kernel/linux.git/scripts/link-vmlinux.sh, branch v5.10.257

kbuild: fix short log for AS in link-vmlinux.sh

2024-07-18T11:05:45+00:00

[ Upstream commit 3430f65d6130ccbc86f0ff45642eeb9e2032a600 ] In convention, short logs print the output file, not the input file. Let's change the suffix for 'AS' since it assembles *.S into *.o. [Before] LD .tmp_vmlinux.kallsyms1 NM .tmp_vmlinux.kallsyms1.syms KSYMS .tmp_vmlinux.kallsyms1.S AS .tmp_vmlinux.kallsyms1.S LD .tmp_vmlinux.kallsyms2 NM .tmp_vmlinux.kallsyms2.syms KSYMS .tmp_vmlinux.kallsyms2.S AS .tmp_vmlinux.kallsyms2.S LD vmlinux [After] LD .tmp_vmlinux.kallsyms1 NM .tmp_vmlinux.kallsyms1.syms KSYMS .tmp_vmlinux.kallsyms1.S AS .tmp_vmlinux.kallsyms1.o LD .tmp_vmlinux.kallsyms2 NM .tmp_vmlinux.kallsyms2.syms KSYMS .tmp_vmlinux.kallsyms2.S AS .tmp_vmlinux.kallsyms2.o LD vmlinux Signed-off-by: Masahiro Yamada Signed-off-by: Sasha Levin

kbuild: Fix changing ELF file type for output of gen_btf for big endian

2024-02-23T07:42:26+00:00

commit e3a9ee963ad8ba677ca925149812c5932b49af69 upstream. Commit 90ceddcb4950 ("bpf: Support llvm-objcopy for vmlinux BTF") changed the ELF type of .btf.vmlinux.bin.o to ET_REL via dd, which works fine for little endian platforms: 00000000 7f 45 4c 46 02 01 01 00 00 00 00 00 00 00 00 00 |.ELF............| -00000010 03 00 b7 00 01 00 00 00 00 00 00 80 00 80 ff ff |................| +00000010 01 00 b7 00 01 00 00 00 00 00 00 80 00 80 ff ff |................| However, for big endian platforms, it changes the wrong byte, resulting in an invalid ELF file type, which ld.lld rejects: 00000000 7f 45 4c 46 02 02 01 00 00 00 00 00 00 00 00 00 |.ELF............| -00000010 00 03 00 16 00 00 00 01 00 00 00 00 00 10 00 00 |................| +00000010 01 03 00 16 00 00 00 01 00 00 00 00 00 10 00 00 |................| Type: : 103 ld.lld: error: .btf.vmlinux.bin.o: unknown file type Fix this by updating the entire 16-bit e_type field rather than just a single byte, so that everything works correctly for all platforms and linkers. 00000000 7f 45 4c 46 02 02 01 00 00 00 00 00 00 00 00 00 |.ELF............| -00000010 00 03 00 16 00 00 00 01 00 00 00 00 00 10 00 00 |................| +00000010 00 01 00 16 00 00 00 01 00 00 00 00 00 10 00 00 |................| Type: REL (Relocatable file) While in the area, update the comment to mention that binutils 2.35+ matches LLD's behavior of rejecting an ET_EXEC input, which occurred after the comment was added. Cc: stable@vger.kernel.org Fixes: 90ceddcb4950 ("bpf: Support llvm-objcopy for vmlinux BTF") Link: https://github.com/llvm/llvm-project/pull/75643 Suggested-by: Masahiro Yamada Signed-off-by: Nathan Chancellor Reviewed-by: Fangrui Song Reviewed-by: Nicolas Schier Reviewed-by: Kees Cook Reviewed-by: Justin Stitt Signed-off-by: Masahiro Yamada [nathan: Fix silent conflict due to lack of 7d153696e5db in older trees] Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman

kbuild: Unify options for BTF generation for vmlinux and modules

2022-10-28T10:57:12+00:00

commit 9741e07ece7c247dd65e1aa01e16b683f01c05a8 upstream. [skipped --btf_gen_floats option in pahole-flags.sh, skipped Makefile.modfinal change, because there's no BTF kmod support, squashing in 'exit 0' change from merge commit fc02cb2b37fe] Using new PAHOLE_FLAGS variable to pass extra arguments to pahole for both vmlinux and modules BTF data generation. Adding new scripts/pahole-flags.sh script that detect and prints pahole options. [ fixed issues found by kernel test robot ] Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20211029125729.70002-1-jolsa@kernel.org Signed-off-by: Greg Kroah-Hartman

