Hi

Am 17.02.23 um 09:37 schrieb Javier Martinez Canillas:

Thomas Zimmermann [off-list ref] writes:

quoted

In fb_get_options(), always duplicate the returned option string and
transfer ownership of the memory to the function's caller.

Until now, only the global option string got duplicated and transferred
to the caller; the per-driver options were owned by fb_get_options().
In the end, it was impossible for the function's caller to detect if
it had to release the string's memory buffer. Hence, all calling drivers
leak the memory buffer. The leaks have existed ever since, but drivers
only call fb_get_option() once as part of module initialization. So the
amount of leaked memory is not significant.

Fix the semantics of fb_get_option() by unconditionally transferring
ownership of the memory buffer to the caller. Later patches can resolve
the memory leaks in the fbdev drivers.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---

[...]

quoted

+	if (option) {
+		if (options)
+			*option = kstrdup(options, GFP_KERNEL);
+		else
+			*option = NULL;
+	}

I know the old code wasn't checking if kstrdup() succeeded, but you should

Kstrdup uses kmalloc, which already warns about failed allocations. I 
think it's discouraged to warn again. (Wasn't there a warning in sparse 
or checkpatch?)  So I'd rather leave it as is.

do it here and let the caller know. And same if (!options). So I guess the
following check can be added (to be consistent with the rest of the code):

	if (!*option)
		retval = 1;

Why is that needed for consistency?

Retval is the state of the output: enabled or not. If there are no 
options, retval should be 0(=enabled). 1(=disabled) is only set by 
video=off or that ofonly thing.

Best regards
Thomas

quoted

  	return retval;
  }
-- 
2.39.1

Best regards,
Javier

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev