Subject: module: convert to stop_machine_create/destroy. Date: Mon, 22 Dec 2008 12:36:31 +0100 From: Heiko Carstens The module code relies on a non-failing stop_machine call. So we create the kstop threads in advance and with that make sure the call won't fail. Signed-off-by: Heiko Carstens Signed-off-by: Rusty Russell --- kernel/module.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) Index: linux-2.6/kernel/module.c =================================================================== --- linux-2.6.orig/kernel/module.c +++ linux-2.6/kernel/module.c @@ -757,8 +757,16 @@ sys_delete_module(const char __user *nam return -EFAULT; name[MODULE_NAME_LEN-1] = '\0'; - if (mutex_lock_interruptible(&module_mutex) != 0) - return -EINTR; + /* Create stop_machine threads since free_module relies on + * a non-failing stop_machine call. */ + ret = stop_machine_create(); + if (ret) + return ret; + + if (mutex_lock_interruptible(&module_mutex) != 0) { + ret = -EINTR; + goto out_stop; + } mod = find_module(name); if (!mod) { @@ -817,6 +825,8 @@ sys_delete_module(const char __user *nam out: mutex_unlock(&module_mutex); +out_stop: + stop_machine_destroy(); return ret; } @@ -1865,6 +1875,13 @@ static noinline struct module *load_modu /* vmalloc barfs on "unusual" numbers. Check here */ if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL) return ERR_PTR(-ENOMEM); + + /* Create stop_machine threads since the error path relies on + * a non-failing stop_machine call. */ + err = stop_machine_create(); + if (err) + goto free_hdr; + if (copy_from_user(hdr, umod, len) != 0) { err = -EFAULT; goto free_hdr; @@ -2257,6 +2274,7 @@ static noinline struct module *load_modu /* Get rid of temporary copy */ vfree(hdr); + stop_machine_destroy(); /* Done! */ return mod; @@ -2279,6 +2297,7 @@ static noinline struct module *load_modu kfree(args); free_hdr: vfree(hdr); + stop_machine_destroy(); return ERR_PTR(err); truncated: