I am having problems getting any kernel modules to build on my machine. Whenever I build a module, modpost always says there are zero modules:
MODPOST 0 modules
To troubleshoot the problem, I wrote a test module (hello.c):
#include <linux/module.h> /* Needed by all modules */
#include <linux/kernel.h> /* Needed for KERN_INFO */
#include <linux/init.h> /* Needed for the macros */
static int __init hello_start(void)
{
printk(KERN_INFO "Loading hello module...\n");
printk(KERN_INFO "Hello world\n");
return 0;
}
static void __exit hello_end(void)
{
printk(KERN_INFO "Goodbye Mr.\n");
}
module_init(hello_start);
module_exit(hello_end);
Here is the Makefile for the module:
obj-m = hello.o
KVERSION = $(shell uname -r)
all:
make -C /lib/modules/$(KVERSION)/build M=$(shell pwd) modules
clean:
make -C /lib/modules/$(KVERSION)/build M=$(shell pwd) clean
When I build it on my machine, I get the following output:
make -C /lib/modules/2.6.32-27-generic/build M=/home/waffleman/tmp/mod-test modules
make[1]: Entering directory `/usr/src/linux-headers-2.6.32-27-generic'
CC [M] /home/waffleman/tmp/mod-test/hello.o
Building modules, stage 2.
MODPOST 0 modules
make[1]: Leaving directory `/usr/src/linux-headers-2.6.32-27-generic'
When I make the module on another machine, it is successful:
make -C /lib/modules/2.6.24-27-generic/build M=/home/somedude/tmp/mod-test modules
make[1]: Entering directory `/usr/src/linux-headers-2.6.24-27-generic'
CC [M] /home/somedude/tmp/mod-test/hello.o
Building modules, stage 2.
MODPOST 1 modules
CC /home/somedude/tmp/mod-test/hello.mod.o
LD [M] /home/somedude/tmp/mod-test/hello.ko
make[1]: Leaving directory `/usr/src/linux-headers-2.6.24-27-generic'
I looked for any relevant documentation about modpost, but found little. Anyone know how modpost decides what to build? Is there an environment that I am possibly missing?
BTW here is what I am running:
uname -a
Linux waffleman-desktop 2.6.32-27-generic #49-Ubuntu SMP Wed Dec 1 23:52:12 UTC 2010 i686 GNU/Linux
Edit
Here is make ran with V=1:
make -C /lib/modules/2.6.32-27-generic/build M=/home/waffleman/tmp/mod-test modules
make[1]: Entering directory `/usr/src/linux-headers-2.6.32-27-generic'
test -e include/linux/autoconf.h -a -e include/config/auto.conf || ( \
echo; \
echo " ERROR: Kernel configuration is invalid."; \
echo " include/linux/autoconf.h or include/config/auto.conf are missing."; \
echo " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
echo; \
/bin/false)
mkdir -p /home/waffleman/tmp/mod-test/.tmp_versions ; rm -f /home/waffleman/tmp/mod-test/.tmp_versions/*
make -f scripts/Makefile.build obj=/home/waffleman/tmp/mod-test
gcc -Wp,-MD,/home/waffleman/tmp/mod-test/.hello.o.d -nostdinc -isystem /usr/lib/gcc/i486-linux-gnu/4.4.3/include -Iinclude -I/usr/src/linux-headers-2.6.32-27-generic/arch/x86/include -include include/linux/autoconf.h -Iubuntu/include -D__KERNEL__ -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -Werror-implicit-function-declaration -Wno-format-security -fno-delete-null-pointer-checks -O2 -m32 -msoft-float -mregparm=3 -freg-struct-return -mpreferred-stack-boundary=2 -march=i586 -mtune=generic -maccumulate-outgoing-args -Wa,-mtune=generic32 -ffreestanding -fstack-protector -DCONFIG_AS_CFI=1 -DCONFIG_AS_CFI_SIGNAL_FRAME=1 -pipe -Wno-sign-compare -fno-asynchronous-unwind-tables -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -Wframe-larger-than=1024 -fno-omit-frame-pointer -fno-optimize-sibling-calls -pg -Wdeclaration-after-statement -Wno-pointer-sign -fno-strict-overflow -fno-dwarf2-cfi-asm -fconserve-stack -DMODULE -D"KBUILD_STR(s)=#s" -D"KBUILD_BASENAME=KBUILD_STR(hello)" -D"KBUILD_MODNAME=KBUILD_STR(hello)" -c -o /home/waffleman/tmp/mod-test/.tmp_hello.o /home/waffleman/tmp/mod-test/hello.c
