10 Nov, 2016
1 commit
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The CRC code for asm exports grabs the preprocessed asm, finds the
___EXPORT_SYMBOL and turns those into EXPORT_SYMBOL in a C program
that can be preprocessed and parsed to create the CRC signatures from
the type.The existing regex matching and replacement is too strict, and doesn't
deal well with whitespace among other things. The line
" EXPORT_SYMBOL(sym)" in a .S file would not match due to initial
whitespace, for example, which resulted in x86's ___preempt_schedule
failing to get CRCs.Reported-by: Philip Müller
Signed-off-by: Nicholas Piggin
Signed-off-by: Michal Marek
01 Nov, 2016
1 commit
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Allow architectures to create asm/asm-prototypes.h file that
provides C prototypes for exported asm functions, which enables
proper CRC versions to be generated for them.Signed-off-by: Nicholas Piggin
Signed-off-by: Michal Marek
23 Oct, 2016
1 commit
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Signed-off-by: Nicholas Piggin
Reported-by: Russell King
Tested-by: Russell King
Signed-off-by: Michal Marek
09 Sep, 2016
1 commit
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ld -r is an incremental link used to create built-in.o files in build
subdirectories. It produces relocatable object files containing all
its input files, and these are are then pulled together and relocated
in the final link. Aside from the bloat, this constrains the final
link relocations, which has bitten large powerpc builds with
unresolvable relocations in the final link.Alan Modra has recommended the kernel use thin archives for linking.
This is an alternative and means that the linker has more information
available to it when it links the kernel.This patch enables a config option architectures can select, which
causes all built-in.o files to be built as thin archives. built-in.o
files in subdirectories do not get symbol table or index attached,
which improves speed and size. The final link pass creates a
built-in.o archive in the root output directory which includes the
symbol table and index. The linker then uses takes this file to link.The --whole-archive linker option is required, because the linker now
has visibility to every individual object file, and it will otherwise
just completely avoid including those without external references
(consider a file with EXPORT_SYMBOL or initcall or hardware exceptions
as its only entry points). The traditional built works "by luck" as
built-in.o files are large enough that they're going to get external
references. However this optimisation is unpredictable for the kernel
(due to above external references), ineffective at culling unused, and
costly because the .o files have to be searched for references.
Superior alternatives for link-time culling should be used instead.Build characteristics for inclink vs thinarc, on a small powerpc64le
pseries VM with a modest .config:inclink thinarc
sizes
vmlinux 15 618 680 15 625 028
sum of all built-in.o 56 091 808 1 054 334
sum excluding root built-in.o 151 430find -name built-in.o | xargs rm ; time make vmlinux
real 22.772s 21.143s
user 13.280s 13.430s
sys 4.310s 2.750s- Final kernel pulled in only about 6K more, which shows how
ineffective the object file culling is.
- Build performance looks improved due to less pagecache activity.
On IO constrained systems it could be a bigger win.
- Build size saving is significant.Side note, the toochain understands archives, so there's some tricks,
$ ar t built-in.o # list all files you linked with
$ size built-in.o # and their sizes
$ objdump -d built-in.o # disassembly (unrelocated) with filenamesImplementation by sfr, minor tweaks by npiggin.
Signed-off-by: Stephen Rothwell
Signed-off-by: Nicholas Piggin
Signed-off-by: Michal Marek
08 Aug, 2016
1 commit
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Collect the symbols exported by anything that goes into lib.a and
add an empty object (lib-exports.o) with explicit undefs for each
of those to obj-y.That allows to relax the rules regarding the use of exports in
lib-* objects - right now an object with export can be in lib-*
only if we are guaranteed that there always will be users in
built-in parts of the tree, otherwise it needs to be in obj-*.
As the result, we have an unholy mix of lib- and obj- in lib/Makefile
and (especially) in arch/*/lib/Makefile. Moreover, a change in
generic part of the kernel can lead to mysteriously missing exports
on some configs. With this change we don't have to worry about
that anymore.One side effect is that built-in.o now pulls everything with exports
from the corresponding lib.a (if such exists). That's exactly what
we want for linking vmlinux and fortunately it's almost the only thing
built-in.o is used in. arch/ia64/hp/sim/boot/bootloader is the only
exception and it's easy to get rid of now - just turn everything in
arch/ia64/lib into lib-* and don't bother with arch/ia64/lib/built-in.o
anymore.[AV: stylistic fix from Michal folded in]
Acked-by: Michal Marek
Signed-off-by: Al Viro
08 Jun, 2016
1 commit
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Infrastructure for building independent shared library targets.
