage/Makefile arch/x86/boot/compressed/Makefile They use ':=' or '=' to clear the LDFLAGS_vmlinux inherited from the top Makefile. We need to take a closer look at the impact to unicore32 and xtensa. arch/unicore32/boot/compressed/Makefile only uses '+=' operator for LDFLAGS_vmlinux. So, the decompressor previously inherited the linker flags from the top Makefile. However, commit 70fac51feaf2 ("unicore32 additional architecture files: boot process") was merged before commit 1f2bfbd00e46 ("kbuild: link of vmlinux moved to a script"). So, I rather consider this is a bug fix of 1f2bfbd00e46. arch/xtensa/boot/boot-elf/Makefile is also affected, but this is also considered a fix for the same reason. It did not inherit LDFLAGS_vmlinux when commit 4bedea945451 ("[PATCH] xtensa: Architecture support for Tensilica Xtensa Part 2") was merged. I deleted $(LDFLAGS_vmlinux), which is now empty. Signed-off-by: Masahiro Yamada Reviewed-by: Nick Desaulniers Tested-by: Nick Desaulniers

bpf: Resolve BTF IDs in vmlinux image

2020-07-13T17:42:02Z

Using BTF_ID_LIST macro to define lists for several helpers using BTF arguments. And running resolve_btfids on vmlinux elf object during linking, so the .BTF_ids section gets the IDs resolved. Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Tested-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200711215329.41165-5-jolsa@kernel.org

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

2020-06-13T22:28:08Z

Alexei Starovoitov says: ==================== pull-request: bpf 2020-06-12 The following pull-request contains BPF updates for your *net* tree. We've added 26 non-merge commits during the last 10 day(s) which contain a total of 27 files changed, 348 insertions(+), 93 deletions(-). The main changes are: 1) sock_hash accounting fix, from Andrey. 2) libbpf fix and probe_mem sanitizing, from Andrii. 3) sock_hash fixes, from Jakub. 4) devmap_val fix, from Jesper. 5) load_bytes_relative fix, from YiFei. ==================== Signed-off-by: David S. Miller

scripts: Require pahole v1.16 when generating BTF

2020-06-09T18:05:49Z

bpf_iter requires the kernel BTF to be generated with pahole >= 1.16, since otherwise the function definitions that the iterator attaches to are not included. This failure mode is indistiguishable from trying to attach to an iterator that really doesn't exist. Since it's really easy to miss this requirement, bump the pahole version check used at build time to at least 1.16. Fixes: 15d83c4d7cef ("bpf: Allow loading of a bpf_iter program") Suggested-by: Ivan Babrou Signed-off-by: Lorenz Bauer Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20200608094257.47366-1-lmb@cloudflare.com

Merge tag 'kbuild-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2020-06-06T19:00:25Z

Pull Kbuild updates from Masahiro Yamada: - fix warnings in 'make clean' for ARCH=um, hexagon, h8300, unicore32 - ensure to rebuild all objects when the compiler is upgraded - exclude system headers from dependency tracking and fixdep processing - fix potential bit-size mismatch between the kernel and BPF user-mode helper - add the new syntax 'userprogs' to build user-space programs for the target architecture (the same arch as the kernel) - compile user-space sample code under samples/ for the target arch instead of the host arch - make headers_install fail if a CONFIG option is leaked to user-space - sanitize the output format of scripts/checkstack.pl - handle ARM 'push' instruction in scripts/checkstack.pl - error out before modpost if a module name conflict is found - error out when multiple directories are passed to M= because this feature is broken for a long time - add CONFIG_DEBUG_INFO_COMPRESSED to support compressed debug info - a lot of cleanups of modpost - dump vmlinux symbols out into vmlinux.symvers, and reuse it in the second pass of modpost - do not run the second pass of modpost if nothing in modules is updated - install modules.builtin(.modinfo) by 'make install' as well as by 'make modules_install' because it is useful even when CONFIG_MODULES=n - add new command line variables, GZIP, BZIP2, LZOP, LZMA, LZ4, and XZ to allow users to use alternatives such as pigz, pbzip2, etc. * tag 'kbuild-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (96 commits) kbuild: add variables for compression tools Makefile: install modules.builtin even if CONFIG_MODULES=n mksysmap: Fix the mismatch of '.L' symbols in System.map kbuild: doc: rename LDFLAGS to KBUILD_LDFLAGS modpost: change elf_info->size to size_t modpost: remove is_vmlinux() helper modpost: strip .o from modname before calling new_module() modpost: set have_vmlinux in new_module() modpost: remove mod->skip struct member modpost: add mod->is_vmlinux struct member modpost: remove is_vmlinux() call in check_for_{gpl_usage,unused}() modpost: remove mod->is_dot_o struct member modpost: move -d option in scripts/Makefile.modpost modpost: remove -s option modpost: remove get_next_text() and make {grab,release_}file static modpost: use read_text_file() and get_line() for reading text files modpost: avoid false-positive file open error modpost: fix potential mmap'ed file overrun in get_src_version() modpost: add read_text_file() and get_line() helpers modpost: do not call get_modinfo() for vmlinux(.o) ...

