Re: drivers/phy/tegra: Completion for exception handling in probe functions with SmPL?

From: Markus Elfring
Date: Wed Oct 30 2019 - 16:51:24 EST


> But I stumble on another unexpected test result.

I got more promising results by the following transformation approach.

@adjustment exists@
expression object;
identifier exit;
@@
object = kzalloc(...)
...
if (...)
-{ kfree(object);
goto
- exit
+ release_memory
;
-}
... when any
device_unregister(...);
-exit
+release_memory
:
+kfree(object);
return ERR_PTR(...);


The scope property of such a SmPL rule occasionally needs also more
software development attention.
https://github.com/coccinelle/coccinelle/blob/ed1eb8e06f800739d3992158d36945c0c4c6f0c7/docs/manual/cocci_syntax.tex#L860

I observe that the pretty-printing for the generated source code will need
further improvements (according to the Linux coding style).

Example:

elfring@Sonne:~/Projekte/Linux/next-patched> spatch drivers/phy/tegra/xusb-tegra186.c ~/Projekte/Coccinelle/janitor/complete_exception_handling_in_probe_functions6.cocci
â
@@ -461,10 +461,8 @@ tegra186_usb2_pad_probe(struct tegra_xus
pad->soc = soc;

err = tegra_xusb_pad_init(pad, padctl, np);
- if (err < 0) {
- kfree(usb2);
- goto out;
- }
+ if (err < 0)
+ goto release_memory;

priv->usb2_trk_clk = devm_clk_get(&pad->dev, "trk");
if (IS_ERR(priv->usb2_trk_clk)) {
@@ -483,7 +481,8 @@ tegra186_usb2_pad_probe(struct tegra_xus

unregister:
device_unregister(&pad->dev);
-out:
+release_memory :
+kfree(usb2);
return ERR_PTR(err);
}
â


How reasonable do you find the presented update suggestion?

Regards,
Markus