Based on work created by the PaX Team.
Signed-off-by: Emese Revfy
Acked-by: Kees Cook
Signed-off-by: Michal Marek
20 Apr, 2016
2 commits
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This command just preprocesses .S files into .s files, so cmd_cpp_s_S
seems more suitable.Signed-off-by: Masahiro Yamada
Signed-off-by: Michal Marek -
This command just preprocesses .c files into .i files, so cmd_cpp_i_c
seems more suitable.Signed-off-by: Masahiro Yamada
Acked-by: Arnaldo Carvalho de Melo
Signed-off-by: Michal Marek
30 Mar, 2016
2 commits
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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
-
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
Acked-by: Rusty Russell
05 Mar, 2016
1 commit
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With CONFIG_STACK_VALIDATION enabled, if the host system doesn't have
a development version of libelf installed, the build fails with errors
like:elf.h:22:18: fatal error: gelf.h: No such file or directory compilation terminated.
Instead of failing to build, instead just print a warning and disable
stack validation.Signed-off-by: Josh Poimboeuf
Cc: Andrew Morton
Cc: Linus Torvalds
Cc: Peter Zijlstra
Cc: Stephen Rothwell
Cc: Sudip Mukherjee
Cc: Thomas Gleixner
Cc: linux-next@vger.kernel.org
Cc: linux@roeck-us.net
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/8c27fe00face60f42e888ddb3142c97e45223165.1457026550.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar
29 Feb, 2016
1 commit
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Add a CONFIG_STACK_VALIDATION option which will run "objtool check" for
each .o file to ensure the validity of its stack metadata.Signed-off-by: Josh Poimboeuf
Cc: Andrew Morton
Cc: Andy Lutomirski
Cc: Arnaldo Carvalho de Melo
Cc: Bernd Petrovitsch
Cc: Borislav Petkov
Cc: Chris J Arges
Cc: Jiri Slaby
Cc: Linus Torvalds
Cc: Michal Marek
Cc: Namhyung Kim
Cc: Pedro Alves
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/92baab69a6bf9bc7043af0bfca9fb964a1d45546.1456719558.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar
25 Nov, 2015
1 commit
-
This allows to write
drm-$(CONFIG_AGP) += drm_agpsupport.o
without having to handle CONFIG_AGP=y vs. CONFIG_AGP=m. Only support
this syntax for modules, since built-in code depending on something
modular cannot work and init/Makefile actually relies on the current
semantics. There are a few drivers which adapted to the current
semantics out of necessity; these are fixed to also work when the
respective subsystem is modular.Acked-by: Peter Chen [chipidea]
Signed-off-by: Michal Marek
29 Jan, 2015
1 commit
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If the kernel is compiled with function tracer support the -pg compile option
is passed to gcc to generate extra code into the prologue of each function.This patch replaces the "open-coded" -pg compile flag with a CC_FLAGS_FTRACE
makefile variable which architectures can override if a different option
should be used for code generation.Acked-by: Steven Rostedt
Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
02 Oct, 2014
1 commit
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Kconfig never defines CONFIG_* as 'n'.
Now obj-n is only used in firmware/Makefile and it can be
replaced with obj-. No makefile uses lib-n.Let's rip off obj-n and lib-n.
Signed-off-by: Masahiro Yamada
Acked-by: Peter Foley
Signed-off-by: Michal Marek
19 Aug, 2014
1 commit
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The comment in scripts/Makefile.build says as follows:
We would rather have a list of rules like
foo.o: $(foo-objs)
but that's not so easy, so we rather make all composite objects depend
on the set of all their partsThis commit makes it possible!
For example, assume a Makefile like this
obj-m = foo.o bar.o
foo-objs := foo1.o foo2.o
bar-objs := bar1.o bar2.oWithout this patch, foo.o depends on all of
foo1.o foo2.o bar1.o bar2.o.
It looks funny that foo.o is regenerated when bar1.c is updated.Now we can handle the dependency of foo.o and bar.o separately.
Signed-off-by: Masahiro Yamada
Signed-off-by: Michal Marek
30 Apr, 2014
1 commit
-
Signed-off-by: Masahiro Yamada
Signed-off-by: Michal Marek
17 Apr, 2014
1 commit
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W=... provides extra gcc checks.
