Patchwork ahci: Fix crashes on duplicate BH registration

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Submitter Jan Kiszka
Date May 9, 2011, 3:48 p.m.
Message ID <4DC80CC3.2030807@siemens.com>
Download mbox | patch
Permalink /patch/94783/
State New
Headers show

Comments

Jan Kiszka - May 9, 2011, 3:48 p.m.
If ahci_dma_set_inactive is called a while there is still a pending BH
from a previous run, we will crash on the second run of
ahci_check_cmd_bh as it overwrites AHCIDevice::check_bh. Avoid this
broken and redundant duplicate registration.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 hw/ide/ahci.c |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)
Kevin Wolf - May 10, 2011, 10:14 a.m.
Am 09.05.2011 17:48, schrieb Jan Kiszka:
> If ahci_dma_set_inactive is called a while there is still a pending BH
> from a previous run, we will crash on the second run of
> ahci_check_cmd_bh as it overwrites AHCIDevice::check_bh. Avoid this
> broken and redundant duplicate registration.
> 
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

Thanks, applied to the block branch.

Kevin

Patch

diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
index c6e0c77..744d19d 100644
--- a/hw/ide/ahci.c
+++ b/hw/ide/ahci.c
@@ -1066,9 +1066,11 @@  static int ahci_dma_set_inactive(IDEDMA *dma)
 
     ad->dma_cb = NULL;
 
-    /* maybe we still have something to process, check later */
-    ad->check_bh = qemu_bh_new(ahci_check_cmd_bh, ad);
-    qemu_bh_schedule(ad->check_bh);
+    if (!ad->check_bh) {
+        /* maybe we still have something to process, check later */
+        ad->check_bh = qemu_bh_new(ahci_check_cmd_bh, ad);
+        qemu_bh_schedule(ad->check_bh);
+    }
 
     return 0;
 }