My main motivation of this commit is to clean up scripts/Kbuild.include
and scripts/Makefile.build.
Currently, CONFIG_TRIM_UNUSED_KSYMS works with a tricky gimmick;
possibly exported symbols are detected by letting $(CPP) replace
EXPORT_SYMBOL* with a special string '=== __KSYM_*===', which is
post-processed by sed, and passed to fixdep. The extra preprocessing
is costly, and hacking cmd_and_fixdep is ugly.
I came up with a new way to find exported symbols; insert a dummy
symbol __ksym_marker_* to each potentially exported symbol. Those
dummy symbols are picked up by $(NM), post-processed by sed, then
appended to .*.cmd files. I collected the post-process part to a
new shell script scripts/gen_ksymdeps.sh for readability. The dummy
symbols are put into the .discard.* section so that the linker
script rips them off the final vmlinux or modules.
A nice side-effect is building with CONFIG_TRIM_UNUSED_KSYMS will
be much faster.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Let $(CC) compile objects into normal files *.o instead of .tmp_*.o
whether CONFIG_MODVERSIONS is enabled or not. With this, the input
file for objtool is always *.o so objtool_o can go away.
I guess the reason of using .tmp_*.o for intermediate objects was
to avoid leaving incomplete *.o file (, whose timestamp says it is
up-to-date) when the genksyms tool failed for some reasons.
It no longer matters because any targets are deleted on errors since
commit 9c2af1c737 ("kbuild: add .DELETE_ON_ERROR special target").
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Currently, fixdep writes dependencies to .*.tmp, which is renamed to
.*.cmd after everything succeeds. This is a very safe way to avoid
corrupted .*.cmd files. The if_changed_dep has carried this safety
mechanism since it was added in 2002.
If fixdep fails for some reasons or a user terminates the build while
fixdep is running, the incomplete output from the fixdep could be
troublesome.
This is my insight about some bad scenarios:
[1] If the compiler succeeds to generate *.o file, but fixdep fails
to write necessary dependencies to .*.cmd file, Make will miss
to rebuild the object when headers or CONFIG options are changed.
In this case, fixdep should not generate .*.cmd file at all so
that 'arg-check' will surely trigger the rebuild of the object.
[2] A partially constructed .*.cmd file may not be a syntactically
correct makefile. The next time Make runs, it would include it,
then fail to parse it. Once this happens, 'make clean' is be the
only way to fix it.
In fact, [1] is no longer a problem since commit 9c2af1c737 ("kbuild:
add .DELETE_ON_ERROR special target"). Make deletes a target file on
any failure in its recipe. Because fixdep is a part of the recipe of
*.o target, if it fails, the *.o is deleted anyway. However, I am a
bit worried about the slight possibility of [2].
So, here is a solution. Let fixdep directly write to a .*.cmd file,
but allow makefiles to include it only when its corresponding target
exists.
This effectively reverts commit 2982c95357 ("kbuild: remove redundant
$(wildcard ...) for cmd_files calculation"), and commit 00d78ab2ba
("kbuild: remove dead code in cmd_files calculation in top Makefile")
because now we must check the presence of targets.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
- optimize kallsyms slightly
- remove check for old CFLAGS usage
- add some compiler flags unconditionally instead of evaluating
$(call cc-option,...)
- fix variable shadowing in host tools
- refactor scripts/mkmakefile
- refactor various makefiles
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=jM4E
-----END PGP SIGNATURE-----
Merge tag 'kbuild-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- optimize kallsyms slightly
- remove check for old CFLAGS usage
- add some compiler flags unconditionally instead of evaluating
$(call cc-option,...)
- fix variable shadowing in host tools
- refactor scripts/mkmakefile
- refactor various makefiles
* tag 'kbuild-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
modpost: Create macro to avoid variable shadowing
ASN.1: Remove unnecessary shadowed local variable
kbuild: use 'else ifeq' for checksrc to improve readability
kbuild: remove unneeded link_multi_deps
kbuild: add -Wno-unused-but-set-variable flag unconditionally
kbuild: add -Wdeclaration-after-statement flag unconditionally
kbuild: add -Wno-pointer-sign flag unconditionally
modpost: remove leftover symbol prefix handling for module device table
kbuild: simplify command line creation in scripts/mkmakefile
kbuild: do not pass $(objtree) to scripts/mkmakefile
kbuild: remove user ID check in scripts/mkmakefile
kbuild: remove VERSION and PATCHLEVEL from $(objtree)/Makefile
kbuild: add --include-dir flag only for out-of-tree build
kbuild: remove dead code in cmd_files calculation in top Makefile
kbuild: hide most of targets when running config or mixed targets
kbuild: remove old check for CFLAGS use
kbuild: prefix Makefile.dtbinst path with $(srctree) unconditionally
kallsyms: remove left-over Blackfin code
kallsyms: reduce size a little on 64-bit
'ifeq ... else ifeq ... endif' notation is supported by GNU Make 3.81
or later, which is the requirement for building the kernel since
commit 37d69ee308 ("docs: bump minimal GNU Make version to 3.81").
