[PATCH] kbuild: distributed build support for Clang ThinLTO

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* [PATCH] kbuild: distributed build support for Clang ThinLTO
@ 2025-04-20  1:02 xur
  2025-04-29 20:34 ` Rong Xu
  0 siblings, 1 reply; 5+ messages in thread
From: xur @ 2025-04-20  1:02 UTC (permalink / raw)
  To: Masahiro Yamada, Nathan Chancellor, Nicolas Schier,
	Nick Desaulniers, Bill Wendling, Justin Stitt, Miguel Ojeda,
	Thomas Gleixner, Alice Ryhl, Sami Tolvanen,
	Mike Rapoport (Microsoft), Rafael Aquini, Michael Ellerman,
	Stafford Horne, Christophe Leroy, Rong Xu, Teresa Johnson
  Cc: linux-kernel, linux-kbuild, llvm

From: Rong Xu <xur@google.com>

Add distributed ThinLTO build support for the Linux kernel.
This new mode offers several advantages: (1) Increased
flexibility in handling user-specified build options.
(2) Improved user-friendliness for developers. (3) Greater
convenience for integrating with objtool and livepatch.

Note that "distributed" in this context refers to a term
that differentiates in-process ThinLTO builds by invoking
backend compilation through the linker, not necessarily
building in distributed environments.

Distributed ThinLTO is enabled via the
`CONFIG_LTO_CLANG_THIN_DIST` Kconfig option. For example:
 > make LLVM=1 defconfig
 > scripts/config -e LTO_CLANG_THIN_DIST
 > make LLVM=1 oldconfig
 > make LLVM=1 vmlinux -j <..>

The implementation changes the top-level Makefile with a
macro for generating `vmlinux.o` for distributed ThinLTO
builds. It uses the existing Kbuild infrastructure to
perform two recursive passes through the subdirectories.
The first pass generates LLVM IR object files, similar to
in-process ThinLTO. Following the thin-link stage, a second
pass compiles these IR files into the final native object
files. The build rules and actions for this two-pass process
are primarily implemented in `scripts/Makefile.build`.

Currently, this patch focuses on building the main kernel
image (`vmlinux`) only. Support for building kernel modules
using this method is planned for a subsequent patch.

Tested on the following arch: x86, arm64, loongarch, and
riscv.

Some implementation details can be found here:
https://discourse.llvm.org/t/rfc-distributed-thinlto-build-for-kernel/85934

Signed-off-by: Rong Xu <xur@google.com>
---
 MAINTAINERS                       |  5 +++
 Makefile                          | 40 ++++++++++++++++++++---
 arch/Kconfig                      | 12 +++++++
 scripts/Makefile.build            | 52 +++++++++++++++++++++++++++---
 scripts/Makefile.lib              |  7 +++-
 scripts/Makefile.vmlinux_o        | 16 +++++++---
 scripts/Makefile.vmlinux_thinlink | 53 +++++++++++++++++++++++++++++++
 scripts/head-object-list.txt      |  1 +
 8 files changed, 171 insertions(+), 15 deletions(-)
 create mode 100644 scripts/Makefile.vmlinux_thinlink

diff --git a/MAINTAINERS b/MAINTAINERS
index c966e71ea60bb..40d3bc223e4b0 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5782,6 +5782,11 @@ F:	scripts/Makefile.clang
 F:	scripts/clang-tools/
 K:	\b(?i:clang|llvm)\b
 
+CLANG/LLVM THINLTO DISTRIBUTED BUILD
+M:	Rong Xu <xur@google.com>
+S:	Supported
+F:	scripts/Makefile.vmlinux_thinlink
+
 CLK API
 M:	Russell King <linux@armlinux.org.uk>
 L:	linux-clk@vger.kernel.org
diff --git a/Makefile b/Makefile
index e65f8735c7bf6..18da9a40dd2c8 100644
--- a/Makefile
+++ b/Makefile
@@ -298,7 +298,8 @@ no-dot-config-targets := $(clean-targets) \
 			 outputmakefile rustavailable rustfmt rustfmtcheck
 no-sync-config-targets := $(no-dot-config-targets) %install modules_sign kernelrelease \
 			  image_name
-single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.rsi %.s %/
+single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.rsi %.s %.final_o \
+	          %.final_a %.o.thinlto.bc %/
 
 config-build	:=
 mixed-build	:=
@@ -991,10 +992,10 @@ export CC_FLAGS_SCS
 endif
 
 ifdef CONFIG_LTO_CLANG
-ifdef CONFIG_LTO_CLANG_THIN
-CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
-else
+ifdef CONFIG_LTO_CLANG_FULL
 CC_FLAGS_LTO	:= -flto
+else # for CONFIG_LTO_CLANG_THIN or CONFIG_LTO_CLANG_THIN_DIST
+CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
 endif
 CC_FLAGS_LTO	+= -fvisibility=hidden
 
@@ -1218,8 +1219,34 @@ vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt FORCE
 	$(call if_changed,ar_vmlinux.a)
 
 PHONY += vmlinux_o
+ifdef CONFIG_LTO_CLANG_THIN_DIST
+vmlinux.thinlink: vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE
+	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_thinlink
+targets += vmlinux.thinlink
+
+vmlinux_final_a := $(patsubst %.a,%.final_a,$(KBUILD_VMLINUX_OBJS))
+quiet_cmd_ar_vmlinux.final_a = AR      $@
+      cmd_ar_vmlinux.final_a = \
+	rm -f $@; \
+	$(AR) cDPrST $@ $(vmlinux_final_a); \
+	$(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)
+
+define rule_gen_vmlinux_final_a
+	+$(Q)$(MAKE) $(build)=. need-builtin=1 thinlto_final_pass=1 need-modorder=1 built-in.final_a
+	$(call cmd_and_savecmd,ar_vmlinux.final_a)
+endef
+
+vmlinux.final_a: vmlinux.thinlink scripts/head-object-list.txt FORCE
+	$(call if_changed_rule,gen_vmlinux_final_a)
+
+targets += vmlinux.final_a
+
+vmlinux_o: vmlinux.final_a
+	$(Q)$(MAKE) thinlto_final_pass=1 -f $(srctree)/scripts/Makefile.vmlinux_o
+else
 vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
 	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o
+endif
 
 vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o
 	@:
@@ -1577,7 +1604,8 @@ CLEAN_FILES += vmlinux.symvers modules-only.symvers \
 	       modules.builtin.ranges vmlinux.o.map vmlinux.unstripped \
 	       compile_commands.json rust/test \
 	       rust-project.json .vmlinux.objs .vmlinux.export.c \
-               .builtin-dtbs-list .builtin-dtb.S
+	       .builtin-dtbs-list .builtin-dtb.S \
+	       .vmlinux_thinlto_bc_files vmlinux.thinlink
 
 # Directories & files removed with 'make mrproper'
 MRPROPER_FILES += include/config include/generated          \
@@ -2028,6 +2056,8 @@ clean: $(clean-dirs)
 		-o -name '*.symtypes' -o -name 'modules.order' \
 		-o -name '*.c.[012]*.*' \
 		-o -name '*.ll' \
+		-o -name '*.final_a' -o -name '*.final_o' \
+		-o -name '*.o.thinlto.bc' \
 		-o -name '*.gcno' \
 		\) -type f -print \
 		-o -name '.tmp_*' -print \
diff --git a/arch/Kconfig b/arch/Kconfig
index b0adb665041f1..cbeeeb9b076d8 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -810,6 +810,18 @@ config LTO_CLANG_THIN
 	    https://clang.llvm.org/docs/ThinLTO.html
 
 	  If unsure, say Y.
+
+config LTO_CLANG_THIN_DIST
+	bool "Clang ThinLTO in distributed mode (EXPERIMENTAL)"
+	depends on HAS_LTO_CLANG && ARCH_SUPPORTS_LTO_CLANG_THIN
+	select LTO_CLANG
+	help
+	  This option enables Clang's ThinLTO in distributed build mode.
+	  In this mode, the linker performs the thin-link, generating
+	  ThinLTO index files. Subsequently, the build system explicitly
+	  invokes ThinLTO backend compilation using these index files
+	  and pre-linked IR objects. The resulting final object files
+	  are with the .final_o suffix.
 endchoice
 
 config ARCH_SUPPORTS_AUTOFDO_CLANG
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 13dcd86e74ca8..87259b0e2bfc8 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -50,18 +50,23 @@ endif
 
 # ===========================================================================
 
+builtin_suffix := $(if $(filter %.final_a, $(MAKECMDGOALS)),final_a,a)
+ifeq ($(thinlto_final_pass),1)
+builtin_suffix := final_a
+endif
+
 # subdir-builtin and subdir-modorder may contain duplications. Use $(sort ...)
-subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))
+subdir-builtin := $(sort $(filter %/built-in.$(builtin_suffix), $(real-obj-y)))
 subdir-modorder := $(sort $(filter %/modules.order, $(obj-m)))
 
 targets-for-builtin := $(extra-y)
 
 ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
-targets-for-builtin += $(obj)/lib.a
+targets-for-builtin += $(obj)/lib.$(builtin_suffix)
 endif
 
 ifdef need-builtin
-targets-for-builtin += $(obj)/built-in.a
+targets-for-builtin += $(obj)/built-in.$(builtin_suffix)
 endif
 
 targets-for-modules := $(foreach x, o mod, \
@@ -337,6 +342,10 @@ $(obj)/%.o: $(obj)/%.S FORCE
 targets += $(filter-out $(subdir-builtin), $(real-obj-y))
 targets += $(filter-out $(subdir-modorder), $(real-obj-m))
 targets += $(lib-y) $(always-y)
+ifeq ($(builtin_suffix), final_a)
+final_o_targets = $(patsubst,%.o,%.final_o,$(targets))
+targets += $(final_targets)
+endif
 
 # Linker scripts preprocessor (.lds.S -> .lds)
 # ---------------------------------------------------------------------------
@@ -347,6 +356,24 @@ quiet_cmd_cpp_lds_S = LDS     $@
 $(obj)/%.lds: $(src)/%.lds.S FORCE
 	$(call if_changed_dep,cpp_lds_S)
 
+ifdef CONFIG_LTO_CLANG_THIN_DIST
+# Generate .final_o (obj) from .o (bitcode) file
+# ---------------------------------------------------------------------------
+quiet_cmd_cc_o_bc = CC $(quiet_modtag) $@
+
+cmd_cc_o_bc      = $(if $(filter bitcode, $(shell file -b $<)),$(CC) \
+		   $(filter-out -Wp% $(LINUXINCLUDE) %.h.gch %.h -D% \
+		   -flto=thin, $(c_flags)) \
+		   -Wno-unused-command-line-argument \
+		   -x ir -fthinlto-index=$<.thinlto.bc -c -o $@ \
+		   $(if $(findstring ../,$<), \
+		   $$(realpath --relative-to=$(srcroot) $<), $<), \
+		   cp $< $@)
+
+$(obj)/%.final_o: $(obj)/%.o FORCE
+	$(call if_changed,cc_o_bc)
+endif
+
 # ASN.1 grammar
 # ---------------------------------------------------------------------------
 quiet_cmd_asn1_compiler = ASN.1   $(basename $@).[ch]
@@ -360,7 +387,7 @@ $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
 # ---------------------------------------------------------------------------
 
 # To build objects in subdirs, we need to descend into the directories
-$(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
+$(subdir-builtin): $(obj)/%/built-in.$(builtin_suffix): $(obj)/% ;
 $(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
 
 #
@@ -377,6 +404,12 @@ quiet_cmd_ar_builtin = AR      $@
 $(obj)/built-in.a: $(real-obj-y) FORCE
 	$(call if_changed,ar_builtin)
 
+ifdef CONFIG_LTO_CLANG_THIN_DIST
+# Rule to compile a set of .final_o files into one .final_a file.
+$(obj)/built-in.final_a: $(patsubst %.o,%.final_o,$(real-obj-y)) FORCE
+	$(call if_changed,ar_builtin)
+endif
+
 # This is a list of build artifacts from the current Makefile and its
 # sub-directories. The timestamp should be updated when any of the member files.
 
