diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 80e40de446c00b384cfea833841c9df724c1bb5a..d1d1da9110851933d5e6058f3ba9effc9191f678 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1830,6 +1830,9 @@
ip= [IP_PNP]
See Documentation/filesystems/nfs/nfsroot.txt.
+ ipcmni_extend [KNL] Extend the maximum number of unique System V
+ IPC identifiers from 32,768 to 16,777,216.
+
irqaffinity= [SMP] Set the default irq affinity mask
The argument is a cpu list, as described above.
diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c
index 49f9bf4ffc7f1ae09bc04b833891fcc7d7a5a5a5..73b7782eccf48928fb5b8b6106538a751f295a0b 100644
--- a/ipc/ipc_sysctl.c
+++ b/ipc/ipc_sysctl.c
@@ -120,7 +120,8 @@ static int proc_ipc_sem_dointvec(struct ctl_table *table, int write,
static int zero;
static int one = 1;
static int int_max = INT_MAX;
-static int ipc_mni = IPCMNI;
+int ipc_mni = IPCMNI;
+int ipc_mni_shift = IPCMNI_SHIFT;
static struct ctl_table ipc_kern_table[] = {
{
@@ -246,3 +247,12 @@ static int __init ipc_sysctl_init(void)
}
device_initcall(ipc_sysctl_init);
+
+static int __init ipc_mni_extend(char *str)
+{
+ ipc_mni = IPCMNI_EXTEND;
+ ipc_mni_shift = IPCMNI_EXTEND_SHIFT;
+ pr_info("IPCMNI extended to %d.\n", ipc_mni);
+ return 0;
+}
+early_param("ipcmni_extend", ipc_mni_extend);
diff --git a/ipc/util.c b/ipc/util.c
index 095274a871f89b9d37f825d9190355a8592a10b3..cf5d1087409e19cb9fdfb5fc37a61178fafd1f48 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -109,7 +109,7 @@ static const struct rhashtable_params ipc_kht_params = {
* @ids: ipc identifier set
*
* Set up the sequence range to use for the ipc identifier range (limited
- * below IPCMNI) then initialise the keys hashtable and ids idr.
+ * below ipc_mni) then initialise the keys hashtable and ids idr.
*/
void ipc_init_ids(struct ipc_ids *ids)
{
@@ -225,7 +225,7 @@ static inline int ipc_idr_alloc(struct ipc_ids *ids, struct kern_ipc_perm *new)
0, GFP_NOWAIT);
}
if (idx >= 0)
- new->id = SEQ_MULTIPLIER * new->seq + idx;
+ new->id = (new->seq << IPCMNI_SEQ_SHIFT) + idx;
return idx;
}
@@ -253,8 +253,8 @@ int ipc_addid(struct ipc_ids *ids, struct kern_ipc_perm *new, int limit)
/* 1) Initialize the refcount so that ipc_rcu_putref works */
refcount_set(&new->refcount, 1);
- if (limit > IPCMNI)
- limit = IPCMNI;
+ if (limit > ipc_mni)
+ limit = ipc_mni;
if (ids->in_use >= limit)
return -ENOSPC;
@@ -737,7 +737,7 @@ static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos,
if (total >= ids->in_use)
return NULL;
- for (; pos < IPCMNI; pos++) {
+ for (; pos < ipc_mni; pos++) {
ipc = idr_find(&ids->ipcs_idr, pos);
if (ipc != NULL) {
*new_pos = pos + 1;
diff --git a/ipc/util.h b/ipc/util.h
index e272be622ae79b4e751202e3d781183975bd0794..9746886757de8ff91ba8c8b2bce5802a25cb543b 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -15,8 +15,34 @@
#include <linux/err.h>
#include <linux/ipc_namespace.h>
-#define IPCMNI 32768 /* <= MAX_INT limit for ipc arrays (including sysctl changes) */
-#define SEQ_MULTIPLIER (IPCMNI)
+/*
+ * The IPC ID contains 2 separate numbers - index and sequence number.
+ * By default,
+ * bits 0-14: index (32k, 15 bits)
+ * bits 15-30: sequence number (64k, 16 bits)
+ *
+ * When IPCMNI extension mode is turned on, the composition changes:
+ * bits 0-23: index (16M, 24 bits)
+ * bits 24-30: sequence number (128, 7 bits)
+ */
+#define IPCMNI_SHIFT 15
+#define IPCMNI_EXTEND_SHIFT 24
+#define IPCMNI (1 << IPCMNI_SHIFT)
+#define IPCMNI_EXTEND (1 << IPCMNI_EXTEND_SHIFT)
+
+#ifdef CONFIG_SYSVIPC_SYSCTL
+extern int ipc_mni;
+extern int ipc_mni_shift;
+
+#define IPCMNI_SEQ_SHIFT ipc_mni_shift
+#define IPCMNI_IDX_MASK ((1 << ipc_mni_shift) - 1)
+
+#else /* CONFIG_SYSVIPC_SYSCTL */
+
+#define ipc_mni IPCMNI
+#define IPCMNI_SEQ_SHIFT IPCMNI_SHIFT
+#define IPCMNI_IDX_MASK ((1 << IPCMNI_SHIFT) - 1)
+#endif /* CONFIG_SYSVIPC_SYSCTL */
void sem_init(void);
void msg_init(void);
@@ -96,9 +122,9 @@ struct pid_namespace *ipc_seq_pid_ns(struct seq_file *);
#define IPC_MSG_IDS 1
#define IPC_SHM_IDS 2
-#define ipcid_to_idx(id) ((id) % SEQ_MULTIPLIER)
-#define ipcid_to_seqx(id) ((id) / SEQ_MULTIPLIER)
-#define IPCID_SEQ_MAX min_t(int, INT_MAX/SEQ_MULTIPLIER, USHRT_MAX)
+#define ipcid_to_idx(id) ((id) & IPCMNI_IDX_MASK)
+#define ipcid_to_seqx(id) ((id) >> IPCMNI_SEQ_SHIFT)
+#define IPCID_SEQ_MAX (INT_MAX >> IPCMNI_SEQ_SHIFT)
/* must be called with ids->rwsem acquired for writing */
int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int);
@@ -123,8 +149,8 @@ static inline int ipc_get_maxidx(struct ipc_ids *ids)
if (ids->in_use == 0)
return -1;
- if (ids->in_use == IPCMNI)
- return IPCMNI - 1;
+ if (ids->in_use == ipc_mni)
+ return ipc_mni - 1;
return ids->max_idx;
}
@@ -216,10 +242,10 @@ void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
static inline int sem_check_semmni(struct ipc_namespace *ns) {
/*
- * Check semmni range [0, IPCMNI]
+ * Check semmni range [0, ipc_mni]
* semmni is the last element of sem_ctls[4] array
*/
- return ((ns->sem_ctls[3] < 0) || (ns->sem_ctls[3] > IPCMNI))
+ return ((ns->sem_ctls[3] < 0) || (ns->sem_ctls[3] > ipc_mni))
? -ERANGE : 0;
}