Re: [PATCH V3 06/22] vl: add helper to request re-exec

[Steven Sistare <steven.sistare@oracle.com>]

On 5/7/2021 10:31 AM, Eric Blake wrote:
> On 5/7/21 7:25 AM, Steve Sistare wrote:
>> Add a qemu_exec_requested() hook that causes the main loop to exit and
>> re-exec qemu using the same initial arguments.  If /usr/bin/qemu-exec
>> exists, exec that instead.  This is an optional site-specific trampoline
>> that may alter the environment before exec'ing the qemu binary.
>>
>> Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
>> ---
> 
>> +static void qemu_exec(void)
>> +{
>> +    const char *helper = "/usr/bin/qemu-exec";
>> +    const char *bin = !access(helper, X_OK) ? helper : argv_main[0];
> 
> Reads awkwardly; I would have used '...= access(helper, X_OK) == 0 ?...'

Will fix.

>> +
>> +    execvp(bin, argv_main);
>> +    error_report("execvp failed, errno %d.", errno);
> 
> error_report should not be used with a trailing dot.  

Will fix.  I was not sure because I see examples both ways, though no dot prevails.
Perhaps it should be added to the style guide and checkpatch.

> Also, %d for errno is awkward, better is:
> 
> error_report("execvp failed: %s", strerror(errno));

I shy away from strerror because it is not thread safe, but I see qemu uses it
extensively.  Will fix.

> 
>> +    exit(1);
> 
> We aren't consistent about use of EXIT_FAILED.

OK, I will use EXIT_FAILURE.

Thanks for reviewing.

- Steve