This is a note to let you know that I've just added the patch titled hwrng: amd - Revert managed API changes to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: hwrng-amd-revert-managed-api-changes.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 69db7009318758769d625b023402161c750f7876 Mon Sep 17 00:00:00 2001 From: Prarit Bhargava <prarit@xxxxxxxxxx> Date: Tue, 14 Mar 2017 07:36:01 -0400 Subject: hwrng: amd - Revert managed API changes From: Prarit Bhargava <prarit@xxxxxxxxxx> commit 69db7009318758769d625b023402161c750f7876 upstream. After commit 31b2a73c9c5f ("hwrng: amd - Migrate to managed API"), the amd-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 message WARNING: CPU: 2 PID: 621 at drivers/base/dd.c:349 driver_probe_device+0x38c is output when the i2c_amd756 driver loads and attempts to register a PCI driver. The PCI & device subsystems assume that no resources have been registered for the device, and the WARN_ON() triggers since amd-rng has already do so. 2. 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 amd-rng driver will never do. As a result, 3. 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 31b2a73c9c5f ("hwrng: amd - Migrate to managed API"). Signed-off-by: Prarit Bhargava <prarit@xxxxxxxxxx> Fixes: 31b2a73c9c5f ("hwrng: amd - 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/amd-rng.c | 42 +++++++++++++++++++++++++++++++-------- 1 file changed, 34 insertions(+), 8 deletions(-) --- a/drivers/char/hw_random/amd-rng.c +++ b/drivers/char/hw_random/amd-rng.c @@ -55,6 +55,7 @@ MODULE_DEVICE_TABLE(pci, pci_tbl); struct amd768_priv { void __iomem *iobase; struct pci_dev *pcidev; + u32 pmbase; }; static int amd_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) @@ -148,33 +149,58 @@ found: if (pmbase == 0) return -EIO; - priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + priv = kzalloc(sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; - if (!devm_request_region(&pdev->dev, pmbase + PMBASE_OFFSET, - PMBASE_SIZE, DRV_NAME)) { + if (!request_region(pmbase + PMBASE_OFFSET, PMBASE_SIZE, DRV_NAME)) { dev_err(&pdev->dev, DRV_NAME " region 0x%x already in use!\n", pmbase + 0xF0); - return -EBUSY; + err = -EBUSY; + goto out; } - priv->iobase = devm_ioport_map(&pdev->dev, pmbase + PMBASE_OFFSET, - PMBASE_SIZE); + priv->iobase = ioport_map(pmbase + PMBASE_OFFSET, PMBASE_SIZE); if (!priv->iobase) { pr_err(DRV_NAME "Cannot map ioport\n"); - return -ENOMEM; + err = -EINVAL; + goto err_iomap; } amd_rng.priv = (unsigned long)priv; + priv->pmbase = pmbase; priv->pcidev = pdev; pr_info(DRV_NAME " detected\n"); - return devm_hwrng_register(&pdev->dev, &amd_rng); + err = hwrng_register(&amd_rng); + if (err) { + pr_err(DRV_NAME " registering failed (%d)\n", err); + goto err_hwrng; + } + return 0; + +err_hwrng: + ioport_unmap(priv->iobase); +err_iomap: + release_region(pmbase + PMBASE_OFFSET, PMBASE_SIZE); +out: + kfree(priv); + return err; } static void __exit mod_exit(void) { + struct amd768_priv *priv; + + priv = (struct amd768_priv *)amd_rng.priv; + + hwrng_unregister(&amd_rng); + + ioport_unmap(priv->iobase); + + release_region(priv->pmbase + PMBASE_OFFSET, PMBASE_SIZE); + + kfree(priv); } module_init(mod_init); Patches currently in stable-queue which might be from prarit@xxxxxxxxxx are queue-4.9/hwrng-amd-revert-managed-api-changes.patch queue-4.9/hwrng-geode-revert-managed-api-changes.patch