#ifndef __sctp_tsnmap_h__
#define __sctp_tsnmap_h__
/* RFC 2960 12.2 Parameters necessary per association (i.e. the TCB)
* Mapping An array of bits or bytes indicating which out of
* Array order TSN's have been received (relative to the
* Last Rcvd TSN). If no gaps exist, i.e. no out of
* order packets have been received, this array
* will be set to all zero. This structure may be
* in the form of a circular buffer or bit array.
*/
struct sctp_tsnmap {
/* This array counts the number of chunks with each TSN.
* It points at one of the two buffers with which we will
* ping-pong between.
*/
unsigned long *tsn_map;
/* This is the TSN at tsn_map[0]. */
__u32 base_tsn;
/* Last Rcvd : This is the last TSN received in
* TSN : sequence. This value is set initially by
* : taking the peer's Initial TSN, received in
* : the INIT or INIT ACK chunk, and subtracting
* : one from it.
*
* Throughout most of the specification this is called the
* "Cumulative TSN ACK Point". In this case, we
* ignore the advice in 12.2 in favour of the term
* used in the bulk of the text.
*/
__u32 cumulative_tsn_ack_point;
/* This is the highest TSN we've marked. */
__u32 max_tsn_seen;
/* This is the minimum number of TSNs we can track. This corresponds
* to the size of tsn_map. Note: the overflow_map allows us to
* potentially track more than this quantity.
*/
__u16 len;
/* Data chunks pending receipt. used by SCTP_STATUS sockopt */
__u16 pending_data;
/* Record duplicate TSNs here. We clear this after
* every SACK. Store up to SCTP_MAX_DUP_TSNS worth of
* information.
*/
__u16 num_dup_tsns;
__be32 dup_tsns[SCTP_MAX_DUP_TSNS];
};
struct sctp_tsnmap_iter {
__u32 start;
};
/* Initialize a block of memory as a tsnmap. */
struct sctp_tsnmap *sctp_tsnmap_init(struct sctp_tsnmap *, __u16 len,
__u32 initial_tsn, gfp_t gfp);
void sctp_tsnmap_free(struct sctp_tsnmap *map);
/* Test the tracking state of this TSN.
* Returns:
* 0 if the TSN has not yet been seen
* >0 if the TSN has been seen (duplicate)
* <0 if the TSN is invalid (too large to track)
*/
int sctp_tsnmap_check(const struct sctp_tsnmap *, __u32 tsn);
/* Mark this TSN as seen. */
int sctp_tsnmap_mark(struct sctp_tsnmap *, __u32 tsn,
struct sctp_transport *trans);
/* Mark this TSN and all lower as seen. */
void sctp_tsnmap_skip(struct sctp_tsnmap *map, __u32 tsn);
/* Retrieve the Cumulative TSN ACK Point. */
static inline __u32 sctp_tsnmap_get_ctsn(const struct sctp_tsnmap *map)
{
return map->cumulative_tsn_ack_point;
}
/* Retrieve the highest TSN we've seen. */
static inline __u32 sctp_tsnmap_get_max_tsn_seen(const struct sctp_tsnmap *map)
{
return map->max_tsn_seen;
}
/* How many duplicate TSNs are stored? */
static inline __u16 sctp_tsnmap_num_dups(struct sctp_tsnmap *map)
{
return map->num_dup_tsns;
}
/* Return pointer to duplicate tsn array as needed by SACK. */
static inline __be32 *sctp_tsnmap_get_dups(struct sctp_tsnmap *map)
{
map->num_dup_tsns = 0;
return map->dup_tsns;
}
/* How many gap ack blocks do we have recorded? */
__u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map,
struct sctp_gap_ack_block *gabs);
/* Refresh the count on pending data. */
__u16 sctp_tsnmap_pending(struct sctp_tsnmap *map);
/* Is there a gap in the TSN map? */
static inline int sctp_tsnmap_has_gap(const struct sctp_tsnmap *map)
{
return map->cumulative_tsn_ack_point != map->max_tsn_seen;
}
/* Mark a duplicate TSN. Note: limit the storage of duplicate TSN
* information.
*/
static inline void sctp_tsnmap_mark_dup(struct sctp_tsnmap *map, __u32 tsn)
{
if (map->num_dup_tsns < SCTP_MAX_DUP_TSNS)
map->dup_tsns[map->num_dup_tsns++] = htonl(tsn);
}
/* Renege a TSN that was seen. */
void sctp_tsnmap_renege(struct sctp_tsnmap *, __u32 tsn);
/* Is there a gap in the TSN map? */
int sctp_tsnmap_has_gap(const struct sctp_tsnmap *);
#endif /* __sctp_tsnmap_h__ */
/td>
| tree | 75f65eba7eac9277971082a2d5a4cf1370562c0c /include/net/llc_sap.h |
|---|
| parent | 7ce7d89f48834cefece7804d38fc5d85382edf77 (diff) |
|---|
cgroup: don't online subsystems before cgroup_name/path() are operational
While refactoring cgroup creation, a5bca2152036 ("cgroup: factor out
cgroup_create() out of cgroup_mkdir()") incorrectly onlined subsystems
before the new cgroup is associated with it kernfs_node. This is fine
for cgroup proper but cgroup_name/path() depend on the associated
kernfs_node and if a subsystem makes the new cgroup_subsys_state
visible, which they're allowed to after onlining, it can lead to NULL
dereference.
The current code performs cgroup creation and subsystem onlining in
cgroup_create() and cgroup_mkdir() makes the cgroup and subsystems
visible afterwards. There's no reason to online the subsystems early
and we can simply drop cgroup_apply_control_enable() call from
cgroup_create() so that the subsystems are onlined and made visible at
the same time.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Fixes: a5bca2152036 ("cgroup: factor out cgroup_create() out of cgroup_mkdir()")
Cc: stable@vger.kernel.org # v4.6+