#include <linux/slab.h>
#include <linux/sysctl.h>
#include <linux/proc_fs.h>
+#include <linux/capability.h>
#include <linux/ctype.h>
#include <linux/utsname.h>
#include <linux/capability.h>
#include <linux/smp_lock.h>
#include <linux/init.h>
#include <linux/kernel.h>
+#include <linux/kobject.h>
+#include <linux/net.h>
#include <linux/sysrq.h>
#include <linux/highuid.h>
#include <linux/writeback.h>
#include <linux/limits.h>
#include <linux/dcache.h>
#include <linux/syscalls.h>
+#include <linux/nfs_fs.h>
+#include <linux/acpi.h>
#include <linux/vserver/cvirt.h>
#include <asm/uaccess.h>
#include <asm/processor.h>
-#ifdef CONFIG_ROOT_NFS
-#include <linux/nfs_fs.h>
-#endif
+extern int proc_nr_files(ctl_table *table, int write, struct file *filp,
+ void __user *buffer, size_t *lenp, loff_t *ppos);
#if defined(CONFIG_SYSCTL)
extern int max_threads;
extern int sysrq_enabled;
extern int core_uses_pid;
+extern int suid_dumpable;
extern char core_pattern[];
extern int cad_pid;
extern int pid_max;
extern int printk_ratelimit_jiffies;
extern int printk_ratelimit_burst;
extern int pid_max_min, pid_max_max;
+extern int sysctl_drop_caches;
+extern int percpu_pagelist_fraction;
#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
int unknown_nmi_panic;
void __user *, size_t *, loff_t *);
#endif
+extern unsigned int vdso_enabled, vdso_populate;
+
+int exec_shield = (1<<3) | (1<<0);
+/* exec_shield is a bitmask:
+ 0: off; vdso at STACK_TOP, 1 page below TASK_SIZE
+ (1<<0) 1: on [also on if !=0]
+ (1<<1) 2: noexecstack by default
+ (1<<2) 4: vdso just below .text of main (unless too low)
+ (1<<3) 8: vdso just below .text of PT_INTERP (unless too low)
+Yes, vdso placement is overloaded here; but exec_shield off
+is a strong incentive to place vdso at STACK_TOP, so the bit
+for vdso just below .text comes along for the ride.
+*/
+
+static int __init setup_exec_shield(char *str)
+{
+ get_option (&str, &exec_shield);
+
+ return 1;
+}
+
+__setup("exec-shield=", setup_exec_shield);
+
/* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
static int maxolduid = 65535;
static int minolduid;
+static int min_percpu_pagelist_fract = 8;
static int ngroups_max = NGROUPS_MAX;
#ifdef CONFIG_KMOD
extern char modprobe_path[];
#endif
-#ifdef CONFIG_HOTPLUG
-extern char hotplug_path[];
-#endif
extern char vshelper_path[];
#ifdef CONFIG_CHR_DEV_SG
extern int sg_big_buff;
extern int unaligned_enabled;
#endif
-#ifdef CONFIG_ARCH_S390
+#ifdef CONFIG_S390
#ifdef CONFIG_MATHEMU
extern int sysctl_ieee_emulation_warnings;
#endif
extern int sysctl_userprocess_debug;
+extern int spin_retry;
#endif
extern int sysctl_hz_timer;
extern int acct_parm[];
#endif
-int randomize_va_space = 1;
+#ifdef CONFIG_IA64
+extern int no_unaligned_warning;
+#endif
static int parse_table(int __user *, int, void __user *, size_t __user *, void __user *, size_t,
ctl_table *, void **);
static ctl_table kern_table[];
static ctl_table vm_table[];
-#ifdef CONFIG_NET
-extern ctl_table net_table[];
-#endif
static ctl_table proc_table[];
static ctl_table fs_table[];
static ctl_table debug_table[];
#ifdef CONFIG_UNIX98_PTYS
extern ctl_table pty_table[];
#endif
+#ifdef CONFIG_INOTIFY
+extern ctl_table inotify_table[];
+#endif
#ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