kbuild: skip per-CPU BTF generation for pahole v1.18-v1.21

2022-10-28T10:55:17+00:00

commit a0b8200d06ad6450c179407baa5f0f52f8cfcc97 upstream. [small context changes due to missing floats support in 5.10] Commit "mm/page_alloc: convert per-cpu list protection to local_lock" will introduce a zero-sized per-CPU variable, which causes pahole to generate invalid BTF. Only pahole versions 1.18 through 1.21 are impacted, as before 1.18 pahole doesn't know anything about per-CPU variables, and 1.22 contains the proper fix for the issue. Luckily, pahole 1.18 got --skip_encoding_btf_vars option disabling BTF generation for per-CPU variables in anticipation of some unanticipated problems. So use this escape hatch to disable per-CPU var BTF info on those problematic pahole versions. Users relying on availability of per-CPU var BTFs would need to upgrade to pahole 1.22+, but everyone won't notice any regressions. Link: https://lkml.kernel.org/r/20210530002536.3193829-1-andrii@kernel.org Signed-off-by: Andrii Nakryiko Acked-by: Mel Gorman Cc: Arnaldo Carvalho de Melo Cc: Hao Luo Cc: Michal Suchanek Cc: Jiri Olsa Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Jiri Olsa Signed-off-by: Greg Kroah-Hartman

kbuild: Quote OBJCOPY var to avoid a pahole call break the build

2022-10-28T10:55:17+00:00

commit ff2e6efda0d5c51b33e2bcc0b0b981ac0a0ef214 upstream. [backported for dependency, skipped Makefile.modfinal change, because module BTF is not supported in 5.10] The ccache tool can be used to speed up cross-compilation, by calling the compiler and binutils through ccache. For example, following should work: $ export ARCH=arm64 CROSS_COMPILE="ccache aarch64-linux-gnu-" $ make M=drivers/gpu/drm/rockchip/ but pahole fails to extract the BTF info from DWARF, breaking the build: CC [M] drivers/gpu/drm/rockchip//rockchipdrm.mod.o LD [M] drivers/gpu/drm/rockchip//rockchipdrm.ko BTF [M] drivers/gpu/drm/rockchip//rockchipdrm.ko aarch64-linux-gnu-objcopy: invalid option -- 'J' Usage: aarch64-linux-gnu-objcopy [option(s)] in-file [out-file] Copies a binary file, possibly transforming it in the process ... make[1]: *** [scripts/Makefile.modpost:156: __modpost] Error 2 make: *** [Makefile:1866: modules] Error 2 this fails because OBJCOPY is set to "ccache aarch64-linux-gnu-copy" and later pahole is executed with the following command line: LLVM_OBJCOPY=$(OBJCOPY) $(PAHOLE) -J --btf_base vmlinux $@ which gets expanded to: LLVM_OBJCOPY=ccache aarch64-linux-gnu-objcopy pahole -J ... instead of: LLVM_OBJCOPY="ccache aarch64-linux-gnu-objcopy" pahole -J ... Fixes: 5f9ae91f7c0d ("kbuild: Build kernel module BTFs if BTF is enabled and pahole supports it") Signed-off-by: Javier Martinez Canillas Signed-off-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Acked-by: Arnaldo Carvalho de Melo Link: https://lore.kernel.org/bpf/20210526215228.3729875-1-javierm@redhat.com Signed-off-by: Greg Kroah-Hartman

bpf: Generate BTF_KIND_FLOAT when linking vmlinux

2022-10-28T10:55:17+00:00

commit db16c1fe92d7ba7d39061faef897842baee2c887 upstream. [backported for dependency only extra_paholeopt variable setup and usage, we don't want floats generated in 5.10] pahole v1.21 supports the --btf_gen_floats flag, which makes it generate the information about the floating-point types [1]. Adjust link-vmlinux.sh to pass this flag to pahole in case it's supported, which is determined using a simple version check. [1] https://lore.kernel.org/dwarves/YHRiXNX1JUF2Az0A@kernel.org/ Signed-off-by: Ilya Leoshkevich Signed-off-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20210413190043.21918-1-iii@linux.ibm.com Signed-off-by: Jiri Olsa Signed-off-by: Greg Kroah-Hartman

x86/retbleed: Add fine grained Kconfig knobs

2022-07-25T09:26:50+00:00

commit f43b9876e857c739d407bc56df288b0ebe1a9164 upstream. Do fine-grained Kconfig for all the various retbleed parts. NOTE: if your compiler doesn't support return thunks this will silently 'upgrade' your mitigation to IBPB, you might not like this. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov [cascardo: there is no CONFIG_OBJTOOL] [cascardo: objtool calling and option parsing has changed] Signed-off-by: Thadeu Lima de Souza Cascardo [bwh: Backported to 5.10: - In scripts/Makefile.build, add the objtool option with an ifdef block, same as for other options - Adjust filename, context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