Having such code in scripts/Makefile.build results in the same flags
being added to KBUILD_CFLAGS multiple times becuase
scripts/Makefile.build is invoked every time Kbuild descends into
the subdirectories.Since the top Makefile is already too cluttered, this commit moves
all of extra gcc check stuff to a new file scripts/Makefile.extrawarn,
which is included from the top Makefile.Signed-off-by: Masahiro Yamada
CC: Sam Ravnborg
Signed-off-by: Michal Marek
10 Apr, 2014
1 commit
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When compiling kernel with clang, disable warnings which are too noisy, and
add the clang flag catch-undefined-behavior.Signed-off-by: Jan-Simon Möller
Signed-off-by: Behan Webster
Signed-off-by: Mark Charlebois
Cc: PaX Team
14 Feb, 2014
1 commit
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The asm-offset.c technique to fish data out of the assembler file
does not work with LTO. Just disable for the asm-offset.c build.Signed-off-by: Andi Kleen
Link: http://lkml.kernel.org/r/1391846481-31491-11-git-send-email-ak@linux.intel.com
Signed-off-by: H. Peter Anvin
20 Mar, 2013
1 commit
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Pass symbol-prefix to genksyms instead of arch, so that the decision
what symbol prefix to use is kept in one place.Basically genksyms used to take a -a $ARCH argument and it used that to
determine whether to add an underscore symbol prefix. It's now changed
to take a -s $SYMBOL_PREFIX argument so that the caller decides whether
a symbol prefix is required. The build system then uses
CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX to determine whether to pass the
argument.Signed-off-by: James Hogan
Signed-off-by: Rusty Russell
08 Oct, 2012
1 commit
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Add a simple ASN.1 grammar compiler. This produces a bytecode output that can
be fed to a decoder to inform the decoder how to interpret the ASN.1 stream it
is trying to parse.Action functions can be specified in the grammar by interpolating:
({ foo })
after a type, for example:
SubjectPublicKeyInfo ::= SEQUENCE {
algorithm AlgorithmIdentifier,
subjectPublicKey BIT STRING ({ do_key_data })
}The decoder is expected to call these after matching this type and parsing the
contents if it is a constructed type.The grammar compiler does not currently support the SET type (though it does
support SET OF) as I can't see a good way of tracking which members have been
encountered yet without using up extra stack space.Currently, the grammar compiler will fail if more than 256 bytes of bytecode
would be produced or more than 256 actions have been specified as it uses
8-bit jump values and action indices to keep space usage down.Signed-off-by: David Howells
Signed-off-by: Rusty Russell
26 Jan, 2012
1 commit
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-Wmissing-field-initializers is too noisy to be useful on W=1. Let's
move it to W=2.Signed-off-by: Kirill A. Shutemov
Signed-off-by: Michal Marek
31 Aug, 2011
1 commit
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Usage of these flags has been deprecated for nearly 4 years by:
commit f77bf01425b11947eeb3b5b54685212c302741b8
Author: Sam Ravnborg
Date: Mon Oct 15 22:25:06 2007 +0200kbuild: introduce ccflags-y, asflags-y and ldflags-y
Moreover, these flags (at least EXTRA_CFLAGS) have been documented for
command line use. By default, gmake(1) do not override command line
setting, so this is likely to result in build failure or unexpected
behavior.Do not advertise for its usage.
Cc: Sam Ravnborg
Cc: linux-kbuild@vger.kernel.org
Signed-off-by: Arnaud Lacombe
Signed-off-by: Michal Marek
25 May, 2011
1 commit
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* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6:
kbuild: make KBUILD_NOCMDDEP=1 handle empty built-in.o
scripts/kallsyms.c: fix potential segfault
scripts/gen_initramfs_list.sh: Convert to a /bin/sh script
kbuild: Fix GNU make v3.80 compatibility
kbuild: Fix passing -Wno-* options to gcc 4.4+
kbuild: move scripts/basic/docproc.c to scripts/docproc.c
kbuild: Fix Makefile.asm-generic for um
kbuild: Allow to combine multiple W= levels
kbuild: Disable -Wunused-but-set-variable for gcc 4.6.0
Fix handling of backlash character in LINUX_COMPILE_BY name
kbuild: asm-generic support
kbuild: implement several W= levels
kbuild: Fix build with binutils <= 2.19
initramfs: Use KBUILD_BUILD_TIMESTAMP for generated entries
kbuild: Allow to override LINUX_COMPILE_BY and LINUX_COMPILE_HOST macros
kbuild: Drop unused LINUX_COMPILE_TIME and LINUX_COMPILE_DOMAIN macros
kbuild: Use the deterministic mode of ar
kbuild: Call gzip with -n
kbuild: move KALLSYMS_EXTRA_PASS from Kconfig to Makefile
Kconfig: improve KALLSYMS_ALL documentationFix up trivial conflict in Makefile
19 May, 2011
1 commit
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Modifications to recordmcount must be performed on all object
files to stay consistent with what the kernel code may expect.
