Re: [Qemu-devel] [PATCH] cpu: Fix crash with empty -cpu option

[Igor Mammedov <imammedo@redhat.com>]

On Thu, 18 Apr 2019 10:23:29 -0300
Eduardo Habkost <ehabkost@redhat.com> wrote:

> On Thu, Apr 18, 2019 at 01:22:16PM +0200, Igor Mammedov wrote:
> > On Thu, 18 Apr 2019 00:45:01 -0300
> > Eduardo Habkost <ehabkost@redhat.com> wrote:
> >   
> > > Fix the following crash:
> > > 
> > >   $ qemu-system-x86_64 -cpu ''
> > >   qemu-system-x86_64: qom/cpu.c:291: cpu_class_by_name: \
> > >       Assertion `cpu_model && cc->class_by_name' failed.
> > > 
> > > Regression test script included.
> > > 
> > > Fixes: commit 99193d8f2ef5 ("cpu: drop unnecessary NULL check and cpu_common_class_by_name()")
> > > Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> > > ---
> > >  exec.c                              |  4 ++++
> > >  tests/acceptance/empty_cpu_model.py | 19 +++++++++++++++++++
> > >  2 files changed, 23 insertions(+)
> > >  create mode 100644 tests/acceptance/empty_cpu_model.py
> > > 
> > > diff --git a/exec.c b/exec.c
> > > index 1ca95df9d8..d816b38863 100644
> > > --- a/exec.c
> > > +++ b/exec.c
> > > @@ -999,6 +999,10 @@ const char *parse_cpu_option(MachineState *machine, const char *cpu_option)
> > >      const char *cpu_type;
> > >  
> > >      model_pieces = g_strsplit(cpu_option, ",", 2);
> > > +    if (!model_pieces[0]) {
> > > +        error_report("-cpu option cannot be empty");
> > > +        exit(1);  
> > 
> > s/1/EXIT_FAILURE/  
> 
> Why?
it's more descriptive in general

> There are 753 instances of "exit(1)" in the tree, and 171
> instances of "exit(EXIT_FAILURE)".
Bad example in past is probably not a good justification,
especially when adding new code (but I'm not going to argue about it).