| Message ID | 355366700.773095.1438811528320.JavaMail.zimbra@xes-inc.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Herbert Xu |
| Headers | show |
> For completeness, this patch also sets device drvdata to NULL after > the private structure is freed in talitos_remove(). [snip] > @@ -2745,6 +2754,7 @@ static int talitos_remove(struct platform_device > *ofdev) > iounmap(priv->reg); > > kfree(priv); > + dev_set_drvdata(dev, NULL); > > return 0; > } I just found this drvdata cleanup hasn't been required for a few years, due to the following commit: commit 0998d0631001288a5974afc0b2a5f568bcdecb4d Author: Hans de Goede <hdegoede@redhat.com> Date: Wed May 23 00:09:34 2012 +0200 device-core: Ensure drvdata = NULL when no driver is bound Should I submit a v3 patch without this cleanup, assuming there aren't other changes requested? -Aaron -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Aug 06, 2015 at 01:45:42PM -0500, Aaron Sierra wrote: > > I just found this drvdata cleanup hasn't been required for a few years, > due to the following commit: > > commit 0998d0631001288a5974afc0b2a5f568bcdecb4d > Author: Hans de Goede <hdegoede@redhat.com> > Date: Wed May 23 00:09:34 2012 +0200 > > device-core: Ensure drvdata = NULL when no driver is bound > > Should I submit a v3 patch without this cleanup, assuming there aren't > other changes requested? I have applied your patch with the dev_set_drvdata change removed. Thanks,
diff --git a/drivers/crypto/talitos.c b/drivers/crypto/talitos.c index 83aca95..74f1a62 100644 --- a/drivers/crypto/talitos.c +++ b/drivers/crypto/talitos.c @@ -766,6 +766,7 @@ static int talitos_rng_init(struct hwrng *rng) static int talitos_register_rng(struct device *dev) { struct talitos_private *priv = dev_get_drvdata(dev); + int err; priv->rng.name = dev_driver_string(dev), priv->rng.init = talitos_rng_init, @@ -773,14 +774,22 @@ static int talitos_register_rng(struct device *dev) priv->rng.data_read = talitos_rng_data_read, priv->rng.priv = (unsigned long)dev; - return hwrng_register(&priv->rng); + err = hwrng_register(&priv->rng); + if (!err) + priv->rng_registered = true; + + return err; } static void talitos_unregister_rng(struct device *dev) { struct talitos_private *priv = dev_get_drvdata(dev); + if (!priv->rng_registered) + return; + hwrng_unregister(&priv->rng); + priv->rng_registered = false; } /* @@ -2727,7 +2736,7 @@ static int talitos_remove(struct platform_device *ofdev) if (hw_supports(dev, DESC_HDR_SEL0_RNG)) talitos_unregister_rng(dev); - for (i = 0; i < priv->num_channels; i++) + for (i = 0; priv->chan && i < priv->num_channels; i++) kfree(priv->chan[i].fifo); kfree(priv->chan); @@ -2745,6 +2754,7 @@ static int talitos_remove(struct platform_device *ofdev) iounmap(priv->reg); kfree(priv); + dev_set_drvdata(dev, NULL); return 0; } diff --git a/drivers/crypto/talitos.h b/drivers/crypto/talitos.h index 163cfe7..0090f32 100644 --- a/drivers/crypto/talitos.h +++ b/drivers/crypto/talitos.h @@ -149,6 +149,7 @@ struct talitos_private { /* hwrng device */ struct hwrng rng; + bool rng_registered; }; extern int talitos_submit(struct device *dev, int ch, struct talitos_desc *desc,
The probe error path for this driver, for all intents and purposes, is the talitos_remove() function due to the common "goto err_out". Without this patch applied, talitos_remove() will panic under these two conditions: 1. If the RNG device hasn't been registered via talitos_register_rng() prior to entry into talitos_remove(), then the attempt to unregister the RNG "device" will cause a panic. 2. If the priv->chan array has not been allocated prior to entry into talitos_remove(), then the per-channel FIFO cleanup will panic because of the dereference of that NULL "array". Both of the above scenarios occur if talitos_probe_irq() fails. This patch resolves issue #1 by introducing a boolean to mask the hwrng_unregister() call in talitos_unregister_rng() if RNG device registration was unsuccessful. It resolves issue #2 by checking that priv->chan is not NULL in the per-channel FIFO cleanup for loop. For completeness, this patch also sets device drvdata to NULL after the private structure is freed in talitos_remove(). Signed-off-by: Aaron Sierra <asierra@xes-inc.com> --- drivers/crypto/talitos.c | 14 ++++++++++++-- drivers/crypto/talitos.h | 1 + 2 files changed, 13 insertions(+), 2 deletions(-)