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IB/core: Introduce GID entry reference counts 

In order to be able to expose pointers to the ib_gid_attrs in the GID
table we need to make it so the value of the pointer cannot be
changed. Thus each GID table entry gets a unique piece of kref'd memory
that is written only during initialization and remains constant for its
lifetime.

This eventually will allow the struct ib_gid_attrs to be returned without
copy from many of query the APIs, but it also provides a way to track when
all users of a HW table index go away.

For roce we no longer allow an in-use HW table index to be re-used for a
new an different entry. When a GID table entry needs to be removed it is
hidden from the find API, but remains as a valid HW index and all
ib_gid_attr points remain valid. The HW index is not relased until all
users put the kref.

Later patches will broadly replace the use of the sgid_index integer with
the kref'd structure.

Ultimately this will prevent security problems where the OS changes the
properties of a HW GID table entry while an active user object is still
using the entry.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This commit is contained in:
Parav Pandit 2018-06-05 08:40:15 +03:00 committed by Jason Gunthorpe
parent 1c36cf912a
commit b150c3862d
2 changed files with 223 additions and 105 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

327
drivers/infiniband/core/cache.c
View File

@ -66,15 +66,24 @@ enum gid_attr_find_mask {
GID_ATTR_FIND_MASK_GID_TYPE = 1UL << 3,
};
enum gid_table_entry_props {
GID_TABLE_ENTRY_INVALID = 1UL << 0,
enum gid_table_entry_state {
GID_TABLE_ENTRY_INVALID = 1,
GID_TABLE_ENTRY_VALID = 2,
/*
* Indicates that entry is pending to be removed, there may
* be active users of this GID entry.
* When last user of the GID entry releases reference to it,
* GID entry is detached from the table.
*/
GID_TABLE_ENTRY_PENDING_DEL = 3,
};
struct ib_gid_table_entry {
unsigned long props;
union ib_gid gid;
struct ib_gid_attr attr;
void *context;
struct kref kref;
struct work_struct del_work;
struct ib_gid_attr attr;
void *context;
enum gid_table_entry_state state;
};
struct ib_gid_table {
@ -90,15 +99,16 @@ struct ib_gid_table {
*
**/
/* Any writer to data_vec must hold this lock and the write side of
* rwlock. readers must hold only rwlock. All writers must be in a
* rwlock. Readers must hold only rwlock. All writers must be in a
* sleepable context.
*/
struct mutex lock;
/* rwlock protects data_vec[ix]->props. */
/* rwlock protects data_vec[ix]->state and entry pointer.
*/
rwlock_t rwlock;
struct ib_gid_table_entry **data_vec;
/* bit field, each bit indicates the index of default GID */
u32 default_gid_indices;
struct ib_gid_table_entry *data_vec;
};
static void dispatch_gid_change_event(struct ib_device *ib_dev, u8 port)
@ -178,26 +188,113 @@ static struct ib_gid_table *rdma_gid_table(struct ib_device *device, u8 port)
return device->cache.ports[port - rdma_start_port(device)].gid;
}
static void del_roce_gid(struct ib_device *device, u8 port_num,
struct ib_gid_table *table, int ix)
static bool is_gid_entry_free(const struct ib_gid_table_entry *entry)
{
pr_debug("%s device=%s port=%d index=%d gid %pI6\n", __func__,
device->name, port_num, ix,
table->data_vec[ix].gid.raw);