Use it to improve the readability.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Since commit c8589d1e9e ("kbuild: handle multi-objs dependency
appropriately"), $^ really represents all the prerequisite of the
composite object being built.
Hence, $(filter %.o,$^) contains all the objects to link together,
which is much simpler than link_multi_deps calculation.
Please note $(filter-out FORCE,$^) does not work here. When a single
object module is turned into a multi object module, $^ will contain
header files that were previously included for building the single
object, and recorded in the .*.cmd file. To filter out such headers,
$(filter %.o,$^) should be used here.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
When building to record the mcount locations the kernel uses
KBUILD_CFLAGS but not KBUILD_CPPFLAGS. This means it lacks
-Qunused-arguments when building with clang, resulting in a lot of
noisy warnings.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
This check has been here for more than a decade since
commit 0c53c8e6eb ("kbuild: check for wrong use of CFLAGS").
Enough time for migration has passed.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Commit cafa0010cd ("Raise the minimum required gcc version to 4.6")
bumped the minimum GCC version to 4.6 for all architectures.
This effectively reverts commit da541b2002 ("objtool: Skip unreachable
warnings for GCC 4.4 and older"), which was a workaround for GCC 4.4 or
older.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: linux-kbuild@vger.kernel.org
Link: https://lkml.kernel.org/r/1535341183-19994-1-git-send-email-yamada.masahiro@socionext.com
Commit a0f97e06a4 ("kbuild: enable 'make CFLAGS=...' to add
additional options to CC") renamed CFLAGS to KBUILD_CFLAGS.
Commit 222d394d30 ("kbuild: enable 'make AFLAGS=...' to add
additional options to AS") renamed AFLAGS to KBUILD_AFLAGS.
Commit 06c5040cdb ("kbuild: enable 'make CPPFLAGS=...' to add
additional options to CPP") renamed CPPFLAGS to KBUILD_CPPFLAGS.
For some reason, LDFLAGS was not renamed.
Using a well-known variable like LDFLAGS may result in accidental
override of the variable.
Kbuild generally uses KBUILD_ prefixed variables for the internally
appended options, so here is one more conversion to sanitize the
naming convention.
I did not touch Makefiles under tools/ since the tools build system
is a different world.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Since commit 0fbe9a245c ("microblaze: add endianness options to
LDFLAGS instead of LD"), you cannot build the kernel for microblaze
with CONFIG_DYNAMIC_FTRACE.
Fixes: 0fbe9a245c ("microblaze: add endianness options to LDFLAGS instead of LD")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
- Restructure of lockdep and latency tracers
This is the biggest change. Joel Fernandes restructured the hooks
from irqs and preemption disabling and enabling. He got rid of
a lot of the preprocessor #ifdef mess that they caused.
He turned both lockdep and the latency tracers to use trace events
inserted in the preempt/irqs disabling paths. But unfortunately,
these started to cause issues in corner cases. Thus, parts of the
code was reverted back to where lockde and the latency tracers
just get called directly (without using the trace events).
But because the original change cleaned up the code very nicely
we kept that, as well as the trace events for preempt and irqs
disabling, but they are limited to not being called in NMIs.
- Have trace events use SRCU for "rcu idle" calls. This was required
for the preempt/irqs off trace events. But it also had to not
allow them to be called in NMI context. Waiting till Paul makes
an NMI safe SRCU API.
- New notrace SRCU API to allow trace events to use SRCU.
- Addition of mcount-nop option support
- SPDX headers replacing GPL templates.
- Various other fixes and clean ups.
- Some fixes are marked for stable, but were not fully tested
before the merge window opened.
