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Diffstat (limited to 'kernel/sysctl.c')
-rw-r--r--kernel/sysctl.c206
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 */
/*