2006-02-19 17:40:01

by Andreas Gruenbacher

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Subject: [PATCH] Modules with old-style parameters won't load

Modules may define static variables as old-style MODULE_PARM() parameters. If
those variables are not actually used the compiler may optimize them out,
which currently leads to a `module: falsely claims to have parameter param'
error, and the module won't load.

Just ignore old-style parameter definitions for parameters that aren't
actually there.

Signed-off-by: Andreas Gruenbacher <[email protected]>

---

Note: currently the CONFIG_OBSOLETE_MODPARM option is hardwired to y. I don't
know when old-style module parameters are expected to go away, but until then
we should make sure that they actually work.

Andreas

Index: linux-2.6.15/kernel/module.c
===================================================================
--- linux-2.6.15.orig/kernel/module.c
+++ linux-2.6.15/kernel/module.c
@@ -763,6 +763,10 @@ static int set_obsolete(const char *val,
max = simple_strtol(p, &endp, 10);
} else
max = min;
+ if (!obsparm->addr) {
+ /* Assume the compiler optimized out an unused parameter. */
+ return 0;
+ }
switch (*endp) {
case 'b':
return param_array(kp->name, val, min, max, obsparm->addr,
@@ -834,12 +838,6 @@ static int obsolete_params(const char *n
obsparm[i].addr
= (void *)find_local_symbol(sechdrs, symindex, strtab,
sym_name);
- if (!obsparm[i].addr) {
- printk("%s: falsely claims to have parameter %s\n",
- name, obsparm[i].name);
- ret = -EINVAL;
- goto out;
- }
kp[i].arg = &obsparm[i];
}


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2006-02-19 18:22:44

by Ingo Oeser

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Subject: Re: [PATCH] Modules with old-style parameters won't load

On Sunday 19 February 2006 18:39, Andreas Gruenbacher wrote:
> Just ignore old-style parameter definitions for parameters that aren't
> actually there.

But please tell the user, that his settings are going to be ignored via
printk, instead of silently ignoring him.

Regards


Ingo Oeser