-----BEGIN PGP SIGNATURE-----
iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCW3ruhRQccm9zdGVkdEBn
b29kbWlzLm9yZwAKCRAp5XQQmuv6qiM7AP47NhYdSnCFCRUJfrt6PovXmQtuCHt3
c3QMoGGdvzh9YAEAqcSXwh7uLhpHUp1LjMAPkXdZVwNddf4zJQ1zyxQ+EAU=
=vgEr
-----END PGP SIGNATURE-----
Merge tag 'trace-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
- Restructure of lockdep and latency tracers
This is the biggest change. Joel Fernandes restructured the hooks
from irqs and preemption disabling and enabling. He got rid of a lot
of the preprocessor #ifdef mess that they caused.
He turned both lockdep and the latency tracers to use trace events
inserted in the preempt/irqs disabling paths. But unfortunately,
these started to cause issues in corner cases. Thus, parts of the
code was reverted back to where lockdep and the latency tracers just
get called directly (without using the trace events). But because the
original change cleaned up the code very nicely we kept that, as well
as the trace events for preempt and irqs disabling, but they are
limited to not being called in NMIs.
- Have trace events use SRCU for "rcu idle" calls. This was required
for the preempt/irqs off trace events. But it also had to not allow
them to be called in NMI context. Waiting till Paul makes an NMI safe
SRCU API.
- New notrace SRCU API to allow trace events to use SRCU.
- Addition of mcount-nop option support
- SPDX headers replacing GPL templates.
- Various other fixes and clean ups.
- Some fixes are marked for stable, but were not fully tested before
the merge window opened.
* tag 'trace-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (44 commits)
tracing: Fix SPDX format headers to use C++ style comments
tracing: Add SPDX License format tags to tracing files
tracing: Add SPDX License format to bpf_trace.c
blktrace: Add SPDX License format header
s390/ftrace: Add -mfentry and -mnop-mcount support
tracing: Add -mcount-nop option support
tracing: Avoid calling cc-option -mrecord-mcount for every Makefile
tracing: Handle CC_FLAGS_FTRACE more accurately
Uprobe: Additional argument arch_uprobe to uprobe_write_opcode()
Uprobes: Simplify uprobe_register() body
tracepoints: Free early tracepoints after RCU is initialized
uprobes: Use synchronize_rcu() not synchronize_sched()
tracing: Fix synchronizing to event changes with tracepoint_synchronize_unregister()
ftrace: Remove unused pointer ftrace_swapper_pid
tracing: More reverting of "tracing: Centralize preemptirq tracepoints and unify their usage"
tracing/irqsoff: Handle preempt_count for different configs
tracing: Partial revert of "tracing: Centralize preemptirq tracepoints and unify their usage"
tracing: irqsoff: Account for additional preempt_disable
trace: Use rcu_dereference_raw for hooks from trace-event subsystem
tracing/kprobes: Fix within_notrace_func() to check only notrace functions
...
Currently if CONFIG_FTRACE_MCOUNT_RECORD is enabled -mrecord-mcount
compiler flag support is tested for every Makefile.
Top 4 cc-option usages:
511 -mrecord-mcount
11 -fno-stack-protector
9 -Wno-override-init
2 -fsched-pressure
To address that move cc-option from scripts/Makefile.build to top Makefile
and export CC_USING_RECORD_MCOUNT to be used in original place.
While doing that also add -mrecord-mcount to CC_FLAGS_FTRACE (if gcc
actually supports it).
Link: http://lkml.kernel.org/r/patch-2.thread-aa7b8d.git-de935bace15a.your-ad-here.call-01533557518-ext-9465@work.hours
Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The host-progs has been kept as an alias of hostprogs-y for a long time
(at least since the beginning of Git era), with the clear prompt:
Usage of host-progs is deprecated. Please replace with hostprogs-y!
Enough time for the migration has passed.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
The comment is the same as in the top-level Makefile.
Also, the comments contain typos:
- the .PHONY variable -> the PHONY variable
- se we can ... -> so we can ...
Instead of fixing the typos, just remove the duplicated comments.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Non gcc-5 builds with CONFIG_STACK_VALIDATION=y and
SKIP_STACK_VALIDATION=1 fail.
Example output:
/bin/sh: init/.tmp_main.o: Permission denied
commit 96f60dfa58 ("trace: Use -mcount-record for dynamic ftrace"),
added a mismatched endif. This causes cmd_objtool to get mistakenly
set.
Relocate endif to balance the newly added -record-mcount check.