if (rdma_cap_roce_gid_table(device, port_num))
device->del_gid(&table->data_vec[ix].attr,
&table->data_vec[ix].context);
dev_put(table->data_vec[ix].attr.ndev);
return !entry;
}
static int add_roce_gid(struct ib_gid_table *table,
const union ib_gid *gid,
const struct ib_gid_attr *attr)
static bool is_gid_entry_valid(const struct ib_gid_table_entry *entry)
{
return entry && entry->state == GID_TABLE_ENTRY_VALID;
}
static void schedule_free_gid(struct kref *kref)
{
struct ib_gid_table_entry *entry =
container_of(kref, struct ib_gid_table_entry, kref);
queue_work(ib_wq, &entry->del_work);
}
static void free_gid_entry(struct ib_gid_table_entry *entry)
{
struct ib_device *device = entry->attr.device;
u8 port_num = entry->attr.port_num;
struct ib_gid_table *table = rdma_gid_table(device, port_num);
pr_debug("%s device=%s port=%d index=%d gid %pI6\n", __func__,
device->name, port_num, entry->attr.index,
entry->attr.gid.raw);
mutex_lock(&table->lock);
if (rdma_cap_roce_gid_table(device, port_num) &&
entry->state != GID_TABLE_ENTRY_INVALID)
device->del_gid(&entry->attr, &entry->context);
write_lock_irq(&table->rwlock);
/*
* The only way to avoid overwriting NULL in table is
* by comparing if it is same entry in table or not!
* If new entry in table is added by the time we free here,
* don't overwrite the table entry.
*/
if (entry == table->data_vec[entry->attr.index])
table->data_vec[entry->attr.index] = NULL;
/* Now this index is ready to be allocated */
write_unlock_irq(&table->rwlock);
mutex_unlock(&table->lock);
if (entry->attr.ndev)
dev_put(entry->attr.ndev);
kfree(entry);
}
/**
* free_gid_work - Release reference to the GID entry
* @work: Work structure to refer to GID entry which needs to be
* deleted.
*
* free_gid_work() frees the entry from the HCA's hardware table
* if provider supports it. It releases reference to netdevice.
*/
static void free_gid_work(struct work_struct *work)
{
struct ib_gid_table_entry *entry =
container_of(work, struct ib_gid_table_entry, del_work);
free_gid_entry(entry);
}
static struct ib_gid_table_entry *
alloc_gid_entry(const struct ib_gid_attr *attr)
{
struct ib_gid_table_entry *entry;
int ix = attr->index;
int ret = 0;
entry = kzalloc(sizeof(*entry), GFP_KERNEL);
if (!entry)
return NULL;
kref_init(&entry->kref);
memcpy(&entry->attr, attr, sizeof(*attr));
if (entry->attr.ndev)
dev_hold(entry->attr.ndev);
INIT_WORK(&entry->del_work, free_gid_work);
entry->state = GID_TABLE_ENTRY_INVALID;
return entry;
}
static void store_gid_entry(struct ib_gid_table *table,
struct ib_gid_table_entry *entry)
{
entry->state = GID_TABLE_ENTRY_VALID;
pr_debug("%s device=%s port=%d index=%d gid %pI6\n", __func__,
entry->attr.device->name, entry->attr.port_num,
entry->attr.index, entry->attr.gid.raw);
lockdep_assert_held(&table->lock);
write_lock_irq(&table->rwlock);
table->data_vec[entry->attr.index] = entry;
write_unlock_irq(&table->rwlock);
}
static void put_gid_entry(struct ib_gid_table_entry *entry)
{
kref_put(&entry->kref, schedule_free_gid);
}
static int add_roce_gid(struct ib_gid_table_entry *entry)
{
const struct ib_gid_attr *attr = &entry->attr;
int ret;
if (!attr->ndev) {
pr_err("%s NULL netdev device=%s port=%d index=%d\n",
@ -205,38 +302,22 @@ static int add_roce_gid(struct ib_gid_table *table,
attr->index);
return -EINVAL;
}
entry = &table->data_vec[ix];
