Commit graph

51 commits

Author SHA1 Message Date
Michal Marek
164f0d2efa kbuild: Fix handling of backslashes in *.cmd files
Commit c353acba ("kbuild: make: fix if_changed when command contains
backslashes") attempted to handle backslashes in *.cmd files, but it
only handled double backslashes for some reason. Changing make-cmd to also
handle single backslashes fixes rebuilds with dash, but it breaks bash
again. The reason is that the two shells disagree about the
interpretation of backslash sequences in the echo builtin. The way out
of this is to print the command with printf '%s\n'. While at it,
document what the individual parts of make-cmd do and why.

Reported-and-tested-by: Konstantin Khlebnikov <koct9i@gmail.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2014-08-07 21:53:20 +02:00
Linus Torvalds
b003d7706a Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kbuild changes from Michal Marek:
 - cleanups in the main Makefiles and Documentation/DocBook/Makefile
 - make O=...  directory is automatically created if needed
 - mrproper/distclean removes the old include/linux/version.h to make
   life easier when bisecting across the commit that moved the version.h
   file

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kbuild: docbook: fix the include error when executing "make help"
  kbuild: create a build directory automatically for out-of-tree build
  kbuild: remove redundant '.*.cmd' pattern from make distclean
  kbuild: move "quote" to Kbuild.include to be consistent
  kbuild: docbook: use $(obj) and $(src) rather than specific path
  kbuild: unconditionally clobber include/linux/version.h on distclean
  kbuild: docbook: specify KERNELDOC dependency correctly
  kbuild: docbook: include cmd files more simply
  kbuild: specify build_docproc as a phony target
2014-04-07 17:52:31 -07:00
Masahiro Yamada
13338935f1 kbuild: move "quote" to Kbuild.include to be consistent
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2014-03-29 22:03:55 +01:00
Andi Kleen
ccbef1674a Kbuild, lto: add ld-version and ld-ifversion macros
To check the linker version. Used by the LTO makefile.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1391846481-31491-9-git-send-email-ak@linux.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-02-13 20:25:00 -08:00
Antony Pavlov
5b83df2b46 kbuild: fix ld-option function
The kbuild's ld-option function is broken because
the command
  $(CC) /dev/null -c -o "$$TMPO"
does not create object file!

I have used a relatively old mips gcc 3.4.6 cross-compiler
and a relatively new gcc 4.7.2 to check this fact
but the results are the same.

EXAMPLE:
  $ rm /tmp/1.o
  $ mips-linux-gcc /dev/null -c -o /tmp/1.o
  mips-linux-gcc: /dev/null: linker input file unused because linking not done
  $ ls -la /tmp/1.o
  ls: cannot access /tmp/1.o: No such file or directory

We can easily fix the problem by adding
the '-x c' compiler option.

EXAMPLE:
  $ rm /tmp/1.o
  $ mips-linux-gcc -x c /dev/null -c -o /tmp/1.o
  $ ls -la /tmp/1.o
  -rw-r--r-- 1 antony antony 778 Apr  2 20:40 /tmp/1.o

Also fix wrong ld-option example.

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2013-04-08 11:47:41 +02:00
Linus Torvalds
d43b7167d4 Merge branch 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kbuild fixes from Michal Marek:
 "Here are two fixes I intended to send after v3.6-rc7, but failed to do
  so.  So please pull them for v3.7-rc1 and they will be picked up by
  stable.

  The first one fixes gcc -x <language> syntax in various build-time
  tests, which icecream and possible other gcc wrappers did not
  understand (and yes, icecream is going to be fixed as well).

  The second one fixes make tar-pkg so that unpacking the tarball does
  not replace the /lib -> /usr/lib symlink on recent Fedora releases."

* 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kbuild: Fix gcc -x syntax
  kbuild: Do not package /boot and /lib in make tar-pkg
2012-10-08 07:56:10 +09:00
Sascha Hauer
c353acba28 kbuild: make: fix if_changed when command contains backslashes
The call if_changed mechanism does not work when the command contains
backslashes.  This basically is an issue with lzo and bzip2 compressed
kernels.  The compressed binaries do not contain the uncompressed image
size, so these use size_append to append the size.  This results in
backslashes in the executed command.  With this if_changed always
detects a change in the command and rebuilds the compressed image even
if nothing has changed.

