clang-lto series for v5.12-rc1
- Clang LTO build infrastructure and arm64-specific enablement (Sami Tolvanen)
- Recursive build CC_FLAGS_LTO fix (Alexander Lobakin)
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Merge tag 'clang-lto-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull clang LTO updates from Kees Cook:
"Clang Link Time Optimization.
This is built on the work done preparing for LTO by arm64 folks,
tracing folks, etc. This includes the core changes as well as the
remaining pieces for arm64 (LTO has been the default build method on
Android for about 3 years now, as it is the prerequisite for the
Control Flow Integrity protections).
While x86 LTO enablement is done, it depends on some pending objtool
clean-ups. It's possible that I'll send a "part 2" pull request for
LTO that includes x86 support.
For merge log posterity, and as detailed in commit dc5723b02e
("kbuild: add support for Clang LTO"), here is the lt;dr to do an LTO
build:
make LLVM=1 LLVM_IAS=1 defconfig
scripts/config -e LTO_CLANG_THIN
make LLVM=1 LLVM_IAS=1
(To do a cross-compile of arm64, add "CROSS_COMPILE=aarch64-linux-gnu-"
and "ARCH=arm64" to the "make" command lines.)
Summary:
- Clang LTO build infrastructure and arm64-specific enablement (Sami
Tolvanen)
- Recursive build CC_FLAGS_LTO fix (Alexander Lobakin)"
* tag 'clang-lto-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
kbuild: prevent CC_FLAGS_LTO self-bloating on recursive rebuilds
arm64: allow LTO to be selected
arm64: disable recordmcount with DYNAMIC_FTRACE_WITH_REGS
arm64: vdso: disable LTO
drivers/misc/lkdtm: disable LTO for rodata.o
efi/libstub: disable LTO
scripts/mod: disable LTO for empty.c
modpost: lto: strip .lto from module names
PCI: Fix PREL32 relocations for LTO
init: lto: fix PREL32 relocations
init: lto: ensure initcall ordering
kbuild: lto: add a default list of used symbols
kbuild: lto: merge module sections
kbuild: lto: limit inlining
kbuild: lto: fix module versioning
kbuild: add support for Clang LTO
tracing: move function tracer options to Kconfig
This commit is contained in:
Linus Torvalds
commit
79db4d2293
24 changed files with 704 additions and 59 deletions
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|
@ -111,7 +111,7 @@ endif
|
|||
# ---------------------------------------------------------------------------
|
||||
|
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quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
|
||||
cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS), $(c_flags)) -fverbose-asm -S -o $@ $<
|
||||
cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS) $(CC_FLAGS_LTO), $(c_flags)) -fverbose-asm -S -o $@ $<
|
||||
|
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$(obj)/%.s: $(src)/%.c FORCE
|
||||
$(call if_changed_dep,cc_s_c)
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||||
|
|
@ -166,6 +166,15 @@ ifdef CONFIG_MODVERSIONS
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# the actual value of the checksum generated by genksyms
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# o remove .tmp_<file>.o to <file>.o
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ifdef CONFIG_LTO_CLANG
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# Generate .o.symversions files for each .o with exported symbols, and link these
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# to the kernel and/or modules at the end.
