[RFC PATCH v3 3/4] ipc: Merge ipc_sysctl and mq_sysctl

From: Alexey Gladkov
Date: Fri Jan 21 2022 - 08:10:26 EST

Both mq_sysctl and ipc_sysctl are in the ipc namespace and both use
identical helpers so they can be merged into a single source file.

Signed-off-by: Alexey Gladkov <legion@xxxxxxxxxx>
---
include/linux/ipc_namespace.h | 41 ++---------
ipc/Makefile | 7 +-
ipc/ipc_sysctl.c | 131 ++++++++++++++++++++++++++++++++--
ipc/mq_sysctl.c | 131 ----------------------------------
ipc/mqueue.c | 5 --
ipc/namespace.c | 4 --
ipc/util.h | 4 +-
7 files changed, 132 insertions(+), 191 deletions(-)
delete mode 100644 ipc/mq_sysctl.c

diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
index 94af746704fa..461540d1cac4 100644
--- a/include/linux/ipc_namespace.h
+++ b/include/linux/ipc_namespace.h
@@ -64,10 +64,8 @@ struct ipc_namespace {
unsigned int mq_msg_default;
unsigned int mq_msgsize_default;

- struct ctl_table_set mq_set;
- struct ctl_table_header *mq_sysctls;
-
struct ctl_table_set set;
+ struct ctl_table_header *mq_sysctls;
struct ctl_table_header *ipc_sysctls;

/* user_ns which owns the ipc ns */
@@ -88,8 +86,6 @@ extern void shm_destroy_orphaned(struct ipc_namespace *ns);
static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
#endif /* CONFIG_SYSVIPC */

-#ifdef CONFIG_POSIX_MQUEUE
-extern int mq_init_ns(struct ipc_namespace *ns);
/*
* POSIX Message Queue default values:
*
@@ -123,6 +119,9 @@ extern int mq_init_ns(struct ipc_namespace *ns);
#define DFLT_MSGSIZE 8192U
#define DFLT_MSGSIZEMAX 8192
#define HARD_MSGSIZEMAX (16*1024*1024)
+
+#ifdef CONFIG_POSIX_MQUEUE
+extern int mq_init_ns(struct ipc_namespace *ns);
#else
static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
#endif
@@ -174,39 +173,7 @@ static inline void put_ipc_ns(struct ipc_namespace *ns)
}
#endif

-#ifdef CONFIG_POSIX_MQUEUE_SYSCTL
-
-void retire_mq_sysctls(struct ipc_namespace *ns);
-bool setup_mq_sysctls(struct ipc_namespace *ns);
-
-#else /* CONFIG_POSIX_MQUEUE_SYSCTL */
-
-static inline void retire_mq_sysctls(struct ipc_namespace *ns)
-{
-}
-
-static inline bool setup_mq_sysctls(struct ipc_namespace *ns)
-{
- return true;
-}
-
-#endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
-
-#ifdef CONFIG_SYSVIPC_SYSCTL
-
bool setup_ipc_sysctls(struct ipc_namespace *ns);
void retire_ipc_sysctls(struct ipc_namespace *ns);

-#else /* CONFIG_SYSVIPC_SYSCTL */
-
-static inline void retire_ipc_sysctls(struct ipc_namespace *ns)
-{
-}
-
-static inline bool setup_ipc_sysctls(struct ipc_namespace *ns)
-{
- return true;
-}
-
-#endif /* CONFIG_SYSVIPC_SYSCTL */
#endif
diff --git a/ipc/Makefile b/ipc/Makefile
index c2558c430f51..f79eab42a4dc 100644
--- a/ipc/Makefile
+++ b/ipc/Makefile
@@ -4,9 +4,6 @@
#