Fix this by escaping backslashes in make-cmd

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Jan Luebbe <jlu@pengutronix.de>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Bernhard Walle <bernhard@bwalle.de>
Cc: Michal Marek <mmarek@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-06 03:04:36 +09:00
Jean Delvare
b1e0d8b70f kbuild: Fix gcc -x syntax
The correct syntax for gcc -x is "gcc -x assembler", not
"gcc -xassembler". Even though the latter happens to work, the former
is what is documented in the manual page and thus what gcc wrappers
such as icecream do expect.

This isn't a cosmetic change. The missing space prevents icecream from
recognizing compilation tasks it can't handle, leading to silent kernel
miscompilations.

Besides me, credits go to Michael Matz and Dirk Mueller for
investigating the miscompilation issue and tracking it down to this
incorrect -x parameter syntax.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Cc: Bernhard Walle <bernhard@bwalle.de>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2012-10-03 09:03:24 +02:00
Bernhard Walle
875de98623 scripts/Kbuild.include: Fix portability problem of "echo -e"
"echo -e" is a GNU extension. When cross-compiling the kernel on a
BSD-like operating system (Mac OS X in my case), this doesn't work.

One could install a GNU version of echo, put that in the $PATH before
the system echo and use "/usr/bin/env echo", but the solution with
printf is simpler.

Since it is no disadvantage on Linux, I hope that gets accepted even if
cross-compiling the Linux kernel on another Unix operating system is
quite a rare use case.

Signed-off-by: Bernhard Walle <bernhard@bwalle.de>
Andreas Bießmann <andreas@biessmann.de>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2012-03-24 23:32:05 +01:00
Arnaud Lacombe
e0318d85be kbuild: add `baseprereq'
On the same model as `basetarget', it represents the filename of first
prerequisite with directory and extension stripped.

Signed-off-by: Arnaud Lacombe <lacombar@gmail.com>
2011-06-09 14:04:38 -04:00
Michal Marek
c4d5ee1398 kbuild: make KBUILD_NOCMDDEP=1 handle empty built-in.o
Based on a patch by Rabin Vincent.

Fix building with KBUILD_NOCMDDEP=1, which currently does not work
because it does not build built-in.o with no dependencies:

  LD      fs/notify/built-in.o
ld: cannot find fs/notify/dnotify/built-in.o: No such file or directory
ld: cannot find fs/notify/inotify/built-in.o: No such file or directory
ld: cannot find fs/notify/fanotify/built-in.o: No such file or directory

Reported-and-tested-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2011-05-16 16:39:28 +02:00
Michal Marek
8417da6f21 kbuild: Fix passing -Wno-* options to gcc 4.4+
Starting with 4.4, gcc will happily accept -Wno-<anything> in the
cc-option test and complain later when compiling a file that has some
other warning. This rather unexpected behavior is intentional as per
http://gcc.gnu.org/PR28322, so work around it by testing for support of
the opposite option (without the no-). Introduce a new Makefile function
cc-disable-warning that does this and update two uses of cc-option in
the toplevel Makefile.

Reported-and-tested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2011-05-03 10:50:54 +02:00
Michal Marek
40df759e2b kbuild: Fix build with binutils <= 2.19
The D option of ar is only available in newer versions.

Signed-off-by: Michal Marek <mmarek@suse.cz>
2011-04-20 15:39:22 +02:00
Michal Marek
bc081dd6e9 kbuild: generate modules.builtin
To make it easier for module-init-tools and scripts like mkinitrd to
distinguish builtin and missing modules, install a modules.builtin file
listing all builtin modules. This is done by generating an additional
config file (tristate.conf) with tristate options set to uppercase 'Y'
or 'M'. If we source that config file, the builtin modules appear in
obj-Y.

Signed-off-by: Michal Marek <mmarek@suse.cz>
2009-12-12 13:08:16 +01:00
Amerigo Wang
a3ee9470e6 kbuild,scripts: use non-builtin echo for '-e'
Alek reported that on Ubuntu, where dash is used, 'echo -e'
can't work, so let's use non-builtin echo in this case.