set -e ; perl /usr/src/linux-headers-2.6.32-27-generic/scripts/recordmcount.pl "i386" "32" "objdump" "objcopy" "gcc" "ld" "nm" "" "" "1" "/home/waffleman/tmp/mod-test/hello.o";
(cat /dev/null; echo kernel//home/waffleman/tmp/mod-test/hello.ko;) > /home/waffleman/tmp/mod-test/modules.order
make -f /usr/src/linux-headers-2.6.32-27-generic/scripts/Makefile.modpost
scripts/mod/modpost -m -a -i /usr/src/linux-headers-2.6.32-27-generic/Module.symvers -I /home/waffleman/tmp/mod-test/Module.symvers -o /home/waffleman/tmp/mod-test/Module.symvers -S -w -s
make[1]: Leaving directory `/usr/src/linux-headers-2.6.32-27-generic'
waffleman#waffleman-desktop:~/tmp/mod-test$ cat /home/waffleman/tmp/mod-test/modules.order
kernel//home/waffleman/tmp/mod-test/hello.ko
I spent all day glued to my computer fighting this precise problem..which ended up mysteriously disappearing like for OP.
I can at least offer this meager detail from my experience: I was getting the same output as OP (for make V=1) and putting print statements in ${kernel_directory}/scripts/makefile.build showed that obj-m was strangely NOT being set after including my makefile, even though it was clearly typed as above.
I did a bunch of fooling around with the line "obj-m += hello.o" and the ones around it. Eventually it magically worked..although it looked exactly the same as before in the end. Maybe I had copied those lines from a tutorial online and it contained some sort of invalid/incorrect character?
For anyone experiencing this, verify that obj-m is in fact getting set to hello.o
If it mysteriously isn't, delete the line, hell the whole Makefile, and retype it.
I know that's not much help; I wish I could reproduce what happened!
In another thread I found that when I copy pasted the makefile contents, the -C after make was using the wrong "-" symbol and I had to re type it. It just so happens that this is the case for the obj-m += ... line above. You need to retype that character to make it valid. This should hopefully be found by anyone following the hello world module tutorial.
I guess you copied the contents of the Makefile from a PDF or some HTML document. The hyphens used are somewhat weird. Just try replacing the hyphens in the makefile; it will work like a charm.
I just ran into this same problem and for me it was caused by changing the default grep options via the GREP_OPTIONS environment variable. I didn't dig into the details, but something in the module build process didn't like my alternate grep output (include file name and line number). Removing the GREP_OPTIONS environment variable fixed things right up.
This happens because when you copy the make file contents from the PDF or any other tutorial websites and use it as it is. While you do a copy-paste, the contents will appear a bit weird in Linux environment. ie; Some special character issues will be there. If you retype the contents in Linux environment and do a make, this should work.
On the machine that fails does your .config have module support disabled?
Try doing "make menuconfig" and make sure module support is enabled.
I can only guess your kernel build environment is botched, because it passes both the theoretical check (the look of the developer) as well as the practical test:
make -C /lib/modules/2.6.36-rc8-32-desktop/build M=/dev/shm modules
make[1]: Entering directory `/usr/src/linux-2.6.36-rc8-32-obj/x86_64/desktop'
make -C ../../../linux-2.6.36-rc8-32 O=/usr/src/linux-2.6.36-rc8-32-obj/x86_64/desktop/. modules
CC [M] /dev/shm/hello.o
Building modules, stage 2.
MODPOST 1 modules
CC /dev/shm/hello.mod.o
LD [M] /dev/shm/hello.ko
make[1]: Leaving directory `/usr/src/linux-2.6.36-rc8-32-obj/x86_64/desktop'
The error mysteriously went away. If anyone has an idea what could cause this. I'd like to know in case there is a next time.