obj-$(CONFIG_SYSVIPC_COMPAT) += compat.o
-obj-$(CONFIG_SYSVIPC) += util.o msgutil.o msg.o sem.o shm.o syscall.o
-obj-$(CONFIG_SYSVIPC_SYSCTL) += ipc_sysctl.o
-obj-$(CONFIG_POSIX_MQUEUE) += mqueue.o msgutil.o
+obj-$(CONFIG_SYSVIPC) += util.o msgutil.o msg.o sem.o shm.o syscall.o ipc_sysctl.o
+obj-$(CONFIG_POSIX_MQUEUE) += mqueue.o msgutil.o ipc_sysctl.o
obj-$(CONFIG_IPC_NS) += namespace.o
-obj-$(CONFIG_POSIX_MQUEUE_SYSCTL) += mq_sysctl.o
-
diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c
index dd87ba12f5e3..9fc8e3e75be7 100644
--- a/ipc/ipc_sysctl.c
+++ b/ipc/ipc_sysctl.c
@@ -201,6 +201,59 @@ static struct ctl_table ipc_sysctls[] = {
{}
};

+static int msg_max_limit_min = MIN_MSGMAX;
+static int msg_max_limit_max = HARD_MSGMAX;
+
+static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
+static int msg_maxsize_limit_max = HARD_MSGSIZEMAX;
+
+static struct ctl_table mq_sysctls[] = {
+ {
+ .procname = "queues_max",
+ .data = &init_ipc_ns.mq_queues_max,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
+ {
+ .procname = "msg_max",
+ .data = &init_ipc_ns.mq_msg_max,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &msg_max_limit_min,
+ .extra2 = &msg_max_limit_max,
+ },
+ {
+ .procname = "msgsize_max",
+ .data = &init_ipc_ns.mq_msgsize_max,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &msg_maxsize_limit_min,
+ .extra2 = &msg_maxsize_limit_max,
+ },
+ {
+ .procname = "msg_default",
+ .data = &init_ipc_ns.mq_msg_default,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &msg_max_limit_min,
+ .extra2 = &msg_max_limit_max,
+ },
+ {
+ .procname = "msgsize_default",
+ .data = &init_ipc_ns.mq_msgsize_default,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &msg_maxsize_limit_min,
+ .extra2 = &msg_maxsize_limit_max,
+ },
+ {}
+};
+
static struct ctl_table_set *set_lookup(struct ctl_table_root *root)
{
return &current->nsproxy->ipc_ns->set;
@@ -215,12 +268,10 @@ static struct ctl_table_root set_root = {
.lookup = set_lookup,
};

-bool setup_ipc_sysctls(struct ipc_namespace *ns)
+static bool register_ipc_sysctl_table(struct ipc_namespace *ns)
{
struct ctl_table *tbl;

- setup_sysctl_set(&ns->set, &set_root, set_is_seen);
-
tbl = kmemdup(ipc_sysctls, sizeof(ipc_sysctls), GFP_KERNEL);
if (tbl) {
int i;
@@ -273,23 +324,91 @@ bool setup_ipc_sysctls(struct ipc_namespace *ns)
}
if (!ns->ipc_sysctls) {
kfree(tbl);
- retire_sysctl_set(&ns->set);
return false;
}

return true;
}

-void retire_ipc_sysctls(struct ipc_namespace *ns)
+static void unregister_ipc_sysctl_table(struct ipc_namespace *ns)
{
struct ctl_table *tbl;

tbl = ns->ipc_sysctls->ctl_table_arg;
unregister_sysctl_table(ns->ipc_sysctls);
- retire_sysctl_set(&ns->set);
kfree(tbl);
}

