[libcamera-devel] [PATCH] Avoid Segmentation Fault when use --help parameter

[Jacopo Mondi]

Hello Emanuel,
   thanks for the patch.

I see a segfault as well when calling cam with the --help option. NIce
catch!

On Sun, Jun 02, 2019 at 10:57:49PM -0300, Emmanuel Arias wrote:
> When Cam::parseOptions receive help args return -EINTR and
> Cam::init return 0 to main. But the first if does not return EXIT_FAILURE
> and continue. That launch a SegFaults
> ---
>  src/cam/main.cpp | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/src/cam/main.cpp b/src/cam/main.cpp
> index dbf0491..d23390a 100644
> --- a/src/cam/main.cpp
> +++ b/src/cam/main.cpp
> @@ -61,7 +61,7 @@ int CamApp::init(int argc, char **argv)
>
>  	ret = parseOptions(argc, argv);
>  	if (ret < 0)
> -		return ret == -EINTR ? 0 : ret;
> +		return ret == -EINTR ? -EINTR : ret;

If ret == -EINTR you return -EINTR, while otherwise you return ret.
Isn't this equivalent to 'return ret' directly :) ?

Furthermore, the main loop that calls CamApp::init() handles the
return code as:

	if (app.init(argc, argv))
		return EXIT_FAILURE;

So you would EXIT_FAILURE on --help, which is not nice.

How about returning ret from CamApp::init() and handle the return code
in the main loop with:

-       if (app.init(argc, argv))
-               return EXIT_FAILURE;
+       int ret = app.init(argc, argv);
+       if (ret)
+               return ret == -EINTR ? 0 : EXIT_FAILURE;

>
>  	cm_ = CameraManager::instance();
>
> @@ -196,7 +196,7 @@ int main(int argc, char **argv)
>
>  	if (app.init(argc, argv))
>  		return EXIT_FAILURE;
> -
> +

This is an unrelated change, so please drop it.

Thank you
    j

>  	struct sigaction sa = {};
>  	sa.sa_handler = &signalHandler;
>  	sigaction(SIGINT, &sa, nullptr);
> --
> 2.11.0
>
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