pci_bridge_region_cleanup need to done after flatview_destroy,
because memory_region_unref need access memory regions in PCIBridgeWindows in
flatview_destroy.
here we delay pci_bridge_region_cleanup to be done in rcu queue work.
bellow are gdb backtraces.
oldcode mr->name will be freed in object_unparent, before flatview_destroy.
0 _int_free (av=0x7fffe00bcb20 <main_arena>, p=0x555556a988c0, have_lock=0) at
malloc.c:3947
1 0x00007fffdfd7c53c in __GI___libc_free (mem=<optimized out>) at malloc.c:2968
2 0x000055555587ad73 in memory_region_finalize (obj=<optimized out>) at
/work/work/loongson/qemu/qemu-latest/memory.c:1731
3 0x0000555555b52e52 in object_deinit (type=0x5555565a54f0,
obj=0x5555567dcbf0) at qom/object.c:462
4 object_finalize (data=0x5555567dcbf0) at qom/object.c:476
5 object_unref (obj=0x5555567dcbf0) at qom/object.c:924
6 0x0000555555b51e57 in object_property_del_child (obj=0x55555695f3d0,
child=child@entry=0x5555567dcbf0, errp=0x0) at qom/object.c:436
7 0x0000555555b525e4 in object_unparent (obj=obj@entry=0x5555567dcbf0) at
qom/object.c:455
8 0x0000555555a7bd70 in pci_bridge_region_cleanup (w=0x5555567dca10,
br=<optimized out>) at hw/pci/pci_bridge.c:229
9 0x0000555555a7c336 in pci_bridge_update_mappings (br=<optimized out>) at
hw/pci/pci_bridge.c:248
10 0x0000555555a7c3ba in pci_bridge_write_config (d=0x55555695f3d0, address=4,
val=44040192, len=4) at hw/pci/pci_bridge.c:272
here mr mr->owner, mr->name has been freed in object_unparent before.
0 memory_region_unref_do (mr=0x5555567dcbf0) at
/work/work/loongson/qemu/qemu-latest/memory.c:296
1 0x0000555555877c49 in flatview_destroy (view=0x555557344020) at
/work/work/loongson/qemu/qemu-latest/memory.c:290
2 0x0000555555c4a0ae in call_rcu_thread (opaque=<optimized out>) at
util/rcu.c:284
3 0x00007fffe00c96ba in start_thread (arg=0x7fffd007c700) at
pthread_create.c:333
4 0x00007fffdfdff41d in clone () at
../sysdeps/unix/sysv/linux/x86_64/clone.S:109
void memory_region_unref(MemoryRegion *mr)
{
if (mr && mr->owner) {
object_unref(mr->owner);
}
}
Signed-off-by: QiaoChong <qiaoch...@loongson.cn>
---
hw/pci/pci_bridge.c | 14 +++++++++++++-
include/hw/pci/pci_bridge.h | 1 +
2 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/hw/pci/pci_bridge.c b/hw/pci/pci_bridge.c
index 40a39f5..c080471 100644
--- a/hw/pci/pci_bridge.c
+++ b/hw/pci/pci_bridge.c
@@ -233,6 +233,18 @@ static void pci_bridge_region_cleanup(PCIBridge *br,
PCIBridgeWindows *w)
g_free(w);
}
+/*
+ * pci_bridge_region_cleanup need to done after flatview_destroy,
+ * because memory_region_unref need access memory regions in PCIBridgeWindows
+ * in flatview_destroy.Here we delay pci_bridge_region_cleanup to be done
+ * in rcu queue work.
+ */
+
+static void pci_bridge_region_cleanup_schedule(PCIBridgeWindows *w)
+{
+ pci_bridge_region_cleanup(NULL, w);
+}
+
void pci_bridge_update_mappings(PCIBridge *br)
{
PCIBridgeWindows *w = br->windows;
@@ -243,7 +255,7 @@ void pci_bridge_update_mappings(PCIBridge *br)
pci_bridge_region_del(br, br->windows);
br->windows = pci_bridge_region_init(br);
memory_region_transaction_commit();
- pci_bridge_region_cleanup(br, w);
+ call_rcu(w, pci_bridge_region_cleanup_schedule, rcu);
}
/* default write_config function for PCI-to-PCI bridge */
diff --git a/include/hw/pci/pci_bridge.h b/include/hw/pci/pci_bridge.h
index 0347da5..0e1fd82 100644
--- a/include/hw/pci/pci_bridge.h
+++ b/include/hw/pci/pci_bridge.h
@@ -37,6 +37,7 @@ typedef struct PCIBridgeWindows PCIBridgeWindows;
* as subregions.
*/
struct PCIBridgeWindows {
+ struct rcu_head rcu;
MemoryRegion alias_pref_mem;
MemoryRegion alias_mem;
MemoryRegion alias_io;
--
2.7.4