Link: http://lkml.kernel.org/r/20180608214746.136554-1-gthelen@google.com
Fixes: 96f60dfa58 ("trace: Use -mcount-record for dynamic ftrace")
Acked-by: Andi Kleen <ak@linux.intel.com>
Tested-by: David Rientjes <rientjes@google.com>
Signed-off-by: Greg Thelen <gthelen@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
triggers. For example:
# cd /sys/kernel/debug/tracing
# echo 'snapshot' > events/ftrace/print/trigger
# echo 'cause snapshot' > trace_marker
The rest of the changes are various clean ups and also one stable fix that
was added late in the cycle.
-----BEGIN PGP SIGNATURE-----
iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCWxftjBQccm9zdGVkdEBn
b29kbWlzLm9yZwAKCRAp5XQQmuv6qosyAQCgmhb+/HgRYIbsKa8Q70E2pMx5A/za
4rQ37Q9PhDUJlAD/aWXfrqcMm+buAU0yY4K+eb+f2feKXWXxdZ/fuh7+nA4=
=lpXM
-----END PGP SIGNATURE-----
Merge tag 'trace-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"One new feature was added to ftrace, which is the trace_marker now
supports triggers. For example:
# cd /sys/kernel/debug/tracing
# echo 'snapshot' > events/ftrace/print/trigger
# echo 'cause snapshot' > trace_marker
The rest of the changes are various clean ups and also one stable fix
that was added late in the cycle"
* tag 'trace-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (21 commits)
tracing: Use match_string() instead of open coding it in trace_set_options()
branch-check: fix long->int truncation when profiling branches
ring-buffer: Fix typo in comment
ring-buffer: Fix a bunch of typos in comments
tracing/selftest: Add test to test simple snapshot trigger for trace_marker
tracing/selftest: Add test to test hist trigger between kernel event and trace_marker
tracing/selftest: Add selftests to test trace_marker histogram triggers
ftrace/selftest: Fix reset_trigger() to handle triggers with filters
ftrace/selftest: Have the reset_trigger code be a bit more careful
tracing: Document trace_marker triggers
tracing: Allow histogram triggers to access ftrace internal events
tracing: Prevent further users of zero size static arrays in trace events
tracing: Have zero size length in filter logic be full string
tracing: Add trigger file for trace_markers tracefs/ftrace/print
tracing: Do not show filter file for ftrace internal events
tracing: Add brackets in ftrace event dynamic arrays
tracing: Have event_trace_init() called by trace_init_tracefs()
tracing: Add __find_event_file() to find event files without restrictions
tracing: Do not reference event data in post call triggers
tracepoints: Fix the descriptions of tracepoint_probe_register{_prio}
...
gcc 5 supports a new -mcount-record option to generate ftrace
tables directly. This avoids the need to run record_mcount
manually.
Use this option when available.
So far doesn't use -mcount-nop, which also exists now.
This is needed to make ftrace work with LTO because the
normal record-mcount script doesn't run over the link
time output.
It should also improve build times slightly in the general
case.
Link: http://lkml.kernel.org/r/20171127213423.27218-12-andi@firstfloor.org
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX was selected by BLACKFIN, METAG.
They were removed by commit 4ba66a9760 ("arch: remove blackfin port"),
commit bb6fb6dfcc ("metag: Remove arch/metag/"), respectively.
No more architecture enables CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX.
Clean up the rest of scripts, and remove the Kconfig entry.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX was selected by BLACKFIN, METAG.
They were removed by commit 4ba66a9760 ("arch: remove blackfin port"),
commit bb6fb6dfcc ("metag: Remove arch/metag/"), respectively.
No more architecture enables CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX,
hence the -s (--symbol-prefix) option is unnecessary.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
GNU Make automatically deletes intermediate files that are updated
in a chain of pattern rules.
Example 1) %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
Example 2) %.o <- %.c <- %.c_shipped
A couple of makefiles mark such targets as .PRECIOUS to prevent Make
from deleting them, but the correct way is to use .SECONDARY.
.SECONDARY
Prerequisites of this special target are treated as intermediate
files but are never automatically deleted.
.PRECIOUS
When make is interrupted during execution, it may delete the target
file it is updating if the file was modified since make started.
If you mark the file as precious, make will never delete the file
if interrupted.
Both can avoid deletion of intermediate files, but the difference is
the behavior when Make is interrupted; .SECONDARY deletes the target,
but .PRECIOUS does not.