@@ -394,6 +427,14 @@ $(obj)/modules.order: $(obj-m) FORCE
 $(obj)/lib.a: $(lib-y) FORCE
 	$(call if_changed,ar)
 
+ifdef CONFIG_LTO_CLANG_THIN_DIST
+quiet_cmd_ar_final = AR      $@
+      cmd_ar_final = rm -f $@; $(AR) cDPrsT $@ $(patsubst %.o,%.final_o,$(real-prereqs))
+
+$(obj)/lib.final_a: $(patsubst %.o,%.final_o,$(lib-y)) FORCE
+	$(call if_changed,ar_final)
+endif
+
 quiet_cmd_ld_multi_m = LD [M]  $@
       cmd_ld_multi_m = $(LD) $(ld_flags) -r -o $@ @$< $(cmd_objtool)
 
@@ -459,7 +500,8 @@ $(single-subdir-goals): $(single-subdirs)
 PHONY += $(subdir-ym)
 $(subdir-ym):
 	$(Q)$(MAKE) $(build)=$@ \
-	need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
+	need-builtin=$(if $(filter $@/built-in.$(builtin_suffix), $(subdir-builtin)),1) \
+	thinlto_final_pass=$(if $(filter final_a, $(builtin_suffix)),1) \
 	need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1) \
 	$(filter $@/%, $(single-subdir-goals))
 
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 2fe73cda0bddb..ce341ed8d1df3 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -34,8 +34,13 @@ else
 obj-m := $(filter-out %/, $(obj-m))
 endif
 
+builtin_suffix := $(if $(filter %.final_a, $(MAKECMDGOALS)),final_a,a)
+ifeq ($(thinlto_final_pass),1)
+        builtin_suffix := final_a
+endif
+
 ifdef need-builtin
-obj-y		:= $(patsubst %/, %/built-in.a, $(obj-y))
+obj-y		:= $(patsubst %/, %/built-in.$(builtin_suffix), $(obj-y))
 else
 obj-y		:= $(filter-out %/, $(obj-y))
 endif
diff --git a/scripts/Makefile.vmlinux_o b/scripts/Makefile.vmlinux_o
index 938c7457717ea..4f04eb2c11412 100644
--- a/scripts/Makefile.vmlinux_o
+++ b/scripts/Makefile.vmlinux_o
@@ -9,6 +9,14 @@ include $(srctree)/scripts/Kbuild.include
 # for objtool
 include $(srctree)/scripts/Makefile.lib
 
+ifeq ($(thinlto_final_pass),1)
+vmlinux_a := vmlinux.final_a
+vmlinux_libs := $(patsubst %.a,%.final_a,$(KBUILD_VMLINUX_LIBS))
+else
+vmlinux_a := vmlinux.a
+vmlinux_libs := $(KBUILD_VMLINUX_LIBS)
+endif
+
 # Generate a linker script to ensure correct ordering of initcalls for Clang LTO
 # ---------------------------------------------------------------------------
 
@@ -18,7 +26,7 @@ quiet_cmd_gen_initcalls_lds = GEN     $@
 	$(PERL) $(real-prereqs) > $@
 
 .tmp_initcalls.lds: $(srctree)/scripts/generate_initcall_order.pl \
-		vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE
+		$(vmlinux_a) $(vmlinux_libs) FORCE
 	$(call if_changed,gen_initcalls_lds)
 
 targets := .tmp_initcalls.lds
@@ -59,8 +67,8 @@ quiet_cmd_ld_vmlinux.o = LD      $@
 	$(LD) ${KBUILD_LDFLAGS} -r -o $@ \
 	$(vmlinux-o-ld-args-y) \
 	$(addprefix -T , $(initcalls-lds)) \
-	--whole-archive vmlinux.a --no-whole-archive \
-	--start-group $(KBUILD_VMLINUX_LIBS) --end-group \
+	--whole-archive $(vmlinux_a) --no-whole-archive \
+	--start-group $(vmlinux_libs) --end-group \
 	$(cmd_objtool)
 
 define rule_ld_vmlinux.o
@@ -68,7 +76,7 @@ define rule_ld_vmlinux.o
 	$(call cmd,gen_objtooldep)
 endef
 
-vmlinux.o: $(initcalls-lds) vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE
+vmlinux.o: $(initcalls-lds) $(vmlinux_a) $(vmlinux_libs) FORCE
 	$(call if_changed_rule,ld_vmlinux.o)
 
 targets += vmlinux.o
diff --git a/scripts/Makefile.vmlinux_thinlink b/scripts/Makefile.vmlinux_thinlink
new file mode 100644
index 0000000000000..13e4026c7d45b
--- /dev/null
+++ b/scripts/Makefile.vmlinux_thinlink
@@ -0,0 +1,53 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+PHONY := __default
+__default: vmlinux.thinlink
+
+include include/config/auto.conf
+include $(srctree)/scripts/Kbuild.include
+
+
+# Generate a linker script to ensure correct ordering of initcalls for Clang LTO
+# ---------------------------------------------------------------------------
+
+quiet_cmd_gen_initcalls_lds = GEN     $@
+      cmd_gen_initcalls_lds = \
+	$(PYTHON3) $(srctree)/scripts/jobserver-exec \
+	$(PERL) $(real-prereqs) > $@
+
+.tmp_initcalls_thinlink.lds: $(srctree)/scripts/generate_initcall_order.pl \
+		vmlinux.a FORCE
+	$(call if_changed,gen_initcalls_lds)
+
+targets := .tmp_initcalls_thinlink.lds
+
+initcalls-lds := .tmp_initcalls_thinlink.lds
+
+quiet_cmd_ld_vmlinux.thinlink = LD      $@
+      cmd_ld_vmlinux.thinlink = \
+	$(AR) t vmlinux.a > .vmlinux_thinlto_bc_files; \
+	$(LD) ${KBUILD_LDFLAGS} -r $(addprefix -T , $(initcalls-lds)) \
+	--thinlto-index-only @.vmlinux_thinlto_bc_files; \
+	touch vmlinux.thinlink
+
+vmlinux.thinlink: vmlinux.a $(initcalls-lds) FORCE
+	$(call if_changed,ld_vmlinux.thinlink)
+
+targets += vmlinux.thinlink
+
+# Add FORCE to the prerequisites of a target to force it to be always rebuilt.
+# ---------------------------------------------------------------------------
+
+PHONY += FORCE
+FORCE:
+
+# Read all saved command lines and dependencies for the $(targets) we
+# may be building above, using $(if_changed{,_dep}). As an
+# optimization, we don't need to read them if the target does not
+# exist, we will rebuild anyway in that case.
+
+existing-targets := $(wildcard $(sort $(targets)))
+
+-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
+
+.PHONY: $(PHONY)
diff --git a/scripts/head-object-list.txt b/scripts/head-object-list.txt
index 7274dfc65af60..b300222e99a6b 100644
--- a/scripts/head-object-list.txt
+++ b/scripts/head-object-list.txt
@@ -18,6 +18,7 @@ arch/arm/kernel/head.o
 arch/csky/kernel/head.o
 arch/hexagon/kernel/head.o
 arch/loongarch/kernel/head.o
+arch/loongarch/kernel/head.final_o
 arch/m68k/68000/head.o
 arch/m68k/coldfire/head.o
 arch/m68k/kernel/head.o
-- 
2.49.0.805.g082f7c87e0-goog


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH] kbuild: distributed build support for Clang ThinLTO
@ 2025-04-20  5:17 kernel test robot
  0 siblings, 0 replies; 5+ messages in thread
From: kernel test robot @ 2025-04-20  5:17 UTC (permalink / raw)
  Cc: oe-kbuild-all, llvm

In-Reply-To: <20250420010214.1963979-1-xur@google.com>
References: <20250420010214.1963979-1-xur@google.com>
TO: xur@google.com
TO: Masahiro Yamada <masahiroy@kernel.org>
TO: Nathan Chancellor <nathan@kernel.org>
TO: Nicolas Schier <nicolas.schier@linux.dev>
TO: Nick Desaulniers <nick.desaulniers+lkml@gmail.com>
TO: Bill Wendling <morbo@google.com>
TO: Justin Stitt <justinstitt@google.com>
TO: Miguel Ojeda <ojeda@kernel.org>
TO: Thomas Gleixner <tglx@linutronix.de>
TO: Alice Ryhl <aliceryhl@google.com>
TO: Sami Tolvanen <samitolvanen@google.com>
TO: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
TO: Rafael Aquini <aquini@redhat.com>
TO: Michael Ellerman <mpe@ellerman.id.au>
TO: Stafford Horne <shorne@gmail.com>
TO: Christophe Leroy <christophe.leroy@csgroup.eu>
TO: Rong Xu <xur@google.com>
TO: Teresa Johnson <tejohnson@google.com>
CC: linux-kernel@vger.kernel.org
CC: linux-kbuild@vger.kernel.org
CC: llvm@lists.linux.dev

Hi,

kernel test robot noticed the following build errors:

