![Linus Torvalds](/assets/img/avatar_default.png)
* git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial: (25 commits) sound: convert "sound" subdirectory to UTF-8 MAINTAINERS: Add cxacru website/mailing list include files: convert "include" subdirectory to UTF-8 general: convert "kernel" subdirectory to UTF-8 documentation: convert the Documentation directory to UTF-8 Convert the toplevel files CREDITS and MAINTAINERS to UTF-8. remove broken URLs from net drivers' output Magic number prefix consistency change to Documentation/magic-number.txt trivial: s/i_sem /i_mutex/ fix file specification in comments drivers/base/platform.c: fix small typo in doc misc doc and kconfig typos Remove obsolete fat_cvf help text Fix occurrences of "the the " Fix minor typoes in kernel/module.c Kconfig: Remove reference to external mqueue library Kconfig: A couple of grammatical fixes in arch/i386/Kconfig Correct comments in genrtc.c to refer to correct /proc file. Fix more "deprecated" spellos. Fix "deprecated" typoes. ... Fix trivial comment conflict in kernel/relay.c.
2272 lines
56 KiB
C
2272 lines
56 KiB
C
/*
|
|
* linux/kernel/sys.c
|
|
*
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/utsname.h>
|
|
#include <linux/mman.h>
|
|
#include <linux/smp_lock.h>
|
|
#include <linux/notifier.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/prctl.h>
|
|
#include <linux/highuid.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/kexec.h>
|
|
#include <linux/workqueue.h>
|
|
#include <linux/capability.h>
|
|
#include <linux/device.h>
|
|
#include <linux/key.h>
|
|
#include <linux/times.h>
|
|
#include <linux/posix-timers.h>
|
|
#include <linux/security.h>
|
|
#include <linux/dcookies.h>
|
|
#include <linux/suspend.h>
|
|
#include <linux/tty.h>
|
|
#include <linux/signal.h>
|
|
#include <linux/cn_proc.h>
|
|
#include <linux/getcpu.h>
|
|
|
|
#include <linux/compat.h>
|
|
#include <linux/syscalls.h>
|
|
#include <linux/kprobes.h>
|
|
|
|
#include <asm/uaccess.h>
|
|
#include <asm/io.h>
|
|
#include <asm/unistd.h>
|
|
|
|
#ifndef SET_UNALIGN_CTL
|
|
# define SET_UNALIGN_CTL(a,b) (-EINVAL)
|
|
#endif
|
|
#ifndef GET_UNALIGN_CTL
|
|
# define GET_UNALIGN_CTL(a,b) (-EINVAL)
|
|
#endif
|
|
#ifndef SET_FPEMU_CTL
|
|
# define SET_FPEMU_CTL(a,b) (-EINVAL)
|
|
#endif
|
|
#ifndef GET_FPEMU_CTL
|
|
# define GET_FPEMU_CTL(a,b) (-EINVAL)
|
|
#endif
|
|
#ifndef SET_FPEXC_CTL
|
|
# define SET_FPEXC_CTL(a,b) (-EINVAL)
|
|
#endif
|
|
#ifndef GET_FPEXC_CTL
|
|
# define GET_FPEXC_CTL(a,b) (-EINVAL)
|
|
#endif
|
|
#ifndef GET_ENDIAN
|
|
# define GET_ENDIAN(a,b) (-EINVAL)
|
|
#endif
|
|
#ifndef SET_ENDIAN
|
|
# define SET_ENDIAN(a,b) (-EINVAL)
|
|
#endif
|
|
|
|
/*
|
|
* this is where the system-wide overflow UID and GID are defined, for
|
|
* architectures that now have 32-bit UID/GID but didn't in the past
|
|
*/
|
|
|
|
int overflowuid = DEFAULT_OVERFLOWUID;
|
|
int overflowgid = DEFAULT_OVERFLOWGID;
|
|
|
|
#ifdef CONFIG_UID16
|
|
EXPORT_SYMBOL(overflowuid);
|
|
EXPORT_SYMBOL(overflowgid);
|
|
#endif
|
|
|
|
/*
|
|
* the same as above, but for filesystems which can only store a 16-bit
|
|
* UID and GID. as such, this is needed on all architectures
|
|
*/
|
|
|
|
int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
|
|
int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
|
|
|
|
EXPORT_SYMBOL(fs_overflowuid);
|
|
EXPORT_SYMBOL(fs_overflowgid);
|
|
|
|
/*
|
|
* this indicates whether you can reboot with ctrl-alt-del: the default is yes
|
|
*/
|
|
|
|
int C_A_D = 1;
|
|
struct pid *cad_pid;
|
|
EXPORT_SYMBOL(cad_pid);
|
|
|
|
/*
|
|
* Notifier list for kernel code which wants to be called
|
|
* at shutdown. This is used to stop any idling DMA operations
|
|
* and the like.
|
|
*/
|
|
|
|
static BLOCKING_NOTIFIER_HEAD(reboot_notifier_list);
|
|
|
|
/*
|
|
* Notifier chain core routines. The exported routines below
|
|
* are layered on top of these, with appropriate locking added.
|
|
*/
|
|
|
|
static int notifier_chain_register(struct notifier_block **nl,
|
|
struct notifier_block *n)
|
|
{
|
|
while ((*nl) != NULL) {
|
|
if (n->priority > (*nl)->priority)
|
|
break;
|
|
nl = &((*nl)->next);
|
|
}
|
|
n->next = *nl;
|
|
rcu_assign_pointer(*nl, n);
|
|
return 0;
|
|
}
|
|
|
|
static int notifier_chain_unregister(struct notifier_block **nl,
|
|
struct notifier_block *n)
|
|
{
|
|
while ((*nl) != NULL) {
|
|
if ((*nl) == n) {
|
|
rcu_assign_pointer(*nl, n->next);
|
|
return 0;
|
|
}
|
|
nl = &((*nl)->next);
|
|
}
|
|
return -ENOENT;
|
|
}
|
|
|
|
/**
|
|
* notifier_call_chain - Informs the registered notifiers about an event.
|
|
* @nl: Pointer to head of the blocking notifier chain
|
|
* @val: Value passed unmodified to notifier function
|
|
* @v: Pointer passed unmodified to notifier function
|
|
* @nr_to_call: Number of notifier functions to be called. Don't care
|
|
* value of this parameter is -1.
|
|
* @nr_calls: Records the number of notifications sent. Don't care
|
|
* value of this field is NULL.
|
|
* @returns: notifier_call_chain returns the value returned by the
|
|
* last notifier function called.
|
|
*/
|
|
|
|
static int __kprobes notifier_call_chain(struct notifier_block **nl,
|
|
unsigned long val, void *v,
|
|
int nr_to_call, int *nr_calls)
|
|
{
|
|
int ret = NOTIFY_DONE;
|
|
struct notifier_block *nb, *next_nb;
|
|
|
|
nb = rcu_dereference(*nl);
|
|
|
|
while (nb && nr_to_call) {
|
|
next_nb = rcu_dereference(nb->next);
|
|
ret = nb->notifier_call(nb, val, v);
|
|
|
|
if (nr_calls)
|
|
(*nr_calls)++;
|
|
|
|
if ((ret & NOTIFY_STOP_MASK) == NOTIFY_STOP_MASK)
|
|
break;
|
|
nb = next_nb;
|
|
nr_to_call--;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Atomic notifier chain routines. Registration and unregistration
|
|
* use a spinlock, and call_chain is synchronized by RCU (no locks).
|
|
*/
|
|
|
|
/**
|
|
* atomic_notifier_chain_register - Add notifier to an atomic notifier chain
|
|
* @nh: Pointer to head of the atomic notifier chain
|
|
* @n: New entry in notifier chain
|
|
*
|
|
* Adds a notifier to an atomic notifier chain.
|
|
*
|
|
* Currently always returns zero.
|
|
*/
|
|
|
|
int atomic_notifier_chain_register(struct atomic_notifier_head *nh,
|
|
struct notifier_block *n)
|
|
{
|
|
unsigned long flags;
|
|
int ret;
|
|
|
|
spin_lock_irqsave(&nh->lock, flags);
|
|
ret = notifier_chain_register(&nh->head, n);
|
|
spin_unlock_irqrestore(&nh->lock, flags);
|
|
return ret;
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(atomic_notifier_chain_register);
|
|
|
|
/**
|
|
* atomic_notifier_chain_unregister - Remove notifier from an atomic notifier chain
|
|
* @nh: Pointer to head of the atomic notifier chain
|
|
* @n: Entry to remove from notifier chain
|
|
*
|
|
* Removes a notifier from an atomic notifier chain.
|
|
*
|
|
* Returns zero on success or %-ENOENT on failure.
|
|
*/
|
|
int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh,
|
|
struct notifier_block *n)
|
|
{
|
|
unsigned long flags;
|
|
int ret;
|
|
|
|
spin_lock_irqsave(&nh->lock, flags);
|
|
ret = notifier_chain_unregister(&nh->head, n);
|
|
spin_unlock_irqrestore(&nh->lock, flags);
|
|
synchronize_rcu();
|
|
return ret;
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(atomic_notifier_chain_unregister);
|
|
|
|
/**
|
|
* __atomic_notifier_call_chain - Call functions in an atomic notifier chain
|
|
* @nh: Pointer to head of the atomic notifier chain
|
|
* @val: Value passed unmodified to notifier function
|
|
* @v: Pointer passed unmodified to notifier function
|
|
* @nr_to_call: See the comment for notifier_call_chain.
|
|
* @nr_calls: See the comment for notifier_call_chain.
|
|
*
|
|
* Calls each function in a notifier chain in turn. The functions
|
|
* run in an atomic context, so they must not block.
|
|
* This routine uses RCU to synchronize with changes to the chain.
|
|
*
|
|
* If the return value of the notifier can be and'ed
|
|
* with %NOTIFY_STOP_MASK then atomic_notifier_call_chain()
|
|
* will return immediately, with the return value of
|
|
* the notifier function which halted execution.
|
|
* Otherwise the return value is the return value
|
|
* of the last notifier function called.
