From c66bb48edd58c3a22072b4f68312c225dc1b0009 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Mon, 3 Apr 2023 11:27:11 +0200 Subject: xen/pvcalls: don't call bind_evtchn_to_irqhandler() under lock bind_evtchn_to_irqhandler() shouldn't be called under spinlock, as it can sleep. This requires to move the calls of create_active() out of the locked regions. This is no problem, as the worst which could happen would be a spurious call of the interrupt handler, causing a spurious wake_up(). Reported-by: Dan Carpenter Link: https://lore.kernel.org/lkml/Y+JUIl64UDmdkboh@kadam/ Signed-off-by: Juergen Gross Reviewed-by: Oleksandr Tyshchenko Reviewed-by: Stefano Stabellini Link: https://lore.kernel.org/r/20230403092711.15285-1-jgross@suse.com Signed-off-by: Juergen Gross --- drivers/xen/pvcalls-front.c | 46 +++++++++++++++++++++++++-------------------- 1 file changed, 26 insertions(+), 20 deletions(-) (limited to 'drivers/xen') diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c index d5d589bda243..b72ee9379d77 100644 --- a/drivers/xen/pvcalls-front.c +++ b/drivers/xen/pvcalls-front.c @@ -227,22 +227,30 @@ again: static void free_active_ring(struct sock_mapping *map); -static void pvcalls_front_free_map(struct pvcalls_bedata *bedata, - struct sock_mapping *map) +static void pvcalls_front_destroy_active(struct pvcalls_bedata *bedata, + struct sock_mapping *map) { int i; unbind_from_irqhandler(map->active.irq, map); - spin_lock(&bedata->socket_lock); - if (!list_empty(&map->list)) - list_del_init(&map->list); - spin_unlock(&bedata->socket_lock); + if (bedata) { + spin_lock(&bedata->socket_lock); + if (!list_empty(&map->list)) + list_del_init(&map->list); + spin_unlock(&bedata->socket_lock); + } for (i = 0; i < (1 << PVCALLS_RING_ORDER); i++) gnttab_end_foreign_access(map->active.ring->ref[i], NULL); gnttab_end_foreign_access(map->active.ref, NULL); free_active_ring(map); +} + +static void pvcalls_front_free_map(struct pvcalls_bedata *bedata, + struct sock_mapping *map) +{ + pvcalls_front_destroy_active(bedata, map); kfree(map); } @@ -433,19 +441,18 @@ int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr, pvcalls_exit_sock(sock); return ret; } - - spin_lock(&bedata->socket_lock); - ret = get_request(bedata, &req_id); + ret = create_active(map, &evtchn); if (ret < 0) { - spin_unlock(&bedata->socket_lock); free_active_ring(map); pvcalls_exit_sock(sock); return ret; } - ret = create_active(map, &evtchn); + + spin_lock(&bedata->socket_lock); + ret = get_request(bedata, &req_id); if (ret < 0) { spin_unlock(&bedata->socket_lock); - free_active_ring(map); + pvcalls_front_destroy_active(NULL, map); pvcalls_exit_sock(sock); return ret; } @@ -821,28 +828,27 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags) pvcalls_exit_sock(sock); return ret; } - spin_lock(&bedata->socket_lock); - ret = get_request(bedata, &req_id); + ret = create_active(map2, &evtchn); if (ret < 0) { - clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, - (void *)&map->passive.flags); - spin_unlock(&bedata->socket_lock); free_active_ring(map2); kfree(map2); + clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, + (void *)&map->passive.flags); pvcalls_exit_sock(sock); return ret; } - ret = create_active(map2, &evtchn); + spin_lock(&bedata->socket_lock); + ret = get_request(bedata, &req_id); if (ret < 0) { - free_active_ring(map2); - kfree(map2); clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, (void *)&map->passive.flags); spin_unlock(&bedata->socket_lock); + pvcalls_front_free_map(bedata, map2); pvcalls_exit_sock(sock); return ret; } + list_add_tail(&map2->list, &bedata->socket_mappings); req = RING_GET_REQUEST(&bedata->ring, req_id); -- cgit v1.2.3