I couldn't find an rpm for v4l2loopback so I tried to compile it on a fresh Fedora 28, but it failed :
$ LANG=en_US.utf8 make
Building v4l2-loopback driver...
make -C /lib/modules/`uname -r`/build M=/opt/v4l2loopback modules
make[1]: Entering directory '/usr/src/kernels/4.17.6-200.fc28.x86_64'
arch/x86/Makefile:184: *** Compiler lacks asm-goto support.. Stop.
make[1]: Leaving directory '/usr/src/kernels/4.17.6-200.fc28.x86_64'
make: *** [Makefile:43: v4l2loopback.ko] Error 2
I found that asm-goto has been supported since gcc 4.5, and I have 8.1.1 installed :
$ LANG=en_US.utf8 gcc -v
Using built-in specs.
COLLECT_GCC=cc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/8/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-redhat-linux
Configured with: ../configure --enable-bootstrap --enable- languages=c,c++,fortran,objc,obj-c++,ada,go,lto --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared --enable-threads=posix --enable-checking=release --enable-multilib --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-gcc-major-version-only --with-linker-hash-style=gnu --enable-plugin --enable-initfini-array --with-isl --enable-libmpx --enable-offload-targets=nvptx-none --without-cuda-driver --enable-gnu-indirect-function --enable-cet --with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux
Thread model: posix
gcc version 8.1.1 20180712 (Red Hat 8.1.1-5) (GCC)
I managed to compile the module by simply commenting the following check in /usr/src/kernels/4.17.6-200.fc28.x86_64/arch/x86/Makefile :
# ifndef CC_HAVE_ASM_GOTO
# $(error Compiler lacks asm-goto support.)
# endif
but obviously this is a dirty workaround. Yet, the Makefile CFLAGS actually had -DCC_HAVE_ASM_GOTO set. I also tried to set CC_HAV_ASM_GOTO in the Makefile but it didn't help.
What's wrong here ? Is it the Makefile, or Fedora, or am I missing something ? I lost familiarity with Makefiles…
I got the same problem. The caches of Makefile were staled/dirty.
In my case, it seems because I terminated make on the fly.
Inspired from this old patch https://lkml.org/lkml/2018/3/19/1474, I changed from the shell-cached to shell in Makefile in base dir to avoid caching and it works:
-ifeq ($(call shell-cached,$(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLAGS)), y)
+ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC) $(KBUILD_CFLAGS)), y)
Then clean to make sure we don't have bad cache:
make clean
make -j9
Related
I am currently hunting a bug using git bisect in linux staging-testing tree.
Some commits are giving following errors after I try to build them:
subcmd-util.h:58:31: error: pointer may be used after ‘realloc’ [-Werror=use-after-free]
58 | ret = realloc(ptr, 1);
check.c:2867:58: error: ‘%d’ directive output may be truncated writing between 1 and 10 bytes into a region of size 9 [-Werror=format-truncation=]
2867 | snprintf(pvname, sizeof(pvname), "pv_ops[%d]", idx);
I tried adding -Wno-error=use-after-free to KBUILD_FLAGS in main Makefile, tried adding
KBUILD_CFLAGS += $(call cc-disable-warning, use-after-free)
I even tried removing -Werror from CFLAGS in Makefile in folder where problematic files are located, but nothing worked.
More information:
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/12.1.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /build/gcc/src/gcc/configure --enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++ --enable-bootstrap --prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=https://bugs.artixlinux.org/ --with-linker-hash-style=gnu --with-system-zlib --enable-__cxa_atexit --enable-cet=auto --enable-checking=release --enable-clocale=gnu --enable-default-pie --enable-default-ssp --enable-gnu-indirect-function --enable-gnu-unique-object --enable-linker-build-id --enable-lto --enable-multilib --enable-plugin --enable-shared --enable-threads=posix --disable-libssp --disable-libstdcxx-pch --disable-werror --with-build-config=bootstrap-lto --enable-link-serialization=1
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 12.1.0 (GCC)
Linux staging tree: git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git.
One of the commits that gives following warnings: 2ab9c9675fe892e7fe9fa8c0a6125e2b40d2889d.
To compile older version of kernel I needed older compiler ("Linux kernel sources are in general not forward-compatible with new compilers"). In my case the kernel version was 5.16.0 and I could compile it with gcc 11. If you have gcc 11 specific warnings then try gcc 10 and so on.