Try to remove modules string from the Makefile:
obj-m = hello.o
KVERSION = $(shell uname -r)
all:
make -C /lib/modules/$(KVERSION)/build M=$(shell pwd) # <--
clean:
make -C /lib/modules/$(KVERSION)/build M=$(shell pwd) clean
I was able to solve this problem by putting the
obj-m += <module name>.o
In a separate file named Kbuild. See Linux/documentation/kbuild/modules.txt for a hint as to why this might work
I had the same problem. Finally, I rebuilt the kernel, rewrote the makefile. It worked finally.
I guess the main reason is because I had M=$(PWD) modules in the following line right after make ARCH=arm...
I solved this problem by correcting Makefile, i.e.:
obj-m := modulename.o
I think it's not about special characters. I couldn't solve even when I manually typed! Then I tried again using kate text editor because previously I used nano and this time it worked like charm by even simple copy and paste. Because of that, I think the issue is the text editor
Related
I'm trying to link a kernel module to a non-LKM source file. The problem is, I'm running into some issues. The names of the two files are chardev.c (the LKM) and foo.c.
My Makefile:
obj-m += chardev.o
obj-y += foo.o
all:
make -C /lib/modules/$(shell uname -r)/build/ M=$(PWD) modules
$(CC) test.c -o test
clean:
make -C /lib/modules/$(shell uname -r)/build/ M=$(PWD) clean
rm test
Inside of chardev.c I've the following line of code: extern int foo;, and inside foo I've the following line of code: int foo = 123;. (Both lines are at file-scope.)
When running make I'm getting the following output:
make -C /lib/modules/4.4.0-31-generic/build/ M=/home/kylemart/Desktop/Device-Driver modules
make[1]: Entering directory `/usr/src/linux-headers-4.4.0-31-generic'
CC [M] /home/kylemart/Desktop/Device-Driver/chardev.o
Building modules, stage 2.
MODPOST 1 modules
WARNING: "foo" [/home/kylemart/Desktop/Device-Driver/chardev.ko] undefined!
CC /home/kylemart/Desktop/Device-Driver/chardev.mod.o
LD [M] /home/kylemart/Desktop/Device-Driver/chardev.ko
make[1]: Leaving directory `/usr/src/linux-headers-4.4.0-31-generic'
cc test.c -o test
Seems things aren't linking properly. What am I doing wrong?
EDIT:
This seems to work, but there's a problem:
obj-m += chardev.o
chardev-objs += foo.o
all:
make -C /lib/modules/$(shell uname -r)/build/ M=$(PWD) modules
$(CC) test.c -o test
clean:
make -C /lib/modules/$(shell uname -r)/build/ M=$(PWD) clean
rm test
Although it compiles without warnings, after installing the compiled module (i.e. sudo insmod chardev.ko) there isn't a new device present in /dev. Previously, without trying to link source files, installing kernel modules as previously stated created a device file. That said, the device is present when running lsmod.
Your all target builds only the module, but not the kernel so that the foo symbol does not exist there.
When compiling a source (here: foo.c) into the kernel, you have to integrate the makefile into the kernel source. E.g. you have to add
obj-y += my-driver/
to the makefile in the previous directory and build the whole kernel. You should probably remove your all: and clean: targets from the makefile to avoid conflicts with kernel builtin rules.
foo.c must contain
EXPORT_SYMBOL(foo);
or
EXPORT_SYMBOL_GPL(foo);
The second makefile...
will generate only the chardev.ko module which is built from only foo.c; chardev.c will not be used for it. When you really want this, you have to change file names; e.g.
obj-m += chardev.o
chardev-objs = chardev-core.o foo.o
First of all, please, don't just tell me this is a duplicate. I know, but the many questions I've looked through have all been given far too specific answers to assist me, and quite frankly half of it went over my head. I'm very new to using Makefiles and I'm baffled by why mine isn't working.
I'm sure it's something painfully simple but please lend a hand, if you need any more information I'll be happy to try to find it, and bear with me because I'm doing all this from my phone because my university's IT department is run by apes. Currently, this is my Makefile:
Makefile for Assignment 1
finish : main.o
g++ -o finish main.o
main.o :
g++ -c -g -Wall main.cpp
clean :
del main.o
(Sorry, it's not being cooperative, I want to make clear that there is the necessary tab in front of the commands)
I'm running this on Windows 10, using a GNU compiler. From what I can see it looks exactly the same as the example Makefile we were provided, aside from filenames. I know I'm in the right directory, nothing is misspelled, the source file should exist cause I'm staring at it sitting next to the makefile. Those are the generic fixes I remember seeing.