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cmd_modversions_c = \
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if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then \
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$(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
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> $@.symversions; \
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fi;
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else
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cmd_modversions_c = \
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if $(OBJDUMP) -h $@ | grep -q __ksymtab; then \
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$(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
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@ -177,9 +186,9 @@ cmd_modversions_c = \
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rm -f $(@D)/.tmp_$(@F:.o=.ver); \
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fi
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endif
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endif
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ifdef CONFIG_FTRACE_MCOUNT_RECORD
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ifndef CC_USING_RECORD_MCOUNT
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ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
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# compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
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ifdef BUILD_C_RECORDMCOUNT
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ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
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@ -206,8 +215,7 @@ recordmcount_source := $(srctree)/scripts/recordmcount.pl
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endif # BUILD_C_RECORDMCOUNT
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cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
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$(sub_cmd_record_mcount))
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endif # CC_USING_RECORD_MCOUNT
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endif # CONFIG_FTRACE_MCOUNT_RECORD
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endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
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ifdef CONFIG_STACK_VALIDATION
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ifneq ($(SKIP_STACK_VALIDATION),1)
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@ -388,6 +396,18 @@ $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
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$(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
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$(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
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# combine symversions for later processing
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quiet_cmd_update_lto_symversions = SYMVER $@
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ifeq ($(CONFIG_LTO_CLANG) $(CONFIG_MODVERSIONS),y y)
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cmd_update_lto_symversions = \
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rm -f $@.symversions \
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$(foreach n, $(filter-out FORCE,$^), \
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$(if $(wildcard $(n).symversions), \
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; cat $(n).symversions >> $@.symversions))
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else
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cmd_update_lto_symversions = echo >/dev/null
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endif
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#
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# Rule to compile a set of .o files into one .a file (without symbol table)
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#
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@ -395,8 +415,11 @@ $(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
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quiet_cmd_ar_builtin = AR $@
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cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs)
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quiet_cmd_ar_and_symver = AR $@
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cmd_ar_and_symver = $(cmd_update_lto_symversions); $(cmd_ar_builtin)
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$(obj)/built-in.a: $(real-obj-y) FORCE
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$(call if_changed,ar_builtin)
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$(call if_changed,ar_and_symver)
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|
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#
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# Rule to create modules.order file
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@ -416,15 +439,26 @@ $(obj)/modules.order: $(obj-m) FORCE
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#
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# Rule to compile a set of .o files into one .a file (with symbol table)
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#
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quiet_cmd_ar_lib = AR $@
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cmd_ar_lib = $(cmd_update_lto_symversions); $(cmd_ar)
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$(obj)/lib.a: $(lib-y) FORCE