int sysctl_legacy_va_layout;
extern struct proc_dir_entry *proc_sys_root;
-static void register_proc_table(ctl_table *, struct proc_dir_entry *);
+static void register_proc_table(ctl_table *, struct proc_dir_entry *, void *);
static void unregister_proc_table(ctl_table *, struct proc_dir_entry *);
#endif
.mode = 0555,
.child = dev_table,
},
+
{ .ctl_name = 0 }
};
.mode = 0644,
.proc_handler = &proc_dointvec,
},
+ {
+ .ctl_name = KERN_EXEC_SHIELD,
+ .procname = "exec-shield",
+ .data = &exec_shield,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = KERN_PRINT_FATAL,
+ .procname = "print-fatal-signals",
+ .data = &print_fatal_signals,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+#ifdef __i386__
+ {
+ .ctl_name = KERN_VDSO,
+ .procname = "vdso",
+ .data = &vdso_enabled,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = KERN_VDSO,
+ .procname = "vdso_populate",
+ .data = &vdso_populate,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+#endif
{
.ctl_name = KERN_CORE_USES_PID,
.procname = "core_uses_pid",
{
.ctl_name = KERN_HOTPLUG,
.procname = "hotplug",
- .data = &hotplug_path,
- .maxlen = HOTPLUG_PATH_LEN,
+ .data = &uevent_helper,
+ .maxlen = UEVENT_HELPER_PATH_LEN,
.mode = 0644,
.proc_handler = &proc_dostring,
.strategy = &sysctl_string,
.extra1 = &minolduid,
.extra2 = &maxolduid,
},
-#ifdef CONFIG_ARCH_S390
+#ifdef CONFIG_S390
#ifdef CONFIG_MATHEMU
{
.ctl_name = KERN_IEEE_EMULATION_WARNINGS,
.proc_handler = &proc_dointvec,
},
#endif
+#if defined(CONFIG_MMU)
{
.ctl_name = KERN_RANDOMIZE,
.procname = "randomize_va_space",
.mode = 0644,
.proc_handler = &proc_dointvec,
},
-
+#endif
+#if defined(CONFIG_S390) && defined(CONFIG_SMP)
+ {
+ .ctl_name = KERN_SPIN_RETRY,
+ .procname = "spin_retry",
+ .data = &spin_retry,
+ .maxlen = sizeof (int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+#endif
+#ifdef CONFIG_ACPI_SLEEP
+ {
+ .ctl_name = KERN_ACPI_VIDEO_FLAGS,
+ .procname = "acpi_video_flags",
+ .data = &acpi_video_flags,
+ .maxlen = sizeof (unsigned long),
+ .mode = 0644,
+ .proc_handler = &proc_doulongvec_minmax,
+ },
+#endif
+#ifdef CONFIG_IA64
+ {
+ .ctl_name = KERN_IA64_UNALIGNED,
+ .procname = "ignore-unaligned-usertrap",
+ .data = &no_unaligned_warning,
+ .maxlen = sizeof (int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+#endif
{ .ctl_name = 0 }
};
{
.ctl_name = VM_DIRTY_WB_CS,
.procname = "dirty_writeback_centisecs",
- .data = &dirty_writeback_centisecs,
- .maxlen = sizeof(dirty_writeback_centisecs),
+ .data = &dirty_writeback_interval,
+ .maxlen = sizeof(dirty_writeback_interval),
.mode = 0644,
.proc_handler = &dirty_writeback_centisecs_handler,
},
{
.ctl_name = VM_DIRTY_EXPIRE_CS,
.procname = "dirty_expire_centisecs",
- .data = &dirty_expire_centisecs,
- .maxlen = sizeof(dirty_expire_centisecs),
+ .data = &dirty_expire_interval,
+ .maxlen = sizeof(dirty_expire_interval),
.mode = 0644,
- .proc_handler = &proc_dointvec,
+ .proc_handler = &proc_dointvec_userhz_jiffies,
},
{
.ctl_name = VM_NR_PDFLUSH_THREADS,
.proc_handler = &lowmem_reserve_ratio_sysctl_handler,
.strategy = &sysctl_intvec,
},
+ {
+ .ctl_name = VM_DROP_PAGECACHE,
+ .procname = "drop_caches",
+ .data = &sysctl_drop_caches,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = drop_caches_sysctl_handler,