Reported-by: Alek Du <alek.du@intel.com>
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2009-10-11 23:21:25 +02:00
Jory A. Pratt
c47efe5548 kbuild: fix cc1 options check to ensure we do not use -fPIC when compiling
The arch/*/boot/Makefile use cc-options to check for GCC command options
and cc-options use the hardened specs when checking for GCC command
options.  When -fPIE is pass to cc1 it can't use -ffreestanding or
-fno-toplevel-reorder.  Then it fail to build stuff with -ffreestanding
and -fno-toplevel-reorder.

Thanks to Fredric Johansson for finding the main problem behind a failed
build using a hardened toolchain.

Signed-off-by: Magnus Granberg <zorry@ume.nu>
Signed-off-by: Jory A. Pratt <anarchy@gentoo.org>
Cc: Fredric Johansson <johansson_fredric@hotmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@kernel.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2009-09-20 12:27:43 +02:00
Sam Ravnborg
691ef3e7fd kbuild: introduce ld-option
ld-option is used to check if $(LD) supports a specific option.

Based on patch from Andi Kleen.

Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
First use is to check if option -X is supported (upcoming patch).
Theis is ne
2009-09-20 12:27:42 +02:00
Sam Ravnborg
f86fd30660 kbuild: rename ld-option to cc-ldoption
ld-option is misnamed as it test options to gcc, not to ld.
Renamed it to reflect this.

Cc: Andi Kleen <andi@firstfloor.org>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2009-09-20 12:27:42 +02:00
Mike Frysinger
fd54f50284 kbuild: use KECHO convenience echo
Convert a few echos in the build system to new $(kecho) so we get correct
output according to build verbosity.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
[sam: added kecho in a few more places for O=... builds]
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-12-03 21:32:01 +01:00
Mike Frysinger
5410ecc0de kbuild: introduce $(kecho) convenience echo
There is a bunch of places in the build system where we do 'echo' to show
some nice status lines.  This means we still get output when running in
silent mode.  So declare a new KECHO variable that only does 'echo' when we
are in a suitable verbose build mode.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
[sam: added Documentation]
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-12-03 21:32:00 +01:00
Sam Ravnborg
5b91c33cf2 kbuild: fix -I option expansion with O=... builds
When adding extra -I options with O=... we could
end up in a situation where there were no parameters to -I.
So we had a commandline that looked like this:

    ... -I -Wall ...

This had the undesired side effect that gcc assumed "-Wall"
was a path to look for include files so this options was
effectively ignored.

This happens only when we build the generated module.mod.c files
as part of the final modules builds and is as such harmless
with current kbuild.
This bug was exposed when we rearranged the options to gcc.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-12-03 21:22:21 +01:00
H. Peter Anvin
43789e2163 kbuild: fix cc-option and cc-option-yn
David Sanders wrote:

> I'm getting this error:
> as: unrecognized option `-mtune=generic32'
> I have binutils 2.17.

Use -c instead of -S in cc-option and cc-option-yn, so we can probe
options related to the assembler.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: kbuild devel <kbuild-devel@lists.sourceforge.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-09 11:52:33 -07:00
Sam Ravnborg
fab1e310d3 kbuild: fix make V=1
When make -s support were added to filechk to
combination created with make V=1 were not
covered.
Fix it by explicitly cover this case too.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Mike Frysinger <vapier@gentoo.org>
2008-02-11 17:43:54 +01:00
Mike Frysinger
d75f4c683f kbuild: silence CHK/UPD messages according to $(quiet)
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-02-09 10:43:58 +01:00
Sam Ravnborg
910b40468a kbuild: introduce cc-cross-prefix
cc-cross-prefix is useful for the architecture that like
to provide a default CROSS_COMPILE value,
but may have several to select between.

Sample usage:

ifneq ($(SUBARCH),$(ARCH))
        ifeq ($(CROSS_COMPILE),)
               CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-)
        endif
endif

Actual usage by the different archs will taken care of later.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2007-10-19 21:46:01 +02:00
Sam Ravnborg
222d394d30 kbuild: enable 'make AFLAGS=...' to add additional options to AS
The variable AFLAGS is a wellknown variable and the usage by
kbuild may result in unexpected behaviour.
On top of that several people over time has asked for a way to
pass in additional flags to gcc.

This patch replace use of AFLAGS with KBUILD_AFLAGS all over
the tree.