|
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$(call if_changed,ar)
|
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$(call if_changed,ar_lib)
|
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|
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# NOTE:
|
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# Do not replace $(filter %.o,^) with $(real-prereqs). When a single object
|
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# module is turned into a multi object module, $^ will contain header file
|
||||
# dependencies recorded in the .*.cmd file.
|
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ifdef CONFIG_LTO_CLANG
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quiet_cmd_link_multi-m = AR [M] $@
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cmd_link_multi-m = \
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$(cmd_update_lto_symversions); \
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rm -f $@; \
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$(AR) cDPrsT $@ $(filter %.o,$^)
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else
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quiet_cmd_link_multi-m = LD [M] $@
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cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^)
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endif
|
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|
||||
$(multi-used-m): FORCE
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$(call if_changed,link_multi-m)
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||||
|
|
|
|||
|
|
@ -119,9 +119,11 @@ target-stem = $(basename $(patsubst $(obj)/%,%,$@))
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# These flags are needed for modversions and compiling, so we define them here
|
||||
# $(modname_flags) defines KBUILD_MODNAME as the name of the module it will
|
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# end up in (or would, if it gets compiled in)
|
||||
name-fix = $(call stringify,$(subst $(comma),_,$(subst -,_,$1)))
|
||||
name-fix-token = $(subst $(comma),_,$(subst -,_,$1))
|
||||
name-fix = $(call stringify,$(call name-fix-token,$1))
|
||||
basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
|
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modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname))
|
||||
modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname)) \
|
||||
-D__KBUILD_MODNAME=kmod_$(call name-fix-token,$(modname))
|
||||
modfile_flags = -DKBUILD_MODFILE=$(call stringify,$(modfile))
|
||||
|
||||
_c_flags = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), \
|
||||
|
|
|
|||
|
|
@ -30,6 +30,12 @@ quiet_cmd_cc_o_c = CC [M] $@
|
|||
|
||||
ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
|
||||
|
||||
ifdef CONFIG_LTO_CLANG
|
||||
# With CONFIG_LTO_CLANG, reuse the object file we compiled for modpost to
|
||||
# avoid a second slow LTO link
|
||||
prelink-ext := .lto
|
||||
endif
|
||||
|
||||
quiet_cmd_ld_ko_o = LD [M] $@
|
||||
cmd_ld_ko_o = \
|
||||
$(LD) -r $(KBUILD_LDFLAGS) \
|
||||
|
|
@ -53,8 +59,9 @@ if_changed_except = $(if $(call newer_prereqs_except,$(2))$(cmd-check), \
|
|||
$(cmd); \
|
||||
printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)
|
||||
|
||||
|
||||
# Re-generate module BTFs if either module's .ko or vmlinux changed
|
||||
$(modules): %.ko: %.o %.mod.o scripts/module.lds $(if $(KBUILD_BUILTIN),vmlinux) FORCE
|
||||
$(modules): %.ko: %$(prelink-ext).o %.mod.o scripts/module.lds $(if $(KBUILD_BUILTIN),vmlinux) FORCE
|
||||
+$(call if_changed_except,ld_ko_o,vmlinux)
|
||||
ifdef CONFIG_DEBUG_INFO_BTF_MODULES
|
||||
+$(if $(newer-prereqs),$(call cmd,btf_ko))
|
||||
|
|
|
|||
|
|
@ -43,6 +43,9 @@ __modpost:
|
|||
include include/config/auto.conf
|
||||
include scripts/Kbuild.include
|
||||
|
||||
# for ld_flags
|
||||
include scripts/Makefile.lib
|
||||
|
||||
MODPOST = scripts/mod/modpost \
|
||||
$(if $(CONFIG_MODVERSIONS),-m) \
|
||||
$(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \
|
||||
|
|
@ -102,12 +105,30 @@ $(input-symdump):
|
|||
@echo >&2 'WARNING: Symbol version dump "$@" is missing.'
|
||||
@echo >&2 ' Modules may not have dependencies or modversions.'
|
||||
|
||||
ifdef CONFIG_LTO_CLANG
|
||||
# With CONFIG_LTO_CLANG, .o files might be LLVM bitcode, so we need to run
|
||||
# LTO to compile them into native code before running modpost
|
||||
prelink-ext := .lto
|
||||
|
||||
quiet_cmd_cc_lto_link_modules = LTO [M] $@
|
||||
cmd_cc_lto_link_modules = \
|
||||
$(LD) $(ld_flags) -r -o $@ \
|
||||
$(shell [ -s $(@:.lto.o=.o.symversions) ] && \
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||||
echo -T $(@:.lto.o=.o.symversions)) \
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||||
--whole-archive $^
|
||||
|
||||
%.lto.o: %.o
|
||||
$(call if_changed,cc_lto_link_modules)
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||||
endif
|
||||
|
||||
modules := $(sort $(shell cat $(MODORDER)))
|
||||
|
||||
# Read out modules.order to pass in modpost.
|
||||
# Otherwise, allmodconfig would fail with "Argument list too long".
|
||||
quiet_cmd_modpost = MODPOST $@
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||||
cmd_modpost = sed 's/ko$$/o/' $< | $(MODPOST) -T -
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cmd_modpost = sed 's/\.ko$$/$(prelink-ext)\.o/' $< | $(MODPOST) -T -
|
||||
|
||||
$(output-symdump): $(MODORDER) $(input-symdump) FORCE
|
||||
$(output-symdump): $(MODORDER) $(input-symdump) $(modules:.ko=$(prelink-ext).o) FORCE
|
||||
$(call if_changed,modpost)
|
||||
|
||||
targets += $(output-symdump)
