LinuxQuestions.org - After adding a system call in the kernel, an error occured.

Hi,

I added a temporary system call in the kernel for a test,
But when a program calls the system call, an error occurs.

When I compiled the following program, an error occured.
# vi testcall_test.c

Code:

#include <linux/unistd.h>



_syscall0(int,testcall);



int main(void)

{

testcall();

return 0;

}

The error messages are...
# gcc -I /usr/src/linux-2.6.14.6/include testcall_test.c -o testcall_test

Code:

/usr/bin/ld: errno: TLS definition in /lib/libc.so.6 section .tbss mismatches non-TLS reference in /tmp/ccCGdJnX.o

/lib/libc.so.6: could not read symbols: Bad value

collect2: ld returned 1 exit status

But when the program calls the system call as the number,
it works properly.
WHAT IS WRONG WITH THE ABOVE?
And how can I solve the problem?
Please, help me.
# vi testcall_test.c

Code:

#include <linux/unistd.h>



// _syscall0(int,testcall);



int main(void)

{

// testcall();



syscall(294);





return 0;

}

(or)
# vi testcall_test.c

Code:

#include <linux/unistd.h>



// _syscall0(int,testcall);



int main(void)

{

// testcall();



syscall(__NR_testcall);





return 0;

}

# gcc -I /usr/src/linux-2.6.14.6/include testcall_test.c -o testcall_test
#

# ls
testcall_test testcall_test.c
# ./testcall_test
testcall success!
#

I heard that the _syscallN() macros are gone in 2.6.20 and later.
But the current kernel version is 2.6.14.6