[src/trunk]: src/sys/kern protect deferred lists' manipulation by config_misc...

[jdolecek <jdolecek%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/4b14640234f7
branches:  trunk
changeset: 969436:4b14640234f7
user:      jdolecek <jdolecek%NetBSD.org@localhost>
date:      Thu Feb 20 21:14:23 2020 +0000

description:
protect deferred lists' manipulation by config_misc_lock, same as
config_pending semaphore itself; right now this also covers
DVF_ATTACH_INPROGRESS flag

diffstat:

 sys/kern/subr_autoconf.c |  82 ++++++++++++++++++++++++++++++++++-------------
 1 files changed, 59 insertions(+), 23 deletions(-)

diffs (196 lines):

diff -r 70e8f44fb6f1 -r 4b14640234f7 sys/kern/subr_autoconf.c
--- a/sys/kern/subr_autoconf.c  Thu Feb 20 19:59:12 2020 +0000
+++ b/sys/kern/subr_autoconf.c  Thu Feb 20 21:14:23 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: subr_autoconf.c,v 1.265 2018/12/01 02:08:16 msaitoh Exp $ */
+/* $NetBSD: subr_autoconf.c,v 1.266 2020/02/20 21:14:23 jdolecek Exp $ */
 
 /*
  * Copyright (c) 1996, 2000 Christopher G. Demetriou
@@ -77,7 +77,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_autoconf.c,v 1.265 2018/12/01 02:08:16 msaitoh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_autoconf.c,v 1.266 2020/02/20 21:14:23 jdolecek Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ddb.h"
@@ -443,16 +443,23 @@
 {
        struct deferred_config *dc;
 
+       mutex_enter(&config_misc_lock);
        while ((dc = TAILQ_FIRST(&interrupt_config_queue)) != NULL) {
                TAILQ_REMOVE(&interrupt_config_queue, dc, dc_queue);
+               mutex_exit(&config_misc_lock);
+
                (*dc->dc_func)(dc->dc_dev);
-               dc->dc_dev->dv_flags &= ~DVF_ATTACH_INPROGRESS;
                if (!device_pmf_is_registered(dc->dc_dev))
                        aprint_debug_dev(dc->dc_dev,
                            "WARNING: power management not supported\n");
                config_pending_decr(dc->dc_dev);
                kmem_free(dc, sizeof(*dc));
+
+               mutex_enter(&config_misc_lock);
+               dc->dc_dev->dv_flags &= ~DVF_ATTACH_INPROGRESS;
        }
+       mutex_exit(&config_misc_lock);
+
        kthread_exit(0);
 }
 
@@ -462,7 +469,7 @@
        int i;
 
        for (i = 0; i < interrupt_config_threads; i++) {
-               (void)kthread_create(PRI_NONE, 0, NULL,
+               (void)kthread_create(PRI_NONE, 0/*XXXSMP */, NULL,
                    config_interrupts_thread, NULL, NULL, "configintr");
        }
 }
@@ -472,11 +479,18 @@
 {
        struct deferred_config *dc;
 
+       mutex_enter(&config_misc_lock);
        while ((dc = TAILQ_FIRST(&mountroot_config_queue)) != NULL) {
                TAILQ_REMOVE(&mountroot_config_queue, dc, dc_queue);
+               mutex_exit(&config_misc_lock);
+
                (*dc->dc_func)(dc->dc_dev);
                kmem_free(dc, sizeof(*dc));
+
+               mutex_enter(&config_misc_lock);
        }
+       mutex_exit(&config_misc_lock);
+
        kthread_exit(0);
 }
 
@@ -495,8 +509,8 @@
        KASSERT(mountroot_config_lwpids);
        for (i = 0; i < mountroot_config_threads; i++) {
                mountroot_config_lwpids[i] = 0;
-               (void)kthread_create(PRI_NONE, KTHREAD_MUSTJOIN, NULL,
-                                    config_mountroot_thread, NULL,
+               (void)kthread_create(PRI_NONE, KTHREAD_MUSTJOIN/* XXXSMP */,
+                                    NULL, config_mountroot_thread, NULL,
                                     &mountroot_config_lwpids[i],
                                     "configroot");
        }
@@ -1958,18 +1972,22 @@
        if (dev->dv_parent == NULL)
                panic("config_defer: can't defer config of a root device");
 
