int cap_capget (struct task_struct *target, kernel_cap_t *effective,
kernel_cap_t *inheritable, kernel_cap_t *permitted)
{
/* Derived from kernel/capability.c:sys_capget. */
*effective = cap_t (target->cap_effective);
*inheritable = cap_t (target->cap_inheritable);
*permitted = cap_t (target->cap_permitted);
return 0;
}
static int badness(struct task_struct *p)
{
int points, cpu_time, run_time;
if (!p->mm)
return 0;
if (p->flags & PF_MEMDIE)
return 0;
/*
* The memory size of the process is the basis for the badness.
*/
points = p->mm->total_vm;
/*
* CPU time is in seconds and run time is in minutes. There is no
* particular reason for this other than that it turned out to work
* very well in practice. This is not safe against jiffie wraps
* but we don't care _that_ much...
*/
cpu_time = (p->times.tms_utime + p->times.tms_stime) >> (SHIFT_HZ + 3);
run_time = (jiffies - p->start_time) >> (SHIFT_HZ + 10);
points /= int_sqrt(cpu_time);
points /= int_sqrt(int_sqrt(run_time));
/*
* Niced processes are most likely less important, so double
* their badness points.
*/
if (p->nice > 0)
points *= 2;
/*
* Superuser processes are usually more important, so we make it
* less likely that we kill those.
*/
if (cap_t(p->cap_effective) & CAP_TO_MASK(CAP_SYS_ADMIN) ||
p->uid == 0 || p->euid == 0)
points /= 4;
/*
* We don't want to kill a process with direct hardware access.
* Not only could that mess up the hardware, but usually users
* tend to only have this flag set on applications they think
* of as important.
*/
if (cap_t(p->cap_effective) & CAP_TO_MASK(CAP_SYS_RAWIO))
points /= 4;
#ifdef DEBUG
printk(KERN_DEBUG "OOMkill: task %d (%s) got %d points\n",
p->pid, p->comm, points);
#endif
return points;
}
asmlinkage long sys_capget(cap_user_header_t header, cap_user_data_t dataptr)
{
int error, pid;
__u32 version;
struct task_struct *target;
struct __user_cap_data_struct data;
if (get_user(version, &header->version))
return -EFAULT;
error = -EINVAL;
if (version != _LINUX_CAPABILITY_VERSION) {
version = _LINUX_CAPABILITY_VERSION;
if (put_user(version, &header->version))
error = -EFAULT;
return error;
}
if (get_user(pid, &header->pid))
return -EFAULT;
if (pid < 0)
return -EINVAL;
error = 0;
spin_lock(&task_capability_lock);
if (pid && pid != current->pid) {
read_lock(&tasklist_lock);
target = find_task_by_pid(pid); /* identify target of query */
if (!target)
error = -ESRCH;
} else {
target = current;
}
if (!error) {
data.permitted = cap_t(target->cap_permitted);
data.inheritable = cap_t(target->cap_inheritable);
data.effective = cap_t(target->cap_effective);
}
if (target != current)
read_unlock(&tasklist_lock);
spin_unlock(&task_capability_lock);
if (!error) {
if (copy_to_user(dataptr, &data, sizeof data))
return -EFAULT;
}
return error;
}
void
nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp)
{
struct svc_cred *cred = &rqstp->rq_cred;
int i;
if (rqstp->rq_userset)
return;
if (exp->ex_flags & NFSEXP_ALLSQUASH) {
cred->cr_uid = exp->ex_anon_uid;
cred->cr_gid = exp->ex_anon_gid;
cred->cr_groups[0] = NOGROUP;
} else if (exp->ex_flags & NFSEXP_ROOTSQUASH) {
if (!cred->cr_uid)
cred->cr_uid = exp->ex_anon_uid;
if (!cred->cr_gid)
cred->cr_gid = exp->ex_anon_gid;
for (i = 0; i < NGROUPS; i++)
if (!cred->cr_groups[i])
cred->cr_groups[i] = exp->ex_anon_gid;
}
if (cred->cr_uid != (uid_t) -1)
current->fsuid = cred->cr_uid;
else
current->fsuid = exp->ex_anon_uid;
if (cred->cr_gid != (gid_t) -1)
current->fsgid = cred->cr_gid;
else
current->fsgid = exp->ex_anon_gid;
for (i = 0; i < NGROUPS; i++) {
gid_t group = cred->cr_groups[i];
if (group == (gid_t) NOGROUP)
break;
current->groups[i] = group;
}
current->ngroups = i;
if ((cred->cr_uid)) {
cap_t(current->cap_effective) &= ~CAP_FS_MASK;
} else {
cap_t(current->cap_effective) |= (CAP_FS_MASK &
current->cap_permitted);
}
rqstp->rq_userset = 1;
}
int cap_task_post_setuid (uid_t old_ruid, uid_t old_euid, uid_t old_suid,
int flags)
{
switch (flags) {
case LSM_SETID_RE:
case LSM_SETID_ID:
case LSM_SETID_RES:
/* Copied from kernel/sys.c:setreuid/setuid/setresuid. */
if (!issecure (SECURE_NO_SETUID_FIXUP)) {
cap_emulate_setxuid (old_ruid, old_euid, old_suid);
}
break;
case LSM_SETID_FS:
{
uid_t old_fsuid = old_ruid;
/* Copied from kernel/sys.c:setfsuid. */
/*
* FIXME - is fsuser used for all CAP_FS_MASK capabilities?
* if not, we might be a bit too harsh here.
*/
if (!issecure (SECURE_NO_SETUID_FIXUP)) {
if (old_fsuid == 0 && current->fsuid != 0) {
cap_t (current->cap_effective) &=
~CAP_FS_MASK;
}
if (old_fsuid != 0 && current->fsuid == 0) {
cap_t (current->cap_effective) |=
(cap_t (current->cap_permitted) &
CAP_FS_MASK);
}
}
break;
}
default:
return -EINVAL;
}
return 0;
}
/**
* We must be careful though to never send SIGKILL a process with
* CAP_SYS_RAW_IO set, send SIGTERM instead (but it's unlikely that
* we select a process with CAP_SYS_RAW_IO set).
*/
void oom_kill_task(struct task_struct *p)
{
printk(KERN_ERR "Out of Memory: Killed process %d (%s).\n", p->pid, p->comm);
/*
* We give our sacrificial lamb high priority and access to
* all the memory it needs. That way it should be able to
* exit() and clear out its resources quickly...
*/
p->counter = 5 * HZ;
/* This process has hardware access, be more careful. */
if (cap_t(p->cap_effective) & CAP_TO_MASK(CAP_SYS_RAWIO)) {
force_sig(SIGTERM, p);
} else {
force_sig(SIGKILL, p);
}
}
