qga: fix assert regression on guest-shutdown

[PATCH] qga: fix assert regression on guest-shutdown

Posted by Marc-André Lureau 5 years, 8 months ago

Since commit 781f2b3d1e ("qga: process_event() simplification"),
send_response() is called unconditionally, but will assert when "rsp" is
NULL. This may happen with QCO_NO_SUCCESS_RESP commands, such as
"guest-shutdown".

Fixes: 781f2b3d1e5ef389b44016a897fd55e7a780bf35
Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
Reported-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 qga/main.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/qga/main.c b/qga/main.c
index f0e454f28d3..3febf3b0fdf 100644
--- a/qga/main.c
+++ b/qga/main.c
@@ -531,7 +531,11 @@ static int send_response(GAState *s, const QDict *rsp)
     QString *payload_qstr, *response_qstr;
     GIOStatus status;
 
-    g_assert(rsp && s->channel);
+    g_assert(s->channel);
+
+    if (!rsp) {
+        return 0;
+    }
 
     payload_qstr = qobject_to_json(QOBJECT(rsp));
     if (!payload_qstr) {
-- 
2.26.2.561.g07d8ea56f2

Re: [PATCH] qga: fix assert regression on guest-shutdown

Posted by Philippe Mathieu-Daudé 5 years, 8 months ago

On 6/4/20 11:44 AM, Marc-André Lureau wrote:
> Since commit 781f2b3d1e ("qga: process_event() simplification"),
> send_response() is called unconditionally, but will assert when "rsp" is
> NULL. This may happen with QCO_NO_SUCCESS_RESP commands, such as
> "guest-shutdown".
> 
> Fixes: 781f2b3d1e5ef389b44016a897fd55e7a780bf35
> Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
> Reported-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>  qga/main.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/qga/main.c b/qga/main.c
> index f0e454f28d3..3febf3b0fdf 100644
> --- a/qga/main.c
> +++ b/qga/main.c
> @@ -531,7 +531,11 @@ static int send_response(GAState *s, const QDict *rsp)
>      QString *payload_qstr, *response_qstr;
>      GIOStatus status;
>  
> -    g_assert(rsp && s->channel);
> +    g_assert(s->channel);
> +
> +    if (!rsp) {
> +        return 0;
> +    }

Why not assert after the check?

Anyway:
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

>  
>      payload_qstr = qobject_to_json(QOBJECT(rsp));
>      if (!payload_qstr) {
>

Re: [PATCH] qga: fix assert regression on guest-shutdown

Posted by Christian Ehrhardt 5 years, 8 months ago

On Thu, Jun 4, 2020 at 11:46 AM Marc-André Lureau <
marcandre.lureau@redhat.com> wrote:

> Since commit 781f2b3d1e ("qga: process_event() simplification"),
> send_response() is called unconditionally, but will assert when "rsp" is
> NULL. This may happen with QCO_NO_SUCCESS_RESP commands, such as
> "guest-shutdown".
>
> Fixes: 781f2b3d1e5ef389b44016a897fd55e7a780bf35
> Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
> Reported-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>  qga/main.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/qga/main.c b/qga/main.c
> index f0e454f28d3..3febf3b0fdf 100644
> --- a/qga/main.c
> +++ b/qga/main.c
> @@ -531,7 +531,11 @@ static int send_response(GAState *s, const QDict *rsp)
>      QString *payload_qstr, *response_qstr;
>      GIOStatus status;
>
> -    g_assert(rsp && s->channel);
> +    g_assert(s->channel);
> +
> +    if (!rsp) {
> +        return 0;
> +    }
>
>
>
Thanks Marc-André,
LGTM and should fix the issues I was seeing.

Reviewed-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>


-- 
Christian Ehrhardt
Staff Engineer, Ubuntu Server
Canonical Ltd

Re: [PATCH] qga: fix assert regression on guest-shutdown

Posted by Christian Ehrhardt 5 years, 8 months ago

On Thu, Jun 4, 2020 at 3:43 PM Christian Ehrhardt <
christian.ehrhardt@canonical.com> wrote:

>
>
> On Thu, Jun 4, 2020 at 11:46 AM Marc-André Lureau <
> marcandre.lureau@redhat.com> wrote:
>
>> Since commit 781f2b3d1e ("qga: process_event() simplification"),
>> send_response() is called unconditionally, but will assert when "rsp" is
>> NULL. This may happen with QCO_NO_SUCCESS_RESP commands, such as
>> "guest-shutdown".
>>
>> Fixes: 781f2b3d1e5ef389b44016a897fd55e7a780bf35
>> Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
>> Reported-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
>> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
>> ---
>>  qga/main.c | 6 +++++-
>>  1 file changed, 5 insertions(+), 1 deletion(-)
>>
>> diff --git a/qga/main.c b/qga/main.c
>> index f0e454f28d3..3febf3b0fdf 100644
>> --- a/qga/main.c
>> +++ b/qga/main.c
>> @@ -531,7 +531,11 @@ static int send_response(GAState *s, const QDict
>> *rsp)
>>      QString *payload_qstr, *response_qstr;
>>      GIOStatus status;
>>
>> -    g_assert(rsp && s->channel);
>> +    g_assert(s->channel);
>> +
>> +    if (!rsp) {
>> +        return 0;
>> +    }
>>
>>
>>
> Thanks Marc-André,
> LGTM and should fix the issues I was seeing.
>
> Reviewed-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
>

In the meantime I also got to test this against the initially reported
issue, LGTM as well (ran as no-change backport onto 4.2).

Tested-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>

Re: [PATCH] qga: fix assert regression on guest-shutdown

Posted by Christian Ehrhardt 5 years, 7 months ago

On Tue, Jun 9, 2020 at 1:15 PM Christian Ehrhardt <
christian.ehrhardt@canonical.com> wrote:

>
>
> On Thu, Jun 4, 2020 at 3:43 PM Christian Ehrhardt <
> christian.ehrhardt@canonical.com> wrote:
>
>>
>>
>> On Thu, Jun 4, 2020 at 11:46 AM Marc-André Lureau <
>> marcandre.lureau@redhat.com> wrote:
>>
>>> Since commit 781f2b3d1e ("qga: process_event() simplification"),
>>> send_response() is called unconditionally, but will assert when "rsp" is
>>> NULL. This may happen with QCO_NO_SUCCESS_RESP commands, such as
>>> "guest-shutdown".
>>>
>>> Fixes: 781f2b3d1e5ef389b44016a897fd55e7a780bf35
>>> Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
>>> Reported-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
>>> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
>>> ---
>>>  qga/main.c | 6 +++++-
>>>  1 file changed, 5 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/qga/main.c b/qga/main.c
>>> index f0e454f28d3..3febf3b0fdf 100644
>>> --- a/qga/main.c
>>> +++ b/qga/main.c
>>> @@ -531,7 +531,11 @@ static int send_response(GAState *s, const QDict
>>> *rsp)
>>>      QString *payload_qstr, *response_qstr;
>>>      GIOStatus status;
>>>
>>> -    g_assert(rsp && s->channel);
>>> +    g_assert(s->channel);
>>> +
>>> +    if (!rsp) {
>>> +        return 0;
>>> +    }
>>>
>>>
>>>
>> Thanks Marc-André,
>> LGTM and should fix the issues I was seeing.
>>
>> Reviewed-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
>>
>
> In the meantime I also got to test this against the initially reported
> issue, LGTM as well (ran as no-change backport onto 4.2).
>
> Tested-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
>

This LGTM with 2*reviews 1*tested and 11 days on the list without any
negative feedback.
I just wanted to re-check if there is anything else left for this to be
committed?