Bug#220624: libc6-dev: breaks builds on 2.4 systems because depending on linux-kernel-headers which contain 2.5 headers
On Thu, Nov 13, 2003 at 03:07:45PM -0700, Alex Tsariounov wrote:
> On Thu, 2003-11-13 at 14:28, Daniel Jacobowitz wrote:
> > On Thu, Nov 13, 2003 at 01:50:58PM -0700, Alex Tsariounov wrote:
> > > Are you saying that it is not and should not be used then?
> >
> > Libc provides the function, as a convenience, esp. for architectures
> > where the _syscall macros in <asm/unistd.h> can't be directly used.
> >
> > However, it does not provide a prototype or associated definitions.
> > Which is what I said.
>
> Well, this is why I said it was philosophical. My root question would
> be: is the system call query_module() (along with it's relatives
> init_module, create_module, delete_module - although they are less
> important here since you need to be root to use them) a public
> interface?
It _was_ a public interface of the kernel. The kernel doesn't provide
usable headers for its public interfaces; this is a known kernel bug
and they're talking about fixing it in 2.7.
It is no longer a public interface of the kernel. It's gone in 2.6.
It's also never been a public interface of glibc. Glibc provides the
wrapper purely as a convenience for accessing the Linux interface.
> If it is, then I would suggest it needs an include file which prototypes
> its use and supplies any needed constants/definitions.
>
> For my case now, and hence this bug, I've decided to quit using the
> query_module() function because of the fud (it's not the first time it's
> been a problem). I've also attached below the example code that I used
> to open this bug modified to use a different method to determine if a
> module is loaded for those who are monitoring this bug stream.
>
> By using this other method (and hence not including linux/module.h), my
> build builds again.
The difference is, this will actually work in 2.6 kernels :)
>
> Thanks,
> Alex Tsariounov
>
> -----8<----- Compile this:
>
> #include <stdio.h>
>
> main(int argc, char *argv[])
> {
> FILE *fp;
> char line[4096];
>
> if (argc<2) {
> printf("Usage: %s module_name\n", argv[0]);
> exit(1);
> }
>
> fp = fopen("/proc/modules", "r");
> if (!fp) {
> perror("Opening /proc/modules");
> exit(1);
> }
>
> while (fgets(line, sizeof(line), fp)) {
> if (strncmp(line, argv[1], strlen(argv[1])) == 0) {
> printf("Found %s loaded in kernel\n", argv[1]);
> exit (0);
> }
> }
>
> printf("Can't find module %s in kernel\n", argv[1]);
> return 1;
> exit(0);
> }
>
> -----8<--------8<-------
>
>
>
--
Daniel Jacobowitz
MontaVista Software Debian GNU/Linux Developer
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