|
|
*/
|
|
|
|
int __kprobes __atomic_notifier_call_chain(struct atomic_notifier_head *nh,
|
|
unsigned long val, void *v,
|
|
int nr_to_call, int *nr_calls)
|
|
{
|
|
int ret;
|
|
|
|
rcu_read_lock();
|
|
ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls);
|
|
rcu_read_unlock();
|
|
return ret;
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(__atomic_notifier_call_chain);
|
|
|
|
int __kprobes atomic_notifier_call_chain(struct atomic_notifier_head *nh,
|
|
unsigned long val, void *v)
|
|
{
|
|
return __atomic_notifier_call_chain(nh, val, v, -1, NULL);
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(atomic_notifier_call_chain);
|
|
/*
|
|
* Blocking notifier chain routines. All access to the chain is
|
|
* synchronized by an rwsem.
|
|
*/
|
|
|
|
/**
|
|
* blocking_notifier_chain_register - Add notifier to a blocking notifier chain
|
|
* @nh: Pointer to head of the blocking notifier chain
|
|
* @n: New entry in notifier chain
|
|
*
|
|
* Adds a notifier to a blocking notifier chain.
|
|
* Must be called in process context.
|
|
*
|
|
* Currently always returns zero.
|
|
*/
|
|
|
|
int blocking_notifier_chain_register(struct blocking_notifier_head *nh,
|
|
struct notifier_block *n)
|
|
{
|
|
int ret;
|
|
|
|
/*
|
|
* This code gets used during boot-up, when task switching is
|
|
* not yet working and interrupts must remain disabled. At
|
|
* such times we must not call down_write().
|
|
*/
|
|
if (unlikely(system_state == SYSTEM_BOOTING))
|
|
return notifier_chain_register(&nh->head, n);
|
|
|
|
down_write(&nh->rwsem);
|
|
ret = notifier_chain_register(&nh->head, n);
|
|
up_write(&nh->rwsem);
|
|
return ret;
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(blocking_notifier_chain_register);
|
|
|
|
/**
|
|
* blocking_notifier_chain_unregister - Remove notifier from a blocking notifier chain
|
|
* @nh: Pointer to head of the blocking notifier chain
|
|
* @n: Entry to remove from notifier chain
|
|
*
|
|
* Removes a notifier from a blocking notifier chain.
|
|
* Must be called from process context.
|
|
*
|
|
* Returns zero on success or %-ENOENT on failure.
|
|
*/
|
|
int blocking_notifier_chain_unregister(struct blocking_notifier_head *nh,
|
|
struct notifier_block *n)
|
|
{
|
|
int ret;
|
|
|
|
/*
|
|
* This code gets used during boot-up, when task switching is
|
|
* not yet working and interrupts must remain disabled. At
|
|
* such times we must not call down_write().
|
|
*/
|
|
if (unlikely(system_state == SYSTEM_BOOTING))
|
|
return notifier_chain_unregister(&nh->head, n);
|
|
|
|
down_write(&nh->rwsem);
|
|
ret = notifier_chain_unregister(&nh->head, n);
|
|
up_write(&nh->rwsem);
|
|
return ret;
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(blocking_notifier_chain_unregister);
|
|
|
|
/**
|
|
* __blocking_notifier_call_chain - Call functions in a blocking notifier chain
|
|
* @nh: Pointer to head of the blocking notifier chain
|
|
* @val: Value passed unmodified to notifier function
|
|
* @v: Pointer passed unmodified to notifier function
|
|
* @nr_to_call: See comment for notifier_call_chain.
|
|
* @nr_calls: See comment for notifier_call_chain.
|
|
*
|
|
* Calls each function in a notifier chain in turn. The functions
|
|
* run in a process context, so they are allowed to block.
|
|
*
|
|
* If the return value of the notifier can be and'ed
|
|
* with %NOTIFY_STOP_MASK then blocking_notifier_call_chain()
|
|
* will return immediately, with the return value of
|
|
* the notifier function which halted execution.
|
|
* Otherwise the return value is the return value
|
|
* of the last notifier function called.
|
|
*/
|
|
|
|
int __blocking_notifier_call_chain(struct blocking_notifier_head *nh,
|
|
unsigned long val, void *v,
|
|
int nr_to_call, int *nr_calls)
|
|
{
|
|
int ret = NOTIFY_DONE;
|
|
|
|
/*
|
|
* We check the head outside the lock, but if this access is
|
|
* racy then it does not matter what the result of the test
|
|
* is, we re-check the list after having taken the lock anyway:
|
|
*/
|
|
if (rcu_dereference(nh->head)) {
|
|
down_read(&nh->rwsem);
|
|
ret = notifier_call_chain(&nh->head, val, v, nr_to_call,
|
|
nr_calls);
|
|
up_read(&nh->rwsem);
|
|
}
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__blocking_notifier_call_chain);
|
|
|
|
int blocking_notifier_call_chain(struct blocking_notifier_head *nh,
|
|
unsigned long val, void *v)
|
|
{
|
|
return __blocking_notifier_call_chain(nh, val, v, -1, NULL);
|
|
}
|
|
EXPORT_SYMBOL_GPL(blocking_notifier_call_chain);
|
|
|
|
/*
|
|
* Raw notifier chain routines. There is no protection;
|
|
* the caller must provide it. Use at your own risk!
|
|
*/
|
|
|
|
/**
|
|
* raw_notifier_chain_register - Add notifier to a raw notifier chain
|
|
* @nh: Pointer to head of the raw notifier chain
|
|
* @n: New entry in notifier chain
|
|
*
|
|
* Adds a notifier to a raw notifier chain.
|
|
* All locking must be provided by the caller.
|
|
*
|
|
* Currently always returns zero.
|
|
*/
|
|
|
|
int raw_notifier_chain_register(struct raw_notifier_head *nh,
|
|
struct notifier_block *n)
|
|
{
|
|
return notifier_chain_register(&nh->head, n);
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(raw_notifier_chain_register);
|
|
|
|
/**
|
|
* raw_notifier_chain_unregister - Remove notifier from a raw notifier chain
|
|
* @nh: Pointer to head of the raw notifier chain
|
|
* @n: Entry to remove from notifier chain
|
|
*
|
|
* Removes a notifier from a raw notifier chain.
|
|
* All locking must be provided by the caller.
|
|
*
|
|
* Returns zero on success or %-ENOENT on failure.
|
|
*/
|
|
int raw_notifier_chain_unregister(struct raw_notifier_head *nh,
|
|
struct notifier_block *n)
|
|
{
|
|
return notifier_chain_unregister(&nh->head, n);
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(raw_notifier_chain_unregister);
|
|
|
|
/**
|
|
* __raw_notifier_call_chain - Call functions in a raw notifier chain
|
|
* @nh: Pointer to head of the raw notifier chain
|
|
* @val: Value passed unmodified to notifier function
|
|
* @v: Pointer passed unmodified to notifier function
|
|
* @nr_to_call: See comment for notifier_call_chain.
|
|
* @nr_calls: See comment for notifier_call_chain
|
|
*
|
|
* Calls each function in a notifier chain in turn. The functions
|
|
* run in an undefined context.
|
|
* All locking must be provided by the caller.
|
|
*
|
|
* If the return value of the notifier can be and'ed
|
|
* with %NOTIFY_STOP_MASK then raw_notifier_call_chain()
|
|
* will return immediately, with the return value of
|
|
* the notifier function which halted execution.
|
|
* Otherwise the return value is the return value
|
|
* of the last notifier function called.
|
|
*/
|
|
|
|
int __raw_notifier_call_chain(struct raw_notifier_head *nh,
|
|
unsigned long val, void *v,
|
|
int nr_to_call, int *nr_calls)
|
|
{
|
|
return notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls);
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(__raw_notifier_call_chain);
|
|
|
|
int raw_notifier_call_chain(struct raw_notifier_head *nh,
|
|
unsigned long val, void *v)
|
|
{
|
|
return __raw_notifier_call_chain(nh, val, v, -1, NULL);
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(raw_notifier_call_chain);
|
|
|
|
/*
|
|
* SRCU notifier chain routines. Registration and unregistration
|
|
* use a mutex, and call_chain is synchronized by SRCU (no locks).
|
|
*/
|
|
|
|
/**
|
|
* srcu_notifier_chain_register - Add notifier to an SRCU notifier chain
|
|
* @nh: Pointer to head of the SRCU notifier chain
|
|
* @n: New entry in notifier chain
|
|
*
|
|
* Adds a notifier to an SRCU notifier chain.
|
|
* Must be called in process context.
|
|
*
|
|
* Currently always returns zero.
|
|
*/
|
|
|
|
int srcu_notifier_chain_register(struct srcu_notifier_head *nh,
|
|
struct notifier_block *n)
|
|
{
|
|
int ret;
|
|
|
|
/*
|
|
* This code gets used during boot-up, when task switching is
|
|
* not yet working and interrupts must remain disabled. At
|
|
* such times we must not call mutex_lock().
|
|
*/
|
|
if (unlikely(system_state == SYSTEM_BOOTING))
|
|
return notifier_chain_register(&nh->head, n);
|
|
|
|
mutex_lock(&nh->mutex);
|
|
ret = notifier_chain_register(&nh->head, n);
|
|
mutex_unlock(&nh->mutex);
|
|
return ret;
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(srcu_notifier_chain_register);
|
|
|
|
/**
|
|
* srcu_notifier_chain_unregister - Remove notifier from an SRCU notifier chain
|
|
* @nh: Pointer to head of the SRCU notifier chain
|
|
* @n: Entry to remove from notifier chain
|
|
*
|
|
* Removes a notifier from an SRCU notifier chain.
|
|
* Must be called from process context.
|
|
*
|
|
* Returns zero on success or %-ENOENT on failure.
|
|
*/
|
|
int srcu_notifier_chain_unregister(struct srcu_notifier_head *nh,
|
|
struct notifier_block *n)
|
|
{
|
|
int ret;
|
|
|
|
/*
|
|
* This code gets used during boot-up, when task switching is
|
|
* not yet working and interrupts must remain disabled. At
|
|
* such times we must not call mutex_lock().