+ .strategy = &sysctl_intvec,
+ },
{
.ctl_name = VM_MIN_FREE_KBYTES,
.procname = "min_free_kbytes",
.strategy = &sysctl_intvec,
.extra1 = &zero,
},
+ {
+ .ctl_name = VM_PERCPU_PAGELIST_FRACTION,
+ .procname = "percpu_pagelist_fraction",
+ .data = &percpu_pagelist_fraction,
+ .maxlen = sizeof(percpu_pagelist_fraction),
+ .mode = 0644,
+ .proc_handler = &percpu_pagelist_fraction_sysctl_handler,
+ .strategy = &sysctl_intvec,
+ .extra1 = &min_percpu_pagelist_fract,
+ },
#ifdef CONFIG_MMU
{
.ctl_name = VM_MAX_MAP_COUNT,
.data = &laptop_mode,
.maxlen = sizeof(laptop_mode),
.mode = 0644,
- .proc_handler = &proc_dointvec,
- .strategy = &sysctl_intvec,
- .extra1 = &zero,
+ .proc_handler = &proc_dointvec_jiffies,
+ .strategy = &sysctl_jiffies,
},
{
.ctl_name = VM_BLOCK_DUMP,
.proc_handler = &proc_dointvec_jiffies,
.strategy = &sysctl_jiffies,
},
+#endif
+#ifdef CONFIG_NUMA
+ {
+ .ctl_name = VM_ZONE_RECLAIM_MODE,
+ .procname = "zone_reclaim_mode",
+ .data = &zone_reclaim_mode,
+ .maxlen = sizeof(zone_reclaim_mode),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ .strategy = &sysctl_intvec,
+ .extra1 = &zero,
+ },
+ {
+ .ctl_name = VM_ZONE_RECLAIM_INTERVAL,
+ .procname = "zone_reclaim_interval",
+ .data = &zone_reclaim_interval,
+ .maxlen = sizeof(zone_reclaim_interval),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec_jiffies,
+ .strategy = &sysctl_jiffies,
+ },
#endif
{ .ctl_name = 0 }
};
.data = &files_stat,
.maxlen = 3*sizeof(int),
.mode = 0444,
- .proc_handler = &proc_dointvec,
+ .proc_handler = &proc_nr_files,
},
{
.ctl_name = FS_MAXFILE,
.data = &aio_nr,
.maxlen = sizeof(aio_nr),
.mode = 0444,
- .proc_handler = &proc_dointvec,
+ .proc_handler = &proc_doulongvec_minmax,
},
{
.ctl_name = FS_AIO_MAX_NR,
.data = &aio_max_nr,
.maxlen = sizeof(aio_max_nr),
.mode = 0644,
- .proc_handler = &proc_dointvec,
+ .proc_handler = &proc_doulongvec_minmax,
+ },
+#ifdef CONFIG_INOTIFY
+ {
+ .ctl_name = FS_INOTIFY,
+ .procname = "inotify",
+ .mode = 0555,
+ .child = inotify_table,
},
+#endif
#endif
+ {
+ .ctl_name = KERN_SETUID_DUMPABLE,
+ .procname = "suid_dumpable",
+ .data = &suid_dumpable,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
{ .ctl_name = 0 }
};
static ctl_table dev_table[] = {
{ .ctl_name = 0 }
-};
+};
extern void init_irq_proc (void);
+static DEFINE_SPINLOCK(sysctl_lock);
+
+/* called under sysctl_lock */
+static int use_table(struct ctl_table_header *p)
+{
+ if (unlikely(p->unregistering))
+ return 0;
+ p->used++;
+ return 1;
+}
+
+/* called under sysctl_lock */
+static void unuse_table(struct ctl_table_header *p)
+{
+ if (!--p->used)
+ if (unlikely(p->unregistering))
+ complete(p->unregistering);
+}
+
+/* called under sysctl_lock, will reacquire if has to wait */
+static void start_unregistering(struct ctl_table_header *p)
+{
+ /*
+ * if p->used is 0, nobody will ever touch that entry again;
+ * we'll eliminate all paths to it before dropping sysctl_lock
+ */
+ if (unlikely(p->used)) {
+ struct completion wait;
+ init_completion(&wait);
+ p->unregistering = &wait;
+ spin_unlock(&sysctl_lock);
+ wait_for_completion(&wait);
+ spin_lock(&sysctl_lock);
+ }
+ /*
+ * do not remove from the list until nobody holds it; walking the
+ * list in do_sysctl() relies on that.
