| Message ID | 20250306161305.10236-1-jgross@suse.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] xen/events: fix get_global_virq_handler() usage without hardware domain | expand |
On 06.03.2025 17:13, Juergen Gross wrote: > Some use cases of get_global_virq_handler() didn't account for the > case of running without hardware domain. > > Fix that by testing get_global_virq_handler() returning NULL where > needed (e.g. when directly dereferencing the result). > > Fixes: 980822c5edd1 ("xen/events: allow setting of global virq handler only for unbound virqs") > Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
diff --git a/xen/common/event_channel.c b/xen/common/event_channel.c index 4ee6b6b4ce..c68aa97135 100644 --- a/xen/common/event_channel.c +++ b/xen/common/event_channel.c @@ -1036,7 +1036,9 @@ int set_global_virq_handler(struct domain *d, uint32_t virq) { old = global_virq_handlers[virq]; hdl = get_global_virq_handler(virq); - if ( hdl != d ) + if ( !hdl ) + global_virq_handlers[virq] = d; + else if ( hdl != d ) { read_lock(&hdl->event_lock); @@ -1091,7 +1093,7 @@ struct domain *lock_dom_exc_handler(void) struct domain *d; d = get_global_virq_handler(VIRQ_DOM_EXC); - if ( unlikely(!get_domain(d)) ) + if ( unlikely(!d) || unlikely(!get_domain(d)) ) return NULL; read_lock(&d->event_lock); @@ -1101,6 +1103,9 @@ struct domain *lock_dom_exc_handler(void) void unlock_dom_exc_handler(struct domain *d) { + if ( likely(!d) ) + return; + read_unlock(&d->event_lock); put_domain(d);
Some use cases of get_global_virq_handler() didn't account for the case of running without hardware domain. Fix that by testing get_global_virq_handler() returning NULL where needed (e.g. when directly dereferencing the result). Fixes: 980822c5edd1 ("xen/events: allow setting of global virq handler only for unbound virqs") Signed-off-by: Juergen Gross <jgross@suse.com> --- V2: - fix use case of unlikely() (Jan Beulich) - add test for NULL in unlock_dom_exc_handler() (Jan Beulich) --- xen/common/event_channel.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)