if ((entry->props & GID_TABLE_ENTRY_INVALID) == 0) {
WARN(1, "GID table corruption device=%s port=%d index=%d\n",
attr->device->name, attr->port_num,
attr->index);
return -EINVAL;
}
if (rdma_cap_roce_gid_table(attr->device, attr->port_num)) {
ret = attr->device->add_gid(gid, attr, &entry->context);
ret = attr->device->add_gid(&attr->gid, attr, &entry->context);
if (ret) {
pr_err("%s GID add failed device=%s port=%d index=%d\n",
__func__, attr->device->name, attr->port_num,
attr->index);
goto add_err;
return ret;
}
}
dev_hold(attr->ndev);
add_err:
if (!ret)
pr_debug("%s device=%s port=%d index=%d gid %pI6\n", __func__,
attr->device->name, attr->port_num, ix, gid->raw);
return ret;
return 0;
}
/**
* add_modify_gid - Add or modify GID table entry
*
* @table: GID table in which GID to be added or modified
* @gid: GID content
* @attr: Attributes of the GID
*
* Returns 0 on success or appropriate error code. It accepts zero
@ -244,34 +325,42 @@ add_err:
* GID. However such zero GIDs are not added to the cache.
*/
static int add_modify_gid(struct ib_gid_table *table,
const union ib_gid *gid,
const struct ib_gid_attr *attr)
{
int ret;
struct ib_gid_table_entry *entry;
int ret = 0;
/*
* Invalidate any old entry in the table to make it safe to write to
* this index.
*/
if (is_gid_entry_valid(table->data_vec[attr->index]))
put_gid_entry(table->data_vec[attr->index]);
/*
* Some HCA's report multiple GID entries with only one valid GID, and
* leave other unused entries as the zero GID. Convert zero GIDs to
* empty table entries instead of storing them.
*/
if (rdma_is_zero_gid(&attr->gid))
return 0;
entry = alloc_gid_entry(attr);
if (!entry)
return -ENOMEM;
if (rdma_protocol_roce(attr->device, attr->port_num)) {
ret = add_roce_gid(table, gid, attr);
ret = add_roce_gid(entry);
if (ret)
return ret;
} else {
/*
* Some HCA's report multiple GID entries with only one
* valid GID, but remaining as zero GID.
* So ignore such behavior for IB link layer and don't
* fail the call, but don't add such entry to GID cache.
*/
if (rdma_is_zero_gid(gid))
return 0;
goto done;
}
lockdep_assert_held(&table->lock);
memcpy(&table->data_vec[attr->index].gid, gid, sizeof(*gid));
memcpy(&table->data_vec[attr->index].attr, attr, sizeof(*attr));
write_lock_irq(&table->rwlock);
table->data_vec[attr->index].props &= ~GID_TABLE_ENTRY_INVALID;
write_unlock_irq(&table->rwlock);
store_gid_entry(table, entry);
return 0;
done:
put_gid_entry(entry);
return ret;
}
/**
@ -286,16 +375,25 @@ static int add_modify_gid(struct ib_gid_table *table,
static void del_gid(struct ib_device *ib_dev, u8 port,
struct ib_gid_table *table, int ix)
{
struct ib_gid_table_entry *entry;
lockdep_assert_held(&table->lock);
pr_debug("%s device=%s port=%d index=%d gid %pI6\n", __func__,
ib_dev->name, port, ix,
table->data_vec[ix]->attr.gid.raw);
write_lock_irq(&table->rwlock);
table->data_vec[ix].props |= GID_TABLE_ENTRY_INVALID;
entry = table->data_vec[ix];
entry->state = GID_TABLE_ENTRY_PENDING_DEL;
/*
* For non RoCE protocol, GID entry slot is ready to use.
*/
if (!rdma_protocol_roce(ib_dev, port))
table->data_vec[ix] = NULL;
write_unlock_irq(&table->rwlock);
if (rdma_protocol_roce(ib_dev, port))
del_roce_gid(ib_dev, port, table, ix);
memset(&table->data_vec[ix].gid, 0, sizeof(table->data_vec[ix].gid));