|
|
*/
|
|
if (unlikely(system_state == SYSTEM_BOOTING))
|
|
return notifier_chain_unregister(&nh->head, n);
|
|
|
|
mutex_lock(&nh->mutex);
|
|
ret = notifier_chain_unregister(&nh->head, n);
|
|
mutex_unlock(&nh->mutex);
|
|
synchronize_srcu(&nh->srcu);
|
|
return ret;
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(srcu_notifier_chain_unregister);
|
|
|
|
/**
|
|
* __srcu_notifier_call_chain - Call functions in an SRCU notifier chain
|
|
* @nh: Pointer to head of the SRCU notifier chain
|
|
* @val: Value passed unmodified to notifier function
|
|
* @v: Pointer passed unmodified to notifier function
|
|
* @nr_to_call: See comment for notifier_call_chain.
|
|
* @nr_calls: See comment for notifier_call_chain
|
|
*
|
|
* Calls each function in a notifier chain in turn. The functions
|
|
* run in a process context, so they are allowed to block.
|
|
*
|
|
* If the return value of the notifier can be and'ed
|
|
* with %NOTIFY_STOP_MASK then srcu_notifier_call_chain()
|
|
* will return immediately, with the return value of
|
|
* the notifier function which halted execution.
|
|
* Otherwise the return value is the return value
|
|
* of the last notifier function called.
|
|
*/
|
|
|
|
int __srcu_notifier_call_chain(struct srcu_notifier_head *nh,
|
|
unsigned long val, void *v,
|
|
int nr_to_call, int *nr_calls)
|
|
{
|
|
int ret;
|
|
int idx;
|
|
|
|
idx = srcu_read_lock(&nh->srcu);
|
|
ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls);
|
|
srcu_read_unlock(&nh->srcu, idx);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__srcu_notifier_call_chain);
|
|
|
|
int srcu_notifier_call_chain(struct srcu_notifier_head *nh,
|
|
unsigned long val, void *v)
|
|
{
|
|
return __srcu_notifier_call_chain(nh, val, v, -1, NULL);
|
|
}
|
|
EXPORT_SYMBOL_GPL(srcu_notifier_call_chain);
|
|
|
|
/**
|
|
* srcu_init_notifier_head - Initialize an SRCU notifier head
|
|
* @nh: Pointer to head of the srcu notifier chain
|
|
*
|
|
* Unlike other sorts of notifier heads, SRCU notifier heads require
|
|
* dynamic initialization. Be sure to call this routine before
|
|
* calling any of the other SRCU notifier routines for this head.
|
|
*
|
|
* If an SRCU notifier head is deallocated, it must first be cleaned
|
|
* up by calling srcu_cleanup_notifier_head(). Otherwise the head's
|
|
* per-cpu data (used by the SRCU mechanism) will leak.
|
|
*/
|
|
|
|
void srcu_init_notifier_head(struct srcu_notifier_head *nh)
|
|
{
|
|
mutex_init(&nh->mutex);
|
|
if (init_srcu_struct(&nh->srcu) < 0)
|
|
BUG();
|
|
nh->head = NULL;
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(srcu_init_notifier_head);
|
|
|
|
/**
|
|
* register_reboot_notifier - Register function to be called at reboot time
|
|
* @nb: Info about notifier function to be called
|
|
*
|
|
* Registers a function with the list of functions
|
|
* to be called at reboot time.
|
|
*
|
|
* Currently always returns zero, as blocking_notifier_chain_register()
|
|
* always returns zero.
|
|
*/
|
|
|
|
int register_reboot_notifier(struct notifier_block * nb)
|
|
{
|
|
return blocking_notifier_chain_register(&reboot_notifier_list, nb);
|
|
}
|
|
|
|
EXPORT_SYMBOL(register_reboot_notifier);
|
|
|
|
/**
|
|
* unregister_reboot_notifier - Unregister previously registered reboot notifier
|
|
* @nb: Hook to be unregistered
|
|
*
|
|
* Unregisters a previously registered reboot
|
|
* notifier function.
|
|
*
|
|
* Returns zero on success, or %-ENOENT on failure.
|
|
*/
|
|
|
|
int unregister_reboot_notifier(struct notifier_block * nb)
|
|
{
|
|
return blocking_notifier_chain_unregister(&reboot_notifier_list, nb);
|
|
}
|
|
|
|
EXPORT_SYMBOL(unregister_reboot_notifier);
|
|
|
|
static int set_one_prio(struct task_struct *p, int niceval, int error)
|
|
{
|
|
int no_nice;
|
|
|
|
if (p->uid != current->euid &&
|
|
p->euid != current->euid && !capable(CAP_SYS_NICE)) {
|
|
error = -EPERM;
|
|
goto out;
|
|
}
|
|
if (niceval < task_nice(p) && !can_nice(p, niceval)) {
|
|
error = -EACCES;
|
|
goto out;
|
|
}
|
|
no_nice = security_task_setnice(p, niceval);
|
|
if (no_nice) {
|
|
error = no_nice;
|
|
goto out;
|
|
}
|
|
if (error == -ESRCH)
|
|
error = 0;
|
|
set_user_nice(p, niceval);
|
|
out:
|
|
return error;
|
|
}
|
|
|
|
asmlinkage long sys_setpriority(int which, int who, int niceval)
|
|
{
|
|
struct task_struct *g, *p;
|
|
struct user_struct *user;
|
|
int error = -EINVAL;
|
|
struct pid *pgrp;
|
|
|
|
if (which > 2 || which < 0)
|
|
goto out;
|
|
|
|
/* normalize: avoid signed division (rounding problems) */
|
|
error = -ESRCH;
|
|
if (niceval < -20)
|
|
niceval = -20;
|
|
if (niceval > 19)
|
|
niceval = 19;
|
|
|
|
read_lock(&tasklist_lock);
|
|
switch (which) {
|
|
case PRIO_PROCESS:
|
|
if (who)
|
|
p = find_task_by_pid(who);
|
|
else
|
|
p = current;
|
|
if (p)
|
|
error = set_one_prio(p, niceval, error);
|
|
break;
|
|
case PRIO_PGRP:
|
|
if (who)
|
|
pgrp = find_pid(who);
|
|
else
|
|
pgrp = task_pgrp(current);
|
|
do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
|
|
error = set_one_prio(p, niceval, error);
|
|
} while_each_pid_task(pgrp, PIDTYPE_PGID, p);
|
|
break;
|
|
case PRIO_USER:
|
|
user = current->user;
|
|
if (!who)
|
|
who = current->uid;
|
|
else
|
|
if ((who != current->uid) && !(user = find_user(who)))
|
|
goto out_unlock; /* No processes for this user */
|
|
|
|
do_each_thread(g, p)
|
|
if (p->uid == who)
|
|
error = set_one_prio(p, niceval, error);
|
|
while_each_thread(g, p);
|
|
if (who != current->uid)
|
|
free_uid(user); /* For find_user() */
|
|
break;
|
|
}
|
|
out_unlock:
|
|
read_unlock(&tasklist_lock);
|
|
out:
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Ugh. To avoid negative return values, "getpriority()" will
|
|
* not return the normal nice-value, but a negated value that
|
|
* has been offset by 20 (ie it returns 40..1 instead of -20..19)
|
|
* to stay compatible.
|
|
*/
|
|
asmlinkage long sys_getpriority(int which, int who)
|
|
{
|
|
struct task_struct *g, *p;
|
|
struct user_struct *user;
|
|
long niceval, retval = -ESRCH;
|
|
struct pid *pgrp;
|
|
|
|
if (which > 2 || which < 0)
|
|
return -EINVAL;
|
|
|
|
read_lock(&tasklist_lock);
|
|
switch (which) {
|
|
case PRIO_PROCESS:
|
|
if (who)
|
|
p = find_task_by_pid(who);
|
|
else
|
|
p = current;
|
|
if (p) {
|
|
niceval = 20 - task_nice(p);
|
|
if (niceval > retval)
|
|
retval = niceval;
|
|
}
|
|
break;
|
|
case PRIO_PGRP:
|
|
if (who)
|
|
pgrp = find_pid(who);
|
|
else
|
|
pgrp = task_pgrp(current);
|
|
do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
|
|
niceval = 20 - task_nice(p);
|
|
if (niceval > retval)
|
|
retval = niceval;
|
|
} while_each_pid_task(pgrp, PIDTYPE_PGID, p);
|
|
break;
|
|
case PRIO_USER:
|
|
user = current->user;
|
|
if (!who)
|
|
who = current->uid;
|
|
else
|
|
if ((who != current->uid) && !(user = find_user(who)))
|
|
goto out_unlock; /* No processes for this user */
|
|
|
|
do_each_thread(g, p)
|
|
if (p->uid == who) {
|
|
niceval = 20 - task_nice(p);
|
|
if (niceval > retval)
|
|
retval = niceval;
|
|
}
|
|
while_each_thread(g, p);
|
|
if (who != current->uid)
|
|
free_uid(user); /* for find_user() */
|
|
break;
|
|
}
|
|
out_unlock:
|
|
read_unlock(&tasklist_lock);
|
|
|
|
return retval;
|
|
}
|
|
|
|
/**
|
|
* emergency_restart - reboot the system
|
|
*
|
|
* Without shutting down any hardware or taking any locks
|
|
* reboot the system. This is called when we know we are in
|
|
* trouble so this is our best effort to reboot. This is
|
|
* safe to call in interrupt context.
|
|
*/
|
|
void emergency_restart(void)
|
|
{
|
|
machine_emergency_restart();
|
|
}
|
|
EXPORT_SYMBOL_GPL(emergency_restart);
|
|
|
|
static void kernel_restart_prepare(char *cmd)
|
|
{
|
|
blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
|
|
system_state = SYSTEM_RESTART;
|
|
device_shutdown();
|
|
}
|
|
|
|
/**
|
|
* kernel_restart - reboot the system
|
|
* @cmd: pointer to buffer containing command to execute for restart
|
|
* or %NULL
|
|
*
|
|
* Shutdown everything and perform a clean reboot.
|
|
* This is not safe to call in interrupt context.
|
|
*/
|
|
void kernel_restart(char *cmd)
|
|
{
|
|
kernel_restart_prepare(cmd);
|
|
if (!cmd)
|
|
printk(KERN_EMERG "Restarting system.\n");
|
|
else
|
|
printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd);
|
|
machine_restart(cmd);
|
|
}
|
|
EXPORT_SYMBOL_GPL(kernel_restart);
|
|
|
|
/**
|
|
* kernel_kexec - reboot the system
|
|
*
|
|
* Move into place and start executing a preloaded standalone
|
|
* executable. If nothing was preloaded return an error.
|
|
*/
|
|
static void kernel_kexec(void)
|
|
{
|
|
#ifdef CONFIG_KEXEC
|
|
struct kimage *image;
|
|
image = xchg(&kexec_image, NULL);
|
|
if (!image)
|
|
return;
|
|
kernel_restart_prepare(NULL);
|
|
printk(KERN_EMERG "Starting new kernel\n");
|
|
machine_shutdown();
|
|
machine_kexec(image);
|
|
#endif
|
|
}
|
|
|
|
void kernel_shutdown_prepare(enum system_states state)
|
|
{
|
|
blocking_notifier_call_chain(&reboot_notifier_list,
|
|
(state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL);
|
|
system_state = state;
|
|
device_shutdown();
|
|
}
|
|
/**
|
|
* kernel_halt - halt the system
|
|
*
|
|
* Shutdown everything and perform a clean system halt.
|
|
*/
|
|
void kernel_halt(void)
|
|
{
|
|
kernel_shutdown_prepare(SYSTEM_HALT);
|
|
printk(KERN_EMERG "System halted.\n");
|
|
machine_halt();
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(kernel_halt);
|
|
|
|
/**
|
|
* kernel_power_off - power_off the system
|
|
*
|
|
* Shutdown everything and perform a clean system power_off.
|
|
*/
|
|
void kernel_power_off(void)
|
|
{
|
|
kernel_shutdown_prepare(SYSTEM_POWER_OFF);
|
|
printk(KERN_EMERG "Power down.\n");
|
|
machine_power_off();
|
|
}
|
|
EXPORT_SYMBOL_GPL(kernel_power_off);
|
|
/*
|
|
* Reboot system call: for obvious reasons only root may call it,
|
|
* and even root needs to set up some magic numbers in the registers
|
|
* so that some mistake won't make this reboot the whole machine.
|
|
* You can also set the meaning of the ctrl-alt-del-key here.
|
|
*
|
|
* reboot doesn't sync: do that yourself before calling this.
|
|
*/
|
|
asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user * arg)
|
|
{
|
|
char buffer[256];
|
|
|
|
/* We only trust the superuser with rebooting the system. */
|
|
if (!capable(CAP_SYS_BOOT))
|
|
return -EPERM;
|
|
|
|
/* For safety, we require "magic" arguments. */
|
|
if (magic1 != LINUX_REBOOT_MAGIC1 ||
|
|
(magic2 != LINUX_REBOOT_MAGIC2 &&
|
|
magic2 != LINUX_REBOOT_MAGIC2A &&
|
|
magic2 != LINUX_REBOOT_MAGIC2B &&
|
|
magic2 != LINUX_REBOOT_MAGIC2C))
|
|
return -EINVAL;
|
|
|
|
/* Instead of trying to make the power_off code look like
|
|
* halt when pm_power_off is not set do it the easy way.
|
|
*/
|
|
if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off)
|
|
cmd = LINUX_REBOOT_CMD_HALT;
|
|
|
|
lock_kernel();
|
|
switch (cmd) {
|
|
case LINUX_REBOOT_CMD_RESTART:
|
|
kernel_restart(NULL);
|
|
break;
|
|
|
|
case LINUX_REBOOT_CMD_CAD_ON:
|
|
C_A_D = 1;
|
|
break;
|
|
|
|
case LINUX_REBOOT_CMD_CAD_OFF:
|
|
C_A_D = 0;
|
|
break;
|
|
|
|
case LINUX_REBOOT_CMD_HALT:
|
|
kernel_halt();
|
|
unlock_kernel();
|
|
do_exit(0);
|
|
break;
|
|
|
|
case LINUX_REBOOT_CMD_POWER_OFF:
|
|
kernel_power_off();
|
|
unlock_kernel();
|
|
do_exit(0);
|
|
break;
|
|
|
|
case LINUX_REBOOT_CMD_RESTART2:
|
|
if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
|
|
unlock_kernel();
|
|
return -EFAULT;
|
|
}
|
|
buffer[sizeof(buffer) - 1] = '\0';
|
|
|
|
kernel_restart(buffer);
|
|
break;
|
|
|
|
case LINUX_REBOOT_CMD_KEXEC:
|
|
kernel_kexec();
|
|
unlock_kernel();
|
|
return -EINVAL;
|
|
|
|
#ifdef CONFIG_SOFTWARE_SUSPEND
|
|
case LINUX_REBOOT_CMD_SW_SUSPEND:
|
|
{
|
|
int ret = hibernate();
|
|
unlock_kernel();
|
|
return ret;
|
|
}
|
|
#endif
|
|
|
|
default:
|
|
unlock_kernel();
|
|
return -EINVAL;
|
|
}
|
|
unlock_kernel();
|
|
return 0;
|
|
}
|
|
|
|
static void deferred_cad(struct work_struct *dummy)
|
|
{
|
|
kernel_restart(NULL);
|
|
}
|
|
|
|
/*
|
|
* This function gets called by ctrl-alt-del - ie the keyboard interrupt.
|
|
* As it's called within an interrupt, it may NOT sync: the only choice
|
|
* is whether to reboot at once, or just ignore the ctrl-alt-del.
|
|
*/
|
|
void ctrl_alt_del(void)
|
|
{
|
|
static DECLARE_WORK(cad_work, deferred_cad);
|
|
|
|
if (C_A_D)
|
|
schedule_work(&cad_work);
|
|
else
|
|
kill_cad_pid(SIGINT, 1);
|
|
}
|
|
|
|
/*
|
|
* Unprivileged users may change the real gid to the effective gid
|
|
* or vice versa. (BSD-style)
|
|
*
|
|
* If you set the real gid at all, or set the effective gid to a value not
|
|
* equal to the real gid, then the saved gid is set to the new effective gid.
|
|
*
|
|
* This makes it possible for a setgid program to completely drop its
|
|
* privileges, which is often a useful assertion to make when you are doing
|
|
* a security audit over a program.
|
|
*
|
|
* The general idea is that a program which uses just setregid() will be
|
|
* 100% compatible with BSD. A program which uses just setgid() will be
|
|
* 100% compatible with POSIX with saved IDs.
|
|
*
|
|
* SMP: There are not races, the GIDs are checked only by filesystem
|
|
* operations (as far as semantic preservation is concerned).
|
|
*/
|
|
asmlinkage long sys_setregid(gid_t rgid, gid_t egid)
|
|
{
|
|
int old_rgid = current->gid;
|
|
int old_egid = current->egid;
|
|
int new_rgid = old_rgid;
|
|
int new_egid = old_egid;
|
|
int retval;
|
|
|
|
retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE);
|
|
if (retval)
|
|
return retval;
|
|
|
|
if (rgid != (gid_t) -1) {
|
|
if ((old_rgid == rgid) ||
|
|
(current->egid==rgid) ||
|
|
capable(CAP_SETGID))
|
|
new_rgid = rgid;
|
|
else
|
|
return -EPERM;
|
|
}
|
|
if (egid != (gid_t) -1) {
|
|
if ((old_rgid == egid) ||
|
|
(current->egid == egid) ||
|
|
(current->sgid == egid) ||
|
|
capable(CAP_SETGID))
|
|
new_egid = egid;
|
|
else
|
|
return -EPERM;
|
|
}
|
|
if (new_egid != old_egid) {
|
|
current->mm->dumpable = suid_dumpable;
|
|
smp_wmb();
|
|
}
|
|
if (rgid != (gid_t) -1 ||
|
|
(egid != (gid_t) -1 && egid != old_rgid))
|
|
current->sgid = new_egid;
|
|
current->fsgid = new_egid;
|
|
current->egid = new_egid;
|
|
current->gid = new_rgid;
|
|
key_fsgid_changed(current);
|
|
proc_id_connector(current, PROC_EVENT_GID);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* setgid() is implemented like SysV w/ SAVED_IDS
|
|
*
|
|
* SMP: Same implicit races as above.
|
|
*/
|
|
asmlinkage long sys_setgid(gid_t gid)
|
|
{
|
|
int old_egid = current->egid;
|
|
int retval;
|
|
|
|
retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID);
|
|
if (retval)
|
|
return retval;
|
|
|
|
if (capable(CAP_SETGID)) {
|
|
if (old_egid != gid) {
|
|
current->mm->dumpable = suid_dumpable;
|
|
smp_wmb();
|
|
}
|
|
current->gid = current->egid = current->sgid = current->fsgid = gid;
|
|
} else if ((gid == current->gid) || (gid == current->sgid)) {
|
|
if (old_egid != gid) {
|
|
current->mm->dumpable = suid_dumpable;
|
|
smp_wmb();
|
|
}
|
|
current->egid = current->fsgid = gid;
|
|
}
|
|
else
|
|
return -EPERM;
|
|
|
|
key_fsgid_changed(current);
|
|
proc_id_connector(current, PROC_EVENT_GID);
|
|
return 0;
|
|
}
|
|
|
|
static int set_user(uid_t new_ruid, int dumpclear)
|
|
{
|
|
struct user_struct *new_user;
|
|
|
|
new_user = alloc_uid(new_ruid);
|
|
if (!new_user)
|
|
return -EAGAIN;
|
|
|
|
if (atomic_read(&new_user->processes) >=
|
|
current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
|
|
new_user != &root_user) {
|
|
free_uid(new_user);
|
|
return -EAGAIN;
|
|
}
|
|
|
|
switch_uid(new_user);
|
|
|
|
if (dumpclear) {
|
|
current->mm->dumpable = suid_dumpable;
|
|
smp_wmb();
|
|
}
|
|
current->uid = new_ruid;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Unprivileged users may change the real uid to the effective uid
|
|
* or vice versa. (BSD-style)
|
|
*
|
|
* If you set the real uid at all, or set the effective uid to a value not
|
|
* equal to the real uid, then the saved uid is set to the new effective uid.
