[PATCH 4.9 62/88] hwrng: geode - Revert managed API changes

From: Greg Kroah-Hartman
Date: Tue Mar 28 2017 - 08:53:14 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Prarit Bhargava <prarit@xxxxxxxxxx>

commit 8c75704ebcac2ffa31ee7bcc359baf701b52bf00 upstream.

After commit e9afc746299d ("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 e9afc746299d ("hwrng: geode - Use linux/io.h
instead of asm/io.h").

Signed-off-by: Prarit Bhargava <prarit@xxxxxxxxxx>
Fixes: 6e9b5e76882c ("hwrng: geode - Migrate to managed API")
Cc: Matt Mackall <mpm@xxxxxxxxxxx>
Cc: Corentin LABBE <clabbe.montjoie@xxxxxxxxx>
Cc: PrasannaKumar Muralidharan <prasannatsmkumar@xxxxxxxxx>
Cc: Wei Yongjun <weiyongjun1@xxxxxxxxxx>
Cc: linux-crypto@xxxxxxxxxxxxxxx
Cc: linux-geode@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/char/hw_random/geode-rng.c | 50 +++++++++++++++++++++++++------------
1 file changed, 35 insertions(+), 15 deletions(-)

--- a/drivers/char/hw_random/geode-rng.c
+++ b/drivers/char/hw_random/geode-rng.c
@@ -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) {
- rng_base = pci_resource_start(pdev, 0);
- if (rng_base == 0)
- return -ENODEV;
-
- mem = devm_ioremap(&pdev->dev, rng_base, 0x58);
- if (!mem)
- return -ENOMEM;
- geode_rng.priv = (unsigned long)mem;
-
- pr_info("AMD Geode RNG detected\n");
- return devm_hwrng_register(&pdev->dev, &geode_rng);
- }
+ if (ent)
+ goto found;
}
-
/* Device not found. */
- return -ENODEV;
+ goto out;
+
+found:
+ rng_base = pci_resource_start(pdev, 0);
+ if (rng_base == 0)
+ goto out;
+ err = -ENOMEM;
+ mem = ioremap(rng_base, 0x58);
+ if (!mem)
+ goto out;
+ geode_rng.priv = (unsigned long)mem;
+
+ pr_info("AMD Geode RNG detected\n");
+ err = hwrng_register(&geode_rng);
+ if (err) {
+ pr_err(PFX "RNG registering failed (%d)\n",
+ err);
+ goto err_unmap;
+ }
+out:
+ return err;
+
+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);