CONFIG_PROFILE_ALL_BRANCHES confuses gcc-5.x to the degree that it prints
incorrect warnings about a lot of variables that it thinks can be used
uninitialized, e.g.:
i2c/busses/i2c-diolan-u2c.c: In function 'diolan_usb_xfer':
i2c/busses/i2c-diolan-u2c.c:391:16: warning: 'byte' may be used uninitialized in this function
iio/gyro/itg3200_core.c: In function 'itg3200_probe':
iio/gyro/itg3200_core.c:213:6: warning: 'val' may be used uninitialized in this function
leds/leds-lp55xx-common.c: In function 'lp55xx_update_bits':
leds/leds-lp55xx-common.c:350:6: warning: 'tmp' may be used uninitialized in this function
misc/bmp085.c: In function 'show_pressure':
misc/bmp085.c:363:10: warning: 'pressure' may be used uninitialized in this function
power/ds2782_battery.c: In function 'ds2786_get_capacity':
power/ds2782_battery.c:214:17: warning: 'raw' may be used uninitialized in this function
These are all false positives that either rob someone's time when trying
to figure out whether they are real, or they get people to send wrong
patches to shut up the warnings.
Nobody normally wants to run a CONFIG_PROFILE_ALL_BRANCHES kernel in
production, so disabling the whole class of warnings for this configuration
has no serious downsides either.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Steven Rostedt <rostedtgoodmis.org>
Signed-off-by: Michal Marek <mmarek@suse.com>
CC_OPTIMIZE_FOR_SIZE disables the often useful -Wmaybe-unused warning,
because that causes a ridiculous amount of false positives when combined
with -Os.
This means a lot of warnings don't show up in testing by the developers
that should see them with an 'allmodconfig' kernel that has
CC_OPTIMIZE_FOR_SIZE enabled, but only later in randconfig builds
that don't.
This changes the Kconfig logic around CC_OPTIMIZE_FOR_SIZE to make
it a 'choice' statement defaulting to CC_OPTIMIZE_FOR_PERFORMANCE
that gets added for this purpose. The allmodconfig and allyesconfig
kernels now default to -O2 with the maybe-unused warning enabled.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michal Marek <mmarek@suse.com>
When the kernel path contains a space or a colon somewhere in the path
name, the modules_install target doesn't work anymore, as the path names
are not enclosed in double quotes. It is also supposed that and O= build
will suffer from the same weakness as modules_install.
Instead of checking and improving kbuild to resist to directories
including these characters, error out early to prevent any build if the
kernel's main directory contains a space.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
The following renames occurred recently:
cmd_cc_i_c --> cmd_cpp_i_c
cmd_as_s_S --> cmd_cpp_s_S
The respective cc_*_c and as_*_S patterns no longer match the above
therefore additional patterns are needed.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Michal Marek <mmarek@suse.com>
The if_changed directive is useless against phony targets.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: 2441e78b19 ("kbuild: better abstract vmlinux sequential prerequisites")
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
When CONFIG_TRIM_UNUSED_KSYMS=y and CONFIG_BUILD_DOCSRC=y it is possible
to get the following error:
ERROR: "cn_del_callback" [Documentation/connector/cn_test.ko] undefined!
ERROR: "cn_add_callback" [Documentation/connector/cn_test.ko] undefined!
ERROR: "cn_netlink_send" [Documentation/connector/cn_test.ko] undefined!
../scripts/Makefile.modpost:91: recipe for target '__modpost' failed
It is not sufficient to do "vmlinux-dirs += Documentation" as this also
depends on the headers_check target, and all of this needs to be done
before adjust_autoksyms.sh is executed.
Let's sort this out by gathering those sequential prerequisites in a make
target of their own, separate from the vmlinux target. And by doing so,
the special autoksyms_recursive target is no longer needed.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
When a different output directory is specified during the build process (with
O= or KBUILD_OUTPUT), the call to adjust_autoksyms.sh script fails with the
following error:
/bin/sh scripts/adjust_autoksyms.sh \
"make KBUILD_MODULES=1 -f ../Makefile autoksyms_recursive"
/bin/sh: scripts/adjust_autoksyms.sh: No such file or directory
make[2]: *** [vmlinux] Error 127
make[1]: *** [sub-make] Error 2
make: *** [__sub-make] Error 2
Using the absolute path with $(srctree) variable solves the problem.
This is in case the CONFIG_TRIM_UNUSED_KSYMS option is specified.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Fixes: 23121ca2b5 ("kbuild: create/adjust generated/autoksyms.h")
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Michal Marek <mmarek@suse.com>
The compiler can accept -DKBUILD_MODNAME="foo", it's just a matter of
quoting. That way, we reduce the gcc command line a bit.
Signed-off-by: Michal Marek <mmarek@suse.com>
This command just preprocesses .S files into .s files, so cmd_cpp_s_S
seems more suitable.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
This command just preprocesses .c files into .i files, so cmd_cpp_i_c
seems more suitable.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
"PHONY += FORCE" is already cared by scripts/Makefile.build,
which these files are included from.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
Since commit 2aedcd098a ('kbuild: suppress annoying "... is up to
date." message'), $(call if_changed,...) is evaluated to "@:"
when there is nothing to do.
