Re: [PATCH] Make `obsolete params' work correctly if MODULE_SYMBOL_PREFIX is non-empty

From: Rusty Russell (rusty@rustcorp.com.au)
Date: Fri Jan 10 2003 - 23:20:47 EST

In message <Pine.LNX.4.44.0301100902380.12833-100000@home.transmeta.com> you wr
ite:
>
> On Fri, 10 Jan 2003, Rusty Russell wrote:
> >
> > Yep. Maximum length of obsolete parameter name in current kernel:
> > seq_default_timer_resolution (28 chars).
>
> Don't do this. Make the limit fixed, and check it.

Just in case someone names a variable over 2000 chars, and uses it as
an old-style module parameter?

Done, with protest. Please apply.

Rusty.
(Miles, your sizeof also merged). 

--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

Name: Make obsolete module parameters work with MODULE_SYMBOL_PREFIX
Author: Miles Bader
Status: Trivial

D: Since these are just symbols in the module object, they need symbol name
D: munging to find the symbol from the parameter name.

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15543-linux-2.5-bk/kernel/module.c .15543-linux-2.5-bk.updated/kernel/module.c
--- .15543-linux-2.5-bk/kernel/module.c	2003-01-10 10:55:43.000000000 +1100
+++ .15543-linux-2.5-bk.updated/kernel/module.c	2003-01-11 15:15:59.000000000 +1100
@@ -680,18 +680,31 @@ static int obsolete_params(const char *n
 		return -ENOMEM;
 
 	DEBUGP("Module %s has %u obsolete params\n", name, num);
-	for (i = 0; i < num; i++)
+	for (i = 0; i < num; i++) {
+		if (strlen(obsparm[i].name) > 1024) {
+			printk("%s: Huge parameter.  Linus 1, Rusty 0.\n",
+			       name);
+			ret = -EINVAL;
+			goto out;
+		}
 		DEBUGP("Param %i: %s type %s\n",
 		       num, obsparm[i].name, obsparm[i].type);
+	}
 
 	for (i = 0; i < num; i++) {
+		char sym_name[strlen(obsparm[i].name)
+			     + sizeof(MODULE_SYMBOL_PREFIX)];
+
+		strcpy(sym_name, MODULE_SYMBOL_PREFIX);
+		strcat(sym_name, obsparm[i].name);
+
 		kp[i].name = obsparm[i].name;
 		kp[i].perm = 000;
 		kp[i].set = set_obsolete;
 		kp[i].get = NULL;
 		obsparm[i].addr
 			= (void *)find_local_symbol(sechdrs, symindex, strtab,
-						    obsparm[i].name);
+						    sym_name);
 		if (!obsparm[i].addr) {
 			printk("%s: falsely claims to have parameter %s\n",
 			       name, obsparm[i].name);
-
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