* [Qemu-devel] [PATCH] scsi-cd: Fix crash after remote cdrom detached
@ 2019-02-14 12:27 Xiang Zheng
2019-02-14 18:07 ` Paolo Bonzini
0 siblings, 1 reply; 4+ messages in thread
From: Xiang Zheng @ 2019-02-14 12:27 UTC (permalink / raw)
To: qemu-devel; +Cc: pbonzini, fam, wanghaibin.wang, lizhengui, Xiang Zheng
There is a small window between the twice blk_is_available in
scsi_disk_emulate_command which would cause crash due to the later
assertion if the remote cdrom is detached in this window.
So this patch replaces assertions with return to avoid qemu crash.
Signed-off-by: Xiang Zheng <zhengxiang9@huawei.com>
---
The qemu error log shows:
qemu-system-aarch64: /home/qemu/hw/scsi/scsi-disk.c:1896: scsi_disk_emulate_command: Assertion `blk_is_available(s->qdev.conf.blk)' failed.
2019-02-15 04:35:18.592: shutting down, reason=crashed
---
hw/scsi/scsi-disk.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
index d4e83ae..6bcafe2 100644
--- a/hw/scsi/scsi-disk.c
+++ b/hw/scsi/scsi-disk.c
@@ -1890,7 +1890,10 @@ static int32_t scsi_disk_emulate_command(SCSIRequest *req, uint8_t *buf)
memset(outbuf, 0, r->buflen);
switch (req->cmd.buf[0]) {
case TEST_UNIT_READY:
- assert(blk_is_available(s->qdev.conf.blk));
+ if (!blk_is_available(s->qdev.conf.blk)) {
+ scsi_check_condition(r, SENSE_CODE(NO_MEDIUM));
+ return 0;
+ }
break;
case INQUIRY:
buflen = scsi_disk_emulate_inquiry(req, outbuf);
--
1.8.3.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [Qemu-devel] [PATCH] scsi-cd: Fix crash after remote cdrom detached
2019-02-14 12:27 [Qemu-devel] [PATCH] scsi-cd: Fix crash after remote cdrom detached Xiang Zheng
@ 2019-02-14 18:07 ` Paolo Bonzini
2019-02-15 3:17 ` Zheng Xiang
0 siblings, 1 reply; 4+ messages in thread
From: Paolo Bonzini @ 2019-02-14 18:07 UTC (permalink / raw)
To: Xiang Zheng, qemu-devel; +Cc: fam, wanghaibin.wang, lizhengui
On 14/02/19 13:27, Xiang Zheng wrote:
> There is a small window between the twice blk_is_available in
> scsi_disk_emulate_command which would cause crash due to the later
> assertion if the remote cdrom is detached in this window.
>
> So this patch replaces assertions with return to avoid qemu crash.
>
> Signed-off-by: Xiang Zheng <zhengxiang9@huawei.com>
> ---
> The qemu error log shows:
>
> qemu-system-aarch64: /home/qemu/hw/scsi/scsi-disk.c:1896: scsi_disk_emulate_command: Assertion `blk_is_available(s->qdev.conf.blk)' failed.
> 2019-02-15 04:35:18.592: shutting down, reason=crashed
Is this with virtio-scsi-dataplane?
Paolo
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Qemu-devel] [PATCH] scsi-cd: Fix crash after remote cdrom detached
2019-02-14 18:07 ` Paolo Bonzini
@ 2019-02-15 3:17 ` Zheng Xiang
2019-02-25 5:44 ` Zheng Xiang
0 siblings, 1 reply; 4+ messages in thread
From: Zheng Xiang @ 2019-02-15 3:17 UTC (permalink / raw)
To: Paolo Bonzini, qemu-devel; +Cc: fam, wanghaibin.wang, lizhengui
Hi Paolo,
On 2019/2/15 2:07, Paolo Bonzini wrote:
> On 14/02/19 13:27, Xiang Zheng wrote:
>> There is a small window between the twice blk_is_available in
>> scsi_disk_emulate_command which would cause crash due to the later
>> assertion if the remote cdrom is detached in this window.