|
|
*
|
|
* This makes it possible for a setuid program to completely drop its
|
|
* privileges, which is often a useful assertion to make when you are doing
|
|
* a security audit over a program.
|
|
*
|
|
* The general idea is that a program which uses just setreuid() will be
|
|
* 100% compatible with BSD. A program which uses just setuid() will be
|
|
* 100% compatible with POSIX with saved IDs.
|
|
*/
|
|
asmlinkage long sys_setreuid(uid_t ruid, uid_t euid)
|
|
{
|
|
int old_ruid, old_euid, old_suid, new_ruid, new_euid;
|
|
int retval;
|
|
|
|
retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE);
|
|
if (retval)
|
|
return retval;
|
|
|
|
new_ruid = old_ruid = current->uid;
|
|
new_euid = old_euid = current->euid;
|
|
old_suid = current->suid;
|
|
|
|
if (ruid != (uid_t) -1) {
|
|
new_ruid = ruid;
|
|
if ((old_ruid != ruid) &&
|
|
(current->euid != ruid) &&
|
|
!capable(CAP_SETUID))
|
|
return -EPERM;
|
|
}
|
|
|
|
if (euid != (uid_t) -1) {
|
|
new_euid = euid;
|
|
if ((old_ruid != euid) &&
|
|
(current->euid != euid) &&
|
|
(current->suid != euid) &&
|
|
!capable(CAP_SETUID))
|
|
return -EPERM;
|
|
}
|
|
|
|
if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0)
|
|
return -EAGAIN;
|
|
|
|
if (new_euid != old_euid) {
|
|
current->mm->dumpable = suid_dumpable;
|
|
smp_wmb();
|
|
}
|
|
current->fsuid = current->euid = new_euid;
|
|
if (ruid != (uid_t) -1 ||
|
|
(euid != (uid_t) -1 && euid != old_ruid))
|
|
current->suid = current->euid;
|
|
current->fsuid = current->euid;
|
|
|
|
key_fsuid_changed(current);
|
|
proc_id_connector(current, PROC_EVENT_UID);
|
|
|
|
return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE);
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* setuid() is implemented like SysV with SAVED_IDS
|
|
*
|
|
* Note that SAVED_ID's is deficient in that a setuid root program
|
|
* like sendmail, for example, cannot set its uid to be a normal
|
|
* user and then switch back, because if you're root, setuid() sets
|
|
* the saved uid too. If you don't like this, blame the bright people
|
|
* in the POSIX committee and/or USG. Note that the BSD-style setreuid()
|
|
* will allow a root program to temporarily drop privileges and be able to
|
|
* regain them by swapping the real and effective uid.
|
|
*/
|
|
asmlinkage long sys_setuid(uid_t uid)
|
|
{
|
|
int old_euid = current->euid;
|
|
int old_ruid, old_suid, new_suid;
|
|
int retval;
|
|
|
|
retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID);
|
|
if (retval)
|
|
return retval;
|
|
|
|
old_ruid = current->uid;
|
|
old_suid = current->suid;
|
|
new_suid = old_suid;
|
|
|
|
if (capable(CAP_SETUID)) {
|
|
if (uid != old_ruid && set_user(uid, old_euid != uid) < 0)
|
|
return -EAGAIN;
|
|
new_suid = uid;
|
|
} else if ((uid != current->uid) && (uid != new_suid))
|
|
return -EPERM;
|
|
|
|
if (old_euid != uid) {
|
|
current->mm->dumpable = suid_dumpable;
|
|
smp_wmb();
|
|
}
|
|
current->fsuid = current->euid = uid;
|
|
current->suid = new_suid;
|
|
|
|
key_fsuid_changed(current);
|
|
proc_id_connector(current, PROC_EVENT_UID);
|
|
|
|
return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID);
|
|
}
|
|
|
|
|
|
/*
|
|
* This function implements a generic ability to update ruid, euid,
|
|
* and suid. This allows you to implement the 4.4 compatible seteuid().
|
|
*/
|
|
asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
|
|
{
|
|
int old_ruid = current->uid;
|
|
int old_euid = current->euid;
|
|
int old_suid = current->suid;
|
|
int retval;
|
|
|
|
retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES);
|
|
if (retval)
|
|
return retval;
|
|
|
|
if (!capable(CAP_SETUID)) {
|
|
if ((ruid != (uid_t) -1) && (ruid != current->uid) &&
|
|
(ruid != current->euid) && (ruid != current->suid))
|
|
return -EPERM;
|
|
if ((euid != (uid_t) -1) && (euid != current->uid) &&
|
|
(euid != current->euid) && (euid != current->suid))
|
|
return -EPERM;
|
|
if ((suid != (uid_t) -1) && (suid != current->uid) &&
|
|
(suid != current->euid) && (suid != current->suid))
|
|
return -EPERM;
|
|
}
|
|
if (ruid != (uid_t) -1) {
|
|
if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0)
|
|
return -EAGAIN;
|
|
}
|
|
if (euid != (uid_t) -1) {
|
|
if (euid != current->euid) {
|
|
current->mm->dumpable = suid_dumpable;
|
|
smp_wmb();
|
|
}
|
|
current->euid = euid;
|
|
}
|
|
current->fsuid = current->euid;
|
|
if (suid != (uid_t) -1)
|
|
current->suid = suid;
|
|
|
|
key_fsuid_changed(current);
|
|
proc_id_connector(current, PROC_EVENT_UID);
|
|
|
|
return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES);
|
|
}
|
|
|
|
asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid)
|
|
{
|
|
int retval;
|
|
|
|
if (!(retval = put_user(current->uid, ruid)) &&
|
|
!(retval = put_user(current->euid, euid)))
|
|
retval = put_user(current->suid, suid);
|
|
|
|
return retval;
|
|
}
|
|
|
|
/*
|
|
* Same as above, but for rgid, egid, sgid.
|
|
*/
|
|
asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
|
|
{
|
|
int retval;
|
|
|
|
retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES);
|
|
if (retval)
|
|
return retval;
|
|
|
|
if (!capable(CAP_SETGID)) {
|
|
if ((rgid != (gid_t) -1) && (rgid != current->gid) &&
|
|
(rgid != current->egid) && (rgid != current->sgid))
|
|
return -EPERM;
|
|
if ((egid != (gid_t) -1) && (egid != current->gid) &&
|
|
(egid != current->egid) && (egid != current->sgid))
|
|
return -EPERM;
|
|
if ((sgid != (gid_t) -1) && (sgid != current->gid) &&
|
|
(sgid != current->egid) && (sgid != current->sgid))
|
|
return -EPERM;
|
|
}
|
|
if (egid != (gid_t) -1) {
|
|
if (egid != current->egid) {
|
|
current->mm->dumpable = suid_dumpable;
|
|
smp_wmb();
|
|
}
|
|
current->egid = egid;
|
|
}
|
|
current->fsgid = current->egid;
|
|
if (rgid != (gid_t) -1)
|
|
current->gid = rgid;
|
|
if (sgid != (gid_t) -1)
|
|
current->sgid = sgid;
|
|
|
|
key_fsgid_changed(current);
|
|
proc_id_connector(current, PROC_EVENT_GID);
|
|
return 0;
|
|
}
|
|
|
|
asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid)
|
|
{
|
|
int retval;
|
|
|
|
if (!(retval = put_user(current->gid, rgid)) &&
|
|
!(retval = put_user(current->egid, egid)))
|
|
retval = put_user(current->sgid, sgid);
|
|
|
|
return retval;
|
|
}
|
|
|
|
|
|
/*
|
|
* "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
|
|
* is used for "access()" and for the NFS daemon (letting nfsd stay at
|
|
* whatever uid it wants to). It normally shadows "euid", except when
|
|
* explicitly set by setfsuid() or for access..
|
|
*/
|
|
asmlinkage long sys_setfsuid(uid_t uid)
|
|
{
|
|
int old_fsuid;
|
|
|
|
old_fsuid = current->fsuid;
|
|
if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS))
|
|
return old_fsuid;
|
|
|
|
if (uid == current->uid || uid == current->euid ||
|
|
uid == current->suid || uid == current->fsuid ||
|
|
capable(CAP_SETUID)) {
|
|
if (uid != old_fsuid) {
|
|
current->mm->dumpable = suid_dumpable;
|
|
smp_wmb();
|
|
}
|
|
current->fsuid = uid;
|
|
}
|
|
|
|
key_fsuid_changed(current);
|
|
proc_id_connector(current, PROC_EVENT_UID);
|
|
|
|
security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS);
|
|
|
|
return old_fsuid;
|
|
}
|
|
|
|
/*
|
|
* Samma på svenska..
|
|
*/
|
|
asmlinkage long sys_setfsgid(gid_t gid)
|
|
{
|
|
int old_fsgid;
|
|
|
|
old_fsgid = current->fsgid;
|
|
if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS))
|
|
return old_fsgid;
|
|
|
|
if (gid == current->gid || gid == current->egid ||
|
|
gid == current->sgid || gid == current->fsgid ||
|
|
capable(CAP_SETGID)) {
|
|
if (gid != old_fsgid) {
|
|
current->mm->dumpable = suid_dumpable;
|
|
smp_wmb();
|
|
}
|
|
current->fsgid = gid;
|
|
key_fsgid_changed(current);
|
|
proc_id_connector(current, PROC_EVENT_GID);
|
|
}
|
|
return old_fsgid;
|
|
}
|
|
|
|
asmlinkage long sys_times(struct tms __user * tbuf)
|
|
{
|
|
/*
|
|
* In the SMP world we might just be unlucky and have one of
|
|
* the times increment as we use it. Since the value is an
|
|
* atomically safe type this is just fine. Conceptually its
|
|
* as if the syscall took an instant longer to occur.