|
||||
|
|
|
|||
270
scripts/generate_initcall_order.pl
Executable file
270
scripts/generate_initcall_order.pl
Executable file
|
|
@ -0,0 +1,270 @@
|
|||
#!/usr/bin/env perl
|
||||
# SPDX-License-Identifier: GPL-2.0
|
||||
#
|
||||
# Generates a linker script that specifies the correct initcall order.
|
||||
#
|
||||
# Copyright (C) 2019 Google LLC
|
||||
|
||||
use strict;
|
||||
use warnings;
|
||||
use IO::Handle;
|
||||
use IO::Select;
|
||||
use POSIX ":sys_wait_h";
|
||||
|
||||
my $nm = $ENV{'NM'} || die "$0: ERROR: NM not set?";
|
||||
my $objtree = $ENV{'objtree'} || '.';
|
||||
|
||||
## currently active child processes
|
||||
my $jobs = {}; # child process pid -> file handle
|
||||
## results from child processes
|
||||
my $results = {}; # object index -> [ { level, secname }, ... ]
|
||||
|
||||
## reads _NPROCESSORS_ONLN to determine the maximum number of processes to
|
||||
## start
|
||||
sub get_online_processors {
|
||||
open(my $fh, "getconf _NPROCESSORS_ONLN 2>/dev/null |")
|
||||
or die "$0: ERROR: failed to execute getconf: $!";
|
||||
my $procs = <$fh>;
|
||||
close($fh);
|
||||
|
||||
if (!($procs =~ /^\d+$/)) {
|
||||
return 1;
|
||||
}
|
||||
|
||||
return int($procs);
|
||||
}
|
||||
|
||||
## writes results to the parent process
|
||||
## format: <file index> <initcall level> <base initcall section name>
|
||||
sub write_results {
|
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my ($index, $initcalls) = @_;
|
||||
|
||||
# sort by the counter value to ensure the order of initcalls within
|
||||
# each object file is correct
|
||||
foreach my $counter (sort { $a <=> $b } keys(%{$initcalls})) {
|
||||
my $level = $initcalls->{$counter}->{'level'};
|
||||
|
||||
# section name for the initcall function
|
||||
my $secname = $initcalls->{$counter}->{'module'} . '__' .
|
||||
$counter . '_' .
|
||||
$initcalls->{$counter}->{'line'} . '_' .
|
||||
$initcalls->{$counter}->{'function'};
|
||||
|
||||
print "$index $level $secname\n";
|
||||
}
|
||||
}
|
||||
|
||||
## reads a result line from a child process and adds it to the $results array
|
||||
sub read_results{
|
||||
my ($fh) = @_;
|
||||
|
||||
# each child prints out a full line w/ autoflush and exits after the
|
||||
# last line, so even if buffered I/O blocks here, it shouldn't block
|
||||
# very long
|
||||
my $data = <$fh>;
|
||||
|
||||
if (!defined($data)) {
|
||||
return 0;
|
||||
}
|
||||
|
||||
chomp($data);
|
||||
|
||||
my ($index, $level, $secname) = $data =~
|
||||
/^(\d+)\ ([^\ ]+)\ (.*)$/;
|
||||
|
||||
if (!defined($index) ||
|
||||
!defined($level) ||
|
||||
!defined($secname)) {
|
||||
die "$0: ERROR: child process returned invalid data: $data\n";
|
||||
}
|
||||
|
||||
$index = int($index);
|
||||
|
||||
if (!exists($results->{$index})) {
|
||||
$results->{$index} = [];
|
||||
}
|
||||
|
||||
push (@{$results->{$index}}, {
|
||||
'level' => $level,
|
||||
'secname' => $secname
|
||||
});
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
||||
## finds initcalls from an object file or all object files in an archive, and
|
||||
## writes results back to the parent process
|
||||
sub find_initcalls {
|
||||
my ($index, $file) = @_;
|
||||
|
||||
die "$0: ERROR: file $file doesn't exist?" if (! -f $file);
|
||||
|
||||
open(my $fh, "\"$nm\" --defined-only \"$file\" 2>/dev/null |")
