On Thu, Jan 03, 2019 at 10:27:52PM +0000, Jason Gunthorpe wrote:
> On Thu, Jan 03, 2019 at 10:05:57AM +0200, Leon Romanovsky wrote:
> > From: Leon Romanovsky <leonro@xxxxxxxxxxxx>
> >
> > Add new general helper to get restrack entry given by ID and
> > their respective type.
> >
> > Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
> > drivers/infiniband/core/restrack.c | 13 +++++++++++++
> > include/rdma/restrack.h | 11 +++++++++++
> > 2 files changed, 24 insertions(+)
> >
> > diff --git a/drivers/infiniband/core/restrack.c b/drivers/infiniband/core/restrack.c
> > index 473422da0856..d65758a3a7b6 100644
> > +++ b/drivers/infiniband/core/restrack.c
> > @@ -249,6 +249,19 @@ int __must_check rdma_restrack_get(struct rdma_restrack_entry *res)
> > }
> > EXPORT_SYMBOL(rdma_restrack_get);
> >
> > +struct rdma_restrack_entry *
> > +rdma_restrack_get_byid(struct rdma_restrack_root *rt,
> > + enum rdma_restrack_type type, u32 id)
> > +{
> > + struct rdma_restrack_entry *res;
> > +
> > + res = xa_load(&rt->xa[type], id);
>
> the previous patch did:
>
> + id = res_to_id(res);
> + ret = xa_insert(&dev->res.xa[res->type], id, res, GFP_KERNEL);
>
> Where res_to_id() returns a pointer casted to an unsigned long - so
> the use of 'u32 id' is wrong here.
I "removed" from this RFC patches which added software ID generation for
drivers without relevant HW/FW and their conversion to use that ID.
At the time of final submission res_to_id() won't return pointers.
>
> Also, it seems to expose kernel pointers to user space, which is a
> security no-no.
We are not, see introduction of ".id" field in nldev.c. It is added once
all drivers are capable to return some unique ID and not pointer.
>
> I think this needs actual device-unique IDs for all objects, no use of
> pointers.
It exists, I didn't post it as part of RFC.
>
> Probably better to use the xarray in the IDR mode and have it generate
> unique ID's for all the cases where a HW ID is not already present.
I'm attaching this patch for your convenience.
From c3cca57ebf246c268b60be9ad364a0275cedb1de Mon Sep 17 00:00:00 2001
From: Leon Romanovsky <leonro@xxxxxxxxxxxx>
Date: Thu, 3 Jan 2019 18:19:43 +0200
Subject: [PATCH 24/25] RDMA/restrack: Implement software ID interface
Provide basic functionality to safely get and put software IDs
for devices which don't do it in HW.
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
---
drivers/infiniband/core/restrack.c | 94 +++++++++++++++++++++++++++++-
include/rdma/restrack.h | 39 +++++++++++++
2 files changed, 132 insertions(+), 1 deletion(-)
diff --git a/drivers/infiniband/core/restrack.c b/drivers/infiniband/core/restrack.c
index bd3c37ca7829..f687dffb042a 100644
--- a/drivers/infiniband/core/restrack.c
+++ b/drivers/infiniband/core/restrack.c
@@ -12,6 +12,24 @@
#include "cma_priv.h"
+struct sw_id {
+ /**
+ * @id: Bitmap to keep SW genrated IDs for devices which
+ * don't have relevant hW/FW to generate them on their own.
+ * It is used for types without other unique identification
+ * available, for example QPs have unique QPN built-in.
