| Message ID | 87a9m6sri3.fsf@rustcorp.com.au (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
One caveat. Sometimes we have manufactured parameters intentionally to cause a module to fail. We should standardize that piece.
Jonathan Masters <jcm@redhat.com> writes:
> One caveat. Sometimes we have manufactured parameters intentionally to cause a module to fail. We should standardize that piece.
Certainly. Can you give an example?
Cheers,
Rusty.
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Dne 1.7.2013 18:33, Jonathan Masters napsal(a): > One caveat. Sometimes we have manufactured parameters intentionally > to cause a module to fail. We should standardize that piece. You have: blacklist foo to prevent udev from loading a module and install foo /bin/true to prevent modprobe from loading the module at all. What is the motivation for inventing a third way, through adding invalid parameters? Thanks, Michal -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Jul 3, 2013 at 2:03 PM, Michal Marek <mmarek@suse.cz> wrote: > Dne 1.7.2013 18:33, Jonathan Masters napsal(a): >> One caveat. Sometimes we have manufactured parameters intentionally >> to cause a module to fail. We should standardize that piece. > > You have: > > blacklist foo > > to prevent udev from loading a module and > > install foo /bin/true > > to prevent modprobe from loading the module at all. What is the > motivation for inventing a third way, through adding invalid parameters? > FWIW, I've occasionally booted with modulename.garbage=1 to prevent modulename from loading at boot. It may be worth adding a more intentional way to do that. --Andy
Dne 3.7.2013 23:17, Andy Lutomirski napsal(a): > On Wed, Jul 3, 2013 at 2:03 PM, Michal Marek <mmarek@suse.cz> wrote: >> Dne 1.7.2013 18:33, Jonathan Masters napsal(a): >>> One caveat. Sometimes we have manufactured parameters intentionally >>> to cause a module to fail. We should standardize that piece. >> >> You have: >> >> blacklist foo >> >> to prevent udev from loading a module and >> >> install foo /bin/true >> >> to prevent modprobe from loading the module at all. What is the >> motivation for inventing a third way, through adding invalid parameters? >> > > FWIW, I've occasionally booted with modulename.garbage=1 to prevent > modulename from loading at boot. It may be worth adding a more > intentional way to do that. Hm, right, there seems to be no clean way to achieve this via a commandline argument. Maybe define a magic module option to tell the module loader not to load a module? Thanks, Michal -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Michal, All, On 2013-07-03 23:23 +0200, Michal Marek spake thusly: > Dne 3.7.2013 23:17, Andy Lutomirski napsal(a): > > On Wed, Jul 3, 2013 at 2:03 PM, Michal Marek <mmarek@suse.cz> wrote: > >> Dne 1.7.2013 18:33, Jonathan Masters napsal(a): > >>> One caveat. Sometimes we have manufactured parameters intentionally > >>> to cause a module to fail. We should standardize that piece. > >> > >> You have: > >> > >> blacklist foo > >> > >> to prevent udev from loading a module and > >> > >> install foo /bin/true > >> > >> to prevent modprobe from loading the module at all. What is the > >> motivation for inventing a third way, through adding invalid parameters? > >> > > > > FWIW, I've occasionally booted with modulename.garbage=1 to prevent > > modulename from loading at boot. It may be worth adding a more > > intentional way to do that. > > Hm, right, there seems to be no clean way to achieve this via a > commandline argument. Maybe define a magic module option to tell the > module loader not to load a module? I was going to suggest that, or a new kernel option: noloadmodules=module1[,module2...] The option may well be cumulative, too, so we could do: noloadmodules=module1,module2 noloadmodules=module3 and none of module{1,2,3} would be loaded. This could allow bootloaders to build up the command line more easily. (Ab)using the module parameter to avoid loading is hackish at best, IMHO. Regards, Yann E. MORIN.
On Wed, Jul 3, 2013 at 6:23 PM, Michal Marek <mmarek@suse.cz> wrote: > Dne 3.7.2013 23:17, Andy Lutomirski napsal(a): >> On Wed, Jul 3, 2013 at 2:03 PM, Michal Marek <mmarek@suse.cz> wrote: >>> Dne 1.7.2013 18:33, Jonathan Masters napsal(a): >>>> One caveat. Sometimes we have manufactured parameters intentionally >>>> to cause a module to fail. We should standardize that piece. >>> >>> You have: >>> >>> blacklist foo >>> >>> to prevent udev from loading a module and >>> >>> install foo /bin/true >>> >>> to prevent modprobe from loading the module at all. What is the >>> motivation for inventing a third way, through adding invalid parameters? >>> >> >> FWIW, I've occasionally booted with modulename.garbage=1 to prevent >> modulename from loading at boot. It may be worth adding a more >> intentional way to do that. > > Hm, right, there seems to be no clean way to achieve this via a > commandline argument. Maybe define a magic module option to tell the > module loader not to load a module? modprobe.blacklist=modname1,modname2,... is already there, though all the silliness of blacklist applies unless "-b" is passed (that's the equivalent behavior of udev) Lucas De Marchi -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Jul 3, 2013 at 2:31 PM, Lucas De Marchi <lucas.demarchi@profusion.mobi> wrote: > On Wed, Jul 3, 2013 at 6:23 PM, Michal Marek <mmarek@suse.cz> wrote: >> Dne 3.7.2013 23:17, Andy Lutomirski napsal(a): >>> On Wed, Jul 3, 2013 at 2:03 PM, Michal Marek <mmarek@suse.cz> wrote: >>>> Dne 1.7.2013 18:33, Jonathan Masters napsal(a): >>>>> One caveat. Sometimes we have manufactured parameters intentionally >>>>> to cause a module to fail. We should standardize that piece. >>>> >>>> You have: >>>> >>>> blacklist foo >>>> >>>> to prevent udev from loading a module and >>>> >>>> install foo /bin/true >>>> >>>> to prevent modprobe from loading the module at all. What is the >>>> motivation for inventing a third way, through adding invalid parameters? >>>> >>> >>> FWIW, I've occasionally booted with modulename.garbage=1 to prevent >>> modulename from loading at boot. It may be worth adding a more >>> intentional way to do that. >> >> Hm, right, there seems to be no clean way to achieve this via a >> commandline argument. Maybe define a magic module option to tell the >> module loader not to load a module? > > modprobe.blacklist=modname1,modname2,... is already there, though all > the silliness of blacklist applies unless "-b" is passed (that's the > equivalent behavior of udev) That would probably be good enough for me. It would be neat if this worked for built-in "modules" as well, but that would probably be quite intrusive. --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/kernel/module.c b/kernel/module.c index 3c2c72d..46db10a 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3206,6 +3206,17 @@ out: return err; } +static int unknown_module_param_cb(char *param, char *val, const char *modname) +{ + /* Check for magic 'dyndbg' arg */ + int ret = ddebug_dyndbg_module_param_cb(param, val, modname); + if (ret != 0) { + printk(KERN_WARNING "%s: unknown parameter '%s' ignored\n", + modname, param); + } + return 0; +} + /* Allocate and load the module: note that size of section 0 is always zero, and we rely on this for optional sections. */ static int load_module(struct load_info *info, const char __user *uargs, @@ -3292,7 +3303,7 @@ static int load_module(struct load_info *info, const char __user *uargs, /* Module is ready to execute: parsing args may do that. */ err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, - -32768, 32767, &ddebug_dyndbg_module_param_cb); + -32768, 32767, unknown_module_param_cb); if (err < 0) goto bug_cleanup;