From ae5f6044c4cdffe2b3361b15c1d6fc67b339f2a4 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Sat, 10 Oct 2026 01:19:11 -0700 Subject: kbuild: Mark the initcall ordering recipe as recursive generate_initcall_order.pl, which orders initcalls for Clang LTO, forks a child per input file, up to the job count scripts/jobserver-exec passes it in PARALLELISM. It used to run from link-vmlinux.sh, which the top-level Makefile invokes as a recursive recipe, but commit 5d45950dfbb15 ("kbuild: move vmlinux.o link to scripts/Makefile.vmlinux_o") moved it into a recipe without "+". GNU Make passes the jobserver pipe only to recipes it treats as recursive, and the make 4.3 in CentOS Stream 9 also hides it in sub-makes (a backport of the fix for GNU Make bug 58232), so jobserver-exec cannot open it and prints: WARNING: Unable to reopen jobserver read-side pipe: FileNotFoundError(2, 'No such file or directory') PARALLELISM is then left unset, and the script caps its children at the number of online CPUs instead of the free job slots. Mark the recipe as recursive again (this makes "make -n" runs the script again too, as it did from link-vmlinux.sh). Masahiro posted the same change and withdrew it because the script was given only vmlinux.a, and so never ran more than one child [1]. But on arm64, LoongArch, and RISC-V with CONFIG_EFI_STUB, KBUILD_VMLINUX_LIBS also gives it the EFI stub's lib.a. Either way, the warning is silenced. Tested ARCH=x86_64 defconfig with CONFIG_LTO_CLANG_THIN=y, LLVM=1 (Clang 24.0.0git), and GNU Make 4.3 plus CentOS Stream 9's make-4.3-cloexec.patch. Fixes: 5d45950dfbb15 ("kbuild: move vmlinux.o link to scripts/Makefile.vmlinux_o") Link: https://lore.kernel.org/all/CAK7LNARCM=rUm8mA8GRQ7ufeyfneGf4OEvHmESKt=zuxs2KrHw@mail.gmail.com/ [1] Assisted-by: LLM Reviewed-by: Nicolas Schier Signed-off-by: Kees Cook Tested-by: Paul E. McKenney Link: https://patch.msgid.link/20261010081914.540611-2-kees@kernel.org Signed-off-by: Nathan Chancellor --- scripts/Makefile.vmlinux_o | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'scripts/Makefile.vmlinux_o') diff --git a/scripts/Makefile.vmlinux_o b/scripts/Makefile.vmlinux_o index 24a3a4fd271c..0b37bd5dc3a4 100644 --- a/scripts/Makefile.vmlinux_o +++ b/scripts/Makefile.vmlinux_o @@ -19,7 +19,7 @@ quiet_cmd_gen_initcalls_lds = GEN $@ .tmp_initcalls.lds: $(srctree)/scripts/generate_initcall_order.pl \ vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE - $(call if_changed,gen_initcalls_lds) + +$(call if_changed,gen_initcalls_lds) targets := .tmp_initcalls.lds -- cgit v1.2.3