+static bool register_mqueue_sysctl_table(struct ipc_namespace *ns)
+{
+ struct ctl_table *tbl;
+
+ tbl = kmemdup(mq_sysctls, sizeof(mq_sysctls), GFP_KERNEL);
+ if (tbl) {
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(mq_sysctls); i++) {
+ if (tbl[i].data == &init_ipc_ns.mq_queues_max)
+ tbl[i].data = &ns->mq_queues_max;
+
+ else if (tbl[i].data == &init_ipc_ns.mq_msg_max)
+ tbl[i].data = &ns->mq_msg_max;
+
+ else if (tbl[i].data == &init_ipc_ns.mq_msgsize_max)
+ tbl[i].data = &ns->mq_msgsize_max;
+
+ else if (tbl[i].data == &init_ipc_ns.mq_msg_default)
+ tbl[i].data = &ns->mq_msg_default;
+
+ else if (tbl[i].data == &init_ipc_ns.mq_msgsize_default)
+ tbl[i].data = &ns->mq_msgsize_default;
+ else
+ tbl[i].data = NULL;
+ }
+
+ ns->mq_sysctls = __register_sysctl_table(&ns->set, "fs/mqueue", tbl);
+ }
+ if (!ns->mq_sysctls) {
+ kfree(tbl);
+ return false;
+ }
+
+ return true;
+}
+
+static void unregister_mqueue_sysctl_table(struct ipc_namespace *ns)
+{
+ struct ctl_table *tbl;
+
+ tbl = ns->mq_sysctls->ctl_table_arg;
+ unregister_sysctl_table(ns->mq_sysctls);
+ kfree(tbl);
+}
+
+bool setup_ipc_sysctls(struct ipc_namespace *ns)
+{
+ setup_sysctl_set(&ns->set, &set_root, set_is_seen);
+
+ if (IS_ENABLED(CONFIG_SYSVIPC_SYSCTL))
+ register_ipc_sysctl_table(ns);
+
+ if (IS_ENABLED(CONFIG_POSIX_MQUEUE_SYSCTL))
+ register_mqueue_sysctl_table(ns);
+
+ return true;
+}
+
+void retire_ipc_sysctls(struct ipc_namespace *ns)
+{
+ if (IS_ENABLED(CONFIG_SYSVIPC_SYSCTL))
+ unregister_ipc_sysctl_table(ns);
+
+ if (IS_ENABLED(CONFIG_POSIX_MQUEUE_SYSCTL))
+ unregister_mqueue_sysctl_table(ns);
+
+ retire_sysctl_set(&ns->set);
+}
+
static int __init ipc_sysctl_init(void)
{
if (!setup_ipc_sysctls(&init_ipc_ns)) {
diff --git a/ipc/mq_sysctl.c b/ipc/mq_sysctl.c
deleted file mode 100644
index fbf6a8b93a26..000000000000
--- a/ipc/mq_sysctl.c
+++ /dev/null
@@ -1,131 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (C) 2007 IBM Corporation
- *
- * Author: Cedric Le Goater <clg@xxxxxxxxxx>
- */
-
-#include <linux/nsproxy.h>
-#include <linux/ipc_namespace.h>
-#include <linux/sysctl.h>
-
-#include <linux/stat.h>
-#include <linux/capability.h>
-#include <linux/slab.h>
-
-static int msg_max_limit_min = MIN_MSGMAX;
-static int msg_max_limit_max = HARD_MSGMAX;
-
-static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
-static int msg_maxsize_limit_max = HARD_MSGSIZEMAX;
-
-static struct ctl_table mq_sysctls[] = {
- {
- .procname = "queues_max",
- .data = &init_ipc_ns.mq_queues_max,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec,
- },
- {
- .procname = "msg_max",
- .data = &init_ipc_ns.mq_msg_max,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec_minmax,
- .extra1 = &msg_max_limit_min,
- .extra2 = &msg_max_limit_max,
- },
- {
- .procname = "msgsize_max",
- .data = &init_ipc_ns.mq_msgsize_max,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec_minmax,
- .extra1 = &msg_maxsize_limit_min,
- .extra2 = &msg_maxsize_limit_max,
- },
- {
- .procname = "msg_default",
- .data = &init_ipc_ns.mq_msg_default,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec_minmax,
- .extra1 = &msg_max_limit_min,
- .extra2 = &msg_max_limit_max,
- },
- {
- .procname = "msgsize_default",
- .data = &init_ipc_ns.mq_msgsize_default,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec_minmax,
- .extra1 = &msg_maxsize_limit_min,
- .extra2 = &msg_maxsize_limit_max,
- },
- {}
-};
-
-static struct ctl_table_set *set_lookup(struct ctl_table_root *root)
-{
- return &current->nsproxy->ipc_ns->mq_set;
-}
-
-static int set_is_seen(struct ctl_table_set *set)
-{
- return &current->nsproxy->ipc_ns->mq_set == set;
-}
-
-static struct ctl_table_root set_root = {
- .lookup = set_lookup,
-};
-
-bool setup_mq_sysctls(struct ipc_namespace *ns)
-{
- struct ctl_table *tbl;
-
- setup_sysctl_set(&ns->mq_set, &set_root, set_is_seen);
-
- tbl = kmemdup(mq_sysctls, sizeof(mq_sysctls), GFP_KERNEL);
- if (tbl) {
- int i;
-
- for (i = 0; i < ARRAY_SIZE(mq_sysctls); i++) {
- if (tbl[i].data == &init_ipc_ns.mq_queues_max)
- tbl[i].data = &ns->mq_queues_max;
-
- else if (tbl[i].data == &init_ipc_ns.mq_msg_max)
- tbl[i].data = &ns->mq_msg_max;
-
- else if (tbl[i].data == &init_ipc_ns.mq_msgsize_max)
- tbl[i].data = &ns->mq_msgsize_max;
-
- else if (tbl[i].data == &init_ipc_ns.mq_msg_default)
- tbl[i].data = &ns->mq_msg_default;
-
- else if (tbl[i].data == &init_ipc_ns.mq_msgsize_default)
- tbl[i].data = &ns->mq_msgsize_default;
- else
- tbl[i].data = NULL;
- }
-
- ns->mq_sysctls = __register_sysctl_table(&ns->mq_set, "fs/mqueue", tbl);
- }
- if (!ns->mq_sysctls) {
- kfree(tbl);
- retire_sysctl_set(&ns->mq_set);
- return false;
- }
-
- return true;
-}
-
-void retire_mq_sysctls(struct ipc_namespace *ns)
-{
- struct ctl_table *tbl;
-
- tbl = ns->mq_sysctls->ctl_table_arg;
- unregister_sysctl_table(ns->mq_sysctls);
- retire_sysctl_set(&ns->mq_set);
- kfree(tbl);
-}
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 1b4a3be71636..f08e9f8db195 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -1711,11 +1711,6 @@ static int __init init_mqueue_fs(void)
if (mqueue_inode_cachep == NULL)
return -ENOMEM;