[auto build test ERROR on masahiroy-kbuild/for-next]
[also build test ERROR on masahiroy-kbuild/fixes linus/master v6.15-rc2 next-20250417]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/xur-google-com/kbuild-distributed-build-support-for-Clang-ThinLTO/20250420-090244
base:   https://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git for-next
patch link:    https://lore.kernel.org/r/20250420010214.1963979-1-xur%40google.com
patch subject: [PATCH] kbuild: distributed build support for Clang ThinLTO
config: i386-buildonly-randconfig-002-20250420 (https://download.01.org/0day-ci/archive/20250420/202504201309.o2F1OHlm-lkp@intel.com/config)
compiler: clang version 20.1.2 (https://github.com/llvm/llvm-project 58df0ef89dd64126512e4ee27b4ac3fd8ddf6247)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250420/202504201309.o2F1OHlm-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202504201309.o2F1OHlm-lkp@intel.com/

All errors (new ones prefixed by >>):

>> Error loading index file 'lib/is_single_threaded.o.thinlto.bc': No such file or directory
--
>> Error loading index file 'lib/plist.o.thinlto.bc': No such file or directory
--
>> Error loading index file 'lib/iomem_copy.o.thinlto.bc': No such file or directory
--
>> Error loading index file 'lib/clz_tab.o.thinlto.bc': No such file or directory
--
>> Error loading index file 'lib/string.o.thinlto.bc': No such file or directory
--
>> Error loading index file 'lib/decompress_unlz4.o.thinlto.bc': No such file or directory
--
>> Error loading index file 'lib/decompress.o.thinlto.bc': No such file or directory
--
>> Error loading index file 'lib/decompress_unxz.o.thinlto.bc': No such file or directory
--
>> Error loading index file 'lib/kobject.o.thinlto.bc': No such file or directory
--
>> Error loading index file 'lib/maple_tree.o.thinlto.bc': No such file or directory
--
>> Error loading index file 'lib/fdt_empty_tree.o.thinlto.bc': No such file or directory
..

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] kbuild: distributed build support for Clang ThinLTO
@ 2025-04-27 15:09 kernel test robot
  0 siblings, 0 replies; 5+ messages in thread
From: kernel test robot @ 2025-04-27 15:09 UTC (permalink / raw)
  To: oe-kbuild; +Cc: lkp

:::::: 
:::::: Manual check reason: "clang compiler bug"
:::::: 

BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
In-Reply-To: <20250420010214.1963979-1-xur@google.com>
References: <20250420010214.1963979-1-xur@google.com>
TO: xur@google.com
TO: Masahiro Yamada <masahiroy@kernel.org>
TO: Nathan Chancellor <nathan@kernel.org>
TO: Nicolas Schier <nicolas.schier@linux.dev>
TO: Nick Desaulniers <nick.desaulniers+lkml@gmail.com>
TO: Bill Wendling <morbo@google.com>
TO: Justin Stitt <justinstitt@google.com>
TO: Miguel Ojeda <ojeda@kernel.org>
TO: Thomas Gleixner <tglx@linutronix.de>
TO: Alice Ryhl <aliceryhl@google.com>
TO: Sami Tolvanen <samitolvanen@google.com>
TO: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
TO: Rafael Aquini <aquini@redhat.com>
TO: Michael Ellerman <mpe@ellerman.id.au>
TO: Stafford Horne <shorne@gmail.com>
TO: Christophe Leroy <christophe.leroy@csgroup.eu>
TO: Rong Xu <xur@google.com>
TO: Teresa Johnson <tejohnson@google.com>
CC: linux-kernel@vger.kernel.org
CC: linux-kbuild@vger.kernel.org
CC: llvm@lists.linux.dev

Hi,

kernel test robot noticed the following build errors:

[auto build test ERROR on masahiroy-kbuild/for-next]
[also build test ERROR on masahiroy-kbuild/fixes linus/master v6.15-rc3 next-20250424]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/xur-google-com/kbuild-distributed-build-support-for-Clang-ThinLTO/20250420-090244
base:   https://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git for-next
patch link:    https://lore.kernel.org/r/20250420010214.1963979-1-xur%40google.com
patch subject: [PATCH] kbuild: distributed build support for Clang ThinLTO
:::::: branch date: 8 days ago
:::::: commit date: 8 days ago
config: um-randconfig-r071-20250427 (https://download.01.org/0day-ci/archive/20250427/202504272258.B50WCW9W-lkp@intel.com/config)
compiler: clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250427/202504272258.B50WCW9W-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/r/202504272258.B50WCW9W-lkp@intel.com/

All errors (new ones prefixed by >>):

   PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
   Stack dump:
   0.	Running pass 'Function Pass Manager' on module 'net/vmw_vsock/virtio_transport_common.o'.
   1.	Running pass 'Prologue/Epilogue Insertion & Frame Finalization' on function '@virtio_transport_reset_no_sock'
    #0 0x000056084a6f2f8b llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (lld+0x7dbf8b)
    #1 0x000056084a6f091b SignalHandler(int) Signals.cpp:0:0
    #2 0x00007f21dd500050 (/lib/x86_64-linux-gnu/libc.so.6+0x3c050)
    #3 0x000056084caddbf2 (anonymous namespace)::PEI::runOnMachineFunction(llvm::MachineFunction&) PrologEpilogInserter.cpp:0:0
    #4 0x000056084c9c2f15 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (.part.0) MachineFunctionPass.cpp:0:0
    #5 0x000056084e24b8b9 llvm::FPPassManager::runOnFunction(llvm::Function&) (lld+0x43348b9)
    #6 0x000056084e24b9ec llvm::FPPassManager::runOnModule(llvm::Module&) (lld+0x43349ec)
    #7 0x000056084e24c318 llvm::legacy::PassManagerImpl::run(llvm::Module&) (lld+0x4335318)
    #8 0x000056084c77f27c codegen(llvm::lto::Config const&, llvm::TargetMachine*, std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream, std::default_delete<llvm::CachedFileStream>>> (unsigned int, llvm::Twine const&)>, unsigned int, llvm::Module&, llvm::ModuleSummaryIndex const&) LTOBackend.cpp:0:0
    #9 0x000056084c78078a llvm::lto::thinBackend(llvm::lto::Config const&, unsigned int, std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream, std::default_delete<llvm::CachedFileStream>>> (unsigned int, llvm::Twine const&)>, llvm::Module&, llvm::ModuleSummaryIndex const&, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>*, std::vector<unsigned char, std::allocator<unsigned char>> const&) (lld+0x286978a)
   #10 0x000056084c770d2d std::_Function_handler<void (), std::_Bind<(anonymous namespace)::InProcessThinBackend::start(unsigned int, llvm::BitcodeModule, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const&, std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>&)::'lambda'(llvm::BitcodeModule, llvm::ModuleSummaryIndex&, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const&, std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const&, llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>&) (llvm::BitcodeModule, std::reference_wrapper<llvm::ModuleSummaryIndex>, std::reference_wrapper<llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const>, std::reference_wrapper<llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const>, std::reference_wrapper<std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const>, std::reference_wrapper<llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const>, std::reference_wrapper<llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>>)>>::_M_invoke(std::_Any_data const&) LTO.cpp:0:0
   #11 0x000056084aa7a32b std::_Function_handler<void (), llvm::ThreadPool::createTaskAndFuture(std::function<void ()>)::'lambda'()>::_M_invoke(std::_Any_data const&) (lld+0xb6332b)
   #12 0x000056084e3a4a9b llvm::ThreadPool::processTasks(llvm::ThreadPoolTaskGroup*) (lld+0x448da9b)
   #13 0x000056084e3a53cc void* llvm::thread::ThreadProxy<std::tuple<llvm::ThreadPool::grow(int)::'lambda'()>>(void*) ThreadPool.cpp:0:0
   #14 0x00007f21dd54d1c4 (/lib/x86_64-linux-gnu/libc.so.6+0x891c4)
   #15 0x00007f21dd5ccac0 clone (/lib/x86_64-linux-gnu/libc.so.6+0x108ac0)
>> /bin/bash: line 1: 3165322 Segmentation fault      ld.lld -m elf_x86_64 -mllvm -import-instr-limit=5 --compress-debug-sections=zlib -z noexecstack -r -o net/vmw_vsock/vmw_vsock_virtio_transport_common.o @net/vmw_vsock/vmw_vsock_virtio_transport_common.mod
--
   PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
   Stack dump:
   0.	Running pass 'Function Pass Manager' on module 'drivers/media/dvb-frontends/mt352.o'.
   1.	Running pass 'Prologue/Epilogue Insertion & Frame Finalization' on function '@mt352_init'
    #0 0x000055d8592e2f8b llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (lld+0x7dbf8b)
    #1 0x000055d8592e091b SignalHandler(int) Signals.cpp:0:0
    #2 0x00007fa5bca01050 (/lib/x86_64-linux-gnu/libc.so.6+0x3c050)
    #3 0x000055d85b6cdbf2 (anonymous namespace)::PEI::runOnMachineFunction(llvm::MachineFunction&) PrologEpilogInserter.cpp:0:0
    #4 0x000055d85b5b2f15 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (.part.0) MachineFunctionPass.cpp:0:0
    #5 0x000055d85ce3b8b9 llvm::FPPassManager::runOnFunction(llvm::Function&) (lld+0x43348b9)
    #6 0x000055d85ce3b9ec llvm::FPPassManager::runOnModule(llvm::Module&) (lld+0x43349ec)
    #7 0x000055d85ce3c318 llvm::legacy::PassManagerImpl::run(llvm::Module&) (lld+0x4335318)
    #8 0x000055d85b36f27c codegen(llvm::lto::Config const&, llvm::TargetMachine*, std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream, std::default_delete<llvm::CachedFileStream>>> (unsigned int, llvm::Twine const&)>, unsigned int, llvm::Module&, llvm::ModuleSummaryIndex const&) LTOBackend.cpp:0:0
    #9 0x000055d85b37078a llvm::lto::thinBackend(llvm::lto::Config const&, unsigned int, std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream, std::default_delete<llvm::CachedFileStream>>> (unsigned int, llvm::Twine const&)>, llvm::Module&, llvm::ModuleSummaryIndex const&, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>*, std::vector<unsigned char, std::allocator<unsigned char>> const&) (lld+0x286978a)
   #10 0x000055d85b360d2d std::_Function_handler<void (), std::_Bind<(anonymous namespace)::InProcessThinBackend::start(unsigned int, llvm::BitcodeModule, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const&, std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>&)::'lambda'(llvm::BitcodeModule, llvm::ModuleSummaryIndex&, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const&, std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const&, llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>&) (llvm::BitcodeModule, std::reference_wrapper<llvm::ModuleSummaryIndex>, std::reference_wrapper<llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const>, std::reference_wrapper<llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const>, std::reference_wrapper<std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const>, std::reference_wrapper<llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const>, std::reference_wrapper<llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>>)>>::_M_invoke(std::_Any_data const&) LTO.cpp:0:0
   #11 0x000055d85966a32b std::_Function_handler<void (), llvm::ThreadPool::createTaskAndFuture(std::function<void ()>)::'lambda'()>::_M_invoke(std::_Any_data const&) (lld+0xb6332b)
   #12 0x000055d85cf94a9b llvm::ThreadPool::processTasks(llvm::ThreadPoolTaskGroup*) (lld+0x448da9b)
   #13 0x000055d85cf953cc void* llvm::thread::ThreadProxy<std::tuple<llvm::ThreadPool::grow(int)::'lambda'()>>(void*) ThreadPool.cpp:0:0
   #14 0x00007fa5bca4e1c4 (/lib/x86_64-linux-gnu/libc.so.6+0x891c4)
   #15 0x00007fa5bcacdac0 clone (/lib/x86_64-linux-gnu/libc.so.6+0x108ac0)
>> /bin/bash: line 1: 3197906 Segmentation fault      ld.lld -m elf_x86_64 -mllvm -import-instr-limit=5 --compress-debug-sections=zlib -z noexecstack -r -o drivers/media/dvb-frontends/.tmp_mt352.o drivers/media/dvb-frontends/mt352.o
--
   PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
   Stack dump:
   0.	Running pass 'Function Pass Manager' on module 'drivers/net/wireless/ti/wlcore/event.o'.
   1.	Running pass 'Prologue/Epilogue Insertion & Frame Finalization' on function '@wl1271_event_handle'
    #0 0x00005642fb777f8b llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (lld+0x7dbf8b)
    #1 0x00005642fb77591b SignalHandler(int) Signals.cpp:0:0
    #2 0x00007fa0935cd050 (/lib/x86_64-linux-gnu/libc.so.6+0x3c050)
    #3 0x00005642fdb62bf2 (anonymous namespace)::PEI::runOnMachineFunction(llvm::MachineFunction&) PrologEpilogInserter.cpp:0:0
    #4 0x00005642fda47f15 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (.part.0) MachineFunctionPass.cpp:0:0
    #5 0x00005642ff2d08b9 llvm::FPPassManager::runOnFunction(llvm::Function&) (lld+0x43348b9)
    #6 0x00005642ff2d09ec llvm::FPPassManager::runOnModule(llvm::Module&) (lld+0x43349ec)
    #7 0x00005642ff2d1318 llvm::legacy::PassManagerImpl::run(llvm::Module&) (lld+0x4335318)
    #8 0x00005642fd80427c codegen(llvm::lto::Config const&, llvm::TargetMachine*, std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream, std::default_delete<llvm::CachedFileStream>>> (unsigned int, llvm::Twine const&)>, unsigned int, llvm::Module&, llvm::ModuleSummaryIndex const&) LTOBackend.cpp:0:0
    #9 0x00005642fd80578a llvm::lto::thinBackend(llvm::lto::Config const&, unsigned int, std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream, std::default_delete<llvm::CachedFileStream>>> (unsigned int, llvm::Twine const&)>, llvm::Module&, llvm::ModuleSummaryIndex const&, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>*, std::vector<unsigned char, std::allocator<unsigned char>> const&) (lld+0x286978a)
   #10 0x00005642fd7f5d2d std::_Function_handler<void (), std::_Bind<(anonymous namespace)::InProcessThinBackend::start(unsigned int, llvm::BitcodeModule, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const&, std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>&)::'lambda'(llvm::BitcodeModule, llvm::ModuleSummaryIndex&, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const&, std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const&, llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>&) (llvm::BitcodeModule, std::reference_wrapper<llvm::ModuleSummaryIndex>, std::reference_wrapper<llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const>, std::reference_wrapper<llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const>, std::reference_wrapper<std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const>, std::reference_wrapper<llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const>, std::reference_wrapper<llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>>)>>::_M_invoke(std::_Any_data const&) LTO.cpp:0:0
   #11 0x00005642fbaff32b std::_Function_handler<void (), llvm::ThreadPool::createTaskAndFuture(std::function<void ()>)::'lambda'()>::_M_invoke(std::_Any_data const&) (lld+0xb6332b)
   #12 0x00005642ff429a9b llvm::ThreadPool::processTasks(llvm::ThreadPoolTaskGroup*) (lld+0x448da9b)
   #13 0x00005642ff42a3cc void* llvm::thread::ThreadProxy<std::tuple<llvm::ThreadPool::grow(int)::'lambda'()>>(void*) ThreadPool.cpp:0:0
   #14 0x00007fa09361a1c4 (/lib/x86_64-linux-gnu/libc.so.6+0x891c4)
   #15 0x00007fa093699ac0 clone (/lib/x86_64-linux-gnu/libc.so.6+0x108ac0)
>> /bin/bash: line 1: 3184204 Segmentation fault      ld.lld -m elf_x86_64 -mllvm -import-instr-limit=5 --compress-debug-sections=zlib -z noexecstack -r -o drivers/net/wireless/ti/wlcore/wlcore.o @drivers/net/wireless/ti/wlcore/wlcore.mod
--
   PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
   Stack dump:
   0.	Running pass 'Function Pass Manager' on module 'drivers/net/wireless/virtual/mac80211_hwsim.o'.
   1.	Running pass 'Prologue/Epilogue Insertion & Frame Finalization' on function '@remove_vqs'
