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>
Underscores in symbol names are translated into slashes for path names.
Filesystems treat consecutive slashes as if there was only one, so
let's do the same in the dependency list for easier grepping, etc.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
The idea of using fixdep was inspired by Kconfig, but autoksyms
belongs to a different group. So, I want to move those touched
files under include/config/ksym/ to include/ksym/.
The directory include/ksym/ can be removed by 'make clean' because
it is meaningless for the external module building.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
kconfig.h was excluded from consideration by fixdep by
6a5be57f0f (fixdep: fix extraneous dependencies) to avoid some false
positive hits
(1) include/config/.h
(2) include/config/h.h
(3) include/config/foo.h
(1) occurred because kconfig.h contains the string CONFIG_ in a
comment. However, since dee81e9886 (fixdep: faster CONFIG_ search), we
have a check that the part after CONFIG_ is non-empty, so this does not
happen anymore (and CONFIG_ appears by itself elsewhere, so that check
is worthwhile).
(2) comes from the include guard, __LINUX_KCONFIG_H. But with the
previous patch, we no longer match that either.
That leaves (3), which amounts to one [1] false dependency (aka stat() call
done by make), which I think we can live with:
We've already had one case [2] where the lack of include/linux/kconfig.h in
the .o.cmd file caused a missing rebuild, and while I originally thought
we should just put kconfig.h in the dependency list without parsing it
for the CONFIG_ pattern, we actually do have some real CONFIG_ symbols
mentioned in it, and one can imagine some translation unit that just
does '#ifdef __BIG_ENDIAN' but doesn't through some other header
actually depend on CONFIG_CPU_BIG_ENDIAN - so changing the target
endianness could end up rebuilding the world, minus that small
TU. Quoting Linus,
... when missing dependencies cause a missed re-compile, the resulting
bugs can be _really_ subtle.
[1] well, two, we now also have CONFIG_BOOGER/booger.h - we could change
that to FOO if we care
[2] https://lkml.org/lkml/2018/2/22/838
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
The string CONFIG_ quite often appears after other alphanumerics,
meaning that that instance cannot be referencing a Kconfig
symbol. Omitting these means make has fewer files to stat() when
deciding what needs to be rebuilt - for a defconfig build, this seems to
remove about 2% of the (wildcard ...) lines from the .o.cmd files.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
uml-config.h hasn't existed in this decade (87e299e5c7 - x86, um: get
rid of uml-config.h). The few remaining UML_CONFIG instances are defined
directly in terms of their real CONFIG symbol in common-offsets.h, so
unlike when the symbols got defined via a sed script, anything that uses
UML_CONFIG_FOO now should also automatically pick up a dependency on
CONFIG_FOO via the normal fixdep mechanism (since common-offsets.h
should at least recursively be a dependency). Hence I believe we should
actually be able to ignore the HELLO_CONFIG_BOOM cases.
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Richard Weinberger <richard@nod.at>
Cc: user-mode-linux-devel@lists.sourceforge.net
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
str_ends_with() tests if the given token ends with a particular string.
Currently, it is used to check file paths without $(srctree).
Actually, we have one more place where this helper is useful. Use it
to check if CONFIG option ends with _MODULE.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
parse_dep_file() has too much indentation, and puts the code far to
the right. This commit refactors the code and reduces the one level
of indentation.
strrcmp() computes 'slen' by itself, but the caller already knows the
length of the token, so 'slen' can be passed via function argument.
With this, we can swap the order of strrcmp() and "*p = \0;"
Also, strrcmp() is an ambiguous function name. Flip the logic and
rename it to str_ends_with().
I added a new helper is_ignored_file() - this returns 1 if the token
represents a file that should be ignored.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
I do not mind global variables where they are useful enough. In this
case, I do not see a good reason to use global variables since they
are just referenced in shallow places. It is easy to pass them via
function arguments.
I squashed print_cmdline() into main() since it is just one line code.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Each token in the depfile is copied to the temporary buffer 's' to
terminate the token with zero. We do not need to do this any more
because the parsed buffer is now writable. Insert '\0' directly in
the buffer without calling memcpy().
<limits.h> is no longer necessary. (It was needed for PATH_MAX).
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Now, do_config_files() and print_deps() are almost the same. Only
the difference is the parser function called (parse_config_file vs
parse_dep_file).
We can reduce the code duplication by factoring out the common code
into read_file() - this function allocates a buffer and loads a file
to it. It returns the pointer to the allocated buffer. (As before,
it bails out by exit(2) for any error.) The caller must free the
buffer when done.
Having empty source files is possible; fixdep should simply skip them.
I deleted the "st.st_size == 0" check, so read_file() allocates 1-byte
buffer for an empty file. strstr() will immediately return NULL, and
this is what we expect.
On the other hand, an empty dep_file should be treated as an error.
