Date: Sun, 24 May 2015 04:14:10 +0000 (UTC) From: Edward Tomasz Napierala <trasz@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r283349 - stable/10/sys/cam Message-ID: <201505240414.t4O4EATu013539@svn.freebsd.org>
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Author: trasz Date: Sun May 24 04:14:09 2015 New Revision: 283349 URL: https://svnweb.freebsd.org/changeset/base/283349 Log: MFC r279554: Make periphdriver_register() take XPT lock when modifying the periph_drivers array. This fixes a panic that sometimes occured when kldloading ctl.ko. PR: 200384 Sponsored by: The FreeBSD Foundation Modified: stable/10/sys/cam/cam_periph.c stable/10/sys/cam/cam_xpt.c Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/cam/cam_periph.c ============================================================================== --- stable/10/sys/cam/cam_periph.c Sun May 24 02:46:08 2015 (r283348) +++ stable/10/sys/cam/cam_periph.c Sun May 24 04:14:09 2015 (r283349) @@ -108,9 +108,19 @@ periphdriver_register(void *data) struct periph_driver **newdrivers, **old; int ndrivers; +again: ndrivers = nperiph_drivers + 2; newdrivers = malloc(sizeof(*newdrivers) * ndrivers, M_CAMPERIPH, M_WAITOK); + xpt_lock_buses(); + if (ndrivers != nperiph_drivers + 2) { + /* + * Lost race against itself; go around. + */ + xpt_unlock_buses(); + free(newdrivers, M_CAMPERIPH); + goto again; + } if (periph_drivers) bcopy(periph_drivers, newdrivers, sizeof(*newdrivers) * nperiph_drivers); @@ -118,9 +128,10 @@ periphdriver_register(void *data) newdrivers[nperiph_drivers + 1] = NULL; old = periph_drivers; periph_drivers = newdrivers; + nperiph_drivers++; + xpt_unlock_buses(); if (old) free(old, M_CAMPERIPH); - nperiph_drivers++; /* If driver marked as early or it is late now, initialize it. */ if (((drv->flags & CAM_PERIPH_DRV_EARLY) != 0 && initialized > 0) || initialized > 1) Modified: stable/10/sys/cam/cam_xpt.c ============================================================================== --- stable/10/sys/cam/cam_xpt.c Sun May 24 02:46:08 2015 (r283348) +++ stable/10/sys/cam/cam_xpt.c Sun May 24 04:14:09 2015 (r283349) @@ -149,6 +149,8 @@ typedef int xpt_pdrvfunc_t (struct perip /* Transport layer configuration information */ static struct xpt_softc xsoftc; +MTX_SYSINIT(xpt_topo_init, &xsoftc.xpt_topo_lock, "XPT topology lock", MTX_DEF); + TUNABLE_INT("kern.cam.boot_delay", &xsoftc.boot_delay); SYSCTL_INT(_kern_cam, OID_AUTO, boot_delay, CTLFLAG_RDTUN, &xsoftc.boot_delay, 0, "Bus registration wait time"); @@ -850,7 +852,6 @@ xpt_init(void *dummy) mtx_init(&xsoftc.xpt_lock, "XPT lock", NULL, MTX_DEF); mtx_init(&xsoftc.xpt_highpower_lock, "XPT highpower lock", NULL, MTX_DEF); - mtx_init(&xsoftc.xpt_topo_lock, "XPT topology lock", NULL, MTX_DEF); xsoftc.xpt_taskq = taskqueue_create("CAM XPT task", M_WAITOK, taskqueue_thread_enqueue, /*context*/&xsoftc.xpt_taskq);
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