From 29e796fd4de54b8f5bc30d897611210ece4fd0f2 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 30 Nov 2007 23:50:18 +1100 Subject: sysctl: Add register_sysctl_paths function There are a number of modules that register a sysctl table somewhere deeply nested in the sysctl hierarchy, such as fs/nfs, fs/xfs, dev/cdrom, etc. They all specify several dummy ctl_tables for the path name. This patch implements register_sysctl_path that takes an additional path name, and makes up dummy sysctl nodes for each component. This patch was originally written by Olaf Kirch and brought to my attention and reworked some by Olaf Hering. I have changed a few additional things so the bugs are mine. After converting all of the easy callers Olaf Hering observed allyesconfig ARCH=i386, the patch reduces the final binary size by 9369 bytes. .text +897 .data -7008 text data bss dec hex filename 26959310 4045899 4718592 35723801 2211a19 ../vmlinux-vanilla 26960207 4038891 4718592 35717690 221023a ../O-allyesconfig/vmlinux So this change is both a space savings and a code simplification. CC: Olaf Kirch CC: Olaf Hering Signed-off-by: Eric W. Biederman Cc: Serge Hallyn Cc: Daniel Lezcano Cc: Cedric Le Goater Cc: Pavel Emelyanov Signed-off-by: Andrew Morton Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- kernel/sysctl.c | 89 +++++++++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 74 insertions(+), 15 deletions(-) (limited to 'kernel') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 8e96558cb8f3..f580542333eb 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1561,11 +1561,12 @@ static __init int sysctl_init(void) core_initcall(sysctl_init); /** - * register_sysctl_table - register a sysctl hierarchy + * register_sysctl_paths - register a sysctl hierarchy + * @path: The path to the directory the sysctl table is in. * @table: the top-level table structure * * Register a sysctl table hierarchy. @table should be a filled in ctl_table - * array. An entry with a ctl_name of 0 terminates the table. + * array. A completely 0 filled entry terminates the table. * * The members of the &struct ctl_table structure are used as follows: * @@ -1628,25 +1629,76 @@ core_initcall(sysctl_init); * This routine returns %NULL on a failure to register, and a pointer * to the table header on success. */ -struct ctl_table_header *register_sysctl_table(struct ctl_table * table) +struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, + struct ctl_table *table) { - struct ctl_table_header *tmp; - tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL); - if (!tmp) + struct ctl_table_header *header; + struct ctl_table *new, **prevp; + unsigned int n, npath; + + /* Count the path components */ + for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath) + ; + + /* + * For each path component, allocate a 2-element ctl_table array. + * The first array element will be filled with the sysctl entry + * for this, the second will be the sentinel (ctl_name == 0). + * + * We allocate everything in one go so that we don't have to + * worry about freeing additional memory in unregister_sysctl_table. + */ + header = kzalloc(sizeof(struct ctl_table_header) + + (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL); + if (!header) return NULL; - tmp->ctl_table = table; - INIT_LIST_HEAD(&tmp->ctl_entry); - tmp->used = 0; - tmp->unregistering = NULL; - sysctl_set_parent(NULL, table); - if (sysctl_check_table(tmp->ctl_table)) { - kfree(tmp); + + new = (struct ctl_table *) (header + 1); + + /* Now connect the dots */ + prevp = &header->ctl_table; + for (n = 0; n < npath; ++n, ++path) { + /* Copy the procname */ + new->procname = path->procname; + new->ctl_name = path->ctl_name; + new->mode = 0555; + + *prevp = new; + prevp = &new->child; + + new += 2; + } + *prevp = table; + + INIT_LIST_HEAD(&header->ctl_entry); + header->used = 0; + header->unregistering = NULL; + sysctl_set_parent(NULL, header->ctl_table); + if (sysctl_check_table(header->ctl_table)) { + kfree(header); return NULL; } spin_lock(&sysctl_lock); - list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry); + list_add_tail(&header->ctl_entry, &root_table_header.ctl_entry); spin_unlock(&sysctl_lock); - return tmp; + + return header; +} + +/** + * register_sysctl_table - register a sysctl table hierarchy + * @table: the top-level table structure + * + * Register a sysctl table hierarchy. @table should be a filled in ctl_table + * array. A completely 0 filled entry terminates the table. + * + * See register_sysctl_paths for more details. + */ +struct ctl_table_header *register_sysctl_table(struct ctl_table *table) +{ + static const struct ctl_path null_path[] = { {} }; + + return register_sysctl_paths(null_path, table); } /** @@ -1675,6 +1727,12 @@ struct ctl_table_header *register_sysctl_table(struct ctl_table * table) return NULL; } +struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, + struct ctl_table *table) +{ + return NULL; +} + void unregister_sysctl_table(struct ctl_table_header * table) { } @@ -2733,6 +2791,7 @@ EXPORT_SYMBOL(proc_dostring); EXPORT_SYMBOL(proc_doulongvec_minmax); EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax); EXPORT_SYMBOL(register_sysctl_table); +EXPORT_SYMBOL(register_sysctl_paths); EXPORT_SYMBOL(sysctl_intvec); EXPORT_SYMBOL(sysctl_jiffies); EXPORT_SYMBOL(sysctl_ms_jiffies); -- cgit v1.2.3 From 23eb06de7d2d333a0f7ebba2da663e00c9c9483e Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 30 Nov 2007 23:52:10 +1100 Subject: sysctl: Remember the ctl_table we passed to register_sysctl_paths By doing this we allow users of register_sysctl_paths that build and dynamically allocate their ctl_table to be simpler. This allows them to just remember the ctl_table_header returned from register_sysctl_paths from which they can now find the ctl_table array they need to free. Signed-off-by: Eric W. Biederman Cc: Serge Hallyn Cc: Daniel Lezcano Cc: Cedric Le Goater Cc: Pavel Emelyanov Signed-off-by: Andrew Morton Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- include/linux/sysctl.h | 1 + kernel/sysctl.c | 1 + 2 files changed, 2 insertions(+) (limited to 'kernel') diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index 3b6e2c9fbb2e..77de3bfd8744 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -1057,6 +1057,7 @@ struct ctl_table_header struct list_head ctl_entry; int used; struct completion *unregistering; + struct ctl_table *ctl_table_arg; }; /* struct ctl_path describes where in the hierarchy a table is added */ diff --git a/kernel/sysctl.c b/kernel/sysctl.c index f580542333eb..89b7d95ecf51 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1669,6 +1669,7 @@ struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, new += 2; } *prevp = table; + header->ctl_table_arg = table; INIT_LIST_HEAD(&header->ctl_entry); header->used = 0; -- cgit v1.2.3 From e51b6ba077791f2f8c876022b37419be7a2ceec3 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 30 Nov 2007 23:54:00 +1100 Subject: sysctl: Infrastructure for per namespace sysctls This patch implements the basic infrastructure for per namespace sysctls. A list of lists of sysctl headers is added, allowing each namespace to have it's own list of sysctl headers. Each list of sysctl headers has a lookup function to find the first sysctl header in the list, allowing the lists to have a per namespace instance. register_sysct_root is added to tell sysctl.c about additional lists of sysctl_headers. As all of the users are expected to be in kernel no unregister function is provided. sysctl_head_next is updated to walk through the list of lists. __register_sysctl_paths is added to add a new sysctl table on a non-default sysctl list. The only intrusive part of this patch is propagating the information to decided which list of sysctls to use for sysctl_check_table. Signed-off-by: Eric