Except CC flags, I also needed set to HOSTCC flags to use gcc-11 compiler:
make HOSTCC=gcc-11 CC=gcc-11
I met strange issues about ELF32/ELF64 format in my building machine.
Both applications and kernle module don't work.
For applications (such as helloworld program), it can be built out to ELF64 but run failed.
For kernel modules it will always be built out to ELF32 format even if append -march=x86-64 to CFLGAS, which leads to Module has invalid ELF structures issue when insmoding.
If append -m64 and it will lead to cc1: error: CPU you selected does not support x86-64 instruction set
I guess when the first question fixed, the next will also be fixed, so I only post the first one here.
Ubunt 18.04, gcc 7.5.0 , x86_64 PC
GCC built out helloworld program to ELF64 binary but cannot run
gcc -o hello -v -c hello.c
...
chmod +x hello
./hello
-bash: ./hello: cannot execute binary file: Exec format error
uname -a
Linux AELAB146 5.4.0-74-generic #83~18.04.1-Ubuntu SMP Tue May 11 16:01:00 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/7/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 7.5.0-3ubuntu1~18.04' --with-bugurl=file:///usr/share/doc/gcc-7/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++ --prefix=/usr --with-gcc-major-version-only --program-suffix=-7 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie --with-system-zlib --with-target-system-zlib --enable-objc-gc=auto --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)
Kernel Module's Makefile
EXTRA_CFLAGS += -Wall (and others blablabla) -m64
KERNEL_BUILD ?= /lib/modules/$(shell uname -r)/build
pcie_objs := common/init.o common/pcie.o common/net.o platform.o
obj-m := pcie.o
pcie.o: $(pcie_objs)
ld -r $^ -o $#
all:
make -C $(KERNEL_BUILD) M=$(PWD) V=1 modules
I'v no idea about why it's so long for the gcc Configured options in my system.
You're not supposed to pass -c to GCC when building an executable. It means to compile and not link, but programs need to be linked to be ran. The fact that you had to do chmod +x hello should have been a clue that you were doing something very wrong. Run gcc -o hello -v hello.c and then ./hello.
I assume your issue with kernel modules is similarly caused by an incorrect command line, but since you didn't post the command line you used for it, I can't see where you went wrong with it.
Good afternoon,
If I'm here today is because I encounter some compilation problems.
For a project, I would like to compile gcc in order to have libgcc.a and libstd++.a for 32 bits.
Unfortunatly I have some problems.
Here are the command lines I used to configure and compile the wanted libraries:
CC="gcc -m32" CXX="g++ -m32" CFLAGS="-O1 -march=i686 -gtoggle" CXXFLAGS="-O1 -march=i686 -gtoggle" ; ../src/gcc/gcc-8.1.0/configure --prefix=/path/compiled/x86/O1/gcc --enable-languages=c,c++ --enable-static i686-linux-gnu
make all-gcc
make install-target-libgcc
When I execute last command line I have those errors:
/usr/bin/ld: skipping incompatible /usr/lib/libc.so when searching for -lc
/usr/bin/ld: skipping incompatible /usr/lib/libc.a when searching for -lc
/usr/bin/ld: cannot find -lc
collect2: error: ld returned 1 exit status
make[1]: *** [Makefile:985: libgcc_s.so] Error 1
My machine:
Archlinux 64 bits, up to date
Output of gcc -v:
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/8.1.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=https://bugs.archlinux.org/ --enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++ --enable-shared --enable-threads=posix --enable-libmpx --with-system-zlib --with-isl --enable-__cxa_atexit --disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch --disable-libssp --enable-gnu-unique-object --enable-linker-build-id --enable-lto --enable-plugin --enable-install-libiberty --with-linker-hash-style=gnu --enable-gnu-indirect-function --enable-multilib --disable-werror --enable-checking=release --enable-default-pie --enable-default-ssp
Thread model: posix
gcc version 8.1.0 (GCC)
Thank you for your help !
EDIT: ANSWER HERE
SO for those who wants to know how to compile libgcc and libstdc++ for 32 on a x86_64 machine:
./configure --target=$TARGET --disable-nls --enable-languages=c,c++ --without-headers --prefix=/path/
make all-gcc
make all-target-libgcc
make all-target-libstdc++-v3
make install-gcc
make install-target-libgcc
make install-target-libstdc++-v3
make clean
Then go to the folder containing your new installation, you'll normaly have two folders: lib32 and lib64. Inside lib32, there is the 32 bits version of libgcc and libstdc++ and in lib64, their 64 bits version.