- if (!setup_mq_sysctls(&init_ipc_ns)) {
- pr_warn("sysctl registration failed\n");
- return -ENOMEM;
- }
-
error = register_filesystem(&mqueue_fs_type);
if (error)
goto out_sysctl;
diff --git a/ipc/namespace.c b/ipc/namespace.c
index 754f3237194a..e18b6b5c2a46 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -60,9 +60,6 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
goto fail_put;

err = -ENOMEM;
- if (!setup_mq_sysctls(ns))
- goto fail_put;
-
if (!setup_ipc_sysctls(ns))
goto fail_put;

@@ -132,7 +129,6 @@ static void free_ipc_ns(struct ipc_namespace *ns)
msg_exit_ns(ns);
shm_exit_ns(ns);

- retire_mq_sysctls(ns);
retire_ipc_sysctls(ns);

dec_ipc_namespaces(ns->ucounts);
diff --git a/ipc/util.h b/ipc/util.h
index 2dd7ce0416d8..e88e486e9048 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -31,18 +31,16 @@
#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;
extern int ipc_min_cycle;

+#ifdef CONFIG_SYSVIPC_SYSCTL
#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 ipc_min_cycle ((int)RADIX_TREE_MAP_SIZE)
#define ipcmni_seq_shift() IPCMNI_SHIFT
#define IPCMNI_IDX_MASK ((1 << IPCMNI_SHIFT) - 1)
#endif /* CONFIG_SYSVIPC_SYSCTL */
--
2.33.0