Commit c445f996 authored Mar 14, 2017 by Prarit Bhargava Committed by Greg Kroah-Hartman Mar 30, 2017

hwrng: geode - Revert managed API changes



commit 8c75704ebcac2ffa31ee7bcc359baf701b52bf00 upstream.

After commit e9afc746 ("hwrng: geode - Use linux/io.h instead of
asm/io.h") the geode-rng driver uses devres with pci_dev->dev to keep
track of resources, but does not actually register a PCI driver.  This
results in the following issues:

1.  The driver leaks memory because the driver does not attach to a
device.  The driver only uses the PCI device as a reference.   devm_*()
functions will release resources on driver detach, which the geode-rng
driver will never do.  As a result,

2.  The driver cannot be reloaded because there is always a use of the
ioport and region after the first load of the driver.

Revert the changes made by  e9afc746 ("hwrng: geode - Use linux/io.h
instead of asm/io.h").

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Fixes: 6e9b5e76 ("hwrng: geode - Migrate to managed API")
Cc: Matt Mackall <mpm@selenic.com>
Cc: Corentin LABBE <clabbe.montjoie@gmail.com>
Cc: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
Cc: Wei Yongjun <weiyongjun1@huawei.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-geode@lists.infradead.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 5d6f7b36

drivers/char/hw_random/geode-rng.c

+35 −15

Original line number	Diff line number	Diff line
		@@ -31,6 +31,9 @@
		#include <linux/module.h>
		#include <linux/pci.h>


		#define PFX KBUILD_MODNAME ": "

		#define GEODE_RNG_DATA_REG 0x50
		#define GEODE_RNG_STATUS_REG 0x54

		@@ -82,6 +85,7 @@ static struct hwrng geode_rng = {

		static int __init mod_init(void)
		{
		int err = -ENODEV;
		struct pci_dev *pdev = NULL;
		const struct pci_device_id *ent;
		void __iomem *mem;
		@@ -89,27 +93,43 @@ static int __init mod_init(void)

		for_each_pci_dev(pdev) {
		ent = pci_match_id(pci_tbl, pdev);
		if (ent) {
		if (ent)
		goto found;
		}
		/* Device not found. */
		goto out;

		found:
		rng_base = pci_resource_start(pdev, 0);
		if (rng_base == 0)
		return -ENODEV;

		mem = devm_ioremap(&pdev->dev, rng_base, 0x58);
		goto out;
		err = -ENOMEM;
		mem = ioremap(rng_base, 0x58);
		if (!mem)
		return -ENOMEM;
		goto out;
		geode_rng.priv = (unsigned long)mem;

		pr_info("AMD Geode RNG detected\n");
		return devm_hwrng_register(&pdev->dev, &geode_rng);
		}
		err = hwrng_register(&geode_rng);
		if (err) {
		pr_err(PFX "RNG registering failed (%d)\n",
		err);
		goto err_unmap;
		}
		out:
		return err;

		/* Device not found. */
		return -ENODEV;
		err_unmap:
		iounmap(mem);
		goto out;
		}

		static void __exit mod_exit(void)
		{
		void __iomem mem = (void __iomem )geode_rng.priv;

		hwrng_unregister(&geode_rng);
		iounmap(mem);
		}

		module_init(mod_init);