Commit bb9d3d56 authored by Rusty Russell's avatar Rusty Russell

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: default avatarJoern Engel <joern@lazybastard.org>
Tested-by: default avatarErez Zadok <ezk@cs.sunysb.edu>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent efa5345e
...@@ -1293,6 +1293,17 @@ static void mod_kobject_remove(struct module *mod) ...@@ -1293,6 +1293,17 @@ static void mod_kobject_remove(struct module *mod)
kobject_put(&mod->mkobj.kobj); kobject_put(&mod->mkobj.kobj);
} }
/*
* 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 * unlink the module with the whole machine is stopped with interrupts off
* - this defends against kallsyms not taking locks * - this defends against kallsyms not taking locks
...@@ -2035,6 +2046,11 @@ static struct module *load_module(void __user *umod, ...@@ -2035,6 +2046,11 @@ static struct module *load_module(void __user *umod,
printk(KERN_WARNING "%s: Ignoring obsolete parameters\n", printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
mod->name); 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 */ /* Size of section 0 is 0, so this works well if no params */
err = parse_args(mod->name, mod->args, err = parse_args(mod->name, mod->args,
(struct kernel_param *) (struct kernel_param *)
...@@ -2043,7 +2059,7 @@ static struct module *load_module(void __user *umod, ...@@ -2043,7 +2059,7 @@ static struct module *load_module(void __user *umod,
/ sizeof(struct kernel_param), / sizeof(struct kernel_param),
NULL); NULL);
if (err < 0) if (err < 0)
goto arch_cleanup; goto unlink;
err = mod_sysfs_setup(mod, err = mod_sysfs_setup(mod,
(struct kernel_param *) (struct kernel_param *)
...@@ -2051,7 +2067,7 @@ static struct module *load_module(void __user *umod, ...@@ -2051,7 +2067,7 @@ static struct module *load_module(void __user *umod,
sechdrs[setupindex].sh_size sechdrs[setupindex].sh_size
/ sizeof(struct kernel_param)); / sizeof(struct kernel_param));
if (err < 0) if (err < 0)
goto arch_cleanup; goto unlink;
add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs); add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs); add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
...@@ -2066,7 +2082,8 @@ static struct module *load_module(void __user *umod, ...@@ -2066,7 +2082,8 @@ static struct module *load_module(void __user *umod,
/* Done! */ /* Done! */
return mod; return mod;
arch_cleanup: unlink:
stop_machine_run(__unlink_module, mod, NR_CPUS);
module_arch_cleanup(mod); module_arch_cleanup(mod);
cleanup: cleanup:
kobject_del(&mod->mkobj.kobj); kobject_del(&mod->mkobj.kobj);
...@@ -2091,17 +2108,6 @@ static struct module *load_module(void __user *umod, ...@@ -2091,17 +2108,6 @@ static struct module *load_module(void __user *umod,
goto free_hdr; 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 */ /* This is where the real work happens */
asmlinkage long asmlinkage long
sys_init_module(void __user *umod, sys_init_module(void __user *umod,
...@@ -2126,10 +2132,6 @@ sys_init_module(void __user *umod, ...@@ -2126,10 +2132,6 @@ sys_init_module(void __user *umod,
return PTR_ERR(mod); 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 */ /* Drop lock so they can recurse */
mutex_unlock(&module_mutex); mutex_unlock(&module_mutex);
......
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