|
|
*/
|
|
if (tbuf) {
|
|
struct tms tmp;
|
|
struct task_struct *tsk = current;
|
|
struct task_struct *t;
|
|
cputime_t utime, stime, cutime, cstime;
|
|
|
|
spin_lock_irq(&tsk->sighand->siglock);
|
|
utime = tsk->signal->utime;
|
|
stime = tsk->signal->stime;
|
|
t = tsk;
|
|
do {
|
|
utime = cputime_add(utime, t->utime);
|
|
stime = cputime_add(stime, t->stime);
|
|
t = next_thread(t);
|
|
} while (t != tsk);
|
|
|
|
cutime = tsk->signal->cutime;
|
|
cstime = tsk->signal->cstime;
|
|
spin_unlock_irq(&tsk->sighand->siglock);
|
|
|
|
tmp.tms_utime = cputime_to_clock_t(utime);
|
|
tmp.tms_stime = cputime_to_clock_t(stime);
|
|
tmp.tms_cutime = cputime_to_clock_t(cutime);
|
|
tmp.tms_cstime = cputime_to_clock_t(cstime);
|
|
if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
|
|
return -EFAULT;
|
|
}
|
|
return (long) jiffies_64_to_clock_t(get_jiffies_64());
|
|
}
|
|
|
|
/*
|
|
* This needs some heavy checking ...
|
|
* I just haven't the stomach for it. I also don't fully
|
|
* understand sessions/pgrp etc. Let somebody who does explain it.
|
|
*
|
|
* OK, I think I have the protection semantics right.... this is really
|
|
* only important on a multi-user system anyway, to make sure one user
|
|
* can't send a signal to a process owned by another. -TYT, 12/12/91
|
|
*
|
|
* Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
|
|
* LBT 04.03.94
|
|
*/
|
|
|
|
asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
|
|
{
|
|
struct task_struct *p;
|
|
struct task_struct *group_leader = current->group_leader;
|
|
int err = -EINVAL;
|
|
|
|
if (!pid)
|
|
pid = group_leader->pid;
|
|
if (!pgid)
|
|
pgid = pid;
|
|
if (pgid < 0)
|
|
return -EINVAL;
|
|
|
|
/* From this point forward we keep holding onto the tasklist lock
|
|
* so that our parent does not change from under us. -DaveM
|
|
*/
|
|
write_lock_irq(&tasklist_lock);
|
|
|
|
err = -ESRCH;
|
|
p = find_task_by_pid(pid);
|
|
if (!p)
|
|
goto out;
|
|
|
|
err = -EINVAL;
|
|
if (!thread_group_leader(p))
|
|
goto out;
|
|
|
|
if (p->real_parent == group_leader) {
|
|
err = -EPERM;
|
|
if (task_session(p) != task_session(group_leader))
|
|
goto out;
|
|
err = -EACCES;
|
|
if (p->did_exec)
|
|
goto out;
|
|
} else {
|
|
err = -ESRCH;
|
|
if (p != group_leader)
|
|
goto out;
|
|
}
|
|
|
|
err = -EPERM;
|
|
if (p->signal->leader)
|
|
goto out;
|
|
|
|
if (pgid != pid) {
|
|
struct task_struct *g =
|
|
find_task_by_pid_type(PIDTYPE_PGID, pgid);
|
|
|
|
if (!g || task_session(g) != task_session(group_leader))
|
|
goto out;
|
|
}
|
|
|
|
err = security_task_setpgid(p, pgid);
|
|
if (err)
|
|
goto out;
|
|
|
|
if (process_group(p) != pgid) {
|
|
detach_pid(p, PIDTYPE_PGID);
|
|
p->signal->pgrp = pgid;
|
|
attach_pid(p, PIDTYPE_PGID, pgid);
|
|
}
|
|
|
|
err = 0;
|
|
out:
|
|
/* All paths lead to here, thus we are safe. -DaveM */
|
|
write_unlock_irq(&tasklist_lock);
|
|
return err;
|
|
}
|
|
|
|
asmlinkage long sys_getpgid(pid_t pid)
|
|
{
|
|
if (!pid)
|
|
return process_group(current);
|
|
else {
|
|
int retval;
|
|
struct task_struct *p;
|
|
|
|
read_lock(&tasklist_lock);
|
|
p = find_task_by_pid(pid);
|
|
|
|
retval = -ESRCH;
|
|
if (p) {
|
|
retval = security_task_getpgid(p);
|
|
if (!retval)
|
|
retval = process_group(p);
|
|
}
|
|
read_unlock(&tasklist_lock);
|
|
return retval;
|
|
}
|
|
}
|
|
|
|
#ifdef __ARCH_WANT_SYS_GETPGRP
|
|
|
|
asmlinkage long sys_getpgrp(void)
|
|
{
|
|
/* SMP - assuming writes are word atomic this is fine */
|
|
return process_group(current);
|
|
}
|
|
|
|
#endif
|
|
|
|
asmlinkage long sys_getsid(pid_t pid)
|
|
{
|
|
if (!pid)
|
|
return process_session(current);
|
|
else {
|
|
int retval;
|
|
struct task_struct *p;
|
|
|
|
read_lock(&tasklist_lock);
|
|
p = find_task_by_pid(pid);
|
|
|
|
retval = -ESRCH;
|
|
if (p) {
|
|
retval = security_task_getsid(p);
|
|
if (!retval)
|
|
retval = process_session(p);
|
|
}
|
|
read_unlock(&tasklist_lock);
|
|
return retval;
|
|
}
|
|
}
|
|
|
|
asmlinkage long sys_setsid(void)
|
|
{
|
|
struct task_struct *group_leader = current->group_leader;
|
|
pid_t session;
|
|
int err = -EPERM;
|
|
|
|
write_lock_irq(&tasklist_lock);
|
|
|
|
/* Fail if I am already a session leader */
|
|
if (group_leader->signal->leader)
|
|
goto out;
|
|
|
|
session = group_leader->pid;
|
|
/* Fail if a process group id already exists that equals the
|
|
* proposed session id.
|
|
*
|
|
* Don't check if session id == 1 because kernel threads use this
|
|
* session id and so the check will always fail and make it so
|
|
* init cannot successfully call setsid.
|
|
*/
|
|
if (session > 1 && find_task_by_pid_type(PIDTYPE_PGID, session))
|
|
goto out;
|
|
|
|
group_leader->signal->leader = 1;
|
|
__set_special_pids(session, session);
|
|
|
|
spin_lock(&group_leader->sighand->siglock);
|
|
group_leader->signal->tty = NULL;
|
|
spin_unlock(&group_leader->sighand->siglock);
|
|
|
|
err = process_group(group_leader);
|
|
out:
|
|
write_unlock_irq(&tasklist_lock);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Supplementary group IDs
|
|
*/
|
|
|
|
/* init to 2 - one for init_task, one to ensure it is never freed */
|
|
struct group_info init_groups = { .usage = ATOMIC_INIT(2) };
|
|
|
|
struct group_info *groups_alloc(int gidsetsize)
|
|
{
|
|
struct group_info *group_info;
|
|
int nblocks;
|
|
int i;
|
|
|
|
nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;
|
|
/* Make sure we always allocate at least one indirect block pointer */
|
|
nblocks = nblocks ? : 1;
|
|
group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);
|
|
if (!group_info)
|
|
return NULL;
|
|
group_info->ngroups = gidsetsize;
|
|
group_info->nblocks = nblocks;
|
|
atomic_set(&group_info->usage, 1);
|
|
|
|
if (gidsetsize <= NGROUPS_SMALL)
|
|
group_info->blocks[0] = group_info->small_block;
|
|
else {
|
|
for (i = 0; i < nblocks; i++) {
|
|
gid_t *b;
|
|
b = (void *)__get_free_page(GFP_USER);
|
|
if (!b)
|
|
goto out_undo_partial_alloc;
|
|
group_info->blocks[i] = b;
|
|
}
|
|
}
|
|
return group_info;
|
|
|
|
out_undo_partial_alloc:
|
|
while (--i >= 0) {
|
|
free_page((unsigned long)group_info->blocks[i]);
|
|
}
|
|
kfree(group_info);
|
|
return NULL;
|
|
}
|
|
|
|
EXPORT_SYMBOL(groups_alloc);
|
|
|
|
void groups_free(struct group_info *group_info)
|
|
{
|
|
if (group_info->blocks[0] != group_info->small_block) {
|
|
int i;
|
|
for (i = 0; i < group_info->nblocks; i++)
|
|
free_page((unsigned long)group_info->blocks[i]);
|
|
}
|
|
kfree(group_info);
|
|
}
|
|
|
|
EXPORT_SYMBOL(groups_free);
|
|
|
|
/* export the group_info to a user-space array */
|
|
static int groups_to_user(gid_t __user *grouplist,
|
|
struct group_info *group_info)
|
|
{
|
|
int i;
|
|
int count = group_info->ngroups;
|
|
|
|
for (i = 0; i < group_info->nblocks; i++) {
|
|
int cp_count = min(NGROUPS_PER_BLOCK, count);
|
|
int off = i * NGROUPS_PER_BLOCK;
|
|
int len = cp_count * sizeof(*grouplist);
|
|
|
|
if (copy_to_user(grouplist+off, group_info->blocks[i], len))
|
|
return -EFAULT;
|
|
|
|
count -= cp_count;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* fill a group_info from a user-space array - it must be allocated already */
|
|
static int groups_from_user(struct group_info *group_info,
|
|
gid_t __user *grouplist)
|
|
{
|
|
int i;
|
|
int count = group_info->ngroups;
|
|
|
|
for (i = 0; i < group_info->nblocks; i++) {
|
|
int cp_count = min(NGROUPS_PER_BLOCK, count);
|
|
int off = i * NGROUPS_PER_BLOCK;
|
|
int len = cp_count * sizeof(*grouplist);
|
|
|
|
if (copy_from_user(group_info->blocks[i], grouplist+off, len))
|
|
return -EFAULT;
|
|
|
|
count -= cp_count;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* a simple Shell sort */
|
|
static void groups_sort(struct group_info *group_info)
|
|
{
|
|
int base, max, stride;
|
|
int gidsetsize = group_info->ngroups;
|
|
|
|
for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
|
|
; /* nothing */
|
|
stride /= 3;
|
|
|
|
while (stride) {
|
|
max = gidsetsize - stride;
|
|
for (base = 0; base < max; base++) {
|
|
int left = base;
|
|
int right = left + stride;
|
|
gid_t tmp = GROUP_AT(group_info, right);
|
|
|
|
while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
|
|
GROUP_AT(group_info, right) =
|
|
GROUP_AT(group_info, left);
|
|
right = left;
|
|
left -= stride;
|
|
}
|
|
GROUP_AT(group_info, right) = tmp;
|
|
}
|
|
stride /= 3;
|
|
}
|
|
}
|
|
|
|
/* a simple bsearch */
|
|
int groups_search(struct group_info *group_info, gid_t grp)
|
|
{
|
|
unsigned int left, right;
|
|
|
|
if (!group_info)
|
|
return 0;
|
|
|
|
left = 0;
|
|
right = group_info->ngroups;
|
|
while (left < right) {
|
|
unsigned int mid = (left+right)/2;
|
|
int cmp = grp - GROUP_AT(group_info, mid);
|
|
if (cmp > 0)
|
|
left = mid + 1;
|
|
else if (cmp < 0)
|
|
right = mid;
|
|
else
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* validate and set current->group_info */
|
|
int set_current_groups(struct group_info *group_info)
|
|
{
|
|
int retval;
|
|
struct group_info *old_info;
|
|
|
|
retval = security_task_setgroups(group_info);
|
|
if (retval)
|
|
return retval;
|
|
|
|
groups_sort(group_info);
|
|
get_group_info(group_info);
|
|
|
|
task_lock(current);
|
|
old_info = current->group_info;
|
|
current->group_info = group_info;
|
|
task_unlock(current);
|
|
|
|
put_group_info(old_info);
|
|
|
|
return 0;
|
|
}
|
|
|
|
EXPORT_SYMBOL(set_current_groups);
|
|
|
|
asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist)
|
|
{
|
|
int i = 0;
|
|
|
|
/*
|
|
* SMP: Nobody else can change our grouplist. Thus we are
|
|
* safe.