|
||||
or die "$0: ERROR: failed to execute \"$nm\": $!";
|
||||
|
||||
my $initcalls = {};
|
||||
|
||||
while (<$fh>) {
|
||||
chomp;
|
||||
|
||||
# check for the start of a new object file (if processing an
|
||||
# archive)
|
||||
my ($path)= $_ =~ /^(.+)\:$/;
|
||||
|
||||
if (defined($path)) {
|
||||
write_results($index, $initcalls);
|
||||
$initcalls = {};
|
||||
next;
|
||||
}
|
||||
|
||||
# look for an initcall
|
||||
my ($module, $counter, $line, $symbol) = $_ =~
|
||||
/[a-z]\s+__initcall__(\S*)__(\d+)_(\d+)_(.*)$/;
|
||||
|
||||
if (!defined($module)) {
|
||||
$module = ''
|
||||
}
|
||||
|
||||
if (!defined($counter) ||
|
||||
!defined($line) ||
|
||||
!defined($symbol)) {
|
||||
next;
|
||||
}
|
||||
|
||||
# parse initcall level
|
||||
my ($function, $level) = $symbol =~
|
||||
/^(.*)((early|rootfs|con|[0-9])s?)$/;
|
||||
|
||||
die "$0: ERROR: invalid initcall name $symbol in $file($path)"
|
||||
if (!defined($function) || !defined($level));
|
||||
|
||||
$initcalls->{$counter} = {
|
||||
'module' => $module,
|
||||
'line' => $line,
|
||||
'function' => $function,
|
||||
'level' => $level,
|
||||
};
|
||||
}
|
||||
|
||||
close($fh);
|
||||
write_results($index, $initcalls);
|
||||
}
|
||||
|
||||
## waits for any child process to complete, reads the results, and adds them to
|
||||
## the $results array for later processing
|
||||
sub wait_for_results {
|
||||
my ($select) = @_;
|
||||
|
||||
my $pid = 0;
|
||||
do {
|
||||
# unblock children that may have a full write buffer
|
||||
foreach my $fh ($select->can_read(0)) {
|
||||
read_results($fh);
|
||||
}
|
||||
|
||||
# check for children that have exited, read the remaining data
|
||||
# from them, and clean up
|
||||
$pid = waitpid(-1, WNOHANG);
|
||||
if ($pid > 0) {
|
||||
if (!exists($jobs->{$pid})) {
|
||||
next;
|
||||
}
|
||||
|
||||
my $fh = $jobs->{$pid};
|
||||
$select->remove($fh);
|
||||
|
||||
while (read_results($fh)) {
|
||||
# until eof
|
||||
}
|
||||
|
||||
close($fh);
|
||||
delete($jobs->{$pid});
|
||||
}
|
||||
} while ($pid > 0);
|
||||
}
|
||||
|
||||
## forks a child to process each file passed in the command line and collects
|
||||
## the results
|
||||
sub process_files {
|
||||
my $index = 0;
|
||||
my $njobs = $ENV{'PARALLELISM'} || get_online_processors();
|
||||
my $select = IO::Select->new();
|
||||
|
||||
while (my $file = shift(@ARGV)) {
|
||||
# fork a child process and read it's stdout
|
||||
my $pid = open(my $fh, '-|');
|
||||
|
||||
if (!defined($pid)) {
|
||||
die "$0: ERROR: failed to fork: $!";
|
||||
} elsif ($pid) {
|
||||
# save the child process pid and the file handle
|
||||
$select->add($fh);
|
||||
$jobs->{$pid} = $fh;
|
||||
} else {
|
||||
# in the child process
|
||||
STDOUT->autoflush(1);
|
||||
find_initcalls($index, "$objtree/$file");
|
||||
exit;
|
||||
}
|
||||
|
||||
$index++;
|
||||
|
||||
# limit the number of children to $njobs
|
||||
if (scalar(keys(%{$jobs})) >= $njobs) {
|
||||
wait_for_results($select);
|
||||
}
|
||||
}
|
||||
|
||||
# wait for the remaining children to complete
|
||||
while (scalar(keys(%{$jobs})) > 0) {
|
||||
wait_for_results($select);
|
||||
}
|
||||
}
|
||||
|
||||
sub generate_initcall_lds() {
|
||||
process_files();
|
||||
|
||||
my $sections = {}; # level -> [ secname, ...]
