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

[Andreas Gruenbacher <agruen@suse.de>]

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 <agruen@suse.de>

---

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];
 	}

From: Andreas Gruenbacher <agruen@suse.de>
Subject: Modules with old-style parameters won't load
References: 148245

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 parameter definitions for parameters that aren't
actually there.

Signed-off-by: Andreas Gruenbacher <agruen@suse.de>

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];
 	}