    #0 0x000055ee073b2f8b llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (lld+0x7dbf8b)
    #1 0x000055ee073b091b SignalHandler(int) Signals.cpp:0:0
    #2 0x00007f74b5dbe050 (/lib/x86_64-linux-gnu/libc.so.6+0x3c050)
    #3 0x000055ee0979dbf2 (anonymous namespace)::PEI::runOnMachineFunction(llvm::MachineFunction&) PrologEpilogInserter.cpp:0:0
    #4 0x000055ee09682f15 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (.part.0) MachineFunctionPass.cpp:0:0
    #5 0x000055ee0af0b8b9 llvm::FPPassManager::runOnFunction(llvm::Function&) (lld+0x43348b9)
    #6 0x000055ee0af0b9ec llvm::FPPassManager::runOnModule(llvm::Module&) (lld+0x43349ec)
    #7 0x000055ee0af0c318 llvm::legacy::PassManagerImpl::run(llvm::Module&) (lld+0x4335318)
    #8 0x000055ee0943f27c codegen(llvm::lto::Config const&, llvm::TargetMachine*, std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream, std::default_delete<llvm::CachedFileStream>>> (unsigned int, llvm::Twine const&)>, unsigned int, llvm::Module&, llvm::ModuleSummaryIndex const&) LTOBackend.cpp:0:0
    #9 0x000055ee0944078a llvm::lto::thinBackend(llvm::lto::Config const&, unsigned int, std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream, std::default_delete<llvm::CachedFileStream>>> (unsigned int, llvm::Twine const&)>, llvm::Module&, llvm::ModuleSummaryIndex const&, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>*, std::vector<unsigned char, std::allocator<unsigned char>> const&) (lld+0x286978a)
   #10 0x000055ee09430d2d std::_Function_handler<void (), std::_Bind<(anonymous namespace)::InProcessThinBackend::start(unsigned int, llvm::BitcodeModule, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const&, std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>&)::'lambda'(llvm::BitcodeModule, llvm::ModuleSummaryIndex&, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const&, std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const&, llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>&) (llvm::BitcodeModule, std::reference_wrapper<llvm::ModuleSummaryIndex>, std::reference_wrapper<llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const>, std::reference_wrapper<llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const>, std::reference_wrapper<std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const>, std::reference_wrapper<llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const>, std::reference_wrapper<llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>>)>>::_M_invoke(std::_Any_data const&) LTO.cpp:0:0
   #11 0x000055ee0773a32b std::_Function_handler<void (), llvm::ThreadPool::createTaskAndFuture(std::function<void ()>)::'lambda'()>::_M_invoke(std::_Any_data const&) (lld+0xb6332b)
   #12 0x000055ee0b064a9b llvm::ThreadPool::processTasks(llvm::ThreadPoolTaskGroup*) (lld+0x448da9b)
   #13 0x000055ee0b0653cc void* llvm::thread::ThreadProxy<std::tuple<llvm::ThreadPool::grow(int)::'lambda'()>>(void*) ThreadPool.cpp:0:0
   #14 0x00007f74b5e0b1c4 (/lib/x86_64-linux-gnu/libc.so.6+0x891c4)
   #15 0x00007f74b5e8aac0 clone (/lib/x86_64-linux-gnu/libc.so.6+0x108ac0)
>> /bin/bash: line 1: 3178217 Segmentation fault      ld.lld -m elf_x86_64 -mllvm -import-instr-limit=5 --compress-debug-sections=zlib -z noexecstack -r -o drivers/net/wireless/virtual/.tmp_mac80211_hwsim.o drivers/net/wireless/virtual/mac80211_hwsim.o
--
   PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
   Stack dump:
   0.	Running pass 'Function Pass Manager' on module 'drivers/net/wireless/ti/wl18xx/main.o'.
   1.	Running pass 'Prologue/Epilogue Insertion & Frame Finalization' on function '@wl18xx_plt_init'
    #0 0x000055865d410f8b llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (lld+0x7dbf8b)
    #1 0x000055865d40e91b SignalHandler(int) Signals.cpp:0:0
    #2 0x00007f23bd0cd050 (/lib/x86_64-linux-gnu/libc.so.6+0x3c050)
    #3 0x000055865f7fbbf2 (anonymous namespace)::PEI::runOnMachineFunction(llvm::MachineFunction&) PrologEpilogInserter.cpp:0:0
    #4 0x000055865f6e0f15 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (.part.0) MachineFunctionPass.cpp:0:0
    #5 0x0000558660f698b9 llvm::FPPassManager::runOnFunction(llvm::Function&) (lld+0x43348b9)
    #6 0x0000558660f699ec llvm::FPPassManager::runOnModule(llvm::Module&) (lld+0x43349ec)
    #7 0x0000558660f6a318 llvm::legacy::PassManagerImpl::run(llvm::Module&) (lld+0x4335318)
    #8 0x000055865f49d27c codegen(llvm::lto::Config const&, llvm::TargetMachine*, std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream, std::default_delete<llvm::CachedFileStream>>> (unsigned int, llvm::Twine const&)>, unsigned int, llvm::Module&, llvm::ModuleSummaryIndex const&) LTOBackend.cpp:0:0
    #9 0x000055865f49e78a llvm::lto::thinBackend(llvm::lto::Config const&, unsigned int, std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream, std::default_delete<llvm::CachedFileStream>>> (unsigned int, llvm::Twine const&)>, llvm::Module&, llvm::ModuleSummaryIndex const&, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>*, std::vector<unsigned char, std::allocator<unsigned char>> const&) (lld+0x286978a)
   #10 0x000055865f48ed2d std::_Function_handler<void (), std::_Bind<(anonymous namespace)::InProcessThinBackend::start(unsigned int, llvm::BitcodeModule, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const&, std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>&)::'lambda'(llvm::BitcodeModule, llvm::ModuleSummaryIndex&, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const&, std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const&, llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>&) (llvm::BitcodeModule, std::reference_wrapper<llvm::ModuleSummaryIndex>, std::reference_wrapper<llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const>, std::reference_wrapper<llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const>, std::reference_wrapper<std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const>, std::reference_wrapper<llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const>, std::reference_wrapper<llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>>)>>::_M_invoke(std::_Any_data const&) LTO.cpp:0:0
   #11 0x000055865d79832b std::_Function_handler<void (), llvm::ThreadPool::createTaskAndFuture(std::function<void ()>)::'lambda'()>::_M_invoke(std::_Any_data const&) (lld+0xb6332b)
   #12 0x00005586610c2a9b llvm::ThreadPool::processTasks(llvm::ThreadPoolTaskGroup*) (lld+0x448da9b)
   #13 0x00005586610c33cc void* llvm::thread::ThreadProxy<std::tuple<llvm::ThreadPool::grow(int)::'lambda'()>>(void*) ThreadPool.cpp:0:0
   #14 0x00007f23bd11a1c4 (/lib/x86_64-linux-gnu/libc.so.6+0x891c4)
   #15 0x00007f23bd199ac0 clone (/lib/x86_64-linux-gnu/libc.so.6+0x108ac0)
>> /bin/bash: line 1: 3183376 Segmentation fault      ld.lld -m elf_x86_64 -mllvm -import-instr-limit=5 --compress-debug-sections=zlib -z noexecstack -r -o drivers/net/wireless/ti/wl18xx/wl18xx.o @drivers/net/wireless/ti/wl18xx/wl18xx.mod
--
   PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
   Stack dump:
   0.	Running pass 'Function Pass Manager' on module 'drivers/crypto/aspeed/aspeed-acry.o'.
   1.	Running pass 'Prologue/Epilogue Insertion & Frame Finalization' on function '@aspeed_acry_done_task'
    #0 0x000055644060ff8b llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (lld+0x7dbf8b)
    #1 0x000055644060d91b SignalHandler(int) Signals.cpp:0:0
    #2 0x00007fe0b83ec050 (/lib/x86_64-linux-gnu/libc.so.6+0x3c050)
    #3 0x00005564429fabf2 (anonymous namespace)::PEI::runOnMachineFunction(llvm::MachineFunction&) PrologEpilogInserter.cpp:0:0
    #4 0x00005564428dff15 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (.part.0) MachineFunctionPass.cpp:0:0
    #5 0x00005564441688b9 llvm::FPPassManager::runOnFunction(llvm::Function&) (lld+0x43348b9)
    #6 0x00005564441689ec llvm::FPPassManager::runOnModule(llvm::Module&) (lld+0x43349ec)
    #7 0x0000556444169318 llvm::legacy::PassManagerImpl::run(llvm::Module&) (lld+0x4335318)
    #8 0x000055644269c27c codegen(llvm::lto::Config const&, llvm::TargetMachine*, std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream, std::default_delete<llvm::CachedFileStream>>> (unsigned int, llvm::Twine const&)>, unsigned int, llvm::Module&, llvm::ModuleSummaryIndex const&) LTOBackend.cpp:0:0
    #9 0x000055644269d78a llvm::lto::thinBackend(llvm::lto::Config const&, unsigned int, std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream, std::default_delete<llvm::CachedFileStream>>> (unsigned int, llvm::Twine const&)>, llvm::Module&, llvm::ModuleSummaryIndex const&, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>*, std::vector<unsigned char, std::allocator<unsigned char>> const&) (lld+0x286978a)
   #10 0x000055644268dd2d std::_Function_handler<void (), std::_Bind<(anonymous namespace)::InProcessThinBackend::start(unsigned int, llvm::BitcodeModule, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const&, std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>&)::'lambda'(llvm::BitcodeModule, llvm::ModuleSummaryIndex&, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const&, std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const&, llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>&) (llvm::BitcodeModule, std::reference_wrapper<llvm::ModuleSummaryIndex>, std::reference_wrapper<llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const>, std::reference_wrapper<llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const>, std::reference_wrapper<std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const>, std::reference_wrapper<llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const>, std::reference_wrapper<llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>>)>>::_M_invoke(std::_Any_data const&) LTO.cpp:0:0
   #11 0x000055644099732b std::_Function_handler<void (), llvm::ThreadPool::createTaskAndFuture(std::function<void ()>)::'lambda'()>::_M_invoke(std::_Any_data const&) (lld+0xb6332b)
   #12 0x00005564442c1a9b llvm::ThreadPool::processTasks(llvm::ThreadPoolTaskGroup*) (lld+0x448da9b)
   #13 0x00005564442c23cc void* llvm::thread::ThreadProxy<std::tuple<llvm::ThreadPool::grow(int)::'lambda'()>>(void*) ThreadPool.cpp:0:0
   #14 0x00007fe0b84391c4 (/lib/x86_64-linux-gnu/libc.so.6+0x891c4)
   #15 0x00007fe0b84b8ac0 clone (/lib/x86_64-linux-gnu/libc.so.6+0x108ac0)
>> /bin/bash: line 1: 3197822 Segmentation fault      ld.lld -m elf_x86_64 -mllvm -import-instr-limit=5 --compress-debug-sections=zlib -z noexecstack -r -o drivers/crypto/aspeed/.tmp_aspeed-acry.o drivers/crypto/aspeed/aspeed-acry.o
--
   PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
   Stack dump:
   0.	Running pass 'Function Pass Manager' on module 'drivers/crypto/aspeed/aspeed-hace.o'.
   1.	Running pass 'Prologue/Epilogue Insertion & Frame Finalization' on function '@aspeed_hace_hash_done_task'
    #0 0x000055ad09a69f8b llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (lld+0x7dbf8b)
    #1 0x000055ad09a6791b SignalHandler(int) Signals.cpp:0:0
    #2 0x00007f9909e34050 (/lib/x86_64-linux-gnu/libc.so.6+0x3c050)