Enjoy !
Problem
I am trying to build a cross compiler on a BeagleBone Black to compile from ARM to x86. The intent of this is to use the low power consuming BeagleBone Black that I had on hand as a build server. It can already compile for windows through mingw-w64, but I need it to also compile the code for Linux x86 systems.
However, when I try to compile gcc on the BeagleBone Black I get the following errors:
/bin/bash ./libtool --tag=CC --mode=compile gcc -DHAVE_CONFIG_H -I. -I../../gcc-4.6.3/gmp -D__GMP_WITHIN_GMP -g -O2 -c -o mpn/div_qr_1n_pi1.lo mpn/div_qr_1n_pi1.c
libtool: compile: gcc -DHAVE_CONFIG_H -I. -I../../gcc-4.6.3/gmp -D__GMP_WITHIN_GMP -g -O2 -c mpn/div_qr_1n_pi1.c -o mpn/div_qr_1n_pi1.o
/tmp/cckCXg2a.s: Assembler messages:
/tmp/cckCXg2a.s:194: Error: thumb conditional instruction should be in IT block -- `movcc r4,#0'
/tmp/cckCXg2a.s:195: Error: thumb conditional instruction should be in IT block -- `movcs r4,#-1'
/tmp/cckCXg2a.s:452: Error: thumb conditional instruction should be in IT block -- `movcc r4,#0'
/tmp/cckCXg2a.s:453: Error: thumb conditional instruction should be in IT block -- `movcs r4,#-1'
make[4]: *** [mpn/div_qr_1n_pi1.lo] Error 1
make[4]: Leaving directory `$HOME/builds/gcc/gmp'
make[3]: *** [all-recursive] Error 1
make[3]: Leaving directory `$HOME/builds/gcc/gmp'
make[2]: *** [all] Error 2
make[2]: Leaving directory `$HOME/builds/gcc/gmp'
make[1]: *** [all-gmp] Error 2
make[1]: Leaving directory `$HOME/builds/gcc'
make: *** [all] Error 2
I know thumbs have something to do with ARM, but I'm mostly at a loss for why this isn't working. What did I do wrong?
Below are the steps I took in trying to create the cross-compiler. This is my first attempt at trying to make a cross-compiler, so most of this information was gleaned from several webpages and manuals.
Steps Taken
To create the cross compiler I downloaded the following packages:
binutils-2.24
gmp-6.0.0a
mpfr-3.1.2
mpc-1.0.2
gcc-4.6.3
linux-3.15.3
glibc-2.19
These were all unpacked into the directory $HOME.
From there I set the following bash environment variables.
export PREFIX="$HOME/cross_compiler/x86_64"
export TARGET="x86_64-linux-gnu"
export PATH="$PREFIX/bin:$PATH"
I then proceeded to configure, build, and install the binutils.
mkdir -p $HOME/builds/binutils
cd $HOME/builds/binutils
../../binutils-2.24/configure --target=$TARGET --prefix="$PREFIX" --disable-nls --disable-werror
make
make install
Binutils built without any errors, so I proceeded to build gcc. First I moved all the extras into the gcc directory.
mv $HOME/gmp-6.0.0a $HOME/gcc-4.6.3/gmp
mv $HOME/mpfr-3.1.2 $HOME/gcc-4.6.3/mpfr
mv $HOME/mpc-1.0.2 $HOME/gcc-4.6.3/mpc
I then configured, without any errors, and tried to build gcc.
