On 08/06/2015 01:14 PM, Matan Barak wrote:
> Separate the cleanup and release IB cache functions.
> The cleanup function delete all GIDs and unregister the event channel,
> while the release function frees all memory. The cleanup function is
> called after all clients were removed (in the device un-registration
> process).
>
> The release function is called after the device was put.
> This is in order to avoid use-after-free errors if ther vendor
> driver's teardown code uses IB cache.
>
> Squash-into: 'IB/core: Add RoCE GID table management'
> Signed-off-by: Matan Barak <matanb@xxxxxxxxxxxx>
I had originally used the v1 of this patch instead of v2. In order to
make sure I didn't miss anything, I hand compared the final results of
the v1 patch to what this patch would have created if I had used it. I
found a few things worth nothing, comments inline below.
> @@ -903,20 +924,28 @@ int ib_cache_setup_one(struct ib_device *device)
> (rdma_end_port(device) -
> rdma_start_port(device) + 1),
> GFP_KERNEL);
> - err = gid_table_setup_one(device);
> -
> - if (!device->cache.pkey_cache || !device->cache.gid_cache ||
> + if (!device->cache.pkey_cache ||
> !device->cache.lmc_cache) {
> printk(KERN_WARNING "Couldn't allocate cache "
> "for %s\n", device->name);
> - err = -ENOMEM;
> - goto err;
> + /* pkey_cache is freed here because we later access it's
> + * elements.
> + */
> + kfree(device->cache.pkey_cache);
> + device->cache.pkey_cache = NULL;
> + return -ENOMEM;
This function is unnecessarily convoluted IMO. A simple change to using
kzalloc() for the pkey_cache alloc eliminates part of the issue. As a
result, I fixed this function up to be different than either patch.
Please look over my results and make sure you agree with my changes.
> }
>
> - for (p = 0; p <= rdma_end_port(device) - rdma_start_port(device); ++p) {
> + for (p = 0; p <= rdma_end_port(device) - rdma_start_port(device); ++p)
> device->cache.pkey_cache[p] = NULL;
For instance this goes away entirely by using kzalloc().
The rest looked ok. I have to fixup the ordering changes between sysfs
and cache to make the v1 patch match the v2 patch.
--
Doug Ledford <dledford@xxxxxxxxxx>
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