The main.o command works perfectly and compiles the source file, but the other two just give me the error
make: *** No rule to make target 'finish/clean'. Stop.
I'm confused, annoyed, new to Makefiles and Stack Overflow and just looking for a helping hand. Any advice would be greatly appreciated.
I am pasting my example:
CC = g++
CFLAGS = -g
test.o: test.cpp
$(CC) $(CFLAGS) -c test.cpp
last.o: last.cpp
$(CC) $(CFLAGS) -c last.cpp
program: test.o last.o
$(CC) $(CFLAGS) -o program test.o last.o
clean:
$(RM) test.o last.o
I was facing similar issue, Try using $(RM) instead of "del"
I am trying to learn makefile, but I fail badly.
One example (which is very primitive) but I should understand it to go ahead is this one
f90_simple: f1.o
gfortran f1.o
mv a.out f90_simple
f90_simple.o: f1.f90
gfortran -c f1.f90
it does not work, and I get this error
I get this error
make: *** No rule to make target `f1.o', needed by `f90_simple'. Stop.
could you please advise me?
thanks
Your first rule says that before f90_simple can be built, the target f1.o must be built.
But there's no rule in your makefile that tells make how to build the target f1.o, and make can't find any built-in rule that can build it (based on the source files make has available), so it prints that error.
You do have a rule that tells make how to build a target f90_simple.o... but that's not the target make is looking for. Most likely you want your makefile to either be:
f90_simple: f1.o
gfortran $^
mv a.out $#
f1.o: f1.f90
gfortran -o $# -c $<
or else:
f90_simple: f90_simple.o
gfortran $^
mv a.out $#
f90_simple.o: f1.f90
gfortran -o $# -c $<
but you can't mix and match them, or make doesn't know what to do.
I think you would really benefit from reading at least the introductory chapters in The GNU Make Manual.
I got the below makefile which works perfectly fine under linux as well as mac os. However it fails to do anything on FreeBSD, and I have no clue why. It gives the following output:
19:31:35 user#host:~/libhttp++/src> make
-
Making HTTP++ library..
make[1]: don't know how to make obj/libhttp++.a. Stop
make[1]: stopped in /usr/home/user/libhttp++/src/obj
*** Error code 2
Stop.
make: stopped in /usr/home/user/libhttp++/src
I also tried gmake, which gives the following output:
19:31:35 user#host:~/libhttp++/src> gmake
-
Making HTTP++ library..
Building Lib ...
ar -rs obj/libhttp++.a obj/html.o obj/http.o obj/object.o
ar: warning: creating obj/libhttp++.a
ar: warning: can't open file: obj/html.o: No such file or directory
ar: warning: can't open file: obj/http.o: No such file or directory
ar: warning: can't open file: obj/object.o: No such file or directory
ar: fatal: Failed to open 'obj/libhttp++.a'
*** Error code 70
Stop.
make[1]: stopped in /usr/home/user/libhttp++/src
gmake: *** [all] Error 1
One issue might be that i'm trying to keep all intermediate object files as well as the lib itself in a separate subdirectory ("obj").
The problem is, I dont know much about makefiles, and the freebsd handbook as well as any example makefiles i could find via google did not help much. The makefile is basically copied from a working linux makefile I found somewhere, and well, it works on linux and mac os. Is there a way to convert it to a format which works on all 3 platforms? any help would be much appreciated.