+ */
+ unsigned long *bitmap;
+ /**
+ * @max: Maximal value of entry in ids bitmap
+ */
+ u32 max;
+ /**
+ * @bitmap_lock: Protect concurent ID updates
+ */
+ spinlock_t bitmap_lock;
+};
+
static int fill_res_noop(struct sk_buff *msg,
struct rdma_restrack_entry *entry)
{
@@ -26,7 +44,7 @@ void rdma_restrack_init(struct rdma_restrack_root *res)
xa_init(&res->xa[i]);
res->fill_res_entry = fill_res_noop;
-
+ res->priv = NULL;
}
static const char *type2str(enum rdma_restrack_type type)
@@ -85,6 +103,8 @@ void rdma_restrack_clean(struct rdma_restrack_root *res)
}
if (!found)
pr_err("restrack: %s", CUT_HERE);
+
+ kfree(res->priv);
}
int rdma_restrack_count(struct rdma_restrack_root *res,
@@ -300,3 +320,75 @@ void rdma_restrack_del(struct rdma_restrack_entry *res)
}
}
EXPORT_SYMBOL(rdma_restrack_del);
+
+int rdma_restrack_alloc_ids(struct rdma_restrack_root *rt,
+ enum rdma_restrack_type type, u32 max)
+{
+ struct sw_id *id;
+
+ if (!rt->priv)
+ /* Possible optimization: allocate only specific type */
+ rt->priv = kcalloc(RDMA_RESTRACK_MAX, sizeof(struct sw_id),
+ GFP_KERNEL);
+
+ if (!rt->priv)
+ return -ENOMEM;
+
+ id = rt->priv + type * sizeof(struct sw_id);
+ id->max = max;
+ spin_lock_init(&id->bitmap_lock);
+ id->bitmap = kcalloc(BITS_TO_LONGS(max), sizeof(long), GFP_KERNEL);
+ if (!id->bitmap) {
+ kfree(rt->priv);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(rdma_restrack_alloc_ids);
+
+void rdma_restrack_free_ids(struct rdma_restrack_root *rt,
+ enum rdma_restrack_type type)
+{
+ struct sw_id *id;
+
+ id = rt->priv + type * sizeof(struct sw_id);
+ id->max = 0;
+ kfree(id->bitmap);
+}
+EXPORT_SYMBOL(rdma_restrack_free_ids);
+
+int rdma_restrack_get_id(struct rdma_restrack_root *rt,
+ enum rdma_restrack_type type, u32 *val)
+{
+ struct sw_id *id;
+ int ret = 0;
+
+ id = rt->priv + type * sizeof(struct sw_id);
+ spin_lock(&id->bitmap_lock);
+ *val = find_first_zero_bit(id->bitmap, id->max);
+ if (*val == id->max) {
+ *val = 0;
+ ret = -EINVAL;
+ goto out;
+ }
+
+ __set_bit(*val, id->bitmap);
+
+out: spin_unlock(&id->bitmap_lock);
+ return ret;
+
+}
+EXPORT_SYMBOL(rdma_restrack_get_id);
+
+void rdma_restrack_put_id(struct rdma_restrack_root *rt,
+ enum rdma_restrack_type type, u32 val)
+{
+ struct sw_id *id;
+
+ id = rt->priv + type * sizeof(struct sw_id);
+ spin_lock(&id->bitmap_lock);
+ __clear_bit(val, id->bitmap);
+ spin_unlock(&id->bitmap_lock);
+}
+EXPORT_SYMBOL(rdma_restrack_put_id);
diff --git a/include/rdma/restrack.h b/include/rdma/restrack.h
index 33108b6a509f..cf74b1176e6f 100644
--- a/include/rdma/restrack.h
+++ b/include/rdma/restrack.h
@@ -70,6 +70,12 @@ struct rdma_restrack_root {
*/
int (*fill_res_entry)(struct sk_buff *msg,
struct rdma_restrack_entry *entry);
+
+ /**
+ * @priv: Private data used internally by restrack and
+ * not supposed to be seen and used by users.
+ */
+ void *priv;
};
/**
@@ -199,4 +205,37 @@ int rdma_nl_put_driver_u64_hex(struct sk_buff *msg, const char *name,
struct rdma_restrack_entry *
rdma_restrack_get_byid(struct rdma_restrack_root *rt,
enum rdma_restrack_type type, u32 id);
+/**
+ * rdma_restrack_alloc_ids() - allocate software IDs bitmap
+ * @rt: root table to work
+ * @type: resource track type
+ * @max: maximal possible value
+ *
+ * Return: 0 on success
+ */
+int rdma_restrack_alloc_ids(struct rdma_restrack_root *rt,
+ enum rdma_restrack_type type, u32 max);
+/**
+ * rdma_restrack_free_ids() - free software IDs bitmap
+ * @rt: root table to work
+ * @type: resource track type
+ */
+void rdma_restrack_free_ids(struct rdma_restrack_root *rt,
+ enum rdma_restrack_type type);
+/**
+ * rdma_restrack_get_id() - get software ID
+ * @rt: root table to work
+ * @type: resource track type
+ * @val: returned value
+ */
+int rdma_restrack_get_id(struct rdma_restrack_root *rt,
+ enum rdma_restrack_type type, u32 *val);
+/**
+ * rdma_restrack_put_id() - return software ID
+ * @rt: root table to work
+ * @type: resource track type
+ * @val: Id to return
+ */
+void rdma_restrack_put_id(struct rdma_restrack_root *rt,
+ enum rdma_restrack_type type, u32 val);
#endif /* _RDMA_RESTRACK_H_ */
--
2.19.1
>
> Jason
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