kernel/linux.git/scripts/Makefile.build, branch v5.2.16

Merge tag 'kbuild-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2019-05-08T19:25:12+00:00

Pull Kbuild updates from Masahiro Yamada: - allow users to invoke 'make' out of the source tree - refactor scripts/mkmakefile - deprecate KBUILD_SRC, which was used to track the source tree location for O= build. - fix recordmcount.pl in case objdump output is localized - turn unresolved symbols in external modules to errors from warnings by default; pass KBUILD_MODPOST_WARN=1 to get them back to warnings - generate modules.builtin.modinfo to collect .modinfo data from built-in modules - misc Makefile cleanups * tag 'kbuild-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (21 commits) .gitignore: add more all*.config patterns moduleparam: Save information about built-in modules in separate file Remove MODULE_ALIAS() calls that take undefined macro .gitignore: add leading and trailing slashes to generated directories scripts/tags.sh: fix direct execution of scripts/tags.sh scripts: override locale from environment when running recordmcount.pl samples: kobject: allow CONFIG_SAMPLE_KOBJECT to become y samples: seccomp: turn CONFIG_SAMPLE_SECCOMP into a bool option kbuild: move Documentation to vmlinux-alldirs kbuild: move samples/ to KBUILD_VMLINUX_OBJS modpost: make KBUILD_MODPOST_WARN also configurable for external modules kbuild: check arch/$(SRCARCH)/include/generated before out-of-tree build kbuild: remove unneeded dependency for include/config/kernel.release memory: squash drivers/memory/Makefile.asm-offsets kbuild: use $(srctree) instead of KBUILD_SRC to check out-of-tree build kbuild: mkmakefile: generate a simple wrapper of top Makefile kbuild: mkmakefile: do not check the generated Makefile marker kbuild: allow Kbuild to start from any directory kbuild: pass $(MAKECMDGOALS) to sub-make as is kbuild: fix warning "overriding recipe for target 'Makefile'" ...

objtool: Add UACCESS validation

2019-04-03T09:02:24+00:00

It is important that UACCESS regions are as small as possible; furthermore the UACCESS state is not scheduled, so doing anything that might directly call into the scheduler will cause random code to be ran with UACCESS enabled. Teach objtool too track UACCESS state and warn about any CALL made while UACCESS is enabled. This very much includes the __fentry__() and __preempt_schedule() calls. Note that exceptions _do_ save/restore the UACCESS state, and therefore they can drive preemption. This also means that all exception handlers must have an otherwise redundant UACCESS disable instruction; therefore ignore this warning for !STT_FUNC code (exception handlers are not normal functions). Signed-off-by: Peter Zijlstra (Intel) Acked-by: Josh Poimboeuf Cc: Borislav Petkov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar

kbuild: use $(srctree) instead of KBUILD_SRC to check out-of-tree build

2019-04-02T14:28:04+00:00

KBUILD_SRC was conventionally used for some different purposes: [1] To remember the source tree path [2] As a flag to check if sub-make is already done [3] As a flag to check if Kbuild runs out of tree For [1], we do not need to remember it because the top Makefile can compute it by $(realpath $(dir $(lastword $(MAKEFILE_LIST)))) [2] has been replaced with self-commenting 'sub_make_done'. For [3], we can distinguish in-tree/out-of-tree by comparing $(srctree) and '.' This commit converts [3] to prepare for the KBUILD_SRC removal. Signed-off-by: Masahiro Yamada

kbuild: strip whitespace in cmd_record_mcount findstring

2019-03-28T14:46:55+00:00

CC_FLAGS_FTRACE may contain trailing whitespace that interferes with findstring. For example, commit 6977f95e63b9 ("powerpc: avoid -mno-sched-epilog on GCC 4.9 and newer") introduced a change such that on my ppc64le box, CC_FLAGS_FTRACE="-pg -mprofile-kernel ". (Note the trailing space.) When cmd_record_mcount is now invoked, findstring fails as the ftrace flags were found at very end of _c_flags, without the trailing space. _c_flags=" ... -pg -mprofile-kernel" CC_FLAGS_FTRACE="-pg -mprofile-kernel " ^ findstring is looking for this extra space Remove the redundant whitespaces from CC_FLAGS_FTRACE in cmd_record_mcount to avoid this problem. [masahiro.yamada: This issue only happens in the released versions of GNU Make. CC_FLAGS_FTRACE will not contain the trailing space if you use the latest GNU Make, which contains commit b90fabc8d6f3 ("* NEWS: Do not insert a space during '+=' if the value is empty.") ] Suggested-by: Masahiro Yamada (refactoring) Fixes: 6977f95e63b9 ("powerpc: avoid -mno-sched-epilog on GCC 4.9 and newer"). Signed-off-by: Joe Lawrence Acked-by: Steven Rostedt (VMware) Signed-off-by: Masahiro Yamada

kbuild: move archive command to scripts/Makefile.lib

2019-03-13T17:39:10+00:00

scripts/Makefile.build and arch/s390/boot/Makefile use the same command (thin archiving with symbol table creation). Avoid the code duplication, and move it to scripts/Makefile.lib. Signed-off-by: Masahiro Yamada

