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[Qemu-devel] [PATCH v2 26/42] ivshmem: Plug leaks on unplug, fix peer di
From: |
Markus Armbruster |
Subject: |
[Qemu-devel] [PATCH v2 26/42] ivshmem: Plug leaks on unplug, fix peer disconnect |
Date: |
Mon, 7 Mar 2016 20:25:38 +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, and tighten it to reject own ID.
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 e568263..2f2f43f 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 v2 41/42] ivshmem: Require master to have ID zero, (continued)
- [Qemu-devel] [PATCH v2 41/42] ivshmem: Require master to have ID zero, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 07/42] event_notifier: Make event_notifier_init_fd() #ifdef CONFIG_EVENTFD, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 22/42] ivshmem: Leave INTx alone when using MSI-X, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 15/42] ivshmem: Clean up after commit 9940c32, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 18/42] ivshmem: Fix harmless misuse of Error, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 27/42] ivshmem: Receive shared memory synchronously in realize(), Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 32/42] ivshmem: Tighten check of property "size", Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 26/42] ivshmem: Plug leaks on unplug, fix peer disconnect,
Markus Armbruster <=
- [Qemu-devel] [PATCH v2 37/42] ivshmem: Replace int role_val by OnOffAuto master, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 39/42] ivshmem: Clean up after the previous commit, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 31/42] ivshmem: Simplify how we cope with short reads from server, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 29/42] ivshmem: Rely on server sending the ID right after the version, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 38/42] ivshmem: Split ivshmem-plain, ivshmem-doorbell off ivshmem, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 30/42] ivshmem: Drop the hackish test for UNIX domain chardev, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 17/42] ivshmem: Don't destroy the chardev on version mismatch, Markus Armbruster, 2016/03/07