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| author | Sripathi Kodi <sripathik@in.ibm.com> | 2010-06-30 16:32:00 +0530 |
|---|---|---|
| committer | Anthony Liguori <aliguori@us.ibm.com> | 2010-07-13 09:06:58 -0500 |
| commit | a03c54f16eb35df6f8a08255cf44230a194c50bc (patch) | |
| tree | 16eeeed325e7b81ac18ee6ac746934e5b92b80b1 /hw | |
| parent | bbe80adf29dbfe6118f8e0a27eea6e77b705df11 (diff) | |
| download | qemu-a03c54f16eb35df6f8a08255cf44230a194c50bc.tar.gz | |
virtio-9p: Avoid SEGV when log file couldn't be opened
While running in debug mode if 9P server is unable to open the log file
it results in a SEGV deep down in glibc:
Program received signal SIGSEGV, Segmentation fault.
0x008fca8c in fwrite () from /lib/libc.so.6
(gdb) bt
#0 0x008fca8c in fwrite () from /lib/libc.so.6
#1 0x081eb87e in pprint_pdu (pdu=0x89a52e1c)
at /data/sripathi/code/qemu/new/qemu-next-upstream/hw/virtio-9p-debug.c:380
#2 0x0806dad8 in submit_pdu (s=0x897dc008, pdu=0x89a52e1c)
at /data/sripathi/code/qemu/new/qemu-next-upstream/hw/virtio-9p.c:3092
#3 0x0806dc63 in handle_9p_output (vdev=0x897dc008, vq=0x86d8218)
at /data/sripathi/code/qemu/new/qemu-next-upstream/hw/virtio-9p.c:3122
#4 0x081ac728 in virtio_queue_notify (vdev=0x897dc008, n=0)
at /data/sripathi/code/qemu/new/qemu-next-upstream/hw/virtio.c:563
#5 0x08063876 in virtio_ioport_write (opaque=0x86d7b98, addr=16, val=0)
at /data/sripathi/code/qemu/new/qemu-next-upstream/hw/virtio-pci.c:222
#6 0x08063e26 in virtio_pci_config_writew (opaque=0x86d7b98, addr=16, val=0)
at /data/sripathi/code/qemu/new/qemu-next-upstream/hw/virtio-pci.c:357
#7 0x080c881a in ioport_write (index=1, address=49296, data=0) at ioport.c:80
#8 0x080c8d4c in cpu_outw (addr=49296, val=0) at ioport.c:204
#9 0x08073010 in kvm_handle_io (port=49296, data=0xab393000, direction=1, size=2, count=1)
at /data/sripathi/code/qemu/new/qemu-next-upstream/kvm-all.c:735
...
...
This is ugly and misleading. The following patch adds a BUG_ON to catch this
error. With this patch we get an abort message like the following, which makes
it easier to analyze:
f12-kvm login: qemu: /data/sripathi/code/qemu/new/qemu-next-upstream/hw/virtio-9p-debug.c:353: pprint_pdu: Assertion `!(!llogfile)' failed.
Signed-off-by: Sripathi Kodi <sripathik@in.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Diffstat (limited to 'hw')
| -rw-r--r-- | hw/virtio-9p-debug.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/hw/virtio-9p-debug.c b/hw/virtio-9p-debug.c index e4ab4bca5f..c1b0e6f066 100644 --- a/hw/virtio-9p-debug.c +++ b/hw/virtio-9p-debug.c @@ -327,6 +327,8 @@ void pprint_pdu(V9fsPDU *pdu) llogfile = fopen("/tmp/pdu.log", "w"); } + BUG_ON(!llogfile); + switch (pdu->id) { case P9_TVERSION: fprintf(llogfile, "TVERSION: ("); |