kbuild: hardcode genksyms path and remove GENKSYMS variable

2019-02-27T12:41:26+00:00

The genksyms source was integrated into the kernel tree in 2003. I do not expect anybody still using the external /sbin/genksyms. Kbuild does not need to provide the ability to override GENKSYMS. Let's remove the GENKSYMS variable, and use the hardcoded path. Since it occurred in the pre-git era, I attached the commit message in case somebody is interested in the historical background. | Author: Kai Germaschewski | Date: Wed Feb 19 04:17:28 2003 -0600 | | kbuild: [PATCH] put genksyms in scripts dir | | This puts genksyms into scripts/genksyms/. | | genksyms used to be maintained externally, though the only possible user | was the kernel build. Moving it into the kernel sources makes it easier to | keep it uptodate, like for example updating it to generate linker scripts | directly instead of postprocessing the generated header file fragments | with sed, as we do currently. | | Also, genksyms does not handle __typeof__, which needs to be fixed since | some of the exported symbol in the kernel are defined using __typeof__. | | (Rusty Russell/me) Signed-off-by: Masahiro Yamada

kbuild: generate modules.order only when CONFIG_MODULES=y

2019-02-20T00:42:46+00:00

Do not generate pointless modules.order when the module support is disabled. Signed-off-by: Masahiro Yamada

kbuild: Disable extra debugging info in .s output

2019-02-20T00:39:39+00:00

Modern gcc adds view assignments, reset assertion checking in .loc directives and a couple more additional debug markers, which clutters the asm output unnecessarily: For example: bsp_resume: .LFB3466: .loc 1 1868 1 is_stmt 1 view -0 .cfi_startproc .loc 1 1869 2 view .LVU73 # arch/x86/kernel/cpu/common.c:1869: if (this_cpu->c_bsp_resume) .loc 1 1869 14 is_stmt 0 view .LVU74 movq this_cpu(%rip), %rax # this_cpu, this_cpu movq 64(%rax), %rax # this_cpu.94_1->c_bsp_resume, _2 # arch/x86/kernel/cpu/common.c:1869: if (this_cpu->c_bsp_resume) .loc 1 1869 5 view .LVU75 testq %rax, %rax # _2 je .L8 #, .loc 1 1870 3 is_stmt 1 view .LVU76 movq $boot_cpu_data, %rdi #, jmp __x86_indirect_thunk_rax or .loc 2 57 9 view .LVU478 .loc 2 57 9 view .LVU479 .loc 2 57 9 view .LVU480 .loc 2 57 9 view .LVU481 .LBB1385: .LBB1383: .LBB1379: .LBB1377: .LBB1375: .loc 2 57 9 view .LVU482 .loc 2 57 9 view .LVU483 movl %edi, %edx # cpu, cpu .LVL87: .loc 2 57 9 is_stmt 0 view .LVU484 That MOV in there is drowned in debugging information and latter makes it hard to follow the asm. And that DWARF info is not really needed for asm output staring. Disable the debug information generation which clutters the asm output unnecessarily: bsp_resume: # arch/x86/kernel/cpu/common.c:1869: if (this_cpu->c_bsp_resume) movq this_cpu(%rip), %rax # this_cpu, this_cpu movq 64(%rax), %rax # this_cpu.94_1->c_bsp_resume, _2 # arch/x86/kernel/cpu/common.c:1869: if (this_cpu->c_bsp_resume) testq %rax, %rax # _2 je .L8 #, # arch/x86/kernel/cpu/common.c:1870: this_cpu->c_bsp_resume(&boot_cpu_data); movq $boot_cpu_data, %rdi #, jmp __x86_indirect_thunk_rax .L8: # arch/x86/kernel/cpu/common.c:1871: } rep ret .size bsp_resume, .-bsp_resume [ bp: write commit message. ] Signed-off-by: Masahiro Yamada Signed-off-by: Borislav Petkov

kbuild: remove unnecessary in-subshell execution

2019-01-28T00:11:17+00:00

The commands surrounded by ( ) are executed in a subshell, but in most cases, we do not need to spawn an extra subshell. Signed-off-by: Masahiro Yamada

kbuild: add real-prereqs shorthand for $(filter-out FORCE,$^)

2019-01-28T00:11:17+00:00

In Kbuild, if_changed and friends must have FORCE as a prerequisite. Hence, $(filter-out FORCE,$^) or $(filter-out $(PHONY),$^) is a common idiom to get the names of all the prerequisites except phony targets. Add real-prereqs as a shorthand. Note: We cannot replace $(filter %.o,$^) in cmd_link_multi-m because $^ may include auto-generated dependencies from the .*.cmd file when a single object module is changed into a multi object module. Refer to commit 69ea912fda74 ("kbuild: remove unneeded link_multi_deps"). I added some comment to avoid accidental breakage. Signed-off-by: Masahiro Yamada Acked-by: Rob Herring