    #3 0x000055ad0be54bf2 (anonymous namespace)::PEI::runOnMachineFunction(llvm::MachineFunction&) PrologEpilogInserter.cpp:0:0
    #4 0x000055ad0bd39f15 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (.part.0) MachineFunctionPass.cpp:0:0
    #5 0x000055ad0d5c28b9 llvm::FPPassManager::runOnFunction(llvm::Function&) (lld+0x43348b9)
    #6 0x000055ad0d5c29ec llvm::FPPassManager::runOnModule(llvm::Module&) (lld+0x43349ec)
    #7 0x000055ad0d5c3318 llvm::legacy::PassManagerImpl::run(llvm::Module&) (lld+0x4335318)
    #8 0x000055ad0baf627c codegen(llvm::lto::Config const&, llvm::TargetMachine*, std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream, std::default_delete<llvm::CachedFileStream>>> (unsigned int, llvm::Twine const&)>, unsigned int, llvm::Module&, llvm::ModuleSummaryIndex const&) LTOBackend.cpp:0:0
    #9 0x000055ad0baf778a llvm::lto::thinBackend(llvm::lto::Config const&, unsigned int, std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream, std::default_delete<llvm::CachedFileStream>>> (unsigned int, llvm::Twine const&)>, llvm::Module&, llvm::ModuleSummaryIndex const&, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>*, std::vector<unsigned char, std::allocator<unsigned char>> const&) (lld+0x286978a)
   #10 0x000055ad0bae7d2d std::_Function_handler<void (), std::_Bind<(anonymous namespace)::InProcessThinBackend::start(unsigned int, llvm::BitcodeModule, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const&, std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>&)::'lambda'(llvm::BitcodeModule, llvm::ModuleSummaryIndex&, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const&, std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const&, llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>&) (llvm::BitcodeModule, std::reference_wrapper<llvm::ModuleSummaryIndex>, std::reference_wrapper<llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const>, std::reference_wrapper<llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const>, std::reference_wrapper<std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const>, std::reference_wrapper<llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const>, std::reference_wrapper<llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>>)>>::_M_invoke(std::_Any_data const&) LTO.cpp:0:0
   #11 0x000055ad09df132b std::_Function_handler<void (), llvm::ThreadPool::createTaskAndFuture(std::function<void ()>)::'lambda'()>::_M_invoke(std::_Any_data const&) (lld+0xb6332b)
   #12 0x000055ad0d71ba9b llvm::ThreadPool::processTasks(llvm::ThreadPoolTaskGroup*) (lld+0x448da9b)
   #13 0x000055ad0d71c3cc void* llvm::thread::ThreadProxy<std::tuple<llvm::ThreadPool::grow(int)::'lambda'()>>(void*) ThreadPool.cpp:0:0
   #14 0x00007f9909e811c4 (/lib/x86_64-linux-gnu/libc.so.6+0x891c4)
   #15 0x00007f9909f00ac0 clone (/lib/x86_64-linux-gnu/libc.so.6+0x108ac0)
>> /bin/bash: line 1: 3197928 Segmentation fault      ld.lld -m elf_x86_64 -mllvm -import-instr-limit=5 --compress-debug-sections=zlib -z noexecstack -r -o drivers/crypto/aspeed/aspeed_crypto.o @drivers/crypto/aspeed/aspeed_crypto.mod
--
   PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
   Stack dump:
   0.	Running pass 'Function Pass Manager' on module 'drivers/vfio/platform/vfio_platform_common.o'.
   1.	Running pass 'Prologue/Epilogue Insertion & Frame Finalization' on function '@vfio_platform_call_reset'
    #0 0x00005634ff27ff8b llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (lld+0x7dbf8b)
    #1 0x00005634ff27d91b SignalHandler(int) Signals.cpp:0:0
    #2 0x00007f2580241050 (/lib/x86_64-linux-gnu/libc.so.6+0x3c050)
    #3 0x000056350166abf2 (anonymous namespace)::PEI::runOnMachineFunction(llvm::MachineFunction&) PrologEpilogInserter.cpp:0:0
    #4 0x000056350154ff15 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (.part.0) MachineFunctionPass.cpp:0:0
    #5 0x0000563502dd88b9 llvm::FPPassManager::runOnFunction(llvm::Function&) (lld+0x43348b9)
    #6 0x0000563502dd89ec llvm::FPPassManager::runOnModule(llvm::Module&) (lld+0x43349ec)
    #7 0x0000563502dd9318 llvm::legacy::PassManagerImpl::run(llvm::Module&) (lld+0x4335318)
    #8 0x000056350130c27c codegen(llvm::lto::Config const&, llvm::TargetMachine*, std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream, std::default_delete<llvm::CachedFileStream>>> (unsigned int, llvm::Twine const&)>, unsigned int, llvm::Module&, llvm::ModuleSummaryIndex const&) LTOBackend.cpp:0:0
    #9 0x000056350130d78a llvm::lto::thinBackend(llvm::lto::Config const&, unsigned int, std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream, std::default_delete<llvm::CachedFileStream>>> (unsigned int, llvm::Twine const&)>, llvm::Module&, llvm::ModuleSummaryIndex const&, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>*, std::vector<unsigned char, std::allocator<unsigned char>> const&) (lld+0x286978a)
   #10 0x00005635012fdd2d std::_Function_handler<void (), std::_Bind<(anonymous namespace)::InProcessThinBackend::start(unsigned int, llvm::BitcodeModule, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const&, std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>&)::'lambda'(llvm::BitcodeModule, llvm::ModuleSummaryIndex&, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const&, std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const&, llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>&) (llvm::BitcodeModule, std::reference_wrapper<llvm::ModuleSummaryIndex>, std::reference_wrapper<llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const>, std::reference_wrapper<llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const>, std::reference_wrapper<std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const>, std::reference_wrapper<llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const>, std::reference_wrapper<llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>>)>>::_M_invoke(std::_Any_data const&) LTO.cpp:0:0
   #11 0x00005634ff60732b std::_Function_handler<void (), llvm::ThreadPool::createTaskAndFuture(std::function<void ()>)::'lambda'()>::_M_invoke(std::_Any_data const&) (lld+0xb6332b)
   #12 0x0000563502f31a9b llvm::ThreadPool::processTasks(llvm::ThreadPoolTaskGroup*) (lld+0x448da9b)
   #13 0x0000563502f323cc void* llvm::thread::ThreadProxy<std::tuple<llvm::ThreadPool::grow(int)::'lambda'()>>(void*) ThreadPool.cpp:0:0
   #14 0x00007f258028e1c4 (/lib/x86_64-linux-gnu/libc.so.6+0x891c4)
   #15 0x00007f258030dac0 clone (/lib/x86_64-linux-gnu/libc.so.6+0x108ac0)
>> /bin/bash: line 1: 3199604 Segmentation fault      ld.lld -m elf_x86_64 -mllvm -import-instr-limit=5 --compress-debug-sections=zlib -z noexecstack -r -o drivers/vfio/platform/vfio-platform-base.o @drivers/vfio/platform/vfio-platform-base.mod
--
   PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
   Stack dump:
   0.	Running pass 'Function Pass Manager' on module 'drivers/fpga/intel-m10-bmc-sec-update.o'.
   1.	Running pass 'Prologue/Epilogue Insertion & Frame Finalization' on function '@m10bmc_sec_cleanup'
    #0 0x000055c206ca9f8b llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (lld+0x7dbf8b)
    #1 0x000055c206ca791b SignalHandler(int) Signals.cpp:0:0
    #2 0x00007fe01c68b050 (/lib/x86_64-linux-gnu/libc.so.6+0x3c050)
    #3 0x000055c209094bf2 (anonymous namespace)::PEI::runOnMachineFunction(llvm::MachineFunction&) PrologEpilogInserter.cpp:0:0
    #4 0x000055c208f79f15 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (.part.0) MachineFunctionPass.cpp:0:0
    #5 0x000055c20a8028b9 llvm::FPPassManager::runOnFunction(llvm::Function&) (lld+0x43348b9)
    #6 0x000055c20a8029ec llvm::FPPassManager::runOnModule(llvm::Module&) (lld+0x43349ec)
    #7 0x000055c20a803318 llvm::legacy::PassManagerImpl::run(llvm::Module&) (lld+0x4335318)
    #8 0x000055c208d3627c codegen(llvm::lto::Config const&, llvm::TargetMachine*, std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream, std::default_delete<llvm::CachedFileStream>>> (unsigned int, llvm::Twine const&)>, unsigned int, llvm::Module&, llvm::ModuleSummaryIndex const&) LTOBackend.cpp:0:0
    #9 0x000055c208d3778a llvm::lto::thinBackend(llvm::lto::Config const&, unsigned int, std::function<llvm::Expected<std::unique_ptr<llvm::CachedFileStream, std::default_delete<llvm::CachedFileStream>>> (unsigned int, llvm::Twine const&)>, llvm::Module&, llvm::ModuleSummaryIndex const&, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>*, std::vector<unsigned char, std::allocator<unsigned char>> const&) (lld+0x286978a)
   #10 0x000055c208d27d2d std::_Function_handler<void (), std::_Bind<(anonymous namespace)::InProcessThinBackend::start(unsigned int, llvm::BitcodeModule, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const&, std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>&)::'lambda'(llvm::BitcodeModule, llvm::ModuleSummaryIndex&, llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const&, llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const&, std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const&, llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const&, llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>&) (llvm::BitcodeModule, std::reference_wrapper<llvm::ModuleSummaryIndex>, std::reference_wrapper<llvm::StringMap<std::unordered_set<unsigned long, std::hash<unsigned long>, std::equal_to<unsigned long>, std::allocator<unsigned long>>, llvm::MallocAllocator> const>, std::reference_wrapper<llvm::DenseSet<llvm::ValueInfo, llvm::DenseMapInfo<llvm::ValueInfo, void>> const>, std::reference_wrapper<std::map<unsigned long, llvm::GlobalValue::LinkageTypes, std::less<unsigned long>, std::allocator<std::pair<unsigned long const, llvm::GlobalValue::LinkageTypes>>> const>, std::reference_wrapper<llvm::DenseMap<unsigned long, llvm::GlobalValueSummary*, llvm::DenseMapInfo<unsigned long, void>, llvm::detail::DenseMapPair<unsigned long, llvm::GlobalValueSummary*>> const>, std::reference_wrapper<llvm::MapVector<llvm::StringRef, llvm::BitcodeModule, llvm::DenseMap<llvm::StringRef, unsigned int, llvm::DenseMapInfo<llvm::StringRef, void>, llvm::detail::DenseMapPair<llvm::StringRef, unsigned int>>, llvm::SmallVector<std::pair<llvm::StringRef, llvm::BitcodeModule>, 0u>>>)>>::_M_invoke(std::_Any_data const&) LTO.cpp:0:0
   #11 0x000055c20703132b std::_Function_handler<void (), llvm::ThreadPool::createTaskAndFuture(std::function<void ()>)::'lambda'()>::_M_invoke(std::_Any_data const&) (lld+0xb6332b)
   #12 0x000055c20a95ba9b llvm::ThreadPool::processTasks(llvm::ThreadPoolTaskGroup*) (lld+0x448da9b)
   #13 0x000055c20a95c3cc void* llvm::thread::ThreadProxy<std::tuple<llvm::ThreadPool::grow(int)::'lambda'()>>(void*) ThreadPool.cpp:0:0
   #14 0x00007fe01c6d81c4 (/lib/x86_64-linux-gnu/libc.so.6+0x891c4)
   #15 0x00007fe01c757ac0 clone (/lib/x86_64-linux-gnu/libc.so.6+0x108ac0)
>> /bin/bash: line 1: 3202671 Segmentation fault      ld.lld -m elf_x86_64 -mllvm -import-instr-limit=5 --compress-debug-sections=zlib -z noexecstack -r -o drivers/fpga/.tmp_intel-m10-bmc-sec-update.o drivers/fpga/intel-m10-bmc-sec-update.o