W. Biederman Cc: Serge Hallyn Cc: Daniel Lezcano Cc: Cedric Le Goater Cc: Pavel Emelyanov Signed-off-by: Andrew Morton Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- include/linux/sysctl.h | 17 ++++++++- kernel/sysctl.c | 93 ++++++++++++++++++++++++++++++++++++++++++++------ kernel/sysctl_check.c | 25 ++++++++------ 3 files changed, 112 insertions(+), 23 deletions(-) (limited to 'kernel') diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index 77de3bfd8744..89faebfe48b8 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -945,7 +945,10 @@ enum /* For the /proc/sys support */ struct ctl_table; +struct nsproxy; extern struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev); +extern struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces, + struct ctl_table_header *prev); extern void sysctl_head_finish(struct ctl_table_header *prev); extern int sysctl_perm(struct ctl_table *table, int op); @@ -1049,6 +1052,13 @@ struct ctl_table void *extra2; }; +struct ctl_table_root { + struct list_head root_list; + struct list_head header_list; + struct list_head *(*lookup)(struct ctl_table_root *root, + struct nsproxy *namespaces); +}; + /* struct ctl_table_header is used to maintain dynamic lists of struct ctl_table trees. */ struct ctl_table_header @@ -1058,6 +1068,7 @@ struct ctl_table_header int used; struct completion *unregistering; struct ctl_table *ctl_table_arg; + struct ctl_table_root *root; }; /* struct ctl_path describes where in the hierarchy a table is added */ @@ -1066,12 +1077,16 @@ struct ctl_path { int ctl_name; }; +void register_sysctl_root(struct ctl_table_root *root); +struct ctl_table_header *__register_sysctl_paths( + struct ctl_table_root *root, struct nsproxy *namespaces, + const struct ctl_path *path, struct ctl_table *table); struct ctl_table_header *register_sysctl_table(struct ctl_table * table); struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, struct ctl_table *table); void unregister_sysctl_table(struct ctl_table_header * table); -int sysctl_check_table(struct ctl_table *table); +int sysctl_check_table(struct nsproxy *namespaces, struct ctl_table *table); #else /* __KERNEL__ */ diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 89b7d95ecf51..45e76f209dcb 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -157,8 +157,16 @@ static int proc_dointvec_taint(struct ctl_table *table, int write, struct file * #endif static struct ctl_table root_table[]; -static struct ctl_table_header root_table_header = - { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) }; +static struct ctl_table_root sysctl_table_root; +static struct ctl_table_header root_table_header = { + .ctl_table = root_table, + .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.header_list), + .root = &sysctl_table_root, +}; +static struct ctl_table_root sysctl_table_root = { + .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list), + .header_list = LIST_HEAD_INIT(root_table_header.ctl_entry), +}; static struct ctl_table kern_table[]; static struct ctl_table vm_table[]; @@ -1371,12 +1379,27 @@ void sysctl_head_finish(struct ctl_table_header *head) spin_unlock(&sysctl_lock); } -struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev) +static struct list_head * +lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces) { + struct list_head *header_list; + header_list = &root->header_list; + if (root->lookup) + header_list = root->lookup(root, namespaces); + return header_list; +} + +struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces, + struct ctl_table_header *prev) +{ + struct ctl_table_root *root; + struct list_head *header_list; struct ctl_table_header *head; struct list_head *tmp; + spin_lock(&sysctl_lock); if (prev) { + head = prev; tmp = &prev->ctl_entry; unuse_table(prev); goto next; @@ -1390,14 +1413,38 @@ struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev) spin_unlock(&sysctl_lock); return head; next: + root = head->root; tmp = tmp->next; - if (tmp == &root_table_header.ctl_entry) - break; + header_list = lookup_header_list(root, namespaces); + if (tmp != header_list) + continue; + + do { + root = list_entry(root->root_list.next, + struct ctl_table_root, root_list); + if (root == &sysctl_table_root) + goto out; + header_list = lookup_header_list(root, namespaces); + } while (list_empty(header_list)); + tmp = header_list->next; } +out: spin_unlock(&sysctl_lock); return NULL; } +struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev) +{ + return __sysctl_head_next(current->nsproxy, prev); +} + +void register_sysctl_root(struct ctl_table_root *root) +{ + spin_lock(&sysctl_lock); + list_add_tail(&root->root_list, &sysctl_table_root.root_list); + spin_unlock(&sysctl_lock); +} + #ifdef CONFIG_SYSCTL_SYSCALL int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp, void __user *newval, size_t newlen) @@ -1554,14 +1601,16 @@ static __init int sysctl_init(void) { int err; sysctl_set_parent(NULL, root_table); - err = sysctl_check_table(root_table); + err = sysctl_check_table(current->nsproxy, root_table); return 0; } core_initcall(sysctl_init); /** - * register_sysctl_paths - register a sysctl hierarchy + * __register_sysctl_paths - register a sysctl hierarchy + * @root: List of sysctl headers to register on + * @namespaces: Data to compute which lists of sysctl entries are visible * @path: The path to the directory the sysctl table is in. * @table: the top-level table structure * @@ -1629,9 +1678,12 @@ core_initcall(sysctl_init); * This routine returns %NULL on a failure to register, and a pointer * to the table header on success. */ -struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, - struct ctl_table *table) +struct ctl_table_header *__register_sysctl_paths( + struct ctl_table_root *root, + struct nsproxy *namespaces, + const struct ctl_path *path, struct ctl_table *table) { + struct list_head *header_list; struct ctl_table_header *header; struct ctl_table *new, **prevp; unsigned int n, npath; @@ -1674,18 +1726,37 @@ struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, INIT_LIST_HEAD(&header->ctl_entry); header->used = 0; header->unregistering = NULL; + header->root = root; sysctl_set_parent(NULL, header->ctl_table); - if (sysctl_check_table(header->ctl_table)) { + if (sysctl_check_table(namespaces, header->ctl_table)) { kfree(header); return NULL; } spin_lock(&sysctl_lock); - list_add_tail(&header->ctl_entry, &root_table_header.ctl_entry); + header_list = lookup_header_list(root, namespaces); + list_add_tail(&header->ctl_entry, header_list); spin_unlock(&sysctl_lock); return header; } +/** + * register_sysctl_table_path - register a sysctl table hierarchy + * @path: The path to the directory the sysctl table is in. + * @table: the top-level table structure + * + * Register a sysctl table hierarchy. @table should be a filled in ctl_table + * array. A completely 0 filled entry terminates the table. + * + * See __register_sysctl_paths for more details. + */ +struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, + struct ctl_table *table) +{ + return __register_sysctl_paths(&sysctl_table_root, current->nsproxy, + path, table); +} + /** * register_sysctl_table - register a sysctl table hierarchy * @table: the top-level table structure diff --git a/kernel/sysctl_check.c b/kernel/sysctl_check.c index d8a5558a47b4..c3206fa50048 100644 --- a/kernel/sysctl_check.c +++ b/kernel/sysctl_check.c @@ -1342,7 +1342,8 @@ static void sysctl_repair_table(struct ctl_table *table) } } -static struct ctl_table *sysctl_check_lookup(struct ctl_table *table) +static struct ctl_table *sysctl_check_lookup(struct nsproxy *namespaces, + struct ctl_table *table) { struct ctl_table_header *head; struct ctl_table *ref, *test; @@ -1350,8 +1351,8 @@ static struct ctl_table *sysctl_check_lookup(struct ctl_table *table) depth = sysctl_depth(table); - for (head = sysctl_head_next(NULL); head; - head = sysctl_head_next(head)) { + for (head = __sysctl_head_next(namespaces, NULL); head; + head = __sysctl_head_next(namespaces, head)) { cur_depth = depth; ref = head->ctl_table; repeat: @@ -1396,13 +1397,14 @@ static void set_fail(const char **fail, struct ctl_table *table, const char *str *fail = str; } -static int sysctl_check_dir(struct ctl_table *table) +static int sysctl_check_dir(struct nsproxy *namespaces, + struct ctl_table *table) { struct ctl_table *ref; int error; error = 0; - ref = sysctl_check_lookup(table); + ref = sysctl_check_lookup(namespaces, table); if (ref) { int match = 0; if ((!table->procname && !ref->procname) || @@ -1427,11 +1429,12 @@ static int sysctl_check_dir(struct ctl_table *table) return error; } -static void sysctl_check_leaf(struct ctl_table *table, const char **fail) +static void sysctl_check_leaf(struct nsproxy *namespaces, + struct ctl_table *table, const char **fail) { struct ctl_table *ref; - ref = sysctl_check_lookup(table); + ref = sysctl_check_lookup(namespaces, table); if (ref && (ref != table)) set_fail(fail, table, "Sysctl already exists"); } @@ -1455,7 +1458,7 @@ static void sysctl_check_bin_path(struct ctl_table *table, const char **fail) } } -int sysctl_check_table(struct ctl_table *table) +int sysctl_check_table(struct nsproxy *namespaces, struct ctl_table *table) { int error = 0; for (; table->ctl_name || table->procname; table++) { @@ -1485,7 +1488,7 @@ int sysctl_check_table(struct ctl_table *table) set_fail(&fail, table, "Directory with extra1"); if (table->extra2) set_fail(&fail, table, "Directory with extra2"); - if (sysctl_check_dir(table)) + if (sysctl_check_dir(namespaces, table)) set_fail(&fail, table, "Inconsistent directory names"); } else { if ((table->strategy == sysctl_data) || @@ -1534,7 +1537,7 @@ int sysctl_check_table(struct ctl_table *table) if (!table->procname && table->proc_handler) set_fail(&fail, table, "proc_handler without procname"); #endif - sysctl_check_leaf(table, &fail); + sysctl_check_leaf(namespaces, table, &fail); } sysctl_check_bin_path(table, &fail); if (fail) { @@ -1542,7 +1545,7 @@ int sysctl_check_table(struct ctl_table *table) error = -EINVAL; } if (table->child) - error |= sysctl_check_table(table->child); + error |= sysctl_check_table(namespaces, table->child); } return error; } -- cgit v1.2.3 From 08913681e484f3f0db949dd0809012e089846216 Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Wed, 5 Dec 2007 01:42:49 -0800 Subject: [NET]: Remove the empty net_table I have removed all the entries from this table (core_table, ipv4_table and tr_table), so now we can safely drop it. Signed-off-by: Pavel Emelyanov Signed-off-by: David S. Miller --- include/linux/net.h | 1 - kernel/sysctl.c | 8 -------- net/sysctl_net.c | 4 ---- 3 files changed, 13 deletions(-) (limited to 'kernel') diff --git a/include/linux/net.h b/include/linux/net.h index f95f12c5840c..c414d90e647b 100644 --- a/include/linux/net.h +++ b/include/linux/net.h @@ -337,7 +337,6 @@ static const struct proto_ops name##_ops = { \ #ifdef CONFIG_SYSCTL #include -extern ctl_table net_table[]; extern int net_msg_cost; extern int net_msg_burst; #endif diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 45e76f209dcb..4bc8e48434a7 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -200,14 +200,6 @@ static struct ctl_table root_table[] = { .mode = 0555, .child = vm_table, }, -#ifdef CONFIG_NET - { - .ctl_name = CTL_NET, - .procname = "net", - .mode = 0555, - .child = net_table, - }, -#endif { .ctl_name = CTL_FS, .procname = "fs", diff --git a/net/sysctl_net.c b/net/sysctl_net.c index 16ad14b5d572..665e856675a4 100644 --- a/net/sysctl_net.c +++ b/net/sysctl_net.c @@ -30,10 +30,6 @@ #include #endif -struct ctl_table net_table[] = { - { 0 }, -}; - static struct list_head * net_ctl_header_lookup(struct ctl_table_root *root, struct nsproxy *namespaces) { -- cgit v1.2.3