Re: devm_kfree
From: Adam Jiang
Date: Mon Dec 26 2011 - 21:48:43 EST
2011/12/26 Julia Lawall <julia.lawall@xxxxxxx>:
> Is it reasonable to use devm_kfree in a probe function that fails or a
> remove function that succeeds?
I cannot catch your question. If the memory is allocated by
devm_kzalloc(), it is not necessary to release with devm_kfree() at
all. It would be release once the driver was detached or destroyed.
>
> Examples from drivers/watchdog/shwdt.c:
>
> sh_wdt_probe:
>
> ...
> out_unreg:
> unregister_reboot_notifier(&sh_wdt_notifier);
> out_unmap:
> - devm_iounmap(&pdev->dev, wdt->base);
> out_err:
> - devm_kfree(&pdev->dev, wdt);
It is necessary?
> out_release:
> - devm_release_mem_region(&pdev->dev, res->start, resource_size(res));
It is necessary?
>
> return rc;
> }
>
>
> sh_wdt_remove:
>
> ...
> unregister_reboot_notifier(&sh_wdt_notifier);
> devm_release_mem_region(&pdev->dev, res->start, resource_size(res));
> devm_iounmap(&pdev->dev, wdt->base);
> devm_kfree(&pdev->dev, wdt);
These lines should be deleted if the driver has detached.
>
> return 0;
> }
>
>
> On the other hand, perhaps devm_kfree is needed in probe function that
> succeeds, eg in drivers/input/keyboard/samsung-keypad.c:
>
> if (pdev->dev.of_node) {
> devm_kfree(&pdev->dev, (void *)pdata->keymap_data->keymap);
> devm_kfree(&pdev->dev, (void *)pdata->keymap_data);
> devm_kfree(&pdev->dev, (void *)pdata);
> }
> return 0;
>
> julia
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/