Patch was tested on following architectures:
alpha, arm, i386, x86_64, mips, sparc, sparc64, ia64, m68k, s390

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2007-10-15 21:59:31 +02:00
Sam Ravnborg
a0f97e06a4 kbuild: enable 'make CFLAGS=...' to add additional options to CC
The variable CFLAGS is a wellknown variable and the usage by
kbuild may result in unexpected behaviour.
On top of that several people over time has asked for a way to
pass in additional flags to gcc.

This patch replace use of CFLAGS with KBUILD_CFLAGS all over the
tree and enabling one to use:
make CFLAGS=...
to specify additional gcc commandline options.

One usecase is when trying to find gcc bugs but other
use cases has been requested too.

Patch was tested on following architectures:
alpha, arm, i386, x86_64, mips, sparc, sparc64, ia64, m68k

Test was simple to do a defconfig build, apply the patch and check
that nothing got rebuild.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2007-10-14 22:21:35 +02:00
Segher Boessenkool
0ab2a272e6 kbuild: New 'cc-fullversion' macro
Prints a six-digit string including the GCC patchlevel.  Also fix
the 'usage' comment for cc-version.

Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2007-07-16 21:15:47 +02:00
Roman Zippel
beda9f3a13 [PATCH] kbuild: more Makefile cleanups
This adds the remaining changes which should have been part of the
review process.

 - the define command is inappropriate (it's primarily for rule
   definitions)
 - execute commands in the current dir as all other commands
 - .*.tmp (but not .*.null) files are also removed up by "make clean"
 - printf has other side effects, just use "echo -e"
 - proper quoting
 - proper indentation

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-09 10:12:20 -08:00
Linus Torvalds
b892afd1e6 kbuild: fix space for good (take 103)
Michal Ostrowski points out what the real problem was: the spaces at the
start of the definition of the 'checker-shell' make function.

Cc: Michal Ostrowski <mostrows@watson.ibm.com>
Acked-by: David Miller <davem@davemloft.net>
Acked-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Acked-by: Oleg Verych <olecom@flower.upol.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-08 08:16:44 -08:00
Linus Torvalds
c4184f117a kbuild: make $(checker-shell ) strip spaces around the result
It looks like GNU make version 3.80 (but apparently not 3.81) adds
leading whitespace to the result of the checker-shell execution.  This
strips them off explicitly.

Also, don't bother symlinking the output file to /dev/null.  It's likely
as expensive as just writing the temp-file, and we need to remove it
anyway afterwards.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-07 20:24:25 -08:00
Oleg Verych
bff288c19e [PATCH] kbuild, Kbuild.include: avoid using spaces in call arguments
Do not use whitespace in arguments of functions in makefiles, as they
propagate further without notice.  Thus we get

  + echo ' y'

  instead of

  + echo y

Fix misleading comments.

Signed-off-by: Oleg Verych <olecom@flower.upol.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-07 15:32:26 -08:00
Oleg Verych
5de043f4bd [PATCH] kbuild: improve option checking, Kbuild.include cleanup
GNU binutils, root users, tmpfiles, external modules ro builds must
 be fixed to do the right thing now.

Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Horst Schirmeier <horst@schirmeier.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Daniel Drake <dsd@gentoo.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Oleg Verych <olecom@flower.upol.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-06 14:30:49 -08:00
Roman Zippel
347a00fb4a [PATCH] kbuild: don't put temp files in source
The as-instr/ld-option need to create temporary files, but create them in the
output directory, when compiling external modules.  Reformat them a bit and
use $(CC) instead of $(AS) as the former is used by kbuild to assemble files.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: <jpdenheijer@gmail.com>
Cc: Horst Schirmeier <horst@schirmeier.com>
Cc: Daniel Drake <dsd@gentoo.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 09:55:39 -08:00
Jan Beulich
adf1423698 [PATCH] i386/x86-64: Work around gcc bug with noreturn functions in unwinder
Current gcc generates calls not jumps to noreturn functions. When that happens the
return address can point to the next function, which confuses the unwinder.

This patch works around it by marking asynchronous exception
frames in contrast normal call frames in the unwind information.  Then teach
the unwinder to decode this.

For normal call frames the unwinder now subtracts one from the address which avoids
this problem.  The standard libgcc unwinder uses the same trick.

It doesn't include adjustment of the printed address (i.e. for the original
example, it'd still be kernel_math_error+0 that gets displayed, but the
unwinder wouldn't get confused anymore.

This only works with binutils 2.6.17+ and some versions of H.J.Lu's 2.6.16
unfortunately because earlier binutils don't support .cfi_signal_frame

[AK: added automatic detection of the new binutils and wrote description]

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:41 +02:00
Andi Kleen
e2414910f2 [PATCH] x86: Detect CFI support in the assembler at runtime
... instead of using a CONFIG option. The config option still controls
if the resulting executable actually has unwind information.

This is useful to prevent compilation errors when users select
CONFIG_STACK_UNWIND on old binutils and also allows to use
CFI in the future for non kernel debugging applications.

Cc: jbeulich@novell.com
Cc: sam@ravnborg.org

Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:30 +02:00
Sam Ravnborg
45d506bd65 kbuild: make V=2 tell why a target is rebuild
tell why a a target got build
   enabled by make V=2
      Output (listed in the order they are checked):
         (1) - due to target is PHONY
         (2) - due to target missing
         (3) - due to: file1.h file2.h
         (4) - due to command line change
         (5) - due to missing .cmd file
         (6) - due to target not in $(targets)
(1) We always build PHONY targets
(2) No target, so we better build it
(3) Prerequisite is newer than target
(4) The command line stored in the file named dir/.target.cmd
    differed from actual command line. This happens when compiler
    options changes
(5) No dir/.target.cmd file (used to store command line)
(6) No dir/.target.cmd file and target not listed in $(targets)
    This is a good hint that there is a bug in the kbuild file

This patch is inspired by a patch from: Milton Miller <miltonm@bga.com>

Cc: Milton Miller <miltonm@bga.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2006-09-25 09:01:49 +02:00
Sam Ravnborg
48f1f0589d kbuild: consistently decide when to rebuild a target
Consistently decide when to rebuild a target across all of
if_changed, if_changed_dep, if_changed_rule.
PHONY targets are now treated alike (ignored) for all targets

While add it make Kbuild.include almost readable by factoring out a few
bits to some common variables and reuse this in Makefile.build.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2006-09-25 09:00:00 +02:00
Sam Ravnborg
8eb3afe0e9 kbuild: always use $(CC) for $(call cc-version)
The possibility to specify an optional parameter did not work out as
expected and it was not used - so remove the possibility.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2006-08-01 11:32:47 +02:00
Roland McGrath
0b0bf7a3cc [PATCH] vDSO hash-style fix
The latest toolchains can produce a new ELF section in DSOs and
dynamically-linked executables.  The new section ".gnu.hash" replaces
".hash", and allows for more efficient runtime symbol lookups by the
dynamic linker.  The new ld option --hash-style={sysv|gnu|both} controls
whether to produce the old ".hash", the new ".gnu.hash", or both.  In some
new systems such as Fedora Core 6, gcc by default passes --hash-style=gnu
to the linker, so that a standard invocation of "gcc -shared" results in
producing a DSO with only ".gnu.hash".  The new ".gnu.hash" sections need
to be dealt with the same way as ".hash" sections in all respects; only the
dynamic linker cares about their contents.  To work with older dynamic
linkers (i.e.  preexisting releases of glibc), a binary must have the old
".hash" section.  The --hash-style=both option produces binaries that a new
dynamic linker can use more efficiently, but an old dynamic linker can
still handle.

The new section runs afoul of the custom linker scripts used to build vDSO
images for the kernel.  On ia64, the failure mode for this is a boot-time
panic because the vDSO's PT_IA_64_UNWIND segment winds up ill-formed.

This patch addresses the problem in two ways.

First, it mentions ".gnu.hash" in all the linker scripts alongside ".hash".
 This produces correct vDSO images with --hash-style=sysv (or old tools),
with --hash-style=gnu, or with --hash-style=both.

Second, it passes the --hash-style=sysv option when building the vDSO
images, so that ".gnu.hash" is not actually produced.  This is the most
conservative choice for compatibility with any old userland.  There is some
concern that some ancient glibc builds (though not any known old production
system) might choke on --hash-style=both binaries.  The optimizations
provided by the new style of hash section do not really matter for a DSO
with a tiny number of symbols, as the vDSO has.  If someone wants to use
=gnu or =both for their vDSO builds and worry less about that
compatibility, just change the option and the linker script changes will
make any choice work fine.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31 13:28:43 -07:00
Sam Ravnborg
5e8d780d74 kbuild: fix ia64 breakage after introducing make -rR
kbuild used $¤(*F to get filename of target without extension.
This was used in several places all over kbuild, but introducing
make -rR broke his for all cases where we specified full path to
target/prerequsite. It is assumed that make -rR disables old style
suffix-rules which is why is suddenly failed.

ia64 was impacted by this change because several div* routines in
arch/ia64/lib are build using explicit paths and then kbuild failed.