+ */
+ list_del_init(&p->ctl_entry);
+}
+
void __init sysctl_init(void)
{
#ifdef CONFIG_PROC_FS
- register_proc_table(root_table, proc_sys_root);
+ register_proc_table(root_table, proc_sys_root, &root_table_header);
init_irq_proc();
#endif
}
void __user *newval, size_t newlen)
{
struct list_head *tmp;
+ int error = -ENOTDIR;
if (nlen <= 0 || nlen >= CTL_MAXNAME)
return -ENOTDIR;
if (!oldlenp || get_user(old_len, oldlenp))
return -EFAULT;
}
+ spin_lock(&sysctl_lock);
tmp = &root_table_header.ctl_entry;
do {
struct ctl_table_header *head =
list_entry(tmp, struct ctl_table_header, ctl_entry);
void *context = NULL;
- int error = parse_table(name, nlen, oldval, oldlenp,
+
+ if (!use_table(head))
+ continue;
+
+ spin_unlock(&sysctl_lock);
+
+ error = parse_table(name, nlen, oldval, oldlenp,
newval, newlen, head->ctl_table,
&context);
- if (context)
- kfree(context);
+ kfree(context);
+
+ spin_lock(&sysctl_lock);
+ unuse_table(head);
if (error != -ENOTDIR)
- return error;
- tmp = tmp->next;
- } while (tmp != &root_table_header.ctl_entry);
- return -ENOTDIR;
+ break;
+ } while ((tmp = tmp->next) != &root_table_header.ctl_entry);
+ spin_unlock(&sysctl_lock);
+ return error;
}
asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
return NULL;
tmp->ctl_table = table;
INIT_LIST_HEAD(&tmp->ctl_entry);
+ tmp->used = 0;
+ tmp->unregistering = NULL;
+ spin_lock(&sysctl_lock);
if (insert_at_head)
list_add(&tmp->ctl_entry, &root_table_header.ctl_entry);
else
list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
+ spin_unlock(&sysctl_lock);
#ifdef CONFIG_PROC_FS
- register_proc_table(table, proc_sys_root);
+ register_proc_table(table, proc_sys_root, tmp);
#endif
return tmp;
}
*/
void unregister_sysctl_table(struct ctl_table_header * header)
{
- list_del(&header->ctl_entry);
+ might_sleep();
+ spin_lock(&sysctl_lock);
+ start_unregistering(header);
#ifdef CONFIG_PROC_FS
unregister_proc_table(header->ctl_table, proc_sys_root);
#endif
+ spin_unlock(&sysctl_lock);
kfree(header);
}
#ifdef CONFIG_PROC_FS
/* Scan the sysctl entries in table and add them all into /proc */
-static void register_proc_table(ctl_table * table, struct proc_dir_entry *root)
+static void register_proc_table(ctl_table * table, struct proc_dir_entry *root, void *set)
{
struct proc_dir_entry *de;
int len;
de = create_proc_entry(table->procname, mode, root);
if (!de)
continue;
+ de->set = set;
de->data = (void *) table;
if (table->proc_handler)
de->proc_fops = &proc_sys_file_operations;
}
table->de = de;
if (de->mode & S_IFDIR)
- register_proc_table(table->child, de);
+ register_proc_table(table->child, de, set);
}
}
continue;
}
+ /*
+ * In any case, mark the entry as goner; we'll keep it
+ * around if it's busy, but we'll know to do nothing with
+ * its fields. We are under sysctl_lock here.