Add the recordmcount files to the main dependencies to make sure
any change to them causes a full recompile.Signed-off-by: Michal Marek
Link: http://lkml.kernel.org/r/20110517133646.GP13293@sepie.suse.cz
Signed-off-by: Steven Rostedt
17 May, 2011
1 commit
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When mcount is called in a section that ftrace will not modify it into
a nop, we want to warn about this. But not warn about this always. Now
if the user builds the kernel with the option RECORDMCOUNT_WARN=1 then
the build will warn about mcount callers that are ignored and will just
waste execution time.Acked-by: Michal Marek
Cc: linux-kbuild@vger.kernel.org
Link: http://lkml.kernel.org/r/20110421023738.714956282@goodmis.org
Signed-off-by: Steven Rostedt
02 May, 2011
1 commit
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Add support for make W=12, make W=123 and so on, to enable warnings from
multiple W= levels. Normally, make W= does not include warnings
from the previous level.Signed-off-by: Michal Marek
Acked-by: Sam Ravnborg
Reviewed-By: Valdis Kletnieks
29 Apr, 2011
1 commit
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Disable the new -Wunused-but-set-variable that was added in gcc 4.6.0
It produces more false positives than useful warnings.This can still be enabled using W=1
Signed-off-by: Dave Jones
Acked-by: Sam Ravnborg
Tested-by: Sam Ravnborg
Signed-off-by: Michal Marek
28 Apr, 2011
1 commit
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Building a kernel with "make W=1" produces far too much noise to be
useful.Divide the warning options in three groups:
W=1 - warnings that may be relevant and does not occur too often
W=2 - warnings that occur quite often but may still be relevant
W=3 - the more obscure warnings, can most likely be ignoredWhen building the whole kernel, those levels produce:
W=1 - 4859 warnings
W=2 - 1394 warnings
W=3 - 86666 warningsrespectively. Warnings have been counted with Geert's script at
http://www.kernel.org/pub/linux/kernel/people/geert/linux-log/linux-log-summary.pl
Many warnings occur from .h files so fixing one file may have a nice
effect on the total number of warnings.With these changes I am actually tempted to try W=1 now and then.
Previously there was just too much noise.Borislav:
- make the W= levels exclusive
- move very noisy and making little sense for the kernel warnings to W=3
- drop -Woverlength-strings due to useless warning message
- copy explanatory text for the different warning levels to 'make help'
- recount warnings per levelSigned-off-by: Sam Ravnborg
Signed-off-by: Borislav Petkov
Cc: Dave Jones
Cc: Geert Uytterhoeven
Signed-off-by: Michal Marek
20 Apr, 2011
1 commit
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The D option of ar is only available in newer versions.
Signed-off-by: Michal Marek
18 Apr, 2011
1 commit
-
Signed-off-by: Michal Marek
09 Mar, 2011
1 commit
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Add a 'W=1' Makefile switch which adds additional checking per build
object.The idea behind this option is targeted at developers who, in the
process of writing their code, want to do the occasionalmake W=1 [target.o]
and let gcc do more extensive code checking for them. Then, they
could eyeball the output for valid gcc warnings about various
bugs/discrepancies which are not reported during the normal build
process.For more background information and a use case, read through this
thread: http://marc.info/?l=kernel-janitors&m=129802065918147&w=2Cc: Michal Marek
Cc: linux-kbuild@vger.kernel.org
Acked-by: Sam Ravnborg
Acked-by: Ingo Molnar
Signed-off-by: Borislav Petkov
Signed-off-by: Michal Marek
19 Nov, 2010
1 commit
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cmd_record_mcount is used to locate the _mcount symbols in the object
files, only the files compiled with -pg has the _mcount symbol, so, it
is only needed for such files, but the current cmd_record_mcount is used
for all of the object files, so, we need to fix it and speed it up.Since -pg may be removed by the method used in kernel/trace/Makefile:
ORIG_CFLAGS := $(KBUILD_CFLAGS)
KBUILD_CFLAGS = $(subst -pg,,$(ORIG_CFLAGS))Or may be removed by the method used in arch/x86/kernel/Makefile:
CFLAGS_REMOVE_file.o = -pg
So, we must check the last variable stores the compiling flags, that is
c_flags(Please refer to cmd_cc_o_c and rule_cc_o_c defined in
scripts/Makefile.build) and since the CFLAGS_REMOVE_file.o is already
filtered in _c_flags(Please refer to scripts/Makefile.lib) and _c_flags
has less symbols, therefore, we only need to check _c_flags.---------------