objtool: Add entry UNRET validation

2022-07-25T09:26:45+00:00

commit a09a6e2399ba0595c3042b3164f3ca68a3cff33e upstream. Since entry asm is tricky, add a validation pass that ensures the retbleed mitigation has been done before the first actual RET instruction. Entry points are those that either have UNWIND_HINT_ENTRY, which acts as UNWIND_HINT_EMPTY but marks the instruction as an entry point, or those that have UWIND_HINT_IRET_REGS at +0. This is basically a variant of validate_branch() that is intra-function and it will simply follow all branches from marked entry points and ensures that all paths lead to ANNOTATE_UNRET_END. If a path hits RET or an indirection the path is a fail and will be reported. There are 3 ANNOTATE_UNRET_END instances: - UNTRAIN_RET itself - exception from-kernel; this path doesn't need UNTRAIN_RET - all early exceptions; these also don't need UNTRAIN_RET Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov Reviewed-by: Josh Poimboeuf Signed-off-by: Borislav Petkov [cascardo: arch/x86/entry/entry_64.S no pt_regs return at .Lerror_entry_done_lfence] [cascardo: tools/objtool/builtin-check.c no link option validation] [cascardo: tools/objtool/check.c opts.ibt is ibt] [cascardo: tools/objtool/include/objtool/builtin.h leave unret option as bool, no struct opts] [cascardo: objtool is still called from scripts/link-vmlinux.sh] [cascardo: no IBT support] Signed-off-by: Thadeu Lima de Souza Cascardo [bwh: Backported to 5.10: - In scripts/link-vmlinux.sh, use "test -n" instead of is_enabled - Adjust context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

x86: Add straight-line-speculation mitigation

2022-07-25T09:26:30+00:00

commit e463a09af2f0677b9485a7e8e4e70b396b2ffb6f upstream. Make use of an upcoming GCC feature to mitigate straight-line-speculation for x86: https://gcc.gnu.org/g:53a643f8568067d7700a9f2facc8ba39974973d3 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102952 https://bugs.llvm.org/show_bug.cgi?id=52323 It's built tested on x86_64-allyesconfig using GCC-12 and GCC-11. Maintenance overhead of this should be fairly low due to objtool validation. Size overhead of all these additional int3 instructions comes to: text data bss dec hex filename 22267751 6933356 2011368 31212475 1dc43bb defconfig-build/vmlinux 22804126 6933356 1470696 31208178 1dc32f2 defconfig-build/vmlinux.sls Or roughly 2.4% additional text. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov Link: https://lore.kernel.org/r/20211204134908.140103474@infradead.org Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman [bwh: Backported to 5.10: - In scripts/Makefile.build, add the objtool option with an ifdef block, same as for other options - Adjust context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

Merge tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2020-10-22T20:13:57+00:00

Pull Kbuild updates from Masahiro Yamada: - Support 'make compile_commands.json' to generate the compilation database more easily, avoiding stale entries - Support 'make clang-analyzer' and 'make clang-tidy' for static checks using clang-tidy - Preprocess scripts/modules.lds.S to allow CONFIG options in the module linker script - Drop cc-option tests from compiler flags supported by our minimal GCC/Clang versions - Use always 12-digits commit hash for CONFIG_LOCALVERSION_AUTO=y - Use sha1 build id for both BFD linker and LLD - Improve deb-pkg for reproducible builds and rootless builds - Remove stale, useless scripts/namespace.pl - Turn -Wreturn-type warning into error - Fix build error of deb-pkg when CONFIG_MODULES=n - Replace 'hostname' command with more portable 'uname -n' - Various Makefile cleanups * tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits) kbuild: Use uname for LINUX_COMPILE_HOST detection kbuild: Only add -fno-var-tracking-assignments for old GCC versions kbuild: remove leftover comment for filechk utility treewide: remove DISABLE_LTO kbuild: deb-pkg: clean up package name variables kbuild: deb-pkg: do not build linux-headers package if CONFIG_MODULES=n kbuild: enforce -Werror=return-type scripts: remove namespace.pl builddeb: Add support for all required debian/rules targets builddeb: Enable rootless builds builddeb: Pass -n to gzip for reproducible packages kbuild: split the build log of kallsyms kbuild: explicitly specify the build id style scripts/setlocalversion: make git describe output more reliable kbuild: remove cc-option test of -Werror=date-time kbuild: remove cc-option test of -fno-stack-check kbuild: remove cc-option test of -fno-strict-overflow kbuild: move CFLAGS_{KASAN,UBSAN,KCSAN} exports to relevant Makefiles kbuild: remove redundant CONFIG_KASAN check from scripts/Makefile.kasan kbuild: do not create built-in objects for external module builds ...