looks to me like you are trying to use kernel code inside of a userland
program. Don't. Use the userland semaphore for userland programs,
#include<semaphore.h>
the sema_* functions are for the kernel code only.
Also you are defining __KERNEL__ this shouldn't be done in userland either.
If, however, you are trying to do a module then dump main and use the modules
entery/exit point macros.
On Friday 03 January 2003 2:19 pm, S P wrote:
> Hi,I am working on some semaphore stuff. Just to check that I am doing the
> right thing I wrote a normal c code using semaphores : Sema_Try.c
> -------------------------------------------------- #include <linux/init.h>
> #include <linux/kernel.h>
> #include <linux/module.h>
> #include <linux/sched.h>
> #include <asm/semaphore.h>
> #include <linux/slab.h> int main(void){ struct semaphore hold_sem;
> sema_init(&hold_sem, 1); down_trylock(&hold_sem); return 1;}
> --------------------------------------------------------- On compilation I
> get the following output: > gcc -Wall -D__KERNEL__ -I
> /usr/src/linux-2.4.7-10/include Sema_Try.c/tmp/ccSdPsrY.o(.text/lock+x):
> undefined reference to '__down_failed_trylock'collect2: ld returned 1 exit
> status __down_failed_trylock is the function invoked by _down_trylock in
> semaphore.c. Could you suggest me something to get over this problem ?
> Thanks,SP
>
>
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--
Tom Bradley
Software Engineer
Jaycor / Titan Systems
--
Kernelnewbies: Help each other learn about the Linux kernel.
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