mkdir -p $HOME/builds/gcc
cd $HOME/builds/gcc
../../gcc-4.6.3/configure --target=$TARGET --prefix="$PREFIX" --disable-nls --enable-languages=c,c++ --enable-shared --with-multilib-list=m32,m64 --enable-threads=posix --enable-tls --without-headers
make
This generated the following errors:
/bin/bash ./libtool --tag=CC --mode=compile gcc -DHAVE_CONFIG_H -I. -I../../gcc-4.6.3/gmp -D__GMP_WITHIN_GMP -g -O2 -c -o mpn/div_qr_1n_pi1.lo mpn/div_qr_1n_pi1.c
libtool: compile: gcc -DHAVE_CONFIG_H -I. -I../../gcc-4.6.3/gmp -D__GMP_WITHIN_GMP -g -O2 -c mpn/div_qr_1n_pi1.c -o mpn/div_qr_1n_pi1.o
/tmp/cckCXg2a.s: Assembler messages:
/tmp/cckCXg2a.s:194: Error: thumb conditional instruction should be in IT block -- `movcc r4,#0'
/tmp/cckCXg2a.s:195: Error: thumb conditional instruction should be in IT block -- `movcs r4,#-1'
/tmp/cckCXg2a.s:452: Error: thumb conditional instruction should be in IT block -- `movcc r4,#0'
/tmp/cckCXg2a.s:453: Error: thumb conditional instruction should be in IT block -- `movcs r4,#-1'
make[4]: *** [mpn/div_qr_1n_pi1.lo] Error 1
make[4]: Leaving directory `$HOME/builds/gcc/gmp'
make[3]: *** [all-recursive] Error 1
make[3]: Leaving directory `$HOME/builds/gcc/gmp'
make[2]: *** [all] Error 2
make[2]: Leaving directory `$HOME/builds/gcc/gmp'
make[1]: *** [all-gmp] Error 2
make[1]: Leaving directory `$HOME/builds/gcc'
make: *** [all] Error 2
BeagleBone Black
Linux version 3.14.1-bone2 (root#imx6q-wandboard-2gb-0) (gcc version 4.6.3 (Debian 4.6.3-14) ) #1 SMP Sun Apr 20 09:56:48 UTC 2014
"gcc -v" output
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/arm-linux-gnueabihf/4.6/lto-wrapper
Target: arm-linux-gnueabihf
Configured with: ../src/configure -v --with-pkgversion='Debian 4.6.3-14' --with-bugurl=file:///usr/share/doc/gcc-4.6/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.6 --enable-shared --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.6 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin --enable-objc-gc --disable-sjlj-exceptions --with-arch=armv7-a --with-fpu=vfpv3-d16 --with-float=hard --with-mode=thumb --enable-checking=release --build=arm-linux-gnueabihf --host=arm-linux-gnueabihf --target=arm-linux-gnueabihf
Thread model: posix
gcc version 4.6.3 (Debian 4.6.3-14)
Desktop
This is the computer I am trying to get the code to run on in the end.
Linux version 3.2.0-65-generic (buildd#brownie) (gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5) ) #98-Ubuntu SMP Wed Jun 11 20:27:07 UTC 2014
"gcc -v" output:
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.6/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.6.3-1ubuntu5' --with-bugurl=file:///usr/share/doc/gcc-4.6/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.6 --enable-shared --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.6 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin --enable-objc-gc --disable-werror --with-arch-32=i686 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Instead of trying to manually build a cross-compiler, I would advise to use one of the existing toolchain generation frameworks: buildroot or crosstool-NG. You need to install some dependencies on your BBB using apt-get, but otherwise it's just a matter of configure; make.
When I issue a command like (for example) make -j 4, I get the following error:
warning: jobserver unavailable: using -j1. Add `+' to parent make rule
I am using the developer toolkit from Scientific Linux 6 under RHEL6:
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/opt/rh/devtoolset-2/root/usr/libexec/gcc/x86_64-redhat-linux/4.8.2/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/opt/rh/devtoolset-2/root/usr --mandir=/opt/rh/devtoolset-2/root/usr/share/man --infodir=/opt/rh/devtoolset-2/root/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-bootstrap --enable-shared --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --enable-languages=c,c++,fortran,lto --enable-plugin --with-linker-hash-style=gnu --enable-initfini-array --disable-libgcj --with-isl=/builddir/build/BUILD/gcc-4.8.2-20140120/obj-x86_64-redhat-linux/isl-install --with-cloog=/builddir/build/BUILD/gcc-4.8.2-20140120/obj-x86_64-redhat-linux/cloog-install --with-mpc=/builddir/build/BUILD/gcc-4.8.2-20140120/obj-x86_64-redhat-linux/mpc-install --with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux
Thread model: posix
gcc version 4.8.2 20140120 (Red Hat 4.8.2-15) (GCC)
I have libmpc 0.8.3 installed:
$ rpm -qa | grep mpc
libmpcdec-1.2.6-6.1.el6.x86_64
libmpc-0.8-3.el6.x86_64
Is there a way to troubleshoot my project's makefile or gcc to determine what is causing the warning and fix it? I do not seem to need the + symbol added to rules when building from OS X via Clang/LLVM. Google searches on the warning text are not returning much information that is apparently useful.
Whenever you run make from inside a makefile you should always use the $(MAKE) variable. Never use the raw, literal command make.