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[Qemu-devel] [PATCH v3 24/40] ivshmem: Plug leaks on unplug, fix peer di
From: |
Markus Armbruster |
Subject: |
[Qemu-devel] [PATCH v3 24/40] ivshmem: Plug leaks on unplug, fix peer disconnect |
Date: |
Tue, 15 Mar 2016 19:34:39 +0100 |
close_peer_eventfds() cleans up three things: ioeventfd triggers if
they exist, eventfds, and the array to store them.
Commit 98609cd (v1.2.0) fixed it not to clean up ioeventfd triggers
when they don't exist (property ioeventfd=off, which is the default).
Unfortunately, the fix also made it skip cleanup of the eventfds and
the array then. This is a memory and file descriptor leak on unplug.
Additionally, the reset of nb_eventfds is skipped. Doesn't matter on
unplug. On peer disconnect, however, this permanently wedges the
interrupt vectors used for that peer's ID. The eventfds stay behind,
but aren't connected to a peer anymore. When the ID gets recycled for
a new peer, the new peer's eventfds get assigned to vectors after the
old ones. Commonly, the device's number of vectors matches the
server's, so the new ones get dropped with a "Too many eventfd
received" message. Interrupts either don't work (common case) or go
to the wrong vector.
Fix by narrowing the conditional to just the ioeventfd trigger
cleanup.
While there, move the "invalid" peer check to the only caller where it
can actually happen, and tighten it to reject own ID.
Cc: Paolo Bonzini <address@hidden>
Signed-off-by: Markus Armbruster <address@hidden>
Reviewed-by: Marc-André Lureau <address@hidden>
---
hw/misc/ivshmem.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
index d8d363e..c6d5dd5 100644
--- a/hw/misc/ivshmem.c
+++ b/hw/misc/ivshmem.c
@@ -428,21 +428,17 @@ static void close_peer_eventfds(IVShmemState *s, int posn)
{
int i, n;
- if (!ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
- return;
- }
- if (posn < 0 || posn >= s->nb_peers) {
- error_report("invalid peer %d", posn);
- return;
- }
-
+ assert(posn >= 0 && posn < s->nb_peers);
n = s->peers[posn].nb_eventfds;
- memory_region_transaction_begin();
- for (i = 0; i < n; i++) {
- ivshmem_del_eventfd(s, posn, i);
+ if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
+ memory_region_transaction_begin();
+ for (i = 0; i < n; i++) {
+ ivshmem_del_eventfd(s, posn, i);
+ }
+ memory_region_transaction_commit();
}
- memory_region_transaction_commit();
+
for (i = 0; i < n; i++) {
event_notifier_cleanup(&s->peers[posn].eventfds[i]);
}
@@ -598,6 +594,10 @@ static void process_msg_shmem(IVShmemState *s, int fd)
static void process_msg_disconnect(IVShmemState *s, uint16_t posn)
{
IVSHMEM_DPRINTF("posn %d has gone away\n", posn);
+ if (posn >= s->nb_peers || posn == s->vm_id) {
+ error_report("invalid peer %d", posn);
+ return;
+ }
close_peer_eventfds(s, posn);
}
--
2.4.3
- [Qemu-devel] [PATCH v3 00/40] ivshmem: Fixes, cleanups, device model split, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 04/40] qemu-doc: Fix ivshmem huge page example, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 02/40] ivshmem-server: Fix and clean up command line help, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 14/40] ivshmem: Drop ivshmem_event() stub, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 08/40] ivshmem-test: Clean up wait for devices to become operational, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 07/40] ivshmem-test: Improve test case /ivshmem/single, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 24/40] ivshmem: Plug leaks on unplug, fix peer disconnect,
Markus Armbruster <=
- [Qemu-devel] [PATCH v3 19/40] ivshmem: Clean up MSI-X conditions, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 06/40] tests/libqos/pci-pc: Fix qpci_pc_iomap() to map BARs aligned, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 12/40] ivshmem: Compile debug prints unconditionally to prevent bit-rot, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 09/40] ivshmem-test: Improve test cases /ivshmem/server-*, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 03/40] ivshmem-server: Don't overload POSIX shmem and file name, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 13/40] ivshmem: Clean up after commit 9940c32, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 17/40] ivshmem: Failed realize() can leave migration blocker behind, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 20/40] ivshmem: Leave INTx alone when using MSI-X, Markus Armbruster, 2016/03/15