|
|
*/
|
|
|
|
if (gidsetsize < 0)
|
|
return -EINVAL;
|
|
|
|
/* no need to grab task_lock here; it cannot change */
|
|
i = current->group_info->ngroups;
|
|
if (gidsetsize) {
|
|
if (i > gidsetsize) {
|
|
i = -EINVAL;
|
|
goto out;
|
|
}
|
|
if (groups_to_user(grouplist, current->group_info)) {
|
|
i = -EFAULT;
|
|
goto out;
|
|
}
|
|
}
|
|
out:
|
|
return i;
|
|
}
|
|
|
|
/*
|
|
* SMP: Our groups are copy-on-write. We can set them safely
|
|
* without another task interfering.
|
|
*/
|
|
|
|
asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist)
|
|
{
|
|
struct group_info *group_info;
|
|
int retval;
|
|
|
|
if (!capable(CAP_SETGID))
|
|
return -EPERM;
|
|
if ((unsigned)gidsetsize > NGROUPS_MAX)
|
|
return -EINVAL;
|
|
|
|
group_info = groups_alloc(gidsetsize);
|
|
if (!group_info)
|
|
return -ENOMEM;
|
|
retval = groups_from_user(group_info, grouplist);
|
|
if (retval) {
|
|
put_group_info(group_info);
|
|
return retval;
|
|
}
|
|
|
|
retval = set_current_groups(group_info);
|
|
put_group_info(group_info);
|
|
|
|
return retval;
|
|
}
|
|
|
|
/*
|
|
* Check whether we're fsgid/egid or in the supplemental group..
|
|
*/
|
|
int in_group_p(gid_t grp)
|
|
{
|
|
int retval = 1;
|
|
if (grp != current->fsgid)
|
|
retval = groups_search(current->group_info, grp);
|
|
return retval;
|
|
}
|
|
|
|
EXPORT_SYMBOL(in_group_p);
|
|
|
|
int in_egroup_p(gid_t grp)
|
|
{
|
|
int retval = 1;
|
|
if (grp != current->egid)
|
|
retval = groups_search(current->group_info, grp);
|
|
return retval;
|
|
}
|
|
|
|
EXPORT_SYMBOL(in_egroup_p);
|
|
|
|
DECLARE_RWSEM(uts_sem);
|
|
|
|
EXPORT_SYMBOL(uts_sem);
|
|
|
|
asmlinkage long sys_newuname(struct new_utsname __user * name)
|
|
{
|
|
int errno = 0;
|
|
|
|
down_read(&uts_sem);
|
|
if (copy_to_user(name, utsname(), sizeof *name))
|
|
errno = -EFAULT;
|
|
up_read(&uts_sem);
|
|
return errno;
|
|
}
|
|
|
|
asmlinkage long sys_sethostname(char __user *name, int len)
|
|
{
|
|
int errno;
|
|
char tmp[__NEW_UTS_LEN];
|
|
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
if (len < 0 || len > __NEW_UTS_LEN)
|
|
return -EINVAL;
|
|
down_write(&uts_sem);
|
|
errno = -EFAULT;
|
|
if (!copy_from_user(tmp, name, len)) {
|
|
memcpy(utsname()->nodename, tmp, len);
|
|
utsname()->nodename[len] = 0;
|
|
errno = 0;
|
|
}
|
|
up_write(&uts_sem);
|
|
return errno;
|
|
}
|
|
|
|
#ifdef __ARCH_WANT_SYS_GETHOSTNAME
|
|
|
|
asmlinkage long sys_gethostname(char __user *name, int len)
|
|
{
|
|
int i, errno;
|
|
|
|
if (len < 0)
|
|
return -EINVAL;
|
|
down_read(&uts_sem);
|
|
i = 1 + strlen(utsname()->nodename);
|
|
if (i > len)
|
|
i = len;
|
|
errno = 0;
|
|
if (copy_to_user(name, utsname()->nodename, i))
|
|
errno = -EFAULT;
|
|
up_read(&uts_sem);
|
|
return errno;
|
|
}
|
|
|
|
#endif
|
|
|
|
/*
|
|
* Only setdomainname; getdomainname can be implemented by calling
|
|
* uname()
|
|
*/
|
|
asmlinkage long sys_setdomainname(char __user *name, int len)
|
|
{
|
|
int errno;
|
|
char tmp[__NEW_UTS_LEN];
|
|
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
if (len < 0 || len > __NEW_UTS_LEN)
|
|
return -EINVAL;
|
|
|
|
down_write(&uts_sem);
|
|
errno = -EFAULT;
|
|
if (!copy_from_user(tmp, name, len)) {
|
|
memcpy(utsname()->domainname, tmp, len);
|
|
utsname()->domainname[len] = 0;
|
|
errno = 0;
|
|
}
|
|
up_write(&uts_sem);
|
|
return errno;
|
|
}
|
|
|
|
asmlinkage long sys_getrlimit(unsigned int resource, struct rlimit __user *rlim)
|
|
{
|
|
if (resource >= RLIM_NLIMITS)
|
|
return -EINVAL;
|
|
else {
|
|
struct rlimit value;
|
|
task_lock(current->group_leader);
|
|
value = current->signal->rlim[resource];
|
|
task_unlock(current->group_leader);
|
|
return copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
|
|
}
|
|
}
|
|
|
|
#ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
|
|
|
|
/*
|
|
* Back compatibility for getrlimit. Needed for some apps.
|
|
*/
|
|
|
|
asmlinkage long sys_old_getrlimit(unsigned int resource, struct rlimit __user *rlim)
|
|
{
|
|
struct rlimit x;
|
|
if (resource >= RLIM_NLIMITS)
|
|
return -EINVAL;
|
|
|
|
task_lock(current->group_leader);
|
|
x = current->signal->rlim[resource];
|
|
task_unlock(current->group_leader);
|
|
if (x.rlim_cur > 0x7FFFFFFF)
|
|
x.rlim_cur = 0x7FFFFFFF;
|
|
if (x.rlim_max > 0x7FFFFFFF)
|
|
x.rlim_max = 0x7FFFFFFF;
|
|
return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
|
|
}
|
|
|
|
#endif
|
|
|
|
asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim)
|
|
{
|
|
struct rlimit new_rlim, *old_rlim;
|
|
unsigned long it_prof_secs;
|
|
int retval;
|
|
|
|
if (resource >= RLIM_NLIMITS)
|
|
return -EINVAL;
|
|
if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
|
|
return -EFAULT;
|
|
if (new_rlim.rlim_cur > new_rlim.rlim_max)
|
|
return -EINVAL;
|
|
old_rlim = current->signal->rlim + resource;
|
|
if ((new_rlim.rlim_max > old_rlim->rlim_max) &&
|
|
!capable(CAP_SYS_RESOURCE))
|
|
return -EPERM;
|
|
if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > NR_OPEN)
|
|
return -EPERM;
|
|
|
|
retval = security_task_setrlimit(resource, &new_rlim);
|
|
if (retval)
|
|
return retval;
|
|
|
|
if (resource == RLIMIT_CPU && new_rlim.rlim_cur == 0) {
|
|
/*
|
|
* The caller is asking for an immediate RLIMIT_CPU
|
|
* expiry. But we use the zero value to mean "it was
|
|
* never set". So let's cheat and make it one second
|
|
* instead
|
|
*/
|
|
new_rlim.rlim_cur = 1;
|
|
}
|
|
|
|
task_lock(current->group_leader);
|
|
*old_rlim = new_rlim;
|
|
task_unlock(current->group_leader);
|
|
|
|
if (resource != RLIMIT_CPU)
|
|
goto out;
|
|
|
|
/*
|
|
* RLIMIT_CPU handling. Note that the kernel fails to return an error
|
|
* code if it rejected the user's attempt to set RLIMIT_CPU. This is a
|
|
* very long-standing error, and fixing it now risks breakage of
|
|
* applications, so we live with it
|
|
*/
|
|
if (new_rlim.rlim_cur == RLIM_INFINITY)
|
|
goto out;
|
|
|
|
it_prof_secs = cputime_to_secs(current->signal->it_prof_expires);
|
|
if (it_prof_secs == 0 || new_rlim.rlim_cur <= it_prof_secs) {
|
|
unsigned long rlim_cur = new_rlim.rlim_cur;
|
|
cputime_t cputime;
|
|
|
|
cputime = secs_to_cputime(rlim_cur);
|
|
read_lock(&tasklist_lock);
|
|
spin_lock_irq(¤t->sighand->siglock);
|
|
set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL);
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
read_unlock(&tasklist_lock);
|
|
}
|
|
out:
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* It would make sense to put struct rusage in the task_struct,
|
|
* except that would make the task_struct be *really big*. After
|
|
* task_struct gets moved into malloc'ed memory, it would
|
|
* make sense to do this. It will make moving the rest of the information
|
|
* a lot simpler! (Which we're not doing right now because we're not
|
|
* measuring them yet).