|
||||
|
||||
# sort results to retain link order and split to sections per
|
||||
# initcall level
|
||||
foreach my $index (sort { $a <=> $b } keys(%{$results})) {
|
||||
foreach my $result (@{$results->{$index}}) {
|
||||
my $level = $result->{'level'};
|
||||
|
||||
if (!exists($sections->{$level})) {
|
||||
$sections->{$level} = [];
|
||||
}
|
||||
|
||||
push(@{$sections->{$level}}, $result->{'secname'});
|
||||
}
|
||||
}
|
||||
|
||||
die "$0: ERROR: no initcalls?" if (!keys(%{$sections}));
|
||||
|
||||
# print out a linker script that defines the order of initcalls for
|
||||
# each level
|
||||
print "SECTIONS {\n";
|
||||
|
||||
foreach my $level (sort(keys(%{$sections}))) {
|
||||
my $section;
|
||||
|
||||
if ($level eq 'con') {
|
||||
$section = '.con_initcall.init';
|
||||
} else {
|
||||
$section = ".initcall${level}.init";
|
||||
}
|
||||
|
||||
print "\t${section} : {\n";
|
||||
|
||||
foreach my $secname (@{$sections->{$level}}) {
|
||||
print "\t\t*(${section}..${secname}) ;\n";
|
||||
}
|
||||
|
||||
print "\t}\n";
|
||||
}
|
||||
|
||||
print "}\n";
|
||||
}
|
||||
|
||||
generate_initcall_lds();
|
||||
|
|
@ -43,11 +43,37 @@ info()
|
|||
fi
|
||||
}
|
||||
|
||||
# Generate a linker script to ensure correct ordering of initcalls.
|
||||
gen_initcalls()
|
||||
{
|
||||
info GEN .tmp_initcalls.lds
|
||||
|
||||
${PYTHON} ${srctree}/scripts/jobserver-exec \
|
||||
${PERL} ${srctree}/scripts/generate_initcall_order.pl \
|
||||
${KBUILD_VMLINUX_OBJS} ${KBUILD_VMLINUX_LIBS} \
|
||||
> .tmp_initcalls.lds
|
||||
}
|
||||
|
||||
# If CONFIG_LTO_CLANG is selected, collect generated symbol versions into
|
||||
# .tmp_symversions.lds
|
||||
gen_symversions()
|
||||
{
|
||||
info GEN .tmp_symversions.lds
|
||||
rm -f .tmp_symversions.lds
|
||||
|
||||
for o in ${KBUILD_VMLINUX_OBJS} ${KBUILD_VMLINUX_LIBS}; do
|
||||
if [ -f ${o}.symversions ]; then
|
||||
cat ${o}.symversions >> .tmp_symversions.lds
|
||||
fi
|
||||
done
|
||||
}
|
||||
|
||||
# Link of vmlinux.o used for section mismatch analysis
|
||||
# ${1} output file
|
||||
modpost_link()
|
||||
{
|
||||
local objects
|
||||
local lds=""
|
||||
|
||||
objects="--whole-archive \
|
||||
${KBUILD_VMLINUX_OBJS} \
|
||||
|
|
@ -56,7 +82,23 @@ modpost_link()
|
|||
${KBUILD_VMLINUX_LIBS} \
|
||||
--end-group"
|
||||
|
||||
${LD} ${KBUILD_LDFLAGS} -r -o ${1} ${objects}
|
||||
if [ -n "${CONFIG_LTO_CLANG}" ]; then
|
||||
gen_initcalls
|
||||
lds="-T .tmp_initcalls.lds"
|
||||
|
||||
if [ -n "${CONFIG_MODVERSIONS}" ]; then
|
||||
gen_symversions
|
||||
lds="${lds} -T .tmp_symversions.lds"
|
||||
fi
|
||||
|
||||
# This might take a while, so indicate that we're doing
|
||||
# an LTO link
|
||||
info LTO ${1}
|
||||
else
|
||||
info LD ${1}
|
||||
fi
|
||||
|
||||
${LD} ${KBUILD_LDFLAGS} -r -o ${1} ${lds} ${objects}
|
||||
}
|
||||
|
||||
objtool_link()
|
||||
|
|
@ -103,13 +145,22 @@ vmlinux_link()
|
|||
fi
|
||||
|
||||
if [ "${SRCARCH}" != "um" ]; then
|
||||
objects="--whole-archive \
|
||||
${KBUILD_VMLINUX_OBJS} \
|
||||
--no-whole-archive \
|
||||
--start-group \
|
||||
${KBUILD_VMLINUX_LIBS} \
|
||||
--end-group \
|
||||
${@}"
