The branch main has been updated by royger: URL: https://cgit.FreeBSD.org/src/commit/?id=834013dea2d29ef943620bfaf7f269f9e581e170
commit 834013dea2d29ef943620bfaf7f269f9e581e170 Author: Elliott Mitchell <[email protected]> AuthorDate: 2021-05-11 19:05:03 +0000 Commit: Roger Pau Monné <[email protected]> CommitDate: 2023-04-14 13:58:50 +0000 xen/intr: rework xen_intr_alloc_isrc() locking Locking for allocation was being done in xen_intr_bind_isrc(), but the unlock was inside xen_intr_alloc_isrc(). While the lock acquisition at the end of xen_intr_alloc_isrc() was to modify xen_intr_port_to_isrc[], NOT allocation. Fix this garbled (though working) locking scheme. Now locking for allocation is strictly in xen_intr_alloc_isrc(), while locking to modify xen_intr_port_to_isrc[] is in xen_intr_bind_isrc(). Reviewed by: royger Differential Revision: https://reviews.freebsd.org/D30726 --- sys/x86/xen/xen_intr.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/sys/x86/xen/xen_intr.c b/sys/x86/xen/xen_intr.c index 6e4b1d9df1f8..cf20f2cdcbf8 100644 --- a/sys/x86/xen/xen_intr.c +++ b/sys/x86/xen/xen_intr.c @@ -317,9 +317,10 @@ xen_intr_alloc_isrc(enum evtchn_type type) unsigned int vector; int error; - KASSERT(mtx_owned(&xen_intr_isrc_lock), ("Evtchn alloc lock not held")); + mtx_lock(&xen_intr_isrc_lock); isrc = xen_intr_find_unused_isrc(type); if (isrc != NULL) { + mtx_unlock(&xen_intr_isrc_lock); return (isrc); } @@ -328,6 +329,7 @@ xen_intr_alloc_isrc(enum evtchn_type type) warned = 1; printf("%s: Xen interrupts exhausted.\n", __func__); } + mtx_unlock(&xen_intr_isrc_lock); return (NULL); } @@ -346,7 +348,6 @@ xen_intr_alloc_isrc(enum evtchn_type type) if (error != 0) panic("%s(): failed registering interrupt %u, error=%d\n", __func__, vector, error); - mtx_lock(&xen_intr_isrc_lock); return (isrc); } @@ -427,16 +428,14 @@ xen_intr_bind_isrc(struct xenisrc **isrcp, evtchn_port_t local_port, } *port_handlep = NULL; - mtx_lock(&xen_intr_isrc_lock); isrc = xen_intr_alloc_isrc(type); - if (isrc == NULL) { - mtx_unlock(&xen_intr_isrc_lock); + if (isrc == NULL) return (ENOSPC); - } isrc->xi_port = local_port; isrc->xi_close = false; - xen_intr_port_to_isrc[local_port] = isrc; refcount_init(&isrc->xi_refcount, 1); + mtx_lock(&xen_intr_isrc_lock); + xen_intr_port_to_isrc[isrc->xi_port] = isrc; mtx_unlock(&xen_intr_isrc_lock); #ifdef SMP