The use of .PRECIOUS is relatively rare since we do not want to keep
partially constructed (possibly corrupted) targets.
Another difference is that .PRECIOUS works with pattern rules whereas
.SECONDARY does not.
.PRECIOUS: $(obj)/%.lex.c
works, but
.SECONDARY: $(obj)/%.lex.c
has no effect. However, for the reason above, I do not want to use
.PRECIOUS which could cause obscure build breakage.
The targets specified as .SECONDARY must be explicit. $(targets)
contains all targets that need to include .*.cmd files. So, the
intermediates you want to keep are mostly in there. Therefore, mark
$(targets) as .SECONDARY. It means primary targets are also marked
as .SECONDARY, but I do not see any drawback for this.
I replaced some .SECONDARY / .PRECIOUS markers with 'targets'. This
will make Kbuild search for non-existing .*.cmd files, but this is
not a noticeable performance issue.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Frank Rowand <frowand.list@gmail.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Our convention is to distinguish file types by suffixes with a period
as a separator.
*-asn1.[ch] is a different pattern from other generated sources such
as *.lex.c, *.tab.[ch], *.dtb.S, etc. More confusing, files with
'-asn1.[ch]' are generated files, but '_asn1.[ch]' are checked-in
files:
net/netfilter/nf_conntrack_h323_asn1.c
include/linux/netfilter/nf_conntrack_h323_asn1.h
include/linux/sunrpc/gss_asn1.h
Rename generated files to *.asn1.[ch] for consistency.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Another common pattern that consists of chained commands is to compile
a DTB as binary data into the kernel image or a module. It is used in
several places in the source tree. Support it in the core Makefile.
$(call if_changed,dt_S_dtb) is more suitable than $(call cmd,dt_S_dtb)
in case cmd_dt_S_dtb is changed in the future.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Frank Rowand <frowand.list@gmail.com>
Files generated by if_changed* must be added to 'targets' to include
*.cmd files. Otherwise, they would be regenerated every time.
The build system automatically adds objects to 'targets' where
appropriate, such as obj-y, extra-y, etc. but does nothing for
intermediate files. So, each Makefile needs to add them by itself.
There are some common cases where objects are generated by chained
rules. Lexers and parsers are compiled like follows:
%.lex.o <- %.lex.c <- %.l
%.tab.o <- %.tab.c <- %.y
They are common patterns, so it is reasonable to take care of them
in the core Makefile instead of requiring each Makefile to do so.
At this moment, you cannot delete 'target += zconf.lex.c' in the
Kconfig Makefile because zconf.lex.c is included from zconf.tab.c
instead of being compiled separately. It should be deleted after
Kconfig is more refactored.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Frank Rowand <frowand.list@gmail.com>
With the incremental linking entirely dropped, we can simplify
the Makefile.
While I am here, I renamed cmd_link_o_target to cmd_ar_builtin.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
When built-in.o was incrementally linked with 'ld -r', the section
mismatch analysis for the individual built-in.o was possible when
CONFIG_DEBUG_SECTION_MISMATCH was enabled.
With the migration to the thin archive, built-in.a (former, built-in.o)
is no longer an ELF file. So, the modpost does nothing useful.
scripts/mod/modpost.c just checks the header to bail out, as follows:
/* Is this a valid ELF file? */
if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
(hdr->e_ident[EI_MAG1] != ELFMAG1) ||
(hdr->e_ident[EI_MAG2] != ELFMAG2) ||
(hdr->e_ident[EI_MAG3] != ELFMAG3)) {
/* Not an ELF file - silently ignore it */
return 0;
}
We have the full analysis in the final link stage anyway, so we would
not miss the section mismatching.
I do not see a good reason to require extra linking only for the
purpose of the per-directory analysis. Just get rid of this part.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
In Kbuild, Makefiles can add the same object to obj-y multiple
times. So,
obj-y += foo.o
obj-y += foo.o
is fine.
However, this is not true when the same object is added multiple
times via composite objects. For example,
obj-y += foo.o bar.o
foo-objs := foo-bar-common.o foo-only.o
bar-objs := foo-bar-common.o bar-only.o
causes build error because two instances of foo-bar-common.o are
linked into the vmlinux.
Makefiles tend to invent ugly work-around, for example
- lib/zstd/Makefile
- drivers/net/ethernet/cavium/liquidio/Makefile
The technique used in Kbuild to avoid the multiple definition error
is to use $(filter $(obj-y), $^). Here, $^ lists the names of all
the prerequisites with duplicated names removed.