|
||||
if [ -n "${CONFIG_LTO_CLANG}" ]; then
|
||||
# Use vmlinux.o instead of performing the slow LTO
|
||||
# link again.
|
||||
objects="--whole-archive \
|
||||
vmlinux.o \
|
||||
--no-whole-archive \
|
||||
${@}"
|
||||
else
|
||||
objects="--whole-archive \
|
||||
${KBUILD_VMLINUX_OBJS} \
|
||||
--no-whole-archive \
|
||||
--start-group \
|
||||
${KBUILD_VMLINUX_LIBS} \
|
||||
--end-group \
|
||||
${@}"
|
||||
fi
|
||||
|
||||
${LD} ${KBUILD_LDFLAGS} ${LDFLAGS_vmlinux} \
|
||||
${strip_debug#-Wl,} \
|
||||
|
|
@ -225,6 +276,8 @@ cleanup()
|
|||
{
|
||||
rm -f .btf.*
|
||||
rm -f .tmp_System.map
|
||||
rm -f .tmp_initcalls.lds
|
||||
rm -f .tmp_symversions.lds
|
||||
rm -f .tmp_vmlinux*
|
||||
rm -f System.map
|
||||
rm -f vmlinux
|
||||
|
|
@ -274,7 +327,6 @@ fi;
|
|||
${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init need-builtin=1
|
||||
|
||||
#link vmlinux.o
|
||||
info LD vmlinux.o
|
||||
modpost_link vmlinux.o
|
||||
objtool_link vmlinux.o
|
||||
|
||||
|
|
|
|||
5
scripts/lto-used-symbollist.txt
Normal file
5
scripts/lto-used-symbollist.txt
Normal file
|
|
@ -0,0 +1,5 @@
|
|||
memcpy
|
||||
memmove
|
||||
memset
|
||||
__stack_chk_fail
|
||||
__stack_chk_guard
|
||||
|
|
@ -1,5 +1,6 @@
|
|||
# SPDX-License-Identifier: GPL-2.0
|
||||
OBJECT_FILES_NON_STANDARD := y
|
||||
CFLAGS_REMOVE_empty.o += $(CC_FLAGS_LTO)
|
||||
|
||||
hostprogs-always-y += modpost mk_elfconfig
|
||||
always-y += empty.o
|
||||
|
|
|
|||
|
|
@ -17,7 +17,6 @@
|
|||
#include <ctype.h>
|
||||
#include <string.h>
|
||||
#include <limits.h>
|
||||
#include <stdbool.h>
|
||||
#include <errno.h>
|
||||
#include "modpost.h"
|
||||
#include "../../include/linux/license.h"
|
||||
|
|
@ -84,14 +83,6 @@ modpost_log(enum loglevel loglevel, const char *fmt, ...)