In this case, parse_dep_file() will error out with "no targets found"
and it is a correct error message.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Commit dee81e9886 ("fixdep: faster CONFIG_ search") changed how to
read files in which CONFIG options are searched. It used malloc()
and read() instead of mmap() because it needed to zero-terminate the
buffer in order to use strstr(). print_deps() was left untouched
since there was no reason to change it.
Now, I have two motivations to change it in the same way.
- do_config_file() and print_deps() do quite similar things; they
open a file, load it onto memory, and pass it to a parser function.
If we use malloc() and read() for print_deps() too, we can factor
out the common code. (I will do this in the next commit.)
- parse_dep_file() copies each token to a temporary buffer because
it needs to zero-terminate it to be passed to printf(). It is not
possible to modify the buffer directly because it is mmap'ed with
O_RDONLY. If we load the file content into a malloc'ed buffer, we
can insert '\0' after each token, and save memcpy(). (I will do
this in the commit after next.)
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
<arpa/inet.h> was included for ntohl(), but it was removed by
commit dee81e9886 ("fixdep: faster CONFIG_ search").
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
do_config_file() should exit with an error code on internal run-time
errors, and not return if it fails as then the error in do_config_file()
would go unnoticed in the current code and allow the build to continue.
The exit with error code will make the build fail in those very
exceptional cases. If this occurs, this actually indicates a deeper
problem in the execution of the kernel build process.
Now, in these error cases, we do not explicitly free memory and close
the file handlers in do_config_file(), as this is covered by exit().
This issue in the fixdep script was introduced with its initial
implementation back in 2002 by the original author Kai Germaschewski with
this commit 04bd72170653 ("kbuild: Make dependencies at compile time")
in the linux history git tree, i.e.,
git://git.kernel.org/pub/scm/linux/kernel/git/history/history.git.
This issue was identified during the review of a previous patch that
intended to address a memory leak detected by a static analysis tool.
Link: https://lkml.org/lkml/2017/12/14/736
Suggested-by: Nicholas Mc Guire <der.herr@hofr.at>
Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Do you think kernel build is 100% dominated by gcc? You are wrong!
One small utility called "fixdep" consistently manages to sneak into
profile's first page (unless you have small monitor of course).
The choke point is this clever code:
for (; m < end; m++) {
if (*m == INT_CONF) { p = (char *) m ; goto conf; }
if (*m == INT_ONFI) { p = (char *) m-1; goto conf; }
if (*m == INT_NFIG) { p = (char *) m-2; goto conf; }
if (*m == INT_FIG_) { p = (char *) m-3; goto conf; }
4 branches per 4 characters is not fast.
Use strstr(3), so that SSE2 etc can be used.
With this patch, fixdep is so deep at the bottom, it is hard to find it.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
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>
Coverity has recently added a check that will find when we don't check
the return code from fstat(2). Copy/paste the checking logic that
print_deps() has with an appropriate re-wording of the perror() message.
Signed-off-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
strrcmp only performs read access to the memory addressed by its
arguments so make them const pointers.
Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Signed-off-by: Michal Marek <mmarek@suse.com>
The clear_config() is called just once at the beginning of this
program, but the global variable hashtab[] is already zero-filled
at the start-up.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
If the target string matches "CONFIG_", move the pointer p
forward. This saves several 7-chars adjustments.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
The current use-case for fixdep is: a source file is run through a single
processing step, which creates a single dependency file as a side-effect,
which fixdep transforms into the file used by the kernel build process.
In order to transparently run the C pre-processor on device-tree files,
we wish to run both gcc -E and dtc on a source file in a single rule.
This generates two dependency files, which must be transformed together
into the file used by the kernel build process. This change modifies
fixdep so it can process the concatenation of multiple separate input
dependency files, and produce a correct unified output.
The code changes have the slight benefit of transforming the loop in
parse_dep_file() into more of a lexer/tokenizer, with the loop body being
more of a parser. Previously, some of this logic was mixed together
before the loop. I also added some comments, which I hope are useful.
Benchmarking shows that on a cross-compiled ARM tegra_defconfig build,
there is less than 0.5 seconds speed decrease with this change, on top
of a build time of ~2m24s. This is probably within the noise.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Rob Herring <rob.herring@calxeda.com>
The introduction of include/linux/kconfig.h created 3 extraneous
dependencies:
include/config/.h
include/config/h.h
include/config/foo.h
Fix this by excluding kconfig.h from fixdep calculations.
Signed-off-by: Peter Foley <pefoley2@verizon.net>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Recent change to fixdep:
commit b7bd182176
Author: Michal Marek <mmarek@suse.cz>
Date: Thu Feb 17 15:13:54 2011 +0100
fixdep: Do not record dependency on the source file itself
changed the format of the *.cmd files without realizing that it is also
used by modpost. Put the path to the source file to the file back, in a
special variable, so that modpost sees all source files when calculating
srcversion for modules.