|
|
*
|
|
* When sampling multiple threads for RUSAGE_SELF, under SMP we might have
|
|
* races with threads incrementing their own counters. But since word
|
|
* reads are atomic, we either get new values or old values and we don't
|
|
* care which for the sums. We always take the siglock to protect reading
|
|
* the c* fields from p->signal from races with exit.c updating those
|
|
* fields when reaping, so a sample either gets all the additions of a
|
|
* given child after it's reaped, or none so this sample is before reaping.
|
|
*
|
|
* Locking:
|
|
* We need to take the siglock for CHILDEREN, SELF and BOTH
|
|
* for the cases current multithreaded, non-current single threaded
|
|
* non-current multithreaded. Thread traversal is now safe with
|
|
* the siglock held.
|
|
* Strictly speaking, we donot need to take the siglock if we are current and
|
|
* single threaded, as no one else can take our signal_struct away, no one
|
|
* else can reap the children to update signal->c* counters, and no one else
|
|
* can race with the signal-> fields. If we do not take any lock, the
|
|
* signal-> fields could be read out of order while another thread was just
|
|
* exiting. So we should place a read memory barrier when we avoid the lock.
|
|
* On the writer side, write memory barrier is implied in __exit_signal
|
|
* as __exit_signal releases the siglock spinlock after updating the signal->
|
|
* fields. But we don't do this yet to keep things simple.
|
|
*
|
|
*/
|
|
|
|
static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
|
|
{
|
|
struct task_struct *t;
|
|
unsigned long flags;
|
|
cputime_t utime, stime;
|
|
|
|
memset((char *) r, 0, sizeof *r);
|
|
utime = stime = cputime_zero;
|
|
|
|
rcu_read_lock();
|
|
if (!lock_task_sighand(p, &flags)) {
|
|
rcu_read_unlock();
|
|
return;
|
|
}
|
|
|
|
switch (who) {
|
|
case RUSAGE_BOTH:
|
|
case RUSAGE_CHILDREN:
|
|
utime = p->signal->cutime;
|
|
stime = p->signal->cstime;
|
|
r->ru_nvcsw = p->signal->cnvcsw;
|
|
r->ru_nivcsw = p->signal->cnivcsw;
|
|
r->ru_minflt = p->signal->cmin_flt;
|
|
r->ru_majflt = p->signal->cmaj_flt;
|
|
|
|
if (who == RUSAGE_CHILDREN)
|
|
break;
|
|
|
|
case RUSAGE_SELF:
|
|
utime = cputime_add(utime, p->signal->utime);
|
|
stime = cputime_add(stime, p->signal->stime);
|
|
r->ru_nvcsw += p->signal->nvcsw;
|
|
r->ru_nivcsw += p->signal->nivcsw;
|
|
r->ru_minflt += p->signal->min_flt;
|
|
r->ru_majflt += p->signal->maj_flt;
|
|
t = p;
|
|
do {
|
|
utime = cputime_add(utime, t->utime);
|
|
stime = cputime_add(stime, t->stime);
|
|
r->ru_nvcsw += t->nvcsw;
|
|
r->ru_nivcsw += t->nivcsw;
|
|
r->ru_minflt += t->min_flt;
|
|
r->ru_majflt += t->maj_flt;
|
|
t = next_thread(t);
|
|
} while (t != p);
|
|
break;
|
|
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
unlock_task_sighand(p, &flags);
|
|
rcu_read_unlock();
|
|
|
|
cputime_to_timeval(utime, &r->ru_utime);
|
|
cputime_to_timeval(stime, &r->ru_stime);
|
|
}
|
|
|
|
int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
|
|
{
|
|
struct rusage r;
|
|
k_getrusage(p, who, &r);
|
|
return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
|
|
}
|
|
|
|
asmlinkage long sys_getrusage(int who, struct rusage __user *ru)
|
|
{
|
|
if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
|
|
return -EINVAL;
|
|
return getrusage(current, who, ru);
|
|
}
|
|
|
|
asmlinkage long sys_umask(int mask)
|
|
{
|
|
mask = xchg(¤t->fs->umask, mask & S_IRWXUGO);
|
|
return mask;
|
|
}
|
|
|
|
asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
|
|
unsigned long arg4, unsigned long arg5)
|
|
{
|
|
long error;
|
|
|
|
error = security_task_prctl(option, arg2, arg3, arg4, arg5);
|
|
if (error)
|
|
return error;
|
|
|
|
switch (option) {
|
|
case PR_SET_PDEATHSIG:
|
|
if (!valid_signal(arg2)) {
|
|
error = -EINVAL;
|
|
break;
|
|
}
|
|
current->pdeath_signal = arg2;
|
|
break;
|
|
case PR_GET_PDEATHSIG:
|
|
error = put_user(current->pdeath_signal, (int __user *)arg2);
|
|
break;
|
|
case PR_GET_DUMPABLE:
|
|
error = current->mm->dumpable;
|
|
break;
|
|
case PR_SET_DUMPABLE:
|
|
if (arg2 < 0 || arg2 > 1) {
|
|
error = -EINVAL;
|
|
break;
|
|
}
|
|
current->mm->dumpable = arg2;
|
|
break;
|
|
|
|
case PR_SET_UNALIGN:
|
|
error = SET_UNALIGN_CTL(current, arg2);
|
|
break;
|
|
case PR_GET_UNALIGN:
|
|
error = GET_UNALIGN_CTL(current, arg2);
|
|
break;
|
|
case PR_SET_FPEMU:
|
|
error = SET_FPEMU_CTL(current, arg2);
|
|
break;
|
|
case PR_GET_FPEMU:
|
|
error = GET_FPEMU_CTL(current, arg2);
|
|
break;
|
|
case PR_SET_FPEXC:
|
|
error = SET_FPEXC_CTL(current, arg2);
|
|
break;
|
|
case PR_GET_FPEXC:
|
|
error = GET_FPEXC_CTL(current, arg2);
|
|
break;
|
|
case PR_GET_TIMING:
|
|
error = PR_TIMING_STATISTICAL;
|
|
break;
|
|
case PR_SET_TIMING:
|
|
if (arg2 == PR_TIMING_STATISTICAL)
|
|
error = 0;
|
|
else
|
|
error = -EINVAL;
|
|
break;
|
|
|
|
case PR_GET_KEEPCAPS:
|
|
if (current->keep_capabilities)
|
|
error = 1;
|
|
break;
|
|
case PR_SET_KEEPCAPS:
|
|
if (arg2 != 0 && arg2 != 1) {
|
|
error = -EINVAL;
|
|
break;
|
|
}
|
|
current->keep_capabilities = arg2;
|
|
break;
|
|
case PR_SET_NAME: {
|
|
struct task_struct *me = current;
|
|
unsigned char ncomm[sizeof(me->comm)];
|
|
|
|
ncomm[sizeof(me->comm)-1] = 0;
|
|
if (strncpy_from_user(ncomm, (char __user *)arg2,
|
|
sizeof(me->comm)-1) < 0)
|
|
return -EFAULT;
|
|
set_task_comm(me, ncomm);
|
|
return 0;
|
|
}
|
|
case PR_GET_NAME: {
|
|
struct task_struct *me = current;
|
|
unsigned char tcomm[sizeof(me->comm)];
|
|
|
|
get_task_comm(tcomm, me);
|
|
if (copy_to_user((char __user *)arg2, tcomm, sizeof(tcomm)))
|
|
return -EFAULT;
|
|
return 0;
|
|
}
|
|
case PR_GET_ENDIAN:
|
|
error = GET_ENDIAN(current, arg2);
|
|
break;
|
|
case PR_SET_ENDIAN:
|
|
error = SET_ENDIAN(current, arg2);
|
|
break;
|
|
|
|
default:
|
|
error = -EINVAL;
|
|
break;
|
|
}
|
|
return error;
|
|
}
|
|
|
|
asmlinkage long sys_getcpu(unsigned __user *cpup, unsigned __user *nodep,
|
|
struct getcpu_cache __user *cache)
|
|
{
|
|
int err = 0;
|
|
int cpu = raw_smp_processor_id();
|
|
if (cpup)
|
|
err |= put_user(cpu, cpup);
|
|
if (nodep)
|
|
err |= put_user(cpu_to_node(cpu), nodep);
|
|
if (cache) {
|
|
/*
|
|
* The cache is not needed for this implementation,
|
|
* but make sure user programs pass something
|
|
* valid. vsyscall implementations can instead make
|
|
* good use of the cache. Only use t0 and t1 because
|
|
* these are available in both 32bit and 64bit ABI (no
|
|
* need for a compat_getcpu). 32bit has enough
|
|
* padding
|
|
*/
|
|
unsigned long t0, t1;
|
|
get_user(t0, &cache->blob[0]);
|
|
get_user(t1, &cache->blob[1]);
|
|
t0++;
|
|
t1++;
|
|
put_user(t0, &cache->blob[0]);
|
|
put_user(t1, &cache->blob[1]);
|
|
}
|
|
return err ? -EFAULT : 0;
|
|
}
|