diff options
Diffstat (limited to 'kernel/sysctl.c')
| -rw-r--r-- | kernel/sysctl.c | 206 |
1 files changed, 178 insertions, 28 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 6b16e16428d..fe471334727 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -43,6 +43,7 @@ #include <linux/limits.h> #include <linux/dcache.h> #include <linux/syscalls.h> +#include <linux/vmstat.h> #include <linux/nfs_fs.h> #include <linux/acpi.h> #include <linux/reboot.h> @@ -80,7 +81,6 @@ extern int sysctl_drop_caches; extern int percpu_pagelist_fraction; extern int compat_log; extern int maps_protect; -extern int sysctl_stat_interval; extern int latencytop_enabled; extern int sysctl_nr_open_min, sysctl_nr_open_max; #ifdef CONFIG_RCU_TORTURE_TEST @@ -88,12 +88,13 @@ extern int rcutorture_runnable; #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */ /* Constants used for minimum and maximum */ -#if defined(CONFIG_DETECT_SOFTLOCKUP) || defined(CONFIG_HIGHMEM) +#if defined(CONFIG_HIGHMEM) || defined(CONFIG_DETECT_SOFTLOCKUP) static int one = 1; #endif #ifdef CONFIG_DETECT_SOFTLOCKUP static int sixty = 60; +static int neg_one = -1; #endif #ifdef CONFIG_MMU @@ -110,7 +111,7 @@ static int min_percpu_pagelist_fract = 8; static int ngroups_max = NGROUPS_MAX; -#ifdef CONFIG_KMOD +#ifdef CONFIG_MODULES extern char modprobe_path[]; #endif #ifdef CONFIG_CHR_DEV_SG @@ -159,12 +160,13 @@ static struct ctl_table root_table[]; 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), + .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list), .root = &sysctl_table_root, + .set = &sysctl_table_root.default_set, }; 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), + .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry), }; static struct ctl_table kern_table[]; @@ -475,7 +477,7 @@ static struct ctl_table kern_table[] = { .proc_handler = &ftrace_enable_sysctl, }, #endif -#ifdef CONFIG_KMOD +#ifdef CONFIG_MODULES { .ctl_name = KERN_MODPROBE, .procname = "modprobe", @@ -623,7 +625,7 @@ static struct ctl_table kern_table[] = { { .ctl_name = KERN_PRINTK_RATELIMIT, .procname = "printk_ratelimit", - .data = &printk_ratelimit_jiffies, + .data = &printk_ratelimit_state.interval, .maxlen = sizeof(int), .mode = 0644, .proc_handler = &proc_dointvec_jiffies, @@ -632,7 +634,7 @@ static struct ctl_table kern_table[] = { { .ctl_name = KERN_PRINTK_RATELIMIT_BURST, .procname = "printk_ratelimit_burst", - .data = &printk_ratelimit_burst, + .data = &printk_ratelimit_state.burst, .maxlen = sizeof(int), .mode = 0644, .proc_handler = &proc_dointvec, @@ -739,13 +741,24 @@ static struct ctl_table kern_table[] = { #ifdef CONFIG_DETECT_SOFTLOCKUP { .ctl_name = CTL_UNNUMBERED, + .procname = "softlockup_panic", + .data = &softlockup_panic, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .strategy = &sysctl_intvec, + .extra1 = &zero, + .extra2 = &one, + }, + { + .ctl_name = CTL_UNNUMBERED, .procname = "softlockup_thresh", .data = &softlockup_thresh, - .maxlen = sizeof(unsigned long), + .maxlen = sizeof(int), .mode = 0644, - .proc_handler = &proc_doulongvec_minmax, + .proc_handler = &proc_dointvec_minmax, .strategy = &sysctl_intvec, - .extra1 = &one, + .extra1 = &neg_one, .extra2 = &sixty, }, { @@ -947,7 +960,7 @@ static struct ctl_table vm_table[] = { #ifdef CONFIG_HUGETLB_PAGE { .procname = "nr_hugepages", - .data = &max_huge_pages, + .data = NULL, .maxlen = sizeof(unsigned long), .mode = 0644, .proc_handler = &hugetlb_sysctl_handler, @@ -973,10 +986,12 @@ static struct ctl_table vm_table[] = { { .ctl_name = CTL_UNNUMBERED, .procname = "nr_overcommit_hugepages", - .data = &sysctl_overcommit_huge_pages, - .maxlen = sizeof(sysctl_overcommit_huge_pages), + .data = NULL, + .maxlen = sizeof(unsigned long), .mode = 0644, .proc_handler = &hugetlb_overcommit_handler, + .extra1 = (void *)&hugetlb_zero, + .extra2 = (void *)&hugetlb_infinity, }, #endif { @@ -1372,6 +1387,9 @@ static void start_unregistering(struct ctl_table_header *p) spin_unlock(&sysctl_lock); wait_for_completion(&wait); spin_lock(&sysctl_lock); + } else { + /* anything non-NULL; we'll never dereference it */ + p->unregistering = ERR_PTR(-EINVAL); } /* * do not remove from the list until nobody holds it; walking the @@ -1380,6 +1398,32 @@ static void start_unregistering(struct ctl_table_header *p) list_del_init(&p->ctl_entry); } +void sysctl_head_get(struct ctl_table_header *head) +{ + spin_lock(&sysctl_lock); + head->count++; + spin_unlock(&sysctl_lock); +} + +void sysctl_head_put(struct ctl_table_header *head) +{ + spin_lock(&sysctl_lock); + if (!