Reported-and-tested-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The dependency is already expressed by the Makefiles, storing it in the
.cmd file breaks build if a .c file is replaced by .S or vice versa,
because the .cmd file contains
foo/bar.o: foo/bar.c ...
foo/bar.c ... :
so the foo/bar.c -> foo/bar.o rule triggers even if there is no
foo/bar.c anymore.
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michal Marek <mmarek@suse.cz>
I noticed fixdep uses ~2% of cpu time in kernel build, in function
use_config()
fixdep spends a lot of cpu cycles in linear searches in its internal
string array. With about 400 stored strings per dep file, this begins to
be noticeable.
Convert fixdep to use a hash table.
kbuild results on my x86_64 allmodconfig
Before patch :
real 10m30.414s
user 61m51.456s
sys 8m28.200s
real 10m12.334s
user 61m50.236s
sys 8m30.448s
real 10m42.947s
user 61m50.028s
sys 8m32.380s
After:
real 10m8.180s
user 61m22.506s
sys 8m32.384s
real 10m35.039s
user 61m21.654s
sys 8m32.212s
real 10m14.487s
user 61m23.498s
sys 8m32.312s
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-next: (30 commits)
Use macros for .data.page_aligned section.
Use macros for .bss.page_aligned section.
Use new __init_task_data macro in arch init_task.c files.
kbuild: Don't define ALIGN and ENTRY when preprocessing linker scripts.
arm, cris, mips, sparc, powerpc, um, xtensa: fix build with bash 4.0
kbuild: add static to prototypes
kbuild: fail build if recordmcount.pl fails
kbuild: set -fconserve-stack option for gcc 4.5
kbuild: echo the record_mcount command
gconfig: disable "typeahead find" search in treeviews
kbuild: fix cc1 options check to ensure we do not use -fPIC when compiling
checkincludes.pl: add option to remove duplicates in place
markup_oops: use modinfo to avoid confusion with underscored module names
checkincludes.pl: provide usage helper
checkincludes.pl: close file as soon as we're done with it
ctags: usability fix
kernel hacking: move STRIP_ASM_SYMS from General
gitignore usr/initramfs_data.cpio.bz2 and usr/initramfs_data.cpio.lzma
kbuild: Check if linker supports the -X option
kbuild: introduce ld-option
...
Fix trivial conflict in scripts/basic/fixdep.c
Ignore drivers/staging/ since it is very likely that new drivers
introduce it again.
Signed-off-by: Markus Heidelberg <markus.heidelberg@web.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Warnings found via gcc -Wmissing-prototypes.
Signed-off-by: Trevor Keith <tsrk@tsrk.net>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
gcc-4.4.1:
HOSTCC scripts/basic/fixdep
scripts/basic/fixdep.c: In function 'traps':
scripts/basic/fixdep.c:377: warning: dereferencing type-punned pointer will break strict-aliasing rules
scripts/basic/fixdep.c:379: warning: dereferencing type-punned pointer will break strict-aliasing rules
(Apparently -fno-strict-aliasing will fix this too)
Signed-off-by: WANG Cong <amwang@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
build scripts: fixdep blows segfault on string CONFIG_MODULE seen
The string "CONFIG_MODULE" appearing anywhere in a source file causes
fixdep to segfault. This string appeared in the wild in the current
mISDN sources (I think they meant CONFIG_MODULES). But it shouldn't
segfault (esp as CONFIG_MODULE appeared in a quoted string).
Signed-off-by: Andy Green <andy@warmcat.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Commit 2e3646e51b changed the way the
split config tree is built, but failed to also adjust fixdep accordingly
- if changing a config option from or to m, files referencing the
respective CONFIG_..._MODULE (but not the corresponding CONFIG_...)
didn't get rebuilt.
The problem is that trisate symbol are represent with three different
symbols:
SYMBOL=n => no symbol defined
SYMBOL=y => CONFIG_SYMBOL defined to '1'
SYMBOL=m => CONFIG_SYMBOL_MODULE defined to '1'
But conf_split_config do not distingush between the =y and =m case, so
only the =y case is honoured.
This is fixed in fixdep so when a CONFIG symbol with _MODULE is found we
skip that part and only look for the CONFIG_SYMBOL version.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While the recent change to also escape # symbols when storing C-file
compilation command lines was helpful, it should be in effect for all
command lines, as much as the dollar escaping should be in effect for
C-source compilation commands. Additionally, for better readability and
maintenance, consolidating all the escaping (single quotes, dollars,
and now sharps) was also desirable.
Signed-Off-By: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Commandlines are contained in the .<target>.cmd files and in case they
contain a '#' char make see this as start of comment.
Teach fixdep to escape the '#' char so make will assing the full commandline.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
scripts/ is full of mismatches between char* params an signed char* arguments,
and viceversa. gcc4 now complaints loud about this. Patch below deletes all
those 'signed'.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Masahiro Yamada