+       dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
+
+       config_pending_incr(dev);
+
+       mutex_enter(&config_misc_lock);
 #ifdef DIAGNOSTIC
-       TAILQ_FOREACH(dc, &deferred_config_queue, dc_queue) {
-               if (dc->dc_dev == dev)
+       struct deferred_config *odc;
+       TAILQ_FOREACH(odc, &deferred_config_queue, dc_queue) {
+               if (odc->dc_dev == dev)
                        panic("config_defer: deferred twice");
        }
 #endif
-
-       dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
        dc->dc_dev = dev;
        dc->dc_func = func;
        TAILQ_INSERT_TAIL(&deferred_config_queue, dc, dc_queue);
-       config_pending_incr(dev);
+       mutex_exit(&config_misc_lock);
 }
 
 /*
@@ -1989,19 +2007,23 @@
                return;
        }
 
+       dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
+
+       config_pending_incr(dev);
+
+       mutex_enter(&config_misc_lock);
 #ifdef DIAGNOSTIC
-       TAILQ_FOREACH(dc, &interrupt_config_queue, dc_queue) {
-               if (dc->dc_dev == dev)
+       struct deferred_config *odc;
+       TAILQ_FOREACH(odc, &interrupt_config_queue, dc_queue) {
+               if (odc->dc_dev == dev)
                        panic("config_interrupts: deferred twice");
        }
 #endif
-
-       dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
        dc->dc_dev = dev;
        dc->dc_func = func;
        TAILQ_INSERT_TAIL(&interrupt_config_queue, dc, dc_queue);
-       config_pending_incr(dev);
        dev->dv_flags |= DVF_ATTACH_INPROGRESS;
+       mutex_exit(&config_misc_lock);
 }
 
 /*
@@ -2021,17 +2043,21 @@
                return;
        }
 
+       dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
+
+       mutex_enter(&config_misc_lock);
 #ifdef DIAGNOSTIC
-       TAILQ_FOREACH(dc, &mountroot_config_queue, dc_queue) {
-               if (dc->dc_dev == dev)
+       struct deferred_config *odc;
+       TAILQ_FOREACH(odc, &mountroot_config_queue, dc_queue) {
+               if (odc->dc_dev == dev)
                        panic("%s: deferred twice", __func__);
        }
 #endif
 
-       dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
        dc->dc_dev = dev;
        dc->dc_func = func;
        TAILQ_INSERT_TAIL(&mountroot_config_queue, dc, dc_queue);
+       mutex_exit(&config_misc_lock);
 }
 
 /*
@@ -2040,17 +2066,27 @@
 static void
 config_process_deferred(struct deferred_config_head *queue, device_t parent)
 {
-       struct deferred_config *dc, *ndc;
-
-       for (dc = TAILQ_FIRST(queue); dc != NULL; dc = ndc) {
-               ndc = TAILQ_NEXT(dc, dc_queue);
+       struct deferred_config *dc;
+
+       mutex_enter(&config_misc_lock);
+       dc = TAILQ_FIRST(queue);
+       while (dc) {
                if (parent == NULL || dc->dc_dev->dv_parent == parent) {
                        TAILQ_REMOVE(queue, dc, dc_queue);
+                       mutex_exit(&config_misc_lock);
+
                        (*dc->dc_func)(dc->dc_dev);
                        config_pending_decr(dc->dc_dev);
                        kmem_free(dc, sizeof(*dc));
+
+                       mutex_enter(&config_misc_lock);
+                       /* Restart, queue might have changed */
+                       dc = TAILQ_FIRST(queue);
+               } else {
+                       dc = TAILQ_NEXT(dc, dc_queue);
                }
        }
+       mutex_exit(&config_misc_lock);
 }
 
 /*