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] kbuild: distributed build support for Clang ThinLTO
  2025-04-20  1:02 xur
@ 2025-04-29 20:34 ` Rong Xu
  2025-05-01  1:20   ` Nathan Chancellor
  0 siblings, 1 reply; 5+ messages in thread
From: Rong Xu @ 2025-04-29 20:34 UTC (permalink / raw)
  To: Masahiro Yamada, Nathan Chancellor, Nicolas Schier,
	Nick Desaulniers, Bill Wendling, Justin Stitt, Miguel Ojeda,
	Thomas Gleixner, Alice Ryhl, Sami Tolvanen,
	Mike Rapoport (Microsoft), Rafael Aquini, Michael Ellerman,
	Stafford Horne, Christophe Leroy, Rong Xu, Teresa Johnson
  Cc: linux-kernel, linux-kbuild, llvm

Just wanted to gently follow up on this patch that I sent previously.

From a toolchain and compiler perspective, I genuinely believe that
kernel ThinLTO builds should use this. I really want to get some feedback
and reviews on this patch.

Thanks,

-Rong

On Sat, Apr 19, 2025 at 6:02 PM <xur@google.com> wrote:
>
> From: Rong Xu <xur@google.com>
>
> Add distributed ThinLTO build support for the Linux kernel.
> This new mode offers several advantages: (1) Increased
> flexibility in handling user-specified build options.
> (2) Improved user-friendliness for developers. (3) Greater
> convenience for integrating with objtool and livepatch.
>
> Note that "distributed" in this context refers to a term
> that differentiates in-process ThinLTO builds by invoking
> backend compilation through the linker, not necessarily
> building in distributed environments.
>
> Distributed ThinLTO is enabled via the
> `CONFIG_LTO_CLANG_THIN_DIST` Kconfig option. For example:
>  > make LLVM=1 defconfig
>  > scripts/config -e LTO_CLANG_THIN_DIST
>  > make LLVM=1 oldconfig
>  > make LLVM=1 vmlinux -j <..>
>
> The implementation changes the top-level Makefile with a
> macro for generating `vmlinux.o` for distributed ThinLTO
> builds. It uses the existing Kbuild infrastructure to
> perform two recursive passes through the subdirectories.
> The first pass generates LLVM IR object files, similar to
> in-process ThinLTO. Following the thin-link stage, a second
> pass compiles these IR files into the final native object
> files. The build rules and actions for this two-pass process
> are primarily implemented in `scripts/Makefile.build`.
>
> Currently, this patch focuses on building the main kernel
> image (`vmlinux`) only. Support for building kernel modules
> using this method is planned for a subsequent patch.
>
> Tested on the following arch: x86, arm64, loongarch, and
> riscv.
>
> Some implementation details can be found here:
> https://discourse.llvm.org/t/rfc-distributed-thinlto-build-for-kernel/85934
>
> Signed-off-by: Rong Xu <xur@google.com>
> ---
>  MAINTAINERS                       |  5 +++
>  Makefile                          | 40 ++++++++++++++++++++---
>  arch/Kconfig                      | 12 +++++++
>  scripts/Makefile.build            | 52 +++++++++++++++++++++++++++---
>  scripts/Makefile.lib              |  7 +++-
>  scripts/Makefile.vmlinux_o        | 16 +++++++---
>  scripts/Makefile.vmlinux_thinlink | 53 +++++++++++++++++++++++++++++++
>  scripts/head-object-list.txt      |  1 +
>  8 files changed, 171 insertions(+), 15 deletions(-)
>  create mode 100644 scripts/Makefile.vmlinux_thinlink
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index c966e71ea60bb..40d3bc223e4b0 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -5782,6 +5782,11 @@ F:       scripts/Makefile.clang
>  F:     scripts/clang-tools/
>  K:     \b(?i:clang|llvm)\b
>
> +CLANG/LLVM THINLTO DISTRIBUTED BUILD
> +M:     Rong Xu <xur@google.com>
> +S:     Supported
> +F:     scripts/Makefile.vmlinux_thinlink
> +
>  CLK API
>  M:     Russell King <linux@armlinux.org.uk>
>  L:     linux-clk@vger.kernel.org
> diff --git a/Makefile b/Makefile
> index e65f8735c7bf6..18da9a40dd2c8 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -298,7 +298,8 @@ no-dot-config-targets := $(clean-targets) \
>                          outputmakefile rustavailable rustfmt rustfmtcheck
>  no-sync-config-targets := $(no-dot-config-targets) %install modules_sign kernelrelease \
>                           image_name
> -single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.rsi %.s %/
> +single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.rsi %.s %.final_o \
> +                 %.final_a %.o.thinlto.bc %/
>
>  config-build   :=
>  mixed-build    :=
> @@ -991,10 +992,10 @@ export CC_FLAGS_SCS
>  endif
>
>  ifdef CONFIG_LTO_CLANG
> -ifdef CONFIG_LTO_CLANG_THIN
> -CC_FLAGS_LTO   := -flto=thin -fsplit-lto-unit
> -else
> +ifdef CONFIG_LTO_CLANG_FULL
>  CC_FLAGS_LTO   := -flto
> +else # for CONFIG_LTO_CLANG_THIN or CONFIG_LTO_CLANG_THIN_DIST
> +CC_FLAGS_LTO   := -flto=thin -fsplit-lto-unit
>  endif
>  CC_FLAGS_LTO   += -fvisibility=hidden
>
> @@ -1218,8 +1219,34 @@ vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt FORCE
>         $(call if_changed,ar_vmlinux.a)
>
>  PHONY += vmlinux_o
> +ifdef CONFIG_LTO_CLANG_THIN_DIST
> +vmlinux.thinlink: vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE
> +       $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_thinlink
> +targets += vmlinux.thinlink
> +
> +vmlinux_final_a := $(patsubst %.a,%.final_a,$(KBUILD_VMLINUX_OBJS))
> +quiet_cmd_ar_vmlinux.final_a = AR      $@
> +      cmd_ar_vmlinux.final_a = \
> +       rm -f $@; \
> +       $(AR) cDPrST $@ $(vmlinux_final_a); \
> +       $(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)
> +
> +define rule_gen_vmlinux_final_a
> +       +$(Q)$(MAKE) $(build)=. need-builtin=1 thinlto_final_pass=1 need-modorder=1 built-in.final_a
> +       $(call cmd_and_savecmd,ar_vmlinux.final_a)
> +endef
> +
> +vmlinux.final_a: vmlinux.thinlink scripts/head-object-list.txt FORCE
> +       $(call if_changed_rule,gen_vmlinux_final_a)
> +
> +targets += vmlinux.final_a
> +
> +vmlinux_o: vmlinux.final_a
> +       $(Q)$(MAKE) thinlto_final_pass=1 -f $(srctree)/scripts/Makefile.vmlinux_o
> +else
>  vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
>         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o
> +endif
>
>  vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o
>         @:
> @@ -1577,7 +1604,8 @@ CLEAN_FILES += vmlinux.symvers modules-only.symvers \
>                modules.builtin.ranges vmlinux.o.map vmlinux.unstripped \
>                compile_commands.json rust/test \
>                rust-project.json .vmlinux.objs .vmlinux.export.c \
> -               .builtin-dtbs-list .builtin-dtb.S
> +              .builtin-dtbs-list .builtin-dtb.S \
> +              .vmlinux_thinlto_bc_files vmlinux.thinlink
>
>  # Directories & files removed with 'make mrproper'
>  MRPROPER_FILES += include/config include/generated          \
> @@ -2028,6 +2056,8 @@ clean: $(clean-dirs)
>                 -o -name '*.symtypes' -o -name 'modules.order' \
>                 -o -name '*.c.[012]*.*' \
>                 -o -name '*.ll' \
> +               -o -name '*.final_a' -o -name '*.final_o' \
> +               -o -name '*.o.thinlto.bc' \
>                 -o -name '*.gcno' \
>                 \) -type f -print \
>                 -o -name '.tmp_*' -print \
> diff --git a/arch/Kconfig b/arch/Kconfig
> index b0adb665041f1..cbeeeb9b076d8 100644
> --- a/arch/Kconfig
> +++ b/arch/Kconfig
> @@ -810,6 +810,18 @@ config LTO_CLANG_THIN
>             https://clang.llvm.org/docs/ThinLTO.html
>
>           If unsure, say Y.
> +
> +config LTO_CLANG_THIN_DIST
> +       bool "Clang ThinLTO in distributed mode (EXPERIMENTAL)"
> +       depends on HAS_LTO_CLANG && ARCH_SUPPORTS_LTO_CLANG_THIN
> +       select LTO_CLANG
> +       help
> +         This option enables Clang's ThinLTO in distributed build mode.
> +         In this mode, the linker performs the thin-link, generating
> +         ThinLTO index files. Subsequently, the build system explicitly
> +         invokes ThinLTO backend compilation using these index files
> +         and pre-linked IR objects. The resulting final object files
> +         are with the .final_o suffix.
>  endchoice
>
>  config ARCH_SUPPORTS_AUTOFDO_CLANG
> diff --git a/scripts/Makefile.build b/scripts/Makefile.build
> index 13dcd86e74ca8..87259b0e2bfc8 100644
> --- a/scripts/Makefile.build
> +++ b/scripts/Makefile.build
> @@ -50,18 +50,23 @@ endif
>
>  # ===========================================================================
>
> +builtin_suffix := $(if $(filter %.final_a, $(MAKECMDGOALS)),final_a,a)
> +ifeq ($(thinlto_final_pass),1)
> +builtin_suffix := final_a
> +endif
> +
>  # subdir-builtin and subdir-modorder may contain duplications. Use $(sort ...)
> -subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))
> +subdir-builtin := $(sort $(filter %/built-in.$(builtin_suffix), $(real-obj-y)))
>  subdir-modorder := $(sort $(filter %/modules.order, $(obj-m)))
>
>  targets-for-builtin := $(extra-y)
>
>  ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
> -targets-for-builtin += $(obj)/lib.a
> +targets-for-builtin += $(obj)/lib.$(builtin_suffix)
>  endif
>
>  ifdef need-builtin
> -targets-for-builtin += $(obj)/built-in.a
> +targets-for-builtin += $(obj)/built-in.$(builtin_suffix)
>  endif
>
>  targets-for-modules := $(foreach x, o mod, \
> @@ -337,6 +342,10 @@ $(obj)/%.o: $(obj)/%.S FORCE
>  targets += $(filter-out $(subdir-builtin), $(real-obj-y))
>  targets += $(filter-out $(subdir-modorder), $(real-obj-m))
>  targets += $(lib-y) $(always-y)
> +ifeq ($(builtin_suffix), final_a)
> +final_o_targets = $(patsubst,%.o,%.final_o,$(targets))
> +targets += $(final_targets)
> +endif
>
>  # Linker scripts preprocessor (.lds.S -> .lds)
>  # ---------------------------------------------------------------------------
> @@ -347,6 +356,24 @@ quiet_cmd_cpp_lds_S = LDS     $@
>  $(obj)/%.lds: $(src)/%.lds.S FORCE
>         $(call if_changed_dep,cpp_lds_S)
>
> +ifdef CONFIG_LTO_CLANG_THIN_DIST
> +# Generate .final_o (obj) from .o (bitcode) file
> +# ---------------------------------------------------------------------------
> +quiet_cmd_cc_o_bc = CC $(quiet_modtag) $@
> +
> +cmd_cc_o_bc      = $(if $(filter bitcode, $(shell file -b $<)),$(CC) \
> +                  $(filter-out -Wp% $(LINUXINCLUDE) %.h.gch %.h -D% \
> +                  -flto=thin, $(c_flags)) \
> +                  -Wno-unused-command-line-argument \
> +                  -x ir -fthinlto-index=$<.thinlto.bc -c -o $@ \
> +                  $(if $(findstring ../,$<), \
> +                  $$(realpath --relative-to=$(srcroot) $<), $<), \
> +                  cp $< $@)
> +
> +$(obj)/%.final_o: $(obj)/%.o FORCE
> +       $(call if_changed,cc_o_bc)
> +endif
> +
>  # ASN.1 grammar
>  # ---------------------------------------------------------------------------
>  quiet_cmd_asn1_compiler = ASN.1   $(basename $@).[ch]
> @@ -360,7 +387,7 @@ $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
>  # ---------------------------------------------------------------------------
>
>  # To build objects in subdirs, we need to descend into the directories
> -$(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
> +$(subdir-builtin): $(obj)/%/built-in.$(builtin_suffix): $(obj)/% ;
>  $(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
>
>  #
> @@ -377,6 +404,12 @@ quiet_cmd_ar_builtin = AR      $@
>  $(obj)/built-in.a: $(real-obj-y) FORCE
>         $(call if_changed,ar_builtin)
>
> +ifdef CONFIG_LTO_CLANG_THIN_DIST
> +# Rule to compile a set of .final_o files into one .final_a file.
> +$(obj)/built-in.final_a: $(patsubst %.o,%.final_o,$(real-obj-y)) FORCE
> +       $(call if_changed,ar_builtin)
> +endif
> +
>  # This is a list of build artifacts from the current Makefile and its
>  # sub-directories. The timestamp should be updated when any of the member files.
>
> @@ -394,6 +427,14 @@ $(obj)/modules.order: $(obj-m) FORCE
>  $(obj)/lib.a: $(lib-y) FORCE
>         $(call if_changed,ar)
>
> +ifdef CONFIG_LTO_CLANG_THIN_DIST
> +quiet_cmd_ar_final = AR      $@
> +      cmd_ar_final = rm -f $@; $(AR) cDPrsT $@ $(patsubst %.o,%.final_o,$(real-prereqs))
> +
> +$(obj)/lib.final_a: $(patsubst %.o,%.final_o,$(lib-y)) FORCE
> +       $(call if_changed,ar_final)
> +endif
> +
>  quiet_cmd_ld_multi_m = LD [M]  $@
>        cmd_ld_multi_m = $(LD) $(ld_flags) -r -o $@ @$< $(cmd_objtool)
>
> @@ -459,7 +500,8 @@ $(single-subdir-goals): $(single-subdirs)
>  PHONY += $(subdir-ym)
>  $(subdir-ym):
>         $(Q)$(MAKE) $(build)=$@ \
> -       need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
> +       need-builtin=$(if $(filter $@/built-in.$(builtin_suffix), $(subdir-builtin)),1) \
> +       thinlto_final_pass=$(if $(filter final_a, $(builtin_suffix)),1) \
>         need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1) \
>         $(filter $@/%, $(single-subdir-goals))
>
> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
> index 2fe73cda0bddb..ce341ed8d1df3 100644
> --- a/scripts/Makefile.lib
> +++ b/scripts/Makefile.lib
> @@ -34,8 +34,13 @@ else
>  obj-m := $(filter-out %/, $(obj-m))
>  endif
>
> +builtin_suffix := $(if $(filter %.final_a, $(MAKECMDGOALS)),final_a,a)
> +ifeq ($(thinlto_final_pass),1)
> +        builtin_suffix := final_a
> +endif
> +
>  ifdef need-builtin
> -obj-y          := $(patsubst %/, %/built-in.a, $(obj-y))
> +obj-y          := $(patsubst %/, %/built-in.$(builtin_suffix), $(obj-y))
>  else
>  obj-y          := $(filter-out %/, $(obj-y))
>  endif
> diff --git a/scripts/Makefile.vmlinux_o b/scripts/Makefile.vmlinux_o
> index 938c7457717ea..4f04eb2c11412 100644
> --- a/scripts/Makefile.vmlinux_o
> +++ b/scripts/Makefile.vmlinux_o
> @@ -9,6 +9,14 @@ include $(srctree)/scripts/Kbuild.include
>  # for objtool
>  include $(srctree)/scripts/Makefile.lib
>
> +ifeq ($(thinlto_final_pass),1)
> +vmlinux_a := vmlinux.final_a
> +vmlinux_libs := $(patsubst %.a,%.final_a,$(KBUILD_VMLINUX_LIBS))
> +else
> +vmlinux_a := vmlinux.a
> +vmlinux_libs := $(KBUILD_VMLINUX_LIBS)
> +endif
> +
>  # Generate a linker script to ensure correct ordering of initcalls for Clang LTO
>  # ---------------------------------------------------------------------------
>
> @@ -18,7 +26,7 @@ quiet_cmd_gen_initcalls_lds = GEN     $@
>         $(PERL) $(real-prereqs) > $@
>
>  .tmp_initcalls.lds: $(srctree)/scripts/generate_initcall_order.pl \
> -               vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE
> +               $(vmlinux_a) $(vmlinux_libs) FORCE
>         $(call if_changed,gen_initcalls_lds)
>
>  targets := .tmp_initcalls.lds
> @@ -59,8 +67,8 @@ quiet_cmd_ld_vmlinux.o = LD      $@
>         $(LD) ${KBUILD_LDFLAGS} -r -o $@ \
>         $(vmlinux-o-ld-args-y) \
>         $(addprefix -T , $(initcalls-lds)) \
> -       --whole-archive vmlinux.a --no-whole-archive \
> -       --start-group $(KBUILD_VMLINUX_LIBS) --end-group \
> +       --whole-archive $(vmlinux_a) --no-whole-archive \
> +       --start-group $(vmlinux_libs) --end-group \
>         $(cmd_objtool)
>
>  define rule_ld_vmlinux.o
> @@ -68,7 +76,7 @@ define rule_ld_vmlinux.o
>         $(call cmd,gen_objtooldep)
>  endef
>
> -vmlinux.o: $(initcalls-lds) vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE
> +vmlinux.o: $(initcalls-lds) $(vmlinux_a) $(vmlinux_libs) FORCE
>         $(call if_changed_rule,ld_vmlinux.o)
>
>  targets += vmlinux.o
> diff --git a/scripts/Makefile.vmlinux_thinlink b/scripts/Makefile.vmlinux_thinlink
> new file mode 100644
> index 0000000000000..13e4026c7d45b
> --- /dev/null
> +++ b/scripts/Makefile.vmlinux_thinlink
> @@ -0,0 +1,53 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +PHONY := __default
> +__default: vmlinux.thinlink
> +
> +include include/config/auto.conf
> +include $(srctree)/scripts/Kbuild.include
> +
> +
> +# Generate a linker script to ensure correct ordering of initcalls for Clang LTO
> +# ---------------------------------------------------------------------------
> +
> +quiet_cmd_gen_initcalls_lds = GEN     $@
> +      cmd_gen_initcalls_lds = \
> +       $(PYTHON3) $(srctree)/scripts/jobserver-exec \
> +       $(PERL) $(real-prereqs) > $@
> +
> +.tmp_initcalls_thinlink.lds: $(srctree)/scripts/generate_initcall_order.pl \
> +               vmlinux.a FORCE
> +       $(call if_changed,gen_initcalls_lds)
> +
> +targets := .tmp_initcalls_thinlink.lds
> +
> +initcalls-lds := .tmp_initcalls_thinlink.lds
> +
> +quiet_cmd_ld_vmlinux.thinlink = LD      $@
> +      cmd_ld_vmlinux.thinlink = \
> +       $(AR) t vmlinux.a > .vmlinux_thinlto_bc_files; \
> +       $(LD) ${KBUILD_LDFLAGS} -r $(addprefix -T , $(initcalls-lds)) \
> +       --thinlto-index-only @.vmlinux_thinlto_bc_files; \
> +       touch vmlinux.thinlink
> +
> +vmlinux.thinlink: vmlinux.a $(initcalls-lds) FORCE
> +       $(call if_changed,ld_vmlinux.thinlink)
> +
> +targets += vmlinux.thinlink
> +
> +# Add FORCE to the prerequisites of a target to force it to be always rebuilt.
> +# ---------------------------------------------------------------------------
> +
> +PHONY += FORCE
> +FORCE:
> +
> +# Read all saved command lines and dependencies for the $(targets) we
> +# may be building above, using $(if_changed{,_dep}). As an
> +# optimization, we don't need to read them if the target does not
> +# exist, we will rebuild anyway in that case.
> +
> +existing-targets := $(wildcard $(sort $(targets)))
> +
> +-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
> +
> +.PHONY: $(PHONY)
> diff --git a/scripts/head-object-list.txt b/scripts/head-object-list.txt
> index 7274dfc65af60..b300222e99a6b 100644
> --- a/scripts/head-object-list.txt
> +++ b/scripts/head-object-list.txt
> @@ -18,6 +18,7 @@ arch/arm/kernel/head.o
>  arch/csky/kernel/head.o
>  arch/hexagon/kernel/head.o
>  arch/loongarch/kernel/head.o
> +arch/loongarch/kernel/head.final_o
>  arch/m68k/68000/head.o
>  arch/m68k/coldfire/head.o
>  arch/m68k/kernel/head.o
> --
> 2.49.0.805.g082f7c87e0-goog
>

