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[Qemu-devel] [PATCH 22/38] ivshmem: Plug leaks on unplug, fix peer disco
From: |
Markus Armbruster |
Subject: |
[Qemu-devel] [PATCH 22/38] ivshmem: Plug leaks on unplug, fix peer disconnect |
Date: |
Mon, 29 Feb 2016 19:40:38 +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.
Cc: Paolo Bonzini <address@hidden>
Signed-off-by: Markus Armbruster <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 fc46666..c366087 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) {
+ error_report("invalid peer %d", posn);
+ return;
+ }
close_peer_eventfds(s, posn);
}
--
2.4.3
- [Qemu-devel] [PATCH 00/38] ivshmem: Fixes, cleanups, device model split, Markus Armbruster, 2016/02/29
- [Qemu-devel] [PATCH 09/38] ivshmem: Add missing newlines to debug printfs, Markus Armbruster, 2016/02/29
- [Qemu-devel] [PATCH 02/38] qemu-doc: Fix ivshmem huge page example, Markus Armbruster, 2016/02/29
- [Qemu-devel] [PATCH 07/38] ivshmem-test: Improve test cases /ivshmem/server-*, Markus Armbruster, 2016/02/29
- [Qemu-devel] [PATCH 11/38] ivshmem: Clean up after commit 9940c32, Markus Armbruster, 2016/02/29
- [Qemu-devel] [PATCH 12/38] ivshmem: Drop ivshmem_event() stub, Markus Armbruster, 2016/02/29
- [Qemu-devel] [PATCH 05/38] ivshmem-test: Improve test case /ivshmem/single, Markus Armbruster, 2016/02/29
- [Qemu-devel] [PATCH 15/38] ivshmem: Failed realize() can leave migration blocker behind, Markus Armbruster, 2016/02/29
- [Qemu-devel] [PATCH 14/38] ivshmem: Fix harmless misuse of Error, Markus Armbruster, 2016/02/29
- [Qemu-devel] [PATCH 10/38] ivshmem: Compile debug prints unconditionally to prevent bit-rot, Markus Armbruster, 2016/02/29
- [Qemu-devel] [PATCH 22/38] ivshmem: Plug leaks on unplug, fix peer disconnect,
Markus Armbruster <=
- [Qemu-devel] [PATCH 06/38] ivshmem-test: Clean up wait for devices to become operational, Markus Armbruster, 2016/02/29
- [Qemu-devel] [PATCH 16/38] ivshmem: Clean up register callbacks, Markus Armbruster, 2016/02/29
- [Qemu-devel] [PATCH 03/38] event_notifier: Make event_notifier_init_fd() #ifdef CONFIG_EVENTFD, Markus Armbruster, 2016/02/29
- [Qemu-devel] [PATCH 13/38] ivshmem: Don't destroy the chardev on version mismatch, Markus Armbruster, 2016/02/29
- [Qemu-devel] [PATCH 21/38] ivshmem: Disentangle ivshmem_read(), Markus Armbruster, 2016/02/29
- [Qemu-devel] [PATCH 32/38] qdev: New DEFINE_PROP_ON_OFF_AUTO, Markus Armbruster, 2016/02/29
- [Qemu-devel] [PATCH 26/38] ivshmem: Drop the hackish test for UNIX domain chardev, Markus Armbruster, 2016/02/29
- [Qemu-devel] [PATCH 19/38] ivshmem: Assert interrupts are set up once, Markus Armbruster, 2016/02/29
- [Qemu-devel] [PATCH 28/38] ivshmem: Tighten check of property "size", Markus Armbruster, 2016/02/29
- [Qemu-devel] [PATCH 30/38] ivshmem: Simplify memory regions for BAR 2 (shared memory), Markus Armbruster, 2016/02/29