We no longer need to add "@:" after $(call if_changed,...) to
suppress "... is up to date." message.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
As in other places, PHONY is a better fit for "modules" and
"modules_install".
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
These targets are marked as PHONY. No need to add FORCE to their
dependency.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
Make sample modules in parallel with the rest of the kernel rather
than having them built from the vmlinux target. This makes the build
slightly faster, and those modules are properly considered when
adjust_autoksyms.sh is executed.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Given the list of exported symbols needed by all modules, we can create
a header file containing preprocessor defines for each of those symbols.
Also, when some symbols are added and/or removed from the list, we can
update the time on the corresponding files used as build dependencies for
those symbols. And finally, if any symbol did change state, the
corresponding source files must be rebuilt.
The insertion or removal of an EXPORT_SYMBOL() entry within a module may
create or remove the need for another exported symbol. This is why this
operation has to be repeated until the list of needed exported symbols
becomes stable. Only then the final kernel and modules link take place.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Like with kconfig options, we now have the ability to compile in and
out individual EXPORT_SYMBOL() declarations based on the content of
include/generated/autoksyms.h. However we don't want the entire
world to be rebuilt whenever that file is touched.
Let's apply the same build dependency trick used for CONFIG_* symbols
where the time stamp of empty files whose paths matching those symbols
is used to trigger fine grained rebuilds. In our case the key is the
symbol name passed to EXPORT_SYMBOL().
However, unlike config options, we cannot just use fixdep to parse
the source code for EXPORT_SYMBOL(ksym) because several variants exist
and parsing them all in a separate tool, and keeping it in synch, is
not trivially maintainable. Furthermore, there are variants such as
EXPORT_SYMBOL_GPL(pci_user_read_config_##size);
that are instanciated via a macro for which we can't easily determine
the actual exported symbol name(s) short of actually running the
preprocessor on them.
Storing the symbol name string in a special ELF section doesn't work
for targets that output assembly or preprocessed source.
So the best way is really to leverage the preprocessor by having it
output actual symbol names anchored by a special sequence that can be
easily filtered out. Then the list of symbols is simply fed to fixdep
to be merged with the other dependencies.
That implies the preprocessor is executed twice for each source file.
A previous attempt relied on a warning pragma for each EXPORT_SYMBOL()
instance that was filtered apart from stderr by the build system with
a sed script during the actual compilation pass. Unfortunately the
preprocessor/compiler diagnostic output isn't stable between versions
and this solution, although more efficient, was deemed too fragile.
Because of the lowercasing performed by fixdep, there might be name
collisions triggering spurious rebuilds for similar symbols. But this
shouldn't be a big issue in practice. (This is the case for CONFIG_*
symbols and I didn't want to be different here, whatever the original
reason for doing so.)
To avoid needless build overhead, the exported symbol name gathering is
performed only when CONFIG_TRIM_UNUSED_KSYMS is selected.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
The generation and postprocessing of automatic dependency rules is
duplicated in rule_cc_o_c, rule_as_o_S and if_changed_dep. Since
this is not a trivial one-liner action, it is now abstracted under
cmd_and_fixdep to simplify things and make future changes in this area
easier.
In the rule_cc_o_c and rule_as_o_S cases that means the order of some
commands has been altered, namely fixdep and related file manipulations
are executed earlier, but they didn't depend on those commands that now
execute later.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Similar to include/generated/autoconf.h, include/generated/autoksyms.h
will contain a list of defines for each EXPORT_SYMBOL() that we want
active. The format is:
#define __KSYM_<symbol_name> 1
This list will be auto-generated with another patch. For now we only
include the preprocessor magic to automatically create or omit the
corresponding struct kernel_symbol declaration.
Given the content of include/generated/autoksyms.h may not be known in
advance, an empty file is created early on to let the build proceed.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Kernel modules are partially linked object files with some undefined
symbols that are expected to be matched with EXPORT_SYMBOL() entries
from elsewhere.
Each .tmp_versions/*.mod file currently contains two line of text
separated by a newline character. The first line has the actual module
file name while the second line has a list of object files constituting
that module. Those files are parsed by modpost (scripts/mod/sumversion.c),
scripts/Makefile.modpost, scripts/Makefile.modsign, etc. Only the
modpost utility cares about the second line while the others retrieve
only the first line.
Therefore we can add a third line to record the list of undefined symbols
aka required EXPORT_SYMBOL() entries for each module into that file
without breaking anything. Like for the second line, symbols are separated
by a blank and the list is terminated with a newline character.
To avoid needless build overhead, the undefined symbols extraction is
performed only when CONFIG_TRIM_UNUSED_KSYMS is selected.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Arnd Bergmann
Robert Jarzmik
Nicolas Pitre
Nicolas Ferre
Michal Marek
Masahiro Yamada
Maxim Zhukov
Linus Torvalds