Date: Tue, 26 Oct 2010 09:34:57 -0400 From: John Baldwin <jhb@freebsd.org> To: freebsd-hackers@freebsd.org Cc: Andriy Gapon <avg@icyb.net.ua>, Selphie Keller <selphie.keller@gmail.com> Subject: Re: SYSCALL_MODULE() macro and modfind() issues Message-ID: <201010260934.57247.jhb@freebsd.org> In-Reply-To: <AANLkTikRqHOJ8voweZhDEfNsRAR_pEoXspLQYrVtGsRH@mail.gmail.com> References: <AANLkTimVUzV3v9=y%2BWuuf%2B1fC4OYxD2Gs4j%2B=SO-M%2BP9@mail.gmail.com> <4CC6830A.10701@icyb.net.ua> <AANLkTikRqHOJ8voweZhDEfNsRAR_pEoXspLQYrVtGsRH@mail.gmail.com>
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On Tuesday, October 26, 2010 4:00:14 am Selphie Keller wrote:
> Thanks Andriy,
>
> Took a look at the change to src/sys/sys/sysent.h
>
> @@ -149,7 +149,7 @@ static struct syscall_module_data name##
> }; \
> \
> static moduledata_t name##_mod = { \
> - #name, \
> + "sys/" #name, \
> syscall_module_handler, \
> &name##_syscall_mod \
> }; \
>
> applied the MFC prefix to pmap port:
>
> --- /usr/ports/sysutils/pmap/work/pmap/pmap/pmap.c.orig 2010-10-26
> 00:55:32.000000000 -0700
> +++ /usr/ports/sysutils/pmap/work/pmap/pmap/pmap.c 2010-10-26
> 00:56:10.000000000 -0700
> @@ -86,12 +86,12 @@ main(int argc, char **argv)
> struct kinfo_proc *kp;
> int pmap_helper_syscall;
>
> - if ((modid = modfind("pmap_helper")) == -1) {
> + if ((modid = modfind("sys/pmap_helper")) == -1) {
> /* module not found, try to load */
> modid = kldload("pmap_helper.ko");
> if (modid == -1)
> err(1, "unable to load pmap_helper module");
> - modid = modfind("pmap_helper");
> + modid = modfind("sys/pmap_helper");
> if (modid == -1)
> err(1, "pmap_helper module loaded but not found");
> }
>
> which restored functionality on freebsd 8.1.
The best approach might be to have something like this:
static int
pmap_find(void)
{
int modid;
modid = modfind("pmap_helper");
if (modid == -1)
modid = modfind("sys/pmap_helper");
return (modid);
}
then in the original main() routine use this:
if ((modid = pmap_find()) == -1) {
/* module not found, try to load */
modid = kldload("pmap_helper.ko");
if (modid == -1)
err(1, "unable to load pmap_helper module");
modid = pmap_find();
if (modid == -1)
err(1, "pmap_helper module loaded but not found");
}
This would make the code work for both old and new versions.
> -Estella Mystagic (Selphie)
>
> On Tue, Oct 26, 2010 at 12:28 AM, Andriy Gapon <avg@icyb.net.ua> wrote:
> > on 26/10/2010 01:01 Selphie Keller said the following:
> >> hi fbsd-hackers,
> >>
> >> Noticed a issue in 8.1-release, 8.1p1-release and 8.1-stable
> >> amd64/i386, to where modfind() will no longer find pmap_helper for the
> >> /usr/ports/sysutils/pmap port, or other syscall modules using
> >> SYSCALL_MODULE() macro.
> >> The issue is that modfind() function no longer finds any modules using
> >> SYSCALL_MODULE() macro to register the kernel module. Making it
> >> difficult for userland apps to call the syscall provided. modfind()
> >> always returns -1 which prevents modstat() from getting the required
> >> information to perform the syscall.
> >>
> >> Also tested, the demo syscall module:
> >
> > After commit r205320 and, apparently, its MFC you need to prefix the
module with
> > "sys/". For example:
> > modstat(modfind("sys/syscall"), &stat);
> >
> > P.S.
> > Perhaps a KPI breakage in a stable branch?
> > --
> > Andriy Gapon
> >
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--
John Baldwin
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