By replacing it with $(filter $(real-obj-y), $^) we can do likewise
for composite objects. For built-in objects, we do not need to keep
the composite object structure. We can simply expand them, and link
$(real-obj-y) to built-in.a.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
When I was refactoring Makefiles, I stupidly mistook 'real-obj-y' for
'real-objs-y' over and over again. Finally, I decide to rename it to
'real-obj-y'. This is consistent with 'obj-y', 'subdir-obj-y'.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Just a cosmetic change to put related code close together.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Cao jin <caoj.fnst@cn.fujitsu.com>
modname can be calculated much more simply. If modname-multi is
empty, it is a single-used object. So, modname = $(basetarget).
Otherwise, modname = $(modname-multi).
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Cao jin <caoj.fnst@cn.fujitsu.com>
Incremental linking is gone, so rename built-in.o to built-in.a, which
is the usual extension for archive files.
This patch does two things, first is a simple search/replace:
git grep -l 'built-in\.o' | xargs sed -i 's/built-in\.o/built-in\.a/g'
The second is to invert nesting of nested text manipulations to avoid
filtering built-in.a out from libs-y2:
-libs-y2 := $(filter-out %.a, $(patsubst %/, %/built-in.a, $(libs-y)))
+libs-y2 := $(patsubst %/, %/built-in.a, $(filter-out %.a, $(libs-y)))
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
This removes the old `ld -r` incremental link option, which has not
been selected by any architecture since June 2017.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* Use BREs where EREs aren't necessary.
* Pass -E instead of -r to use EREs. This will be standardized in the
next POSIX revision[0]. GNU sed supports this since 4.2 (May 2009),
and busybox since 1.22.0 (Jan 2014).
* Use the [:space:] character class instead of ` \t` in bracket
expressions. In bracket expressions, POSIX says that <backslash> loses
its special meaning, so a conforming implementation cannot expand \t
to <tab>[1].
* In BREs, use interval expressions (\{n,m\}) instead of non-standard
features like \+ and \?.
* Use a loop instead of -s flag.
There are still plenty of other cases of non-standard sed invocations
(use of ERE features in BREs, in-place editing), but this fixes some
core ones.
[0] http://austingroupbugs.net/view.php?id=528
[1] http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html#tag_09_03_05
Signed-off-by: Michael Forney <forney@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Disable retpoline validation in objtool if your compiler sucks, and otherwise
select the validation stuff for CONFIG_RETPOLINE=y (most builds would already
have it set due to ORC).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
David allowed retpolines in .init.text, except for modules, which will
trip up objtool retpoline validation, fix that.
Requested-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
David requested a objtool validation pass for CONFIG_RETPOLINE=y enabled
builds, where it validates no unannotated indirect jumps or calls are
left.
Add an additional .discard.retpoline_safe section to allow annotating
the few indirect sites that are required and safe.
Requested-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 pti bits and fixes from Thomas Gleixner:
"This last update contains:
- An objtool fix to prevent a segfault with the gold linker by
changing the invocation order. That's not just for gold, it's a
general robustness improvement.
- An improved error message for objtool which spares tearing hairs.
- Make KASAN fail loudly if there is not enough memory instead of
oopsing at some random place later
- RSB fill on context switch to prevent RSB underflow and speculation
through other units.
- Make the retpoline/RSB functionality work reliably for both Intel
and AMD
- Add retpoline to the module version magic so mismatch can be
detected
- A small (non-fix) update for cpufeatures which prevents cpu feature
clashing for the upcoming extra mitigation bits to ease
backporting"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
module: Add retpoline tag to VERMAGIC
x86/cpufeature: Move processor tracing out of scattered features
objtool: Improve error message for bad file argument
objtool: Fix seg fault with gold linker
x86/retpoline: Add LFENCE to the retpoline/RSB filling RSB macros
x86/retpoline: Fill RSB on context switch for affected CPUs
x86/kasan: Panic if there is not enough memory to boot
Objtool segfaults when the gold linker is used with
CONFIG_MODVERSIONS=y and CONFIG_UNWINDER_ORC=y.
With CONFIG_MODVERSIONS=y, the .o file gets passed to the linker before
being passed to objtool. The gold linker seems to strip unused ELF
symbols by default, which confuses objtool and causes the seg fault when
it's trying to generate ORC metadata.
