Re: [PATCH] block2mtd lockdep_init_map warning

Erez Zadok
2008-01-20T21:02:03Z

In message <20080116212054.GA891@lazybastard.org>, =?utf-8?B?SsO2cm4=?= Engel writes:
[...]
> Patch didn't compile due to function ordering. Here is an updated version.

Joern/Peter, I've tested this updated patch with v2.6.24-rc8-74-ga7da60f.
It worked fine for me.

Thanks,
Erez.

> Acked-and-tested-by: Joern Engel <joern@lazybastard.org>
>
> diff --git a/kernel/module.c b/kernel/module.c
> index c2e3e2e..0397b1e 100644
> --- a/kernel/module.c
> +++ b/kernel/module.c
> @@ -1645,6 +1645,17 @@ static inline void add_kallsyms(struct module *mod,
> }
> #endif /* CONFIG_KALLSYMS */
>
> +/*
> + * 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;
> +}
> +
> /* Allocate and load the module: note that size of section 0 is always
> zero, and we rely on this for optional sections. */
> static struct module *load_module(void __user *umod,
> @@ -2023,6 +2034,11 @@ 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 *)
> @@ -2031,7 +2047,7 @@ 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 *)
> @@ -2039,7 +2055,7 @@ 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);
>
> @@ -2054,7 +2070,8 @@ 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:
> module_unload_free(mod);
> @@ -2076,17 +2093,6 @@ 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,
> @@ -2111,10 +2117,6 @@ 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);