>>
>> So this patch replaces assertions with return to avoid qemu crash.
>>
>> Signed-off-by: Xiang Zheng <zhengxiang9@huawei.com>
>> ---
>> The qemu error log shows:
>>
>> qemu-system-aarch64: /home/qemu/hw/scsi/scsi-disk.c:1896: scsi_disk_emulate_command: Assertion `blk_is_available(s->qdev.conf.blk)' failed.
>> 2019-02-15 04:35:18.592: shutting down, reason=crashed
>
> Is this with virtio-scsi-dataplane?
>
No, the QEMU commandline about scsi is bellow:
-device virtio-scsi-pci,id=scsi0,bus=pci.4,addr=0x0 \
-drive file=/mnt/zhengxiang/guestos.qcow2,format=qcow2,if=none,id=drive-scsi0-0-0-0,cache=none,aio=native \
-device scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0,bootindex=1 \
-drive file=/home/tmp.iso,format=raw,if=none,id=drive-scsi0-0-0-1,readonly=on,cache=none,aio=threads \
-device scsi-cd,bus=scsi0.0,channel=0,scsi-id=0,lun=1,drive=drive-scsi0-0-0-1,id=scsi0-0-0-1
This problem can be reproduced by detaching and attaching remote cdrom repeatly.
--
Thanks,
Xiang
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Qemu-devel] [PATCH] scsi-cd: Fix crash after remote cdrom detached
2019-02-15 3:17 ` Zheng Xiang
@ 2019-02-25 5:44 ` Zheng Xiang
0 siblings, 0 replies; 4+ messages in thread
From: Zheng Xiang @ 2019-02-25 5:44 UTC (permalink / raw)
To: Paolo Bonzini, qemu-devel; +Cc: fam, wanghaibin.wang, lizhengui
Ping?
On 2019/2/15 11:17, Zheng Xiang wrote:
> Hi Paolo,
>
> On 2019/2/15 2:07, Paolo Bonzini wrote:
>> On 14/02/19 13:27, Xiang Zheng wrote:
>>> There is a small window between the twice blk_is_available in
>>> scsi_disk_emulate_command which would cause crash due to the later
>>> assertion if the remote cdrom is detached in this window.
>>>
>>> So this patch replaces assertions with return to avoid qemu crash.
>>>
>>> Signed-off-by: Xiang Zheng <zhengxiang9@huawei.com>
>>> ---
>>> The qemu error log shows:
>>>
>>> qemu-system-aarch64: /home/qemu/hw/scsi/scsi-disk.c:1896: scsi_disk_emulate_command: Assertion `blk_is_available(s->qdev.conf.blk)' failed.
>>> 2019-02-15 04:35:18.592: shutting down, reason=crashed
>>
>> Is this with virtio-scsi-dataplane?
>>
>
> No, the QEMU commandline about scsi is bellow:
> -device virtio-scsi-pci,id=scsi0,bus=pci.4,addr=0x0 \
> -drive file=/mnt/zhengxiang/guestos.qcow2,format=qcow2,if=none,id=drive-scsi0-0-0-0,cache=none,aio=native \
> -device scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0,bootindex=1 \
> -drive file=/home/tmp.iso,format=raw,if=none,id=drive-scsi0-0-0-1,readonly=on,cache=none,aio=threads \
> -device scsi-cd,bus=scsi0.0,channel=0,scsi-id=0,lun=1,drive=drive-scsi0-0-0-1,id=scsi0-0-0-1
>
> This problem can be reproduced by detaching and attaching remote cdrom repeatly.
>
--
Thanks,
Xiang
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-02-25 5:45 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2019-02-14 12:27 [Qemu-devel] [PATCH] scsi-cd: Fix crash after remote cdrom detached Xiang Zheng
2019-02-14 18:07 ` Paolo Bonzini
2019-02-15 3:17 ` Zheng Xiang
2019-02-25 5:44 ` Zheng Xiang
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