module: better OOPS and lockdep coverage for loading modules
If we put the module in the linked list *before* calling into to, we
get the module name and functions in the OOPS (is_module_address can
find the module). It also helps lockdep in a similar way.
Acked-and-tested-by: Joern Engel <joern@lazybastard.org>
Tested-by: Erez Zadok <ezk@cs.sunysb.edu>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/kernel/module.c b/kernel/module.c
index 276abd7..12067ff 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1294,6 +1294,17 @@
}
/*
+ * link the module with the whole machine is stopped with interrupts off
+ * - this defends against kallsyms not taking locks
+ */
+static int __link_module(void *_mod)
+{
+ struct module *mod = _mod;
+ list_add(&mod->list, &modules);
+ return 0;
+}
+
+/*
* unlink the module with the whole machine is stopped with interrupts off
* - this defends against kallsyms not taking locks
*/
@@ -2035,6 +2046,11 @@
printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
mod->name);
+ /* Now sew it into the lists so we can get lockdep and oops
+ * info during argument parsing. Noone should access us, since
+ * strong_try_module_get() will fail. */
+ stop_machine_run(__link_module, mod, NR_CPUS);
+
/* Size of section 0 is 0, so this works well if no params */
err = parse_args(mod->name, mod->args,
(struct kernel_param *)
@@ -2043,7 +2059,7 @@
/ sizeof(struct kernel_param),
NULL);
if (err < 0)
- goto arch_cleanup;
+ goto unlink;
err = mod_sysfs_setup(mod,
(struct kernel_param *)
@@ -2051,7 +2067,7 @@
sechdrs[setupindex].sh_size
/ sizeof(struct kernel_param));
if (err < 0)
- goto arch_cleanup;
+ goto unlink;
add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
@@ -2066,7 +2082,8 @@
/* Done! */
return mod;
- arch_cleanup:
+ unlink:
+ stop_machine_run(__unlink_module, mod, NR_CPUS);
module_arch_cleanup(mod);
cleanup:
kobject_del(&mod->mkobj.kobj);
@@ -2091,17 +2108,6 @@
goto free_hdr;
}
-/*
- * link the module with the whole machine is stopped with interrupts off
- * - this defends against kallsyms not taking locks
- */
-static int __link_module(void *_mod)
-{
- struct module *mod = _mod;
- list_add(&mod->list, &modules);
- return 0;
-}
-
/* This is where the real work happens */
asmlinkage long
sys_init_module(void __user *umod,
@@ -2126,10 +2132,6 @@
return PTR_ERR(mod);
}
- /* Now sew it into the lists. They won't access us, since
- strong_try_module_get() will fail. */
- stop_machine_run(__link_module, mod, NR_CPUS);
-
/* Drop lock so they can recurse */
mutex_unlock(&module_mutex);