modpost: generate vmlinux.symvers and reuse it for the second modpost

2020-06-06T14:38:12Z

The full build runs modpost twice, first for vmlinux.o and second for modules. The first pass dumps all the vmlinux symbols into Module.symvers, but the second pass parses vmlinux again instead of reusing the dump file, presumably because it needs to avoid accumulating stale symbols. Loading symbol info from a dump file is faster than parsing an ELF object. Besides, modpost deals with various issues to parse vmlinux in the second pass. A solution is to make the first pass dumps symbols into a separate file, vmlinux.symvers. The second pass reads it, and parses module .o files. The merged symbol information is dumped into Module.symvers in the same way as before. This makes further modpost cleanups possible. Also, it fixes the problem of 'make vmlinux', which previously overwrote Module.symvers, throwing away module symbols. I slightly touched scripts/link-vmlinux.sh so that vmlinux is re-linked when you cross this commit. Otherwise, vmlinux.symvers would not be generated. Signed-off-by: Masahiro Yamada

kbuild/objtool: Add objtool-vmlinux.o pass

2020-04-22T08:53:51Z

Now that objtool is capable of processing vmlinux.o and actually has something useful to do there, (conditionally) add it to the final link pass. This will increase build time by a few seconds. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Miroslav Benes Reviewed-by: Alexandre Chartre Acked-by: Josh Poimboeuf Link: https://lkml.kernel.org/r/20200416115119.287494491@infradead.org Signed-off-by: Ingo Molnar

bpf: Support llvm-objcopy for vmlinux BTF

2020-03-19T11:32:38Z

Simplify gen_btf logic to make it work with llvm-objcopy. The existing 'file format' and 'architecture' parsing logic is brittle and does not work with llvm-objcopy/llvm-objdump. 'file format' output of llvm-objdump>=11 will match GNU objdump, but 'architecture' (bfdarch) may not. .BTF in .tmp_vmlinux.btf is non-SHF_ALLOC. Add the SHF_ALLOC flag because it is part of vmlinux image used for introspection. C code can reference the section via linker script defined __start_BTF and __stop_BTF. This fixes a small problem that previous .BTF had the SHF_WRITE flag (objcopy -I binary -O elf* synthesized .data). Additionally, `objcopy -I binary` synthesized symbols _binary__btf_vmlinux_bin_start and _binary__btf_vmlinux_bin_stop (not used elsewhere) are replaced with more commonplace __start_BTF and __stop_BTF. Add 2>/dev/null because GNU objcopy (but not llvm-objcopy) warns "empty loadable segment detected at vaddr=0xffffffff81000000, is this intentional?" We use a dd command to change the e_type field in the ELF header from ET_EXEC to ET_REL so that lld will accept .btf.vmlinux.bin.o. Accepting ET_EXEC as an input file is an extremely rare GNU ld feature that lld does not intend to support, because this is error-prone. The output section description .BTF in include/asm-generic/vmlinux.lds.h avoids potential subtle orphan section placement issues and suppresses --orphan-handling=warn warnings. Fixes: df786c9b9476 ("bpf: Force .BTF section start to zero when dumping from vmlinux") Fixes: cb0cc635c7a9 ("powerpc: Include .BTF section") Reported-by: Nathan Chancellor Signed-off-by: Fangrui Song Signed-off-by: Daniel Borkmann Tested-by: Stanislav Fomichev Tested-by: Andrii Nakryiko Reviewed-by: Stanislav Fomichev Reviewed-by: Kees Cook Acked-by: Andrii Nakryiko Acked-by: Michael Ellerman (powerpc) Link: https://github.com/ClangBuiltLinux/linux/issues/871 Link: https://lore.kernel.org/bpf/20200318222746.173648-1-maskray@google.com

kbuild: Remove debug info from kallsyms linking

2020-03-04T17:36:33Z

When CONFIG_DEBUG_INFO is enabled, the two kallsyms linking steps spend time collecting and writing the dwarf sections to the temporary output files. kallsyms does not need this information, and leaving it off halves their linking time. This is especially noticeable without CONFIG_DEBUG_INFO_REDUCED. The BTF linking stage, however, does still need those details. Refactor the BTF and kallsyms generation stages slightly for more regularized temporary names. Skip debug during kallsyms links. Additionally move "info BTF" to the correct place since commit 8959e39272d6 ("kbuild: Parameterize kallsyms generation and correct reporting"), which added "info LD ..." to vmlinux_link calls. For a full debug info build with BTF, my link time goes from 1m06s to 0m54s, saving about 12 seconds, or 18%. Signed-off-by: Kees Cook Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/202003031814.4AEA3351@keescook