From bb9d3d56e792d2619cc0903df4ac01d86ac1261d Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Tue, 29 Jan 2008 17:13:21 -0500 Subject: [PATCH] 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 Tested-by: Erez Zadok Signed-off-by: Rusty Russell --- kernel/module.c | 38 ++++++++++++++++++++------------------ 1 file changed, 20 insertions(+), 18 deletions(-) diff --git a/kernel/module.c b/kernel/module.c index 276abd7b7ff7..12067ff34d01 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1293,6 +1293,17 @@ static void mod_kobject_remove(struct module *mod) 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 * - this defends against kallsyms not taking locks @@ -2035,6 +2046,11 @@ static struct module *load_module(void __user *umod, 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 @@ static struct module *load_module(void __user *umod, / 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 @@ static struct module *load_module(void __user *umod, 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 @@ static struct module *load_module(void __user *umod, /* 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 @@ static struct module *load_module(void __user *umod, 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 @@ sys_init_module(void __user *umod, 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);