[Qemu-devel] [PATCH] gtk: use qemu_chr_alloc() to allocate CharDriverState

[Qemu-devel] [PATCH] gtk: use qemu_chr_alloc() to allocate CharDriverState

[Daniel P. Berrange]

The gd_vc_handler() callback is using g_malloc0() to
allocate the CharDriverState struct. As a result the
logfd field is getting initialized to 0, instead of
-1 when no logfile is requested.

The result is that when running

 $ qemu-system-i386 -nodefaults -chardev vc,id=mon0 -mon chardev=mon0

qemu duplicates all monitor output to stdout as well
as the GTK window.

Not using qemu_chr_alloc() was already a bug, but harmless
until this commit

  commit d0d7708ba29cbcc343364a46bff981e0ff88366f
  Author: Daniel P. Berrange <berrange@redhat.com>
  Date:   Mon Jan 11 12:44:41 2016 +0000

    qemu-char: add logfile facility to all chardev backends

which exposed the problem as a behaviour regression

Reported-by: Hervé Poussineau <hpoussin@reactos.org>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 ui/gtk.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/ui/gtk.c b/ui/gtk.c
index ce7018e..c8dbd5c 100644
--- a/ui/gtk.c
+++ b/ui/gtk.c
@@ -1598,11 +1598,16 @@ static void gd_vc_chr_set_echo(CharDriverState *chr, bool echo)
 static int nb_vcs;
 static CharDriverState *vcs[MAX_VCS];
 
-static CharDriverState *gd_vc_handler(ChardevVC *unused, Error **errp)
+static CharDriverState *gd_vc_handler(ChardevVC *vc, Error **errp)
 {
+    ChardevCommon *common = qapi_ChardevVC_base(vc);
     CharDriverState *chr;
 
-    chr = g_malloc0(sizeof(*chr));
+    chr = qemu_chr_alloc(common, errp);
+    if (!chr) {
+        return NULL;
+    }
+
     chr->chr_write = gd_vc_chr_write;
     chr->chr_set_echo = gd_vc_chr_set_echo;
 
-- 
2.5.0

Re: [Qemu-devel] [PATCH] gtk: use qemu_chr_alloc() to allocate CharDriverState

[Eric Blake]

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On 01/21/2016 04:56 AM, Daniel P. Berrange wrote:
> The gd_vc_handler() callback is using g_malloc0() to
> allocate the CharDriverState struct. As a result the
> logfd field is getting initialized to 0, instead of
> -1 when no logfile is requested.
> 
> The result is that when running
> 
>  $ qemu-system-i386 -nodefaults -chardev vc,id=mon0 -mon chardev=mon0
> 
> qemu duplicates all monitor output to stdout as well
> as the GTK window.
> 
> Not using qemu_chr_alloc() was already a bug, but harmless
> until this commit
> 
>   commit d0d7708ba29cbcc343364a46bff981e0ff88366f
>   Author: Daniel P. Berrange <berrange@redhat.com>
>   Date:   Mon Jan 11 12:44:41 2016 +0000
> 
>     qemu-char: add logfile facility to all chardev backends
> 
> which exposed the problem as a behaviour regression
> 
> Reported-by: Hervé Poussineau <hpoussin@reactos.org>
> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
> ---
>  ui/gtk.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH] gtk: use qemu_chr_alloc() to allocate CharDriverState

[Peter Maydell]

On 21 January 2016 at 11:56, Daniel P. Berrange <berrange@redhat.com> wrote:
> The gd_vc_handler() callback is using g_malloc0() to
> allocate the CharDriverState struct. As a result the
> logfd field is getting initialized to 0, instead of
> -1 when no logfile is requested.
>
> The result is that when running
>
>  $ qemu-system-i386 -nodefaults -chardev vc,id=mon0 -mon chardev=mon0
>
> qemu duplicates all monitor output to stdout as well
> as the GTK window.
>
> Not using qemu_chr_alloc() was already a bug, but harmless
> until this commit

A quick check with coccinelle:

@@
typedef CharDriverState;
CharDriverState *x;
@@

- x = g_malloc0(...)
+ x = qemu_chr_alloc(foo)


revealed only this ui/gtk.c allocation plus the actual
implementation of qemu_chr_alloc() as places where we try
to do a manual g_malloc0() of a CharDriverState. So I
think this is the only bit that needs changing.

thanks
-- PMM

Re: [Qemu-devel] [PATCH] gtk: use qemu_chr_alloc() to allocate CharDriverState

[Hervé Poussineau]

Le 21/01/2016 12:56, Daniel P. Berrange a écrit :
> The gd_vc_handler() callback is using g_malloc0() to
> allocate the CharDriverState struct. As a result the
> logfd field is getting initialized to 0, instead of
> -1 when no logfile is requested.
>
> The result is that when running
>
>   $ qemu-system-i386 -nodefaults -chardev vc,id=mon0 -mon chardev=mon0
>
> qemu duplicates all monitor output to stdout as well
> as the GTK window.
>
> Not using qemu_chr_alloc() was already a bug, but harmless
> until this commit
>
>    commit d0d7708ba29cbcc343364a46bff981e0ff88366f
>    Author: Daniel P. Berrange <berrange@redhat.com>
>    Date:   Mon Jan 11 12:44:41 2016 +0000
>
>      qemu-char: add logfile facility to all chardev backends
>
> which exposed the problem as a behaviour regression
>
> Reported-by: Hervé Poussineau <hpoussin@reactos.org>
> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

Tested-by: Hervé Poussineau <hpoussin@reactos.org>

Hervé

Re: [Qemu-devel] [PATCH] gtk: use qemu_chr_alloc() to allocate CharDriverState

[Gerd Hoffmann]

On Do, 2016-01-21 at 11:56 +0000, Daniel P. Berrange wrote:
> The gd_vc_handler() callback is using g_malloc0() to
> allocate the CharDriverState struct. As a result the
> logfd field is getting initialized to 0, instead of
> -1 when no logfile is requested.

added to patch queue.

thanks,
  Gerd