+ */
+ de->data = NULL;
+
/* Don't unregister proc entries that are still being used.. */
if (atomic_read(&de->count))
continue;
size_t count, loff_t *ppos)
{
int op;
- struct proc_dir_entry *de;
+ struct proc_dir_entry *de = PDE(file->f_dentry->d_inode);
struct ctl_table *table;
size_t res;
- ssize_t error;
+ ssize_t error = -ENOTDIR;
- de = PDE(file->f_dentry->d_inode);
- if (!de || !de->data)
- return -ENOTDIR;
- table = (struct ctl_table *) de->data;
- if (!table || !table->proc_handler)
- return -ENOTDIR;
- op = (write ? 002 : 004);
- if (ctl_perm(table, op))
- return -EPERM;
-
- res = count;
-
- error = (*table->proc_handler) (table, write, file, buf, &res, ppos);
- if (error)
- return error;
- return res;
+ spin_lock(&sysctl_lock);
+ if (de && de->data && use_table(de->set)) {
+ /*
+ * at that point we know that sysctl was not unregistered
+ * and won't be until we finish
+ */
+ spin_unlock(&sysctl_lock);
+ table = (struct ctl_table *) de->data;
+ if (!table || !table->proc_handler)
+ goto out;
+ error = -EPERM;
+ op = (write ? 002 : 004);
+ if (ctl_perm(table, op))
+ goto out;
+
+ /* careful: calling conventions are nasty here */
+ res = count;
+ error = (*table->proc_handler)(table, write, file,
+ buf, &res, ppos);
+ if (!error)
+ error = res;
+ out:
+ spin_lock(&sysctl_lock);
+ unuse_table(de->set);
+ }
+ spin_unlock(&sysctl_lock);
+ return error;
}
static int proc_opensys(struct inode *inode, struct file *file)
int write, void *data)
{
if (write) {
+ if (*lvalp > LONG_MAX / HZ)
+ return 1;
*valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
} else {
int val = *valp;
int write, void *data)
{
if (write) {
+ if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
+ return 1;
*valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
} else {
int val = *valp;
* @filp: the file structure
* @buffer: the user buffer
* @lenp: the size of the user buffer
+ * @ppos: pointer to the file position
*
* Reads/writes up to table->maxlen/sizeof(unsigned int) integer
* values from/to the user buffer, treated as an ASCII string.
void __user *oldval, size_t __user *oldlenp,
void __user *newval, size_t newlen, void **context)
{
- size_t l, len;
-
if (!table->data || !table->maxlen)
return -ENOTDIR;
if (oldval && oldlenp) {
- if (get_user(len, oldlenp))
+ size_t bufsize;
+ if (get_user(bufsize, oldlenp))
return -EFAULT;
- if (len) {
- l = strlen(table->data);
- if (len > l) len = l;
- if (len >= table->maxlen)
+ if (bufsize) {
+ size_t len = strlen(table->data), copied;
+
+ /* This shouldn't trigger for a well-formed sysctl */
+ if (len > table->maxlen)
len = table->maxlen;
- if(copy_to_user(oldval, table->data, len))
- return -EFAULT;
- if(put_user(0, ((char __user *) oldval) + len))
+
+ /* Copy up to a max of bufsize-1 bytes of the string */
+ copied = (len >= bufsize) ? bufsize - 1 : len;
+
+ if (copy_to_user(oldval, table->data, copied) ||
+ put_user(0, (char __user *)(oldval + copied)))
return -EFAULT;
- if(put_user(len, oldlenp))
+ if (put_user(len, oldlenp))
return -EFAULT;
}
}
if (newval && newlen) {
- len = newlen;
+ size_t len = newlen;
if (len > table->maxlen)
len = table->maxlen;
if(copy_from_user(table->data, newval, len))
len--;
((char *) table->data)[len] = 0;
}
- return 0;
+ return 1;
}
/*
git://git.onelab.eu / linux-2.6.git / blobdiff