makefile:
#--------------------------------------------------------------------------
# defines
#--------------------------------------------------------------------------
LIBDIR = ../lib
INCDIR = ../include
OBJDIR = obj
CXX = g++
doLib = ar -rs
doCompile = $(CXX) $(CXXFLAGS)
doLink = $(CXX) $(LFLAGS)
doClean = rm -f *.o *~ *.a
#--------------------------------------------------------------------------
# Library
#--------------------------------------------------------------------------
OBJECTS = $(OBJDIR)/html.o \
$(OBJDIR)/http.o \
$(OBJDIR)/object.o
LIBXMLPATH=~/Development/libxml2_2
LIBCURLPATH=~/Development/libcurl
#CDEF += -D__FORIOS__
CXXFLAGS ?= -I ./ -I $(LIBXMLPATH)/include -I $(LIBCURLPATH)/include/curl $(CDEF) -c -ggdb -Wreturn-type -Wformat -pedantic -Wunused-variable -Wunused-label -Wunused-value -Wno-long-long
DISTLIB = http++
#--------------------------------------------------------------------------
# compile lib objects
#--------------------------------------------------------------------------
lib: all
all:
#(echo -; echo Making HTTP++ library..; make $(OBJDIR)/lib$(DISTLIB).a)
$(OBJDIR)/lib$(DISTLIB).a: $(OBJECTS)
#echo Building Lib ...
$(doLib) $# $(OBJECTS)
clean:
#(echo Cleanup HTTP++ library)
$(doClean)
(cd $(OBJDIR); $(doClean))
install:
#(echo Installing HTTP++ library in ../include ../lib)
(mkdir -p $(LIBDIR); mkdir -p $(INCDIR))
(cp -p *hpp *h $(INCDIR)/ ; cp -p $(OBJDIR)/lib$(DISTLIB).a $(LIBDIR)/)
#--------------------------------------------------------------------------
# Compiler Call
#--------------------------------------------------------------------------
$(OBJDIR)/%.o: %.cc
#echo Compile "$(*F)" ...
$(doCompile) $(*F).cc -o $#
#--------------------------------------------------------------------------
# dependencies
#--------------------------------------------------------------------------
CHECK = def.h
$(OBJDIR)/html.o : html.cc $(CHECK) html.hpp
$(OBJDIR)/http.o : http.cc $(CHECK) http.hpp
$(OBJDIR)/object.o : object.cc $(CHECK) object.hp
GNU make has a number of extensions beyond the make on BSDs (which is sometimes available on non-BSD boxes as bsdmake). You can look at the FreeBSD man page for make to see the differences, but the most salient one is that the syntax
%.target: %.source
is only available on GNU make (there's a similar syntax, though less flexible, in BSD make).
I'd have thought that gmake would work, though. Hmm...
Looking at the makefile, I can't see anything that creates $(OBJDIR), so it might be that that's the problem – it's the first thing I'd try to fix, at any rate. If so, then just mkdir obj beforehand might work.
Yesterday I found the problem:
all:
#(echo -; echo Making HTTP++ library..; make $(OBJDIR)/lib$(DISTLIB).a)
This line is bad when the makefile is used with gmake, because it calls make instead of gmake. So the fix is:
all:
#(echo -; echo Making HTTP++ library..; gmake $(OBJDIR)/lib$(DISTLIB).a)
Now it works perfectly without any adjustments when using gmake.
I am trying to compile a program on ubuntu 12.04 64bit using make.While compiling i get an error
/bin/bash: -c: line 0: syntax error near unexpected token `(
This is after I changed the symlink of /bin/sh to /bin/bash instead of dash. (I did it because i had the same kind of error before and looking around the internet I found that the script may call bash functions which are not available in sh/dash.)
I also tried putting SHELL = /bin/bash at the top of my makefile but still no use...
Any help would be much appreciated.
