On 15.11.2021 23:27, Stefano Stabellini wrote:
> From: Stefano Stabellini <stefano.stabellini@xxxxxxxxxx>
>
> In case of errors in xenbus_init (e.g. missing xen_store_gfn parameter),
> we goto out_error but we forget to reset xen_store_domain_type to
> XS_UNKNOWN. As a consequence xenbus_probe_initcall and other initcalls
> will still try to initialize xenstore resulting into a crash at boot.
>
> [ 2.479830] Call trace:
> [ 2.482314] xb_init_comms+0x18/0x150
> [ 2.486354] xs_init+0x34/0x138
> [ 2.489786] xenbus_probe+0x4c/0x70
> [ 2.498432] xenbus_probe_initcall+0x2c/0x7c
> [ 2.503944] do_one_initcall+0x54/0x1b8
> [ 2.507358] kernel_init_freeable+0x1ac/0x210
> [ 2.511617] kernel_init+0x28/0x130
> [ 2.516112] ret_from_fork+0x10/0x20
>
> Cc: <Stable@xxxxxxxxxxxxxxx>
> Cc: jbeulich@xxxxxxxx
> Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxx>
For the immediate purpose as described this looks okay, so
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
However, aren't there further pieces missing on this error patch:
- clearing of xenstored_ready in case it got set,
- rolling back xenstored_local_init() (XS_LOCAL) and xen_remap()
(XS_HVM).
And shouldn't xs_init() failure when called from xenbus_probe()
also result in the driver not giving the appearance of being usable?
> --- a/drivers/xen/xenbus/xenbus_probe.c
> +++ b/drivers/xen/xenbus/xenbus_probe.c
> @@ -909,7 +909,7 @@ static struct notifier_block xenbus_resume_nb = {
>
> static int __init xenbus_init(void)
> {
> - int err = 0;
> + int err;
> uint64_t v = 0;
> xen_store_domain_type = XS_UNKNOWN;
>
Minor remark: You may want to take the opportunity and add the
missing blank line here to visually separate the assignment from
the declarations.
Jan