Objtool should really be running immediately after GCC anyway, without a
linker call in between. Change the makefile ordering so that objtool is
called before the linker.
Reported-and-tested-by: Markus <M4rkusXXL@web.de>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: ee9f8fce99 ("x86/unwind: Add the ORC unwinder")
Link: http://lkml.kernel.org/r/355f04da33581f4a3bf82e5b512973624a1e23a2.1516025651.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
- Use pwd instead of /bin/pwd for portability
- Clean up Makefiles
- Fix ld-option for clang
- Fix malloc'ed data size in Kconfig
- Fix parallel building along with coccicheck
- Fix a minor issue of package building
- Prompt to use "rpm-pkg" instead of "rpm"
- Clean up *.i and *.lst patterns by "make clean"
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=a2Td
-----END PGP SIGNATURE-----
Merge tag 'kbuild-v4.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull more Kbuild updates from Masahiro Yamada:
- use 'pwd' instead of '/bin/pwd' for portability
- clean up Makefiles
- fix ld-option for clang
- fix malloc'ed data size in Kconfig
- fix parallel building along with coccicheck
- fix a minor issue of package building
- prompt to use "rpm-pkg" instead of "rpm"
- clean up *.i and *.lst patterns by "make clean"
* tag 'kbuild-v4.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: drop $(extra-y) from real-objs-y
kbuild: clean up *.i and *.lst patterns by make clean
kbuild: rpm: prompt to use "rpm-pkg" if "rpm" target is used
kbuild: pkg: use --transform option to prefix paths in tar
coccinelle: fix parallel build with CHECK=scripts/coccicheck
kconfig/symbol.c: use correct pointer type argument for sizeof
kbuild: Set KBUILD_CFLAGS before incl. arch Makefile
kbuild: remove all dummy assignments to obj-
kbuild: create built-in.o automatically if parent directory wants it
kbuild: /bin/pwd -> pwd
a new "Co-Developed-by" tag described by Greg, and a build enhancement from
Willy to generate docs warnings during a kernel build (but only when
additional warnings have been requested in general).
-----BEGIN PGP SIGNATURE-----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=ydAe
-----END PGP SIGNATURE-----
Merge tag 'docs-4.15-2' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"A few late-arriving docs updates that have no real reason to wait.
There's a new "Co-Developed-by" tag described by Greg, and a build
enhancement from Willy to generate docs warnings during a kernel build
(but only when additional warnings have been requested in general)"
* tag 'docs-4.15-2' of git://git.lwn.net/linux:
Add optional check for bad kernel-doc comments
Documentation: fix profile= options in kernel-parameters.txt
documentation/svga.txt: update outdated file
kokr/memory-barriers.txt: Fix typo in paring example
kokr/memory-barriers/txt: Replace uses of "transitive"
Documentation/process: add Co-Developed-by: tag for patches with multiple authors
Implement a '-none' output mode for kernel-doc which will only output
warning messages, and suppresses the warning message about there being
no kernel-doc in the file.
If the build has requested additional warnings, automatically check all
.c files. This patch does not check .h files. Enabling the warning
by default would add about 1300 warnings, so it's default off for now.
People who care can use this to check they didn't break the docs and
maybe we'll get all the warnings fixed and be able to enable this check
by default in the future.
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
"obj-y += foo/" syntax requires Kbuild to visit the "foo" subdirectory
and link built-in.o from that directory. This means foo/Makefile is
responsible for creating built-in.o even if there is no object to
link (in this case, built-in.o is an empty archive).
We have had several fixups like commit 4b024242e8 ("kbuild: Fix
linking error built-in.o no such file or directory"), then ended up
with a complex condition as follows:
ifneq ($(strip $(obj-y) $(obj-m) $(obj-) $(subdir-m) $(lib-target)),)
builtin-target := $(obj)/built-in.o
endif
We still have more cases not covered by the above, so we need to add
obj- := dummy.o
in several places just for creating empty built-in.o.
A key point is, the parent Makefile knows whether built-in.o is needed
or not. If a subdirectory needs to create built-in.o, its parent can
tell the fact when descending.
If non-empty $(need-builtin) flag is passed from the parent, built-in.o
should be created. $(obj-y) should be still checked to support the
single target "%/". All of ugly tricks will go away.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
One of the most remarkable improvements in this cycle is, Kbuild is
now able to cache the result of shell commands. Some variables are
expensive to compute, for example, $(call cc-option,...) invokes the
compiler. It is not efficient to redo this computation every time,
even when we are not actually building anything. Kbuild creates a
hidden file ".cache.mk" that contains invoked shell commands and
their results. The speed-up should be noticeable.