edit
SHELL = /bin/bash
CC = gcc
CFLAGS= -std=gnu99 -L/ATLAS/lib/ubuntu12.04 -lflint -lgsl -lcblas -latlas -lm -lmpfr -lmpir -lrt -Wall -fopenmp
default: GPVSignature
GPVSignature: GPVSignature.o Keygeneration.o chol_parallel.o Sampling2.o sha1.o sha2.o timing.o
$(CC) $(CFLAGS) -o GPVSignature GPVSignature.o Keygeneration.o chol_parallel.o Sampling2.o sha1.o sha2.o timing.o
clean:
rm -f GPVSignature *.o
SSH_AGENT_PID=2065
GPG_AGENT_INFO=/tmp/keyring-alBJt6/gpg:0:1
TERM=xterm
SHELL=/bin/bash
XDG_SESSION_COOKIE=ff0e3de12be325b4ae6276d100000009-1353535027.801191-1696704263
WINDOWID=56623110
GNOME_KEYRING_CONTROL=/tmp/keyring-alBJt6
NO_PROXY=localhost,127.0.0.0/8
USER=salman
http_proxy=http:(---)
LS_COLORS=rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40; 33;01:or=40;31;01:su=37;41:sg=30;43:ca=30;41:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arj=01;31:*.taz=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.zip=01;31:*.z=01;31:*.Z=01;31:*.dz=01;31:*.gz=01;31:*.lz=01;31:*.xz=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;31:*.sar=01;31:*.rar=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.jpg=01;35:*.jpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.axv=01;35:*.anx=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=00;36:*.au=00;36:*.flac=00;36:*.mid=00;36:*.midi=00;36:*.mka=00;36:*.mp3=00;36:*.mpc=00;36:*.ogg=00;36:*.ra=00;36:*.wav=00;36:*.axa=00;36:*.oga=00;36:*.spx=00;36:*.xspf=00;36:
XDG_SESSION_PATH=/org/freedesktop/DisplayManager/Session0
XDG_SEAT_PATH=/org/freedesktop/DisplayManager/Seat0
SSH_AUTH_SOCK=/tmp/keyring-alBJt6/ssh
SESSION_MANAGER=local/ubuntu:#/tmp/.ICE-unix/2026,unix/ubuntu:/tmp/.ICE-unix/2026
DEFAULTS_PATH=/usr/share/gconf/ubuntu.default.path
XDG_CONFIG_DIRS=/etc/xdg/xdg-ubuntu:/etc/xdg
PATH=/usr/lib/lightdm/lightdm:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin: /bin:/usr/games
DESKTOP_SESSION=ubuntu
PWD=/home/salman/
GNOME_KEYRING_PID=2015
LANG=en_US.UTF-8
MANDATORY_PATH=/usr/share/gconf/ubuntu.mandatory.path
UBUNTU_MENUPROXY=libappmenu.so
COMPIZ_CONFIG_PROFILE=ubuntu
GDMSESSION=ubuntu
HOME=/home/salman
SHLVL=1
GNOME_DESKTOP_SESSION_ID=this-is-deprecated
no_proxy=localhost,127.0.0.0/8
LOGNAME=salman
BUS_SESSION_BUS_ADDRESS=unix:abstract=/tmp/dbus-RUfHXImIYm,guid=c49ca476a7f4b008964105c90000004e
LESSOPEN=| /usr/bin/lesspipe %s
DISPLAY=:0
XDG_CURRENT_DESKTOP=Unity
LESSCLOSE=/usr/bin/lesspipe %s %s
COLORTERM=gnome-terminal
XAUTHORITY=/home/salman/.Xauthority
_=/usr/bin/env
OLDPWD=/home/salman/Desktop
How about this?:
SHELL:=/bin/bash
CC:=gcc
CFLAGS:=-std=gnu99 -L/ATLAS/lib/ubuntu12.04 -lflint -lgsl -lcblas -latlas -lm -lmpfr -lmpir -lrt -Wall -fopenmp
default: GPVSignature
GPVSignature: GPVSignature.c Keygeneration.c chol_parallel.c Sampling2.c sha1.c sha2.c timing.c
clean:
rm -f GPVSignature *.o
The indentation under the clean: line (before the rm) is a TAB character! This is important. My guess is that you don't have the indentation correct on the recipe lines (under GPVSignature: and under clean:). Also, you don't need to give an explicit recipe, because GNU make comes with a number of recipes of its own.
Note: I am assuming the file extensions are .c here, because it is customary and you use gcc, not g++. If that's not the case you need to introduce a pattern rule to tell GNU make how to create .o files from whatever extension you are using for your source files.
Even assuming your original recipe, I'd suggest the following more succinct line:
$(CC) $(CFLAGS) -o $# $^
... also indented by a single tab character (unless you tell GNU make to use a different character, which you obviously don't).
Two more things.
Is the Makefile/GNUmakefile a simple ASCII text file or a UTF-8 file with BOM? Execute file Makefile and post the output, please.
Check the following screenshots. This (second screenshot) is how it should look correctly indented with tabs in Vim (assuming you have the syntax file installed) ... specifically note the colors of the recipe for GPVSignature. The first screenshot is wrong, the second is
Other than that I am out of ideas. And there would have to be something you aren't mentioning.