--head->count) + kfree(head); + spin_unlock(&sysctl_lock); +} + +struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head) +{ + if (!head) + BUG(); + spin_lock(&sysctl_lock); + if (!use_table(head)) + head = ERR_PTR(-ENOENT); + spin_unlock(&sysctl_lock); + return head; +} + void sysctl_head_finish(struct ctl_table_header *head) { if (!head) @@ -1389,14 +1433,20 @@ void sysctl_head_finish(struct ctl_table_header *head) spin_unlock(&sysctl_lock); } +static struct ctl_table_set * +lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces) +{ + struct ctl_table_set *set = &root->default_set; + if (root->lookup) + set = root->lookup(root, namespaces); + return set; +} + 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_set *set = lookup_header_set(root, namespaces); + return &set->list; } struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces, @@ -1466,9 +1516,9 @@ static int do_sysctl_strategy(struct ctl_table_root *root, int op = 0, rc; if (oldval) - op |= 004; + op |= MAY_READ; if (newval) - op |= 002; + op |= MAY_WRITE; if (sysctl_perm(root, table, op)) return -EPERM; @@ -1510,7 +1560,7 @@ repeat: if (n == table->ctl_name) { int error; if (table->child) { - if (sysctl_perm(root, table, 001)) + if (sysctl_perm(root, table, MAY_EXEC)) return -EPERM; name++; nlen--; @@ -1585,7 +1635,7 @@ static int test_perm(int mode, int op) mode >>= 6; else if (in_egroup_p(0)) mode >>= 3; - if ((mode & op & 0007) == op) + if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0) return 0; return -EACCES; } @@ -1595,7 +1645,7 @@ int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op) int error; int mode; - error = security_sysctl(table, op); + error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC)); if (error) return error; @@ -1630,6 +1680,54 @@ static __init int sysctl_init(void) core_initcall(sysctl_init); +static struct ctl_table *is_branch_in(struct ctl_table *branch, + struct ctl_table *table) +{ + struct ctl_table *p; + const char *s = branch->procname; + + /* branch should have named subdirectory as its first element */ + if (!s || !branch->child) + return NULL; + + /* ... and nothing else */ + if (branch[1].procname || branch[1].ctl_name) + return NULL; + + /* table should contain subdirectory with the same name */ + for (p = table; p->procname || p->ctl_name; p++) { + if (!p->child) + continue; + if (p->procname && strcmp(p->procname, s) == 0) + return p; + } + return NULL; +} + +/* see if attaching q to p would be an improvement */ +static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q) +{ + struct ctl_table *to = p->ctl_table, *by = q->ctl_table; + struct ctl_table *next; + int is_better = 0; + int not_in_parent = !p->attached_by; + + while ((next = is_branch_in(by, to)) != NULL) { + if (by == q->attached_by) + is_better = 1; + if (to == p->attached_by) + not_in_parent = 1; + by = by->child; + to = next->child; + } + + if (is_better && not_in_parent) { + q->attached_by = by; + q->attached_to = to; + q->parent = p; + } +} + /** * __register_sysctl_paths - register a sysctl hierarchy * @root: List of sysctl headers to register on @@ -1706,10 +1804,10 @@ struct ctl_table_header *__register_sysctl_paths( 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; + struct ctl_table_set *set; /* Count the path components */ for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath) @@ -1751,6 +1849,7 @@ struct ctl_table_header *__register_sysctl_paths( header->unregistering = NULL; header->root = root; sysctl_set_parent(NULL, header->ctl_table); + header->count = 1; #ifdef CONFIG_SYSCTL_SYSCALL_CHECK if (sysctl_check_table(namespaces, header->ctl_table)) { kfree(header); @@ -1758,8 +1857,20 @@ struct ctl_table_header *__register_sysctl_paths( } #endif spin_lock(&sysctl_lock); - header_list = lookup_header_list(root, namespaces); - list_add_tail(&header->ctl_entry, header_list); + header->set = lookup_header_set(root, namespaces); + header->attached_by = header->ctl_table; + header->attached_to = root_table; + header->parent = &root_table_header; + for (set = header->set; set; set = set->parent) { + struct ctl_table_header *p; + list_for_each_entry(p, &set->list, ctl_entry) { + if (p->unregistering) + continue; + try_attach(p, header); + } + } + header->parent->count++; + list_add_tail(&header->ctl_entry, &header->set->list); spin_unlock(&sysctl_lock); return header; @@ -1814,8 +1925,37 @@ void unregister_sysctl_table(struct ctl_table_header * header) spin_lock(&sysctl_lock); start_unregistering(header); + if (!--header->parent->count) { + WARN_ON(1); + kfree(header->parent); + } + if (!--header->count) + kfree(header); + spin_unlock(&sysctl_lock); +} + +int sysctl_is_seen(struct ctl_table_header *p) +{ + struct ctl_table_set *set = p->set; + int res; + spin_lock(&sysctl_lock); + if (p->unregistering) + res = 0; + else if (!set->is_seen) + res = 1; + else + res = set->is_seen(set); spin_unlock(&sysctl_lock); - kfree(header); + return res; +} + +void setup_sysctl_set(struct ctl_table_set *p, + struct ctl_table_set *parent, + int (*is_seen)(struct ctl_table_set *)) +{ + INIT_LIST_HEAD(&p->list); + p->parent = parent ? parent : &sysctl_table_root.default_set; + p->is_seen = is_seen; } #else /* !CONFIG_SYSCTL */ @@ -1834,6 +1974,16 @@ void unregister_sysctl_table(struct ctl_table_header * table) { } +void setup_sysctl_set(struct ctl_table_set *p, + struct ctl_table_set *parent, + int (*is_seen)(struct ctl_table_set *)) +{ +} + +void sysctl_head_put(struct ctl_table_header *head) +{ +} + #endif /* CONFIG_SYSCTL */ /* |