Thanks to David Mosberger-Tang <David.Mosberger@acm.org> for an explanation
what was the root-cause and for testing on ia64.

This patch also fixes two uses of $(*F) in arch/um

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2006-07-01 09:58:02 +02:00
Linus Torvalds
d38b69689c Revert "kbuild: fix make -rR breakage"
This reverts commit e5c44fd88c.

Thanks to Daniel Ritz and Michal Piotrowski for noticing the problem.

Daniel says:

  "[The] reason is a recent change that made modules always shows as
   module.mod.  it breaks modprobe and probably many scripts..besides
   lsmod looking horrible

   stuff like this in modprobe.conf:
        install pcmcia_core /sbin/modprobe --ignore-install pcmcia_core; /sbin/modprobe pcmcia
   makes modprobe fork/exec endlessly calling itself...until oom
   interrupts it"

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 16:59:26 -07:00
Sam Ravnborg
e5c44fd88c kbuild: fix make -rR breakage
make failed to supply the filename when using make -rR and using $(*F)
to get target filename without extension.
This bug was not reproduceable in small scale but using:
$(basename $(notdir $@)) fixes it with same functionality.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2006-06-24 23:13:59 +02:00
Sam Ravnborg
d9df92e22a kbuild: properly pass options to hostcc when doing make O=..
This fix a longstanding bug where proper options was not
passed to hostcc in case of a make O=.. build.
This bug showed up in (not yet merged) klibc, and is not known
to have any counterpart in-kernel.
Fixed by moving the flags macro to Kbuild.include so it can be used
by both Makefile.lib and Makefile.host.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2006-04-07 08:36:49 +02:00
Paul Smith
4f1933620f kbuild: change kbuild to not rely on incorrect GNU make behavior
The kbuild system takes advantage of an incorrect behavior in GNU make.
Once this behavior is fixed, all files in the kernel rebuild every time,
even if nothing has changed.  This patch ensures kbuild works with both
the incorrect and correct behaviors of GNU make.

For more details on the incorrect behavior, see:

http://lists.gnu.org/archive/html/bug-make/2006-03/msg00003.html

Changes in this patch:
  - Keep all targets that are to be marked .PHONY in a variable, PHONY.
  - Add .PHONY: $(PHONY) to mark them properly.
  - Remove any $(PHONY) files from the $? list when determining whether
    targets are up-to-date or not.

Signed-off-by: Paul Smith <psmith@gnu.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2006-03-06 00:09:51 +01:00
Sam Ravnborg
9d6e7a709c kbuild: fix comment in Kbuild.include
Noted by Olaf Hering <olh@suse.de>

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2006-02-19 09:51:22 +01:00
Jan Beulich
6176aa9ae4 kbuild: consolidate command line escaping
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>
2006-02-19 09:51:21 +01:00
Sam Ravnborg
20a468b513 kbuild: make cc-version available in kbuild files
Move $(CC) support functions to Kbuild.include so they are available
in the kbuild files.
In addition the following was done:
	o as-option documented in Documentation/kbuild/makefiles.txt
	o Moved documentation to new section to match
	  new scope of functions
	o added cc-ifversion used to conditionally select a text string
	  dependent on actual $(CC) version
	o documented cc-ifversion
	o change so Kbuild.include is read before the kbuild file

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2006-02-19 09:51:20 +01:00
Sam Ravnborg
d51bfb7852 kbuild: introduce escsq to escapre single quotes
This makes things a little bit more reader friendly and gvim is less
confused.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2006-01-06 22:35:59 +01:00
Sam Ravnborg
0a504f259c kbuild: add objectify
Use foo := $(call objectify, $(foo)) to prefix $(foo) with $(obj)/ unless
$(foo) is an absolute path.
For now no in-tree users - soon to come.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2005-09-10 21:02:11 +02:00