python: Treat None-return of greeting cmd

[PATCH] python: Treat None-return of greeting cmd

Posted by Lukáš Doktor 6 years ago

In case qemu process dies the "monitor.cmd" returns None which gets
passed to the "__negotiate_capabilities" and leads to unhandled
exception. Let's only check the resp in case it has a value.

Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>
---
 python/qemu/qmp.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/python/qemu/qmp.py b/python/qemu/qmp.py
index 5c8cf6a056..a3e5de718a 100644
--- a/python/qemu/qmp.py
+++ b/python/qemu/qmp.py
@@ -73,7 +73,7 @@ class QEMUMonitorProtocol(object):
             raise QMPConnectError
         # Greeting seems ok, negotiate capabilities
         resp = self.cmd('qmp_capabilities')
-        if "return" in resp:
+        if resp and "return" in resp:
             return greeting
         raise QMPCapabilitiesError
 
-- 
2.21.0

Re: [PATCH] python: Treat None-return of greeting cmd

Posted by Philippe Mathieu-Daudé 6 years ago


On 1/20/20 8:12 AM, Lukáš Doktor wrote:
> In case qemu process dies the "monitor.cmd" returns None which gets
> passed to the "__negotiate_capabilities" and leads to unhandled
> exception. Let's only check the resp in case it has a value.
> 
> Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>
> ---
>   python/qemu/qmp.py | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/python/qemu/qmp.py b/python/qemu/qmp.py
> index 5c8cf6a056..a3e5de718a 100644
> --- a/python/qemu/qmp.py
> +++ b/python/qemu/qmp.py
> @@ -73,7 +73,7 @@ class QEMUMonitorProtocol(object):
>               raise QMPConnectError
>           # Greeting seems ok, negotiate capabilities
>           resp = self.cmd('qmp_capabilities')
> -        if "return" in resp:
> +        if resp and "return" in resp:
>               return greeting
>           raise QMPCapabilitiesError
>   
> 

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

Re: [PATCH] python: Treat None-return of greeting cmd

Posted by Wainer dos Santos Moschetta 6 years ago

On 1/20/20 5:12 AM, Lukáš Doktor wrote:
> In case qemu process dies the "monitor.cmd" returns None which gets
> passed to the "__negotiate_capabilities" and leads to unhandled
> exception. Let's only check the resp in case it has a value.
>
> Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>
> ---
>   python/qemu/qmp.py | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>

>
> diff --git a/python/qemu/qmp.py b/python/qemu/qmp.py
> index 5c8cf6a056..a3e5de718a 100644
> --- a/python/qemu/qmp.py
> +++ b/python/qemu/qmp.py
> @@ -73,7 +73,7 @@ class QEMUMonitorProtocol(object):
>               raise QMPConnectError
>           # Greeting seems ok, negotiate capabilities
>           resp = self.cmd('qmp_capabilities')
> -        if "return" in resp:
> +        if resp and "return" in resp:
>               return greeting
>           raise QMPCapabilitiesError
>

Re: [PATCH] python: Treat None-return of greeting cmd

Posted by Philippe Mathieu-Daudé 6 years ago

On 1/20/20 8:12 AM, Lukáš Doktor wrote:
> In case qemu process dies the "monitor.cmd" returns None which gets
> passed to the "__negotiate_capabilities" and leads to unhandled
> exception. Let's only check the resp in case it has a value.
> 
> Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>
> ---
>   python/qemu/qmp.py | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/python/qemu/qmp.py b/python/qemu/qmp.py
> index 5c8cf6a056..a3e5de718a 100644
> --- a/python/qemu/qmp.py
> +++ b/python/qemu/qmp.py
> @@ -73,7 +73,7 @@ class QEMUMonitorProtocol(object):
>               raise QMPConnectError
>           # Greeting seems ok, negotiate capabilities
>           resp = self.cmd('qmp_capabilities')
> -        if "return" in resp:
> +        if resp and "return" in resp:
>               return greeting
>           raise QMPCapabilitiesError
>   
> 

Thanks, applied to my python-next tree:
https://gitlab.com/philmd/qemu/commits/python-next