memset(&table->data_vec[ix].attr, 0, sizeof(table->data_vec[ix].attr));
table->data_vec[ix].context = NULL;
put_gid_entry(entry);
}
/* rwlock should be read locked, or lock should be held */
@ -308,8 +406,8 @@ static int find_gid(struct ib_gid_table *table, const union ib_gid *gid,
int empty = pempty ? -1 : 0;
while (i < table->sz && (found < 0 || empty < 0)) {
struct ib_gid_table_entry *data = &table->data_vec[i];
struct ib_gid_attr *attr = &data->attr;
struct ib_gid_table_entry *data = table->data_vec[i];
struct ib_gid_attr *attr;
int curr_index = i;
i++;
@ -320,9 +418,9 @@ static int find_gid(struct ib_gid_table *table, const union ib_gid *gid,
* so lookup free slot only if requested.
*/
if (pempty && empty < 0) {
if (data->props & GID_TABLE_ENTRY_INVALID &&
(default_gid ==
is_gid_index_default(table, curr_index))) {
if (is_gid_entry_free(data) &&
default_gid ==
is_gid_index_default(table, curr_index)) {
/*
* Found an invalid (free) entry; allocate it.
* If default GID is requested, then our
@ -337,22 +435,23 @@ static int find_gid(struct ib_gid_table *table, const union ib_gid *gid,
/*
* Additionally find_gid() is used to find valid entry during
* lookup operation, where validity needs to be checked. So
* find the empty entry first to continue to search for a free
* slot and ignore its INVALID flag.
* lookup operation; so ignore the entries which are marked as
* pending for removal and the entries which are marked as
* invalid.
*/
if (data->props & GID_TABLE_ENTRY_INVALID)
if (!is_gid_entry_valid(data))
continue;
if (found >= 0)
continue;
attr = &data->attr;
if (mask & GID_ATTR_FIND_MASK_GID_TYPE &&
attr->gid_type != val->gid_type)
continue;
if (mask & GID_ATTR_FIND_MASK_GID &&
memcmp(gid, &data->gid, sizeof(*gid)))
memcmp(gid, &data->attr.gid, sizeof(*gid)))
continue;
if (mask & GID_ATTR_FIND_MASK_NETDEV &&
@ -409,7 +508,8 @@ static int __ib_cache_gid_add(struct ib_device *ib_dev, u8 port,
attr->device = ib_dev;
attr->index = empty;
attr->port_num = port;
ret = add_modify_gid(table, gid, attr);
attr->gid = *gid;
ret = add_modify_gid(table, attr);
if (!ret)
dispatch_gid_change_event(ib_dev, port);
@ -505,7 +605,8 @@ int ib_cache_gid_del_all_netdev_gids(struct ib_device *ib_dev, u8 port,
mutex_lock(&table->lock);
for (ix = 0; ix < table->sz; ix++) {
if (table->data_vec[ix].attr.ndev == ndev) {
if (is_gid_entry_valid(table->data_vec[ix]) &&
table->data_vec[ix]->attr.ndev == ndev) {
del_gid(ib_dev, port, table, ix);
deleted = true;
}
@ -529,12 +630,13 @@ static int __ib_cache_gid_get(struct ib_device *ib_dev, u8 port, int index,
if (index < 0 || index >= table->sz)
return -EINVAL;
if (table->data_vec[index].props & GID_TABLE_ENTRY_INVALID)
if (!is_gid_entry_valid(table->data_vec[index]))
return -EINVAL;
memcpy(gid, &table->data_vec[index].gid, sizeof(*gid));
memcpy(gid, &table->data_vec[index]->attr.gid, sizeof(*gid));
if (attr) {
memcpy(attr, &table->data_vec[index].attr, sizeof(*attr));
memcpy(attr, &table->data_vec[index]->attr,
sizeof(*attr));
if (attr->ndev)
dev_hold(attr->ndev);
}
@ -681,13 +783,14 @@ static int ib_cache_gid_find_by_filter(struct ib_device *ib_dev,
for (i = 0; i < table->sz; i++) {
struct ib_gid_attr attr;
if (table->data_vec[i].props & GID_TABLE_ENTRY_INVALID)
if (!is_gid_entry_valid(table->data_vec[i]))
continue;
if (memcmp(gid, &table->data_vec[i].gid, sizeof(*gid)))