Summary:
- Fix arch build issues (hexagon, sh)
- Clean up various Makefiles and scripts
- Fix wrong usage of {CFLAGS,LDFLAGS}_MODULE in arch Makefiles
- Cache variables that are expensive to compute
- Improve cc-ldopton and ld-option for Clang
- Optimize output directory creation
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=zIdO
-----END PGP SIGNATURE-----
Merge tag 'kbuild-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
"One of the most remarkable improvements in this cycle is, Kbuild is
now able to cache the result of shell commands. Some variables are
expensive to compute, for example, $(call cc-option,...) invokes the
compiler. It is not efficient to redo this computation every time,
even when we are not actually building anything. Kbuild creates a
hidden file ".cache.mk" that contains invoked shell commands and their
results. The speed-up should be noticeable.
Summary:
- Fix arch build issues (hexagon, sh)
- Clean up various Makefiles and scripts
- Fix wrong usage of {CFLAGS,LDFLAGS}_MODULE in arch Makefiles
- Cache variables that are expensive to compute
- Improve cc-ldopton and ld-option for Clang
- Optimize output directory creation"
* tag 'kbuild-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (30 commits)
kbuild: move coccicheck help from scripts/Makefile.help to top Makefile
sh: decompressor: add shipped files to .gitignore
frv: .gitignore: ignore vmlinux.lds
selinux: remove unnecessary assignment to subdir-
kbuild: specify FORCE in Makefile.headersinst as .PHONY target
kbuild: remove redundant mkdir from ./Kbuild
kbuild: optimize object directory creation for incremental build
kbuild: create object directories simpler and faster
kbuild: filter-out PHONY targets from "targets"
kbuild: remove redundant $(wildcard ...) for cmd_files calculation
kbuild: create directory for make cache only when necessary
sh: select KBUILD_DEFCONFIG depending on ARCH
kbuild: fix linker feature test macros when cross compiling with Clang
kbuild: shrink .cache.mk when it exceeds 1000 lines
kbuild: do not call cc-option before KBUILD_CFLAGS initialization
kbuild: Cache a few more calls to the compiler
kbuild: Add a cache for generated variables
kbuild: add forward declaration of default target to Makefile.asm-generic
kbuild: remove KBUILD_SUBDIR_ASFLAGS and KBUILD_SUBDIR_CCFLAGS
hexagon/kbuild: replace CFLAGS_MODULE with KBUILD_CFLAGS_MODULE
...
The previous commit largely optimized the object directory creation.
We can optimize it more for incremental build.
There are already *.cmd files in the output directory. The existing
*.cmd files have been picked up by $(wildcard ...). Obviously,
directories containing them exist too, so we can skip "mkdir -p".
With this, Kbuild runs almost zero "mkdir -p" in incremental building.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
For the out-of-tree build, scripts/Makefile.build creates output
directories, but this operation is not efficient.
scripts/Makefile.lib calculates obj-dirs as follows:
obj-dirs := $(dir $(multi-objs) $(obj-y))
Please notice $(sort ...) is not used here. Usually the result is
as many "./" as objects here.
For a lot of duplicated paths, the following command is invoked.
_dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d)))
Then, the costly shell command is run over and over again.
I see many points for optimization:
[1] Use $(sort ...) to cut down duplicated paths before passing them
to system call
[2] Use single $(shell ...) instead of repeating it with $(foreach ...)
This will reduce forking.
[3] We can calculate obj-dirs more simply. Most of objects are already
accumulated in $(targets). So, $(dir $(targets)) is fine and more
comprehensive.
I also removed ugly code in arch/x86/entry/vdso/Makefile. This is now
really unnecessary.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
The variable "targets" contains object paths for which existing .*.cmd
files should be included.
scripts/Makefile.build automatically adds $(MAKECMDGOALS) to "targets"
as follows:
targets += $(extra-y) $(MAKECMDGOALS) $(always)
The $(MAKECMDGOALS) is a PHONY target in several places. PHONY targets
never create .*.cmd files.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
I do not see any reason why $(wildcard ...) needs to be called twice
for computing cmd_files. Remove the first one.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Masahiro Yamada