module_register_init fails, but driver is still loaded?

[Sergey Kandaurov]

On 4 August 2011 20:23, Garrett Cooper <yanegomi at gmail.com> wrote:
> Hi hackers,
>    I noticed that if anything fails while initializing a driver, the
> driver stays attached to the kernel as a module instead of being
> kicked when all references to the driver go to 0. Is this desired
> behavior (it doesn't seem like it, but I can see potential pros and
> cons of kicking the driver out of the kernel immediately when a
> failure state occurs)? I've seen this on 7.2 ~ 9-CURRENT. Example
> sourcecode and invocation attached below.

Hi.
I have cooked something that might work, though I don't know how much
is it correct from locking & cleanup side. Can you try it? Anyway, in its
current form we cannot return error from module_register_init() because
it's usually called from SYSINIT, so kldload(8) will say nonsense:
can't load ./bad_module.ko: No error: 0.

Index: sys/kern/kern_module.c
===================================================================
--- sys/kern/kern_module.c      (revision 224471)
+++ sys/kern/kern_module.c      (working copy)
@@ -112,6 +117,7 @@ module_register_init(const void *arg)
        const moduledata_t *data = (const moduledata_t *)arg;
        int error;
        module_t mod;
+       linker_file_t lf;

        mtx_lock(&Giant);
        MOD_SLOCK;
@@ -123,12 +129,14 @@ module_register_init(const void *arg)
        error = MOD_EVENT(mod, MOD_LOAD);
        if (error) {
                MOD_EVENT(mod, MOD_UNLOAD);
+               lf = mod->file;
                MOD_XLOCK;
                module_release(mod);
                MOD_XUNLOCK;
                printf("module_register_init: MOD_LOAD (%s, %p, %p) error"
                    " %d\n", data->name, (void *)data->evhand, data->priv,
                    error);
+               linker_release_module(NULL, NULL, lf);
        } else {
                MOD_XLOCK;
                if (mod->file) {


-- 
wbr,
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