if (memcmp(gid, &table->data_vec[i]->attr.gid,
sizeof(*gid)))
continue;
memcpy(&attr, &table->data_vec[i].attr, sizeof(attr));
memcpy(&attr, &table->data_vec[i]->attr, sizeof(attr));
if (filter(gid, &attr, context)) {
found = true;
@ -705,9 +808,7 @@ static int ib_cache_gid_find_by_filter(struct ib_device *ib_dev,
static struct ib_gid_table *alloc_gid_table(int sz)
{
struct ib_gid_table *table =
kzalloc(sizeof(struct ib_gid_table), GFP_KERNEL);
int i;
struct ib_gid_table *table = kzalloc(sizeof(*table), GFP_KERNEL);
if (!table)
return NULL;
@ -720,12 +821,6 @@ static struct ib_gid_table *alloc_gid_table(int sz)
table->sz = sz;
rwlock_init(&table->rwlock);
/* Mark all entries as invalid so that allocator can allocate
* one of the invalid (free) entry.
*/
for (i = 0; i < sz; i++)
table->data_vec[i].props |= GID_TABLE_ENTRY_INVALID;
return table;
err_free_table:
@ -733,12 +828,30 @@ err_free_table:
return NULL;
}
static void release_gid_table(struct ib_gid_table *table)
static void release_gid_table(struct ib_device *device, u8 port,
struct ib_gid_table *table)
{
if (table) {
kfree(table->data_vec);
kfree(table);
bool leak = false;
int i;
if (!table)
return;
for (i = 0; i < table->sz; i++) {
if (is_gid_entry_free(table->data_vec[i]))
continue;
if (kref_read(&table->data_vec[i]->kref) > 1) {
pr_err("GID entry ref leak for %s (index %d) ref=%d\n",
device->name, i,
kref_read(&table->data_vec[i]->kref));
leak = true;
}
}
if (leak)
return;
kfree(table->data_vec);
kfree(table);
}
static void cleanup_gid_table_port(struct ib_device *ib_dev, u8 port,
@ -752,7 +865,7 @@ static void cleanup_gid_table_port(struct ib_device *ib_dev, u8 port,
mutex_lock(&table->lock);
for (i = 0; i < table->sz; ++i) {
if (!rdma_is_zero_gid(&table->data_vec[i].gid)) {
if (is_gid_entry_valid(table->data_vec[i])) {
del_gid(ib_dev, port, table, i);
deleted = true;
}
@ -821,7 +934,7 @@ static void gid_table_release_one(struct ib_device *ib_dev)
for (port = 0; port < ib_dev->phys_port_cnt; port++) {
table = ib_dev->cache.ports[port].gid;
release_gid_table(table);
release_gid_table(ib_dev, port, table);
ib_dev->cache.ports[port].gid = NULL;
}
}
@ -1100,7 +1213,6 @@ static int config_non_roce_gid_cache(struct ib_device *device,
{
struct ib_gid_attr gid_attr = {};
struct ib_gid_table *table;
union ib_gid gid;
int ret = 0;
int i;
@ -1112,14 +1224,14 @@ static int config_non_roce_gid_cache(struct ib_device *device,
for (i = 0; i < gid_tbl_len; ++i) {
if (!device->query_gid)
continue;
ret = device->query_gid(device, port, i, &gid);
ret = device->query_gid(device, port, i, &gid_attr.gid);
if (ret) {
pr_warn("query_gid failed (%d) for %s (index %d)\n",
ret, device->name, i);
goto err;
}
gid_attr.index = i;
add_modify_gid(table, &gid, &gid_attr);
add_modify_gid(table, &gid_attr);
}
err:
mutex_unlock(&table->lock);
@ -1302,4 +1414,9 @@ void ib_cache_cleanup_one(struct ib_device *device)
ib_unregister_event_handler(&device->cache.event_handler);
flush_workqueue(ib_wq);
gid_table_cleanup_one(device);
/*
* Flush the wq second time for any pending GID delete work.
*/
flush_workqueue(ib_wq);
}

1
include/rdma/ib_verbs.h
View File

@ -94,6 +94,7 @@ enum ib_gid_type {
struct ib_gid_attr {
struct net_device *ndev;
struct ib_device *device;
union ib_gid gid;
enum ib_gid_type gid_type;
u16 index;
u8 port_num;