2015-06-17 16:33:33

by Dheepthi K

Subject: [PATCH 1/1] NVMe : Corrected memory freeing.

Memory freeing order has been corrected incase of
allocation failure.

Signed-off-by: Dheepthi K <[email protected]>
---
drivers/block/nvme-core.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c
index 683dff2..9bac53b 100644
--- a/drivers/block/nvme-core.c
+++ b/drivers/block/nvme-core.c
@@ -2947,11 +2947,11 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
dev->entry = kzalloc_node(num_possible_cpus() * sizeof(*dev->entry),
GFP_KERNEL, node);
if (!dev->entry)
- goto free;
+ goto free_dev;
dev->queues = kzalloc_node((num_possible_cpus() + 1) * sizeof(void *),
GFP_KERNEL, node);
if (!dev->queues)
- goto free;
+ goto free_entry;

INIT_LIST_HEAD(&dev->namespaces);
dev->reset_workfn = nvme_reset_failed_dev;
@@ -2987,9 +2987,10 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
nvme_release_instance(dev);
put_pci:
pci_dev_put(dev->pci_dev);
- free:
kfree(dev->queues);
+ free_entry:
kfree(dev->entry);
+ free_dev:
kfree(dev);
return result;
}
--
1.7.9.5

2015-06-17 16:24:23

by Matthew Wilcox

Subject: Re: [PATCH 1/1] NVMe : Corrected memory freeing.

On Wed, Jun 17, 2015 at 09:40:59PM +0530, Dheepthi K wrote:
> Memory freeing order has been corrected incase of
> allocation failure.

This doesn't fix a bug. kfree(NULL) is a no-op, and 'dev' is allocated
with kzalloc, so the current error path will call kfree(NULL).

> @@ -2947,11 +2947,11 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> dev->entry = kzalloc_node(num_possible_cpus() * sizeof(*dev->entry),
> GFP_KERNEL, node);
> if (!dev->entry)
> - goto free;
> + goto free_dev;
> dev->queues = kzalloc_node((num_possible_cpus() + 1) * sizeof(void *),
> GFP_KERNEL, node);
> if (!dev->queues)
> - goto free;
> + goto free_entry;
>
> INIT_LIST_HEAD(&dev->namespaces);
> dev->reset_workfn = nvme_reset_failed_dev;
> @@ -2987,9 +2987,10 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> nvme_release_instance(dev);
> put_pci:
> pci_dev_put(dev->pci_dev);
> - free:
> kfree(dev->queues);
> + free_entry:
> kfree(dev->entry);
> + free_dev:
> kfree(dev);
> return result;
> }
> --
> 1.7.9.5

2015-06-17 16:25:04

by Keith Busch

Subject: Re: [PATCH 1/1] NVMe : Corrected memory freeing.

On Wed, 17 Jun 2015, Dheepthi K wrote:
> Memory freeing order has been corrected incase of
> allocation failure.

This isn't necessary. The nvme_dev is zero'ed on allocation, and
kfree(NULL or (void *)0) is okay to do.


> Signed-off-by: Dheepthi K <[email protected]>
> ---
> drivers/block/nvme-core.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c
> index 683dff2..9bac53b 100644
> --- a/drivers/block/nvme-core.c
> +++ b/drivers/block/nvme-core.c
> @@ -2947,11 +2947,11 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> dev->entry = kzalloc_node(num_possible_cpus() * sizeof(*dev->entry),
> GFP_KERNEL, node);
> if (!dev->entry)
> - goto free;
> + goto free_dev;
> dev->queues = kzalloc_node((num_possible_cpus() + 1) * sizeof(void *),
> GFP_KERNEL, node);
> if (!dev->queues)
> - goto free;
> + goto free_entry;
>
> INIT_LIST_HEAD(&dev->namespaces);
> dev->reset_workfn = nvme_reset_failed_dev;
> @@ -2987,9 +2987,10 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> nvme_release_instance(dev);
> put_pci:
> pci_dev_put(dev->pci_dev);
> - free:
> kfree(dev->queues);
> + free_entry:
> kfree(dev->entry);
> + free_dev:
> kfree(dev);
> return result;
> }