|
|||
error_occurred = true;
|
||||
}
|
||||
|
||||
static inline bool strends(const char *str, const char *postfix)
|
||||
{
|
||||
if (strlen(str) < strlen(postfix))
|
||||
return false;
|
||||
|
||||
return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
|
||||
}
|
||||
|
||||
void *do_nofail(void *ptr, const char *expr)
|
||||
{
|
||||
if (!ptr)
|
||||
|
|
@ -1988,6 +1979,10 @@ static char *remove_dot(char *s)
|
|||
size_t m = strspn(s + n + 1, "0123456789");
|
||||
if (m && (s[n + m] == '.' || s[n + m] == 0))
|
||||
s[n] = 0;
|
||||
|
||||
/* strip trailing .lto */
|
||||
if (strends(s, ".lto"))
|
||||
s[strlen(s) - 4] = '\0';
|
||||
}
|
||||
return s;
|
||||
}
|
||||
|
|
@ -2011,6 +2006,9 @@ static void read_symbols(const char *modname)
|
|||
/* strip trailing .o */
|
||||
tmp = NOFAIL(strdup(modname));
|
||||
tmp[strlen(tmp) - 2] = '\0';
|
||||
/* strip trailing .lto */
|
||||
if (strends(tmp, ".lto"))
|
||||
tmp[strlen(tmp) - 4] = '\0';
|
||||
mod = new_module(tmp);
|
||||
free(tmp);
|
||||
}
|
||||
|
|
|
|||
|
|
@ -2,6 +2,7 @@
|
|||
#include <stdio.h>
|
||||
#include <stdlib.h>
|
||||
#include <stdarg.h>
|
||||
#include <stdbool.h>
|
||||
#include <string.h>
|
||||
#include <sys/types.h>
|
||||
#include <sys/stat.h>
|
||||
|
|
@ -180,6 +181,14 @@ static inline unsigned int get_secindex(const struct elf_info *info,
|
|||
return info->symtab_shndx_start[sym - info->symtab_start];
|
||||
}
|
||||
|
||||
static inline bool strends(const char *str, const char *postfix)
|
||||
{
|
||||
if (strlen(str) < strlen(postfix))
|
||||
return false;
|
||||
|
||||
return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
|
||||
}
|
||||
|
||||
/* file2alias.c */
|
||||
extern unsigned int cross_build;
|
||||
void handle_moddevtable(struct module *mod, struct elf_info *info,
|
||||
|
|
|
|||
|
|
@ -391,10 +391,14 @@ void get_src_version(const char *modname, char sum[], unsigned sumlen)
|
|||
struct md4_ctx md;
|
||||
char *fname;
|
||||
char filelist[PATH_MAX + 1];
|
||||
int postfix_len = 1;
|
||||
|
||||
if (strends(modname, ".lto.o"))
|
||||
postfix_len = 5;
|
||||
|
||||
/* objects for a module are listed in the first line of *.mod file. */
|
||||
snprintf(filelist, sizeof(filelist), "%.*smod",
|
||||
(int)strlen(modname) - 1, modname);
|
||||
(int)strlen(modname) - postfix_len, modname);
|
||||
|
||||
buf = read_text_file(filelist);
|
||||
|
||||
|
|
|
|||
|
|
@ -23,6 +23,30 @@ SECTIONS {
|
|||
.init_array 0 : ALIGN(8) { *(SORT(.init_array.*)) *(.init_array) }
|
||||
|
||||
__jump_table 0 : ALIGN(8) { KEEP(*(__jump_table)) }
|
||||
|
||||
__patchable_function_entries : { *(__patchable_function_entries) }
|
||||
|
||||
/*
|
||||
* With CONFIG_LTO_CLANG, LLD always enables -fdata-sections and
|
||||
* -ffunction-sections, which increases the size of the final module.
|
||||
* Merge the split sections in the final binary.
|
||||
*/
|
||||
.bss : {
|
||||
*(.bss .bss.[0-9a-zA-Z_]*)
|
||||
*(.bss..L*)
|
||||
}
|
||||
|
||||
.data : {
|
||||
*(.data .data.[0-9a-zA-Z_]*)
|
||||
*(.data..L*)
|
||||
}
|
||||
|
||||
.rodata : {
|
||||
*(.rodata .rodata.[0-9a-zA-Z_]*)
|
||||
*(.rodata..L*)
|
||||
}
|
||||
|
||||
.text : { *(.text .text.[0-9a-zA-Z_]*) }
|
||||
}
|
||||
|
||||
/* bring in arch-specific sections */
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue