*/
#include <linux/slab.h>
-#include <linux/module.h>
+#include <linux/export.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/freezer.h>
#include <linux/pid_namespace.h>
#include <linux/nsproxy.h>
+#include <linux/user_namespace.h>
#define CREATE_TRACE_POINTS
#include <trace/events/signal.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
#include <asm/siginfo.h>
+#include <asm/cacheflush.h>
#include "audit.h" /* audit_signal_info() */
/*
(handler == SIG_DFL && sig_kernel_ignore(sig));
}
-static int sig_task_ignored(struct task_struct *t, int sig,
- int from_ancestor_ns)
+static int sig_task_ignored(struct task_struct *t, int sig, bool force)
{
void __user *handler;
handler = sig_handler(t, sig);
if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) &&
- handler == SIG_DFL && !from_ancestor_ns)
+ handler == SIG_DFL && !force)
return 1;
return sig_handler_ignored(handler, sig);
}
-static int sig_ignored(struct task_struct *t, int sig, int from_ancestor_ns)
+static int sig_ignored(struct task_struct *t, int sig, bool force)
{
/*
* Blocked signals are never ignored, since the
if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig))
return 0;
- if (!sig_task_ignored(t, sig, from_ancestor_ns))
+ if (!sig_task_ignored(t, sig, force))
return 0;
/*
* Returns true if the signal should be actually delivered, otherwise
* it should be dropped.
*/
-static int prepare_signal(int sig, struct task_struct *p, int from_ancestor_ns)
+static int prepare_signal(int sig, struct task_struct *p, bool force)
{
struct signal_struct *signal = p->signal;
struct task_struct *t;
}
}
- return !sig_ignored(p, sig, from_ancestor_ns);
+ return !sig_ignored(p, sig, force);
}
/*
return (sig < SIGRTMIN) && sigismember(&signals->signal, sig);
}
+/*
+ * map the uid in struct cred into user namespace *ns
+ */
+static inline uid_t map_cred_ns(const struct cred *cred,
+ struct user_namespace *ns)
+{
+ return user_ns_map_uid(ns, cred, cred->uid);
+}
+
+#ifdef CONFIG_USER_NS
+static inline void userns_fixup_signal_uid(struct siginfo *info, struct task_struct *t)
+{
+ if (current_user_ns() == task_cred_xxx(t, user_ns))
+ return;
+
+ if (SI_FROMKERNEL(info))
+ return;
+
+ info->si_uid = user_ns_map_uid(task_cred_xxx(t, user_ns),
+ current_cred(), info->si_uid);
+}
+#else
+static inline void userns_fixup_signal_uid(struct siginfo *info, struct task_struct *t)
+{
+ return;
+}
+#endif
+
static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
int group, int from_ancestor_ns)
{
struct sigpending *pending;
struct sigqueue *q;
int override_rlimit;
-
- trace_signal_generate(sig, info, t);
+ int ret = 0, result;
assert_spin_locked(&t->sighand->siglock);
- if (!prepare_signal(sig, t, from_ancestor_ns))
- return 0;
+ result = TRACE_SIGNAL_IGNORED;
+ if (!prepare_signal(sig, t,
+ from_ancestor_ns || (info == SEND_SIG_FORCED)))
+ goto ret;
pending = group ? &t->signal->shared_pending : &t->pending;
/*
* exactly one non-rt signal, so that we can get more
* detailed information about the cause of the signal.
*/
+ result = TRACE_SIGNAL_ALREADY_PENDING;
if (legacy_queue(pending, sig))
- return 0;
+ goto ret;
+
+ result = TRACE_SIGNAL_DELIVERED;
/*
* fast-pathed signals for kernel-internal things like SIGSTOP
* or SIGKILL.
q->info.si_pid = 0;
break;
}
+
+ userns_fixup_signal_uid(&q->info, t);
+
} else if (!is_si_special(info)) {
if (sig >= SIGRTMIN && info->si_code != SI_USER) {
/*
* signal was rt and sent by user using something
* other than kill().
*/
- trace_signal_overflow_fail(sig, group, info);
- return -EAGAIN;
+ result = TRACE_SIGNAL_OVERFLOW_FAIL;
+ ret = -EAGAIN;
+ goto ret;
} else {
/*
* This is a silent loss of information. We still
* send the signal, but the *info bits are lost.
*/
- trace_signal_lose_info(sig, group, info);
+ result = TRACE_SIGNAL_LOSE_INFO;
}
}
signalfd_notify(t, sig);
sigaddset(&pending->signal, sig);
complete_signal(sig, t, group);
- return 0;
+ret:
+ trace_signal_generate(sig, info, t, group, result);
+ return ret;
}
static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
return error;
}
+static int kill_as_cred_perm(const struct cred *cred,
+ struct task_struct *target)
+{
+ const struct cred *pcred = __task_cred(target);
+ if (cred->user_ns != pcred->user_ns)
+ return 0;
+ if (cred->euid != pcred->suid && cred->euid != pcred->uid &&
+ cred->uid != pcred->suid && cred->uid != pcred->uid)
+ return 0;
+ return 1;
+}
+
/* like kill_pid_info(), but doesn't use uid/euid of "current" */
-int kill_pid_info_as_uid(int sig, struct siginfo *info, struct pid *pid,
- uid_t uid, uid_t euid, u32 secid)
+int kill_pid_info_as_cred(int sig, struct siginfo *info, struct pid *pid,
+ const struct cred *cred, u32 secid)
{
int ret = -EINVAL;
struct task_struct *p;
- const struct cred *pcred;
unsigned long flags;
if (!valid_signal(sig))
ret = -ESRCH;
goto out_unlock;
}
- pcred = __task_cred(p);
- if (si_fromuser(info) &&
- euid != pcred->suid && euid != pcred->uid &&
- uid != pcred->suid && uid != pcred->uid) {
+ if (si_fromuser(info) && !kill_as_cred_perm(cred, p)) {
ret = -EPERM;
goto out_unlock;
}
rcu_read_unlock();
return ret;
}
-EXPORT_SYMBOL_GPL(kill_pid_info_as_uid);
+EXPORT_SYMBOL_GPL(kill_pid_info_as_cred);
/*
* kill_something_info() interprets pid in interesting ways just like kill(2).
int sig = q->info.si_signo;
struct sigpending *pending;
unsigned long flags;
- int ret;
+ int ret, result;
BUG_ON(!(q->flags & SIGQUEUE_PREALLOC));
goto ret;
ret = 1; /* the signal is ignored */
- if (!prepare_signal(sig, t, 0))
+ result = TRACE_SIGNAL_IGNORED;
+ if (!prepare_signal(sig, t, false))
goto out;
ret = 0;
*/
BUG_ON(q->info.si_code != SI_TIMER);
q->info.si_overrun++;
+ result = TRACE_SIGNAL_ALREADY_PENDING;
goto out;
}
q->info.si_overrun = 0;
list_add_tail(&q->list, &pending->list);
sigaddset(&pending->signal, sig);
complete_signal(sig, t, group);
+ result = TRACE_SIGNAL_DELIVERED;
out:
+ trace_signal_generate(sig, &q->info, t, group, result);
unlock_task_sighand(t, &flags);
ret:
return ret;
BUG_ON(!tsk->ptrace &&
(tsk->group_leader != tsk || !thread_group_empty(tsk)));
+ if (sig != SIGCHLD) {
+ /*
+ * This is only possible if parent == real_parent.
+ * Check if it has changed security domain.
+ */
+ if (tsk->parent_exec_id != tsk->parent->self_exec_id)
+ sig = SIGCHLD;
+ }
+
info.si_signo = sig;
info.si_errno = 0;
/*
*/
rcu_read_lock();
info.si_pid = task_pid_nr_ns(tsk, tsk->parent->nsproxy->pid_ns);
- info.si_uid = __task_cred(tsk)->uid;
+ info.si_uid = map_cred_ns(__task_cred(tsk),
+ task_cred_xxx(tsk->parent, user_ns));
rcu_read_unlock();
- info.si_utime = cputime_to_clock_t(cputime_add(tsk->utime,
- tsk->signal->utime));
- info.si_stime = cputime_to_clock_t(cputime_add(tsk->stime,
- tsk->signal->stime));
+ info.si_utime = cputime_to_clock_t(tsk->utime + tsk->signal->utime);
+ info.si_stime = cputime_to_clock_t(tsk->stime + tsk->signal->stime);
info.si_status = tsk->exit_code & 0x7f;
if (tsk->exit_code & 0x80)
*/
rcu_read_lock();
info.si_pid = task_pid_nr_ns(tsk, parent->nsproxy->pid_ns);
- info.si_uid = __task_cred(tsk)->uid;
+ info.si_uid = map_cred_ns(__task_cred(tsk),
+ task_cred_xxx(parent, user_ns));
rcu_read_unlock();
info.si_utime = cputime_to_clock_t(tsk->utime);
*/
if (!(sig->flags & SIGNAL_STOP_STOPPED))
sig->group_exit_code = signr;
- else
- WARN_ON_ONCE(!current->ptrace);
sig->group_stop_count = 0;
info->si_signo = signr;
info->si_errno = 0;
info->si_code = SI_USER;
+ rcu_read_lock();
info->si_pid = task_pid_vnr(current->parent);
- info->si_uid = task_uid(current->parent);
+ info->si_uid = map_cred_ns(__task_cred(current->parent),
+ current_user_ns());
+ rcu_read_unlock();
}
/* If the (new) signal is now blocked, requeue it. */
return signr;
}
+/**
+ * block_sigmask - add @ka's signal mask to current->blocked
+ * @ka: action for @signr
+ * @signr: signal that has been successfully delivered
+ *
+ * This function should be called when a signal has succesfully been
+ * delivered. It adds the mask of signals for @ka to current->blocked
+ * so that they are blocked during the execution of the signal
+ * handler. In addition, @signr will be blocked unless %SA_NODEFER is
+ * set in @ka->sa.sa_flags.
+ */
+void block_sigmask(struct k_sigaction *ka, int signr)
+{
+ sigset_t blocked;
+
+ sigorsets(&blocked, ¤t->blocked, &ka->sa.sa_mask);
+ if (!(ka->sa.sa_flags & SA_NODEFER))
+ sigaddset(&blocked, signr);
+ set_current_blocked(&blocked);
+}
+
/*
* It could be that complete_signal() picked us to notify about the
* group-wide signal. Other threads should be notified now to take
int group_stop = 0;
sigset_t unblocked;
+ /*
+ * @tsk is about to have PF_EXITING set - lock out users which
+ * expect stable threadgroup.
+ */
+ threadgroup_change_begin(tsk);
+
if (thread_group_empty(tsk) || signal_group_exit(tsk->signal)) {
tsk->flags |= PF_EXITING;
+ threadgroup_change_end(tsk);
return;
}
* see wants_signal(), do_signal_stop().
*/
tsk->flags |= PF_EXITING;
+
+ threadgroup_change_end(tsk);
+
if (!signal_pending(tsk))
goto out;
SYSCALL_DEFINE1(ssetmask, int, newmask)
{
- int old;
-
- spin_lock_irq(¤t->sighand->siglock);
- old = current->blocked.sig[0];
+ int old = current->blocked.sig[0];
+ sigset_t newset;
- siginitset(¤t->blocked, newmask & ~(sigmask(SIGKILL)|
- sigmask(SIGSTOP)));
- recalc_sigpending();
- spin_unlock_irq(¤t->sighand->siglock);
+ siginitset(&newset, newmask & ~(sigmask(SIGKILL) | sigmask(SIGSTOP)));
+ set_current_blocked(&newset);
return old;
}
return -EFAULT;
sigdelsetmask(&newset, sigmask(SIGKILL)|sigmask(SIGSTOP));
- spin_lock_irq(¤t->sighand->siglock);
current->saved_sigmask = current->blocked;
- current->blocked = newset;
- recalc_sigpending();
- spin_unlock_irq(¤t->sighand->siglock);
+ set_current_blocked(&newset);
current->state = TASK_INTERRUPTIBLE;
schedule();
projects / linux-flexiantxendom0-3.2.10.git / blobdiff