Changes from v1:o Don't touch Makefile for CONFIG_FTRACE_MCOUNT_RECORD is enough
o Use _c_flags intead of KBUILD_CFLAGS to cover CONFIG_REMOVE_file.o = -pg
(feedback from Steven Rostedt )Acked-by: Michal Marek
Signed-off-by: Wu Zhangjin
LKML-Reference:[ changed if [ .. == .. ] to if [ .. = .. ] to handle dash environments ]
Signed-off-by: Steven Rostedt
22 Oct, 2010
1 commit
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* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (278 commits)
arm: remove machine_desc.io_pg_offst and .phys_io
arm: use addruart macro to establish debug mappings
arm: return both physical and virtual addresses from addruart
arm/debug: consolidate addruart macros for CONFIG_DEBUG_ICEDCC
ARM: make struct machine_desc definition coherent with its comment
eukrea_mbimxsd-baseboard: Pass the correct GPIO to gpio_free
cpuimx27: fix compile when ULPI is selected
mach-pcm037_eet: fix compile errors
Fixing ethernet driver compilation error for i.MX31 ADS board
cpuimx51: update board support
mx5: add cpuimx51sd module and its baseboard
iomux-mx51: fix GPIO_1_xx 's IOMUX configuration
imx-esdhc: update devices registration
mx51: add resources for SD/MMC on i.MX51
iomux-mx51: fix SD1 and SD2's iomux configuration
clock-mx51: rename CLOCK1 to CLOCK_CCGR for better readability
clock-mx51: factorize clk_set_parent and clk_get_rate
eukrea_mbimxsd: add support for DVI displays
cpuimx25 & cpuimx35: fix OTG port registration in host mode
i.MX31 and i.MX35 : fix errate TLSbo65953 and ENGcm09472
...
19 Oct, 2010
1 commit
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When DYNAMIC_FTRACE is enabled and we use the C version of recordmcount,
all objects are run through the recordmcount program to create a
separate section that stores all the callers of mcount.The build process has a special file: scripts/mod/empty.o. This is
built from empty.c which is literally an empty file (except for a
single comment). This file is used to find information about the target
elf format, like endianness and word size.The problem comes up when we need to build recordmcount. The
build process requires that empty.o is built first. The build rules
for empty.o will try to execute recordmcount on the empty.o file.
We get an error that recordmcount does not exist.To avoid this recursion, the build file will skip running recordmcount
if the file that it is building is script/mod/empty.o.[ extra comment Suggested-by: Sam Ravnborg ]
Reported-by: Ingo Molnar
Tested-by: Ingo Molnar
Cc: Michal Marek
Cc: linux-kbuild@vger.kernel.org
Signed-off-by: Steven Rostedt
16 Oct, 2010
1 commit
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The C version of recordmcount is compiled to a binary, which will
end up located in the objtree. If the kernel is built with O=path,
the srctree will not include the binary recordmcount caller.Cc: Michal Marek
Cc: linux-kbuild@vger.kernel.org
Signed-off-by: Steven Rostedt
15 Oct, 2010
1 commit
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This patch adds the support for the C version of recordmcount and
compile times show ~ 12% improvement.After verifying this works, other archs can add:
HAVE_C_MCOUNT_RECORD
in its Kconfig and it will use the C version of recordmcount
instead of the perl version.Cc:
Cc: Michal Marek
Cc: linux-kbuild@vger.kernel.org
Cc: John Reiser
Signed-off-by: Steven Rostedt
02 Sep, 2010
1 commit
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On ARM, we have two ABIs, and the ABI used is controlled via a config
option. Object files built with one ABI can't be merged with object
files built with the other ABI. So, record_mcount.pl needs to use the
same compiler flags as the kernel when generating the object file with
the mcount locations. Ensure this by passing CFLAGS to the script.Acked-by: Steven Rostedt
Signed-off-by: Rabin Vincent
Signed-off-by: Russell King
03 Aug, 2010
1 commit
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It is now possible to assign options to AS and CC
on the command line - which is only used for built-in code.{A,C}FLAGS_KERNEL was used both in the top-level Makefile
in the arch makefiles, thus users had no way to specify
additional options to AS, CC without overriding
the original value.Introduce a new set of variables KBUILD_{A,C}FLAGS_KERNEL
that is used by arch specific files and free up
{A,C}FLAGS_KERNEL so they can be assigned on
the command line.All arch Makefiles that used the old variables has been updated.
Signed-off-by: Sam Ravnborg
Cc: Tony Luck
Cc: Hirokazu Takata
Signed-off-by: Michal Marek