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] kbuild: distributed build support for Clang ThinLTO
  2025-04-29 20:34 ` Rong Xu
@ 2025-05-01  1:20   ` Nathan Chancellor
  0 siblings, 0 replies; 5+ messages in thread
From: Nathan Chancellor @ 2025-05-01  1:20 UTC (permalink / raw)
  To: Rong Xu
  Cc: Masahiro Yamada, Nicolas Schier, Nick Desaulniers, Bill Wendling,
	Justin Stitt, Miguel Ojeda, Thomas Gleixner, Alice Ryhl,
	Sami Tolvanen, Mike Rapoport (Microsoft), Rafael Aquini,
	Michael Ellerman, Stafford Horne, Christophe Leroy,
	Teresa Johnson, linux-kernel, linux-kbuild, llvm

Hi Rong,

On Tue, Apr 29, 2025 at 01:34:00PM -0700, Rong Xu wrote:
> Just wanted to gently follow up on this patch that I sent previously.
> 
> From a toolchain and compiler perspective, I genuinely believe that
> kernel ThinLTO builds should use this. I really want to get some feedback
> and reviews on this patch.

My apologies for some radio silence, other regressions and issues have
been higher priority until now. I will try to take a closer look at this
soon but I do have one comment based on your comment above and the
Kconfig help text...

> On Sat, Apr 19, 2025 at 6:02 PM <xur@google.com> wrote:
...
> > diff --git a/arch/Kconfig b/arch/Kconfig
> > index b0adb665041f1..cbeeeb9b076d8 100644
> > --- a/arch/Kconfig
> > +++ b/arch/Kconfig
> > @@ -810,6 +810,18 @@ config LTO_CLANG_THIN
> >             https://clang.llvm.org/docs/ThinLTO.html
> >
> >           If unsure, say Y.
> > +
> > +config LTO_CLANG_THIN_DIST
> > +       bool "Clang ThinLTO in distributed mode (EXPERIMENTAL)"
> > +       depends on HAS_LTO_CLANG && ARCH_SUPPORTS_LTO_CLANG_THIN
> > +       select LTO_CLANG
> > +       help
> > +         This option enables Clang's ThinLTO in distributed build mode.
> > +         In this mode, the linker performs the thin-link, generating
> > +         ThinLTO index files. Subsequently, the build system explicitly
> > +         invokes ThinLTO backend compilation using these index files
> > +         and pre-linked IR objects. The resulting final object files
> > +         are with the .final_o suffix.
> >  endchoice

This says what the option does but it does not really say why the user
would want to use this over CONFIG_LTO_CLANG_THIN_DIST; even as someone
relatively familiar with these technologies, I am not sure what this
means for the build or resulting kernel. Is there any reason why a user
would want to use in-process ThinLTO instead of distributed? You seem to
make the case above and in Discourse that the kernel would benefit from
this, so should we just wholesale replace in-process ThinLTO with the
distributed one?

Cheers,
Nathan

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2025-05-01  1:20 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-04-27 15:09 [PATCH] kbuild: distributed build support for Clang ThinLTO kernel test robot
  -- strict thread matches above, loose matches on Subject: below --
2025-04-20  5:17 kernel test robot
2025-04-20  1:02 xur
2025-04-29 20:34 ` Rong Xu
2025-05-01  1:20   ` Nathan Chancellor

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