/* Given the mask, find the first available signal that should be serviced. */
+#define SYNCHRONOUS_MASK \
+ (sigmask(SIGSEGV) | sigmask(SIGBUS) | sigmask(SIGILL) | \
+ sigmask(SIGTRAP) | sigmask(SIGFPE))
+
int next_signal(struct sigpending *pending, sigset_t *mask)
{
unsigned long i, *s, *m, x;
s = pending->signal.sig;
m = mask->sig;
+
+ /*
+ * Handle the first word specially: it contains the
+ * synchronous signals that need to be dequeued first.
+ */
+ x = *s &~ *m;
+ if (x) {
+ if (x & SYNCHRONOUS_MASK)
+ x &= SYNCHRONOUS_MASK;
+ sig = ffz(~x) + 1;
+ return sig;
+ }
+
switch (_NSIG_WORDS) {
default:
- for (i = 0; i < _NSIG_WORDS; ++i, ++s, ++m)
- if ((x = *s &~ *m) != 0) {
- sig = ffz(~x) + i*_NSIG_BPW + 1;
- break;
- }
+ for (i = 1; i < _NSIG_WORDS; ++i) {
+ x = *++s &~ *++m;
+ if (!x)
+ continue;
+ sig = ffz(~x) + i*_NSIG_BPW + 1;
+ break;
+ }
break;
- case 2: if ((x = s[0] &~ m[0]) != 0)
- sig = 1;
- else if ((x = s[1] &~ m[1]) != 0)
- sig = _NSIG_BPW + 1;
- else
+ case 2:
+ x = s[1] &~ m[1];
+ if (!x)
break;
- sig += ffz(~x);
+ sig = ffz(~x) + _NSIG_BPW + 1;
break;
- case 1: if ((x = *s &~ *m) != 0)
- sig = ffz(~x) + 1;
+ case 1:
+ /* Nothing to do */
break;
}
struct user_struct *user;
/*
- * We won't get problems with the target's UID changing under us
- * because changing it requires RCU be used, and if t != current, the
- * caller must be holding the RCU readlock (by way of a spinlock) and
- * we use RCU protection here
+ * Protect access to @t credentials. This can go away when all
+ * callers hold rcu read lock.
*/
+ rcu_read_lock();
user = get_uid(__task_cred(t)->user);
atomic_inc(&user->sigpending);
+ rcu_read_unlock();
if (override_rlimit ||
atomic_read(&user->sigpending) <=
- t->signal->rlim[RLIMIT_SIGPENDING].rlim_cur) {
+ task_rlimit(t, RLIMIT_SIGPENDING)) {
q = kmem_cache_alloc(sigqueue_cachep, flags);
} else {
print_dropped_signal(sig);
*/
info->si_signo = sig;
info->si_errno = 0;
- info->si_code = 0;
+ info->si_code = SI_USER;
info->si_pid = 0;
info->si_uid = 0;
}
return 1;
}
+static inline int is_si_special(const struct siginfo *info)
+{
+ return info <= SEND_SIG_FORCED;
+}
+
+static inline bool si_fromuser(const struct siginfo *info)
+{
+ return info == SEND_SIG_NOINFO ||
+ (!is_si_special(info) && SI_FROMUSER(info));
+}
+
/*
* Bad permissions for sending the signal
* - the caller must hold at least the RCU read lock
if (!valid_signal(sig))
return -EINVAL;
- if (info != SEND_SIG_NOINFO && (is_si_special(info) || SI_FROMKERNEL(info)))
+ if (!si_fromuser(info))
return 0;
error = audit_signal_info(sig, t); /* Let audit system see the signal */
int from_ancestor_ns = 0;
#ifdef CONFIG_PID_NS
- if (!is_si_special(info) && SI_FROMUSER(info) &&
- task_pid_nr_ns(current, task_active_pid_ns(t)) <= 0)
- from_ancestor_ns = 1;
+ from_ancestor_ns = si_fromuser(info) &&
+ !task_pid_nr_ns(current, task_active_pid_ns(t));
#endif
return __send_signal(sig, info, t, group, from_ancestor_ns);
for (i = 0; i < 16; i++) {
unsigned char insn;
- __get_user(insn, (unsigned char *)(regs->ip + i));
+ if (get_user(insn, (unsigned char *)(regs->ip + i)))
+ break;
printk("%02x ", insn);
}
}
return ret;
}
-void
-force_sig_specific(int sig, struct task_struct *t)
-{
- force_sig_info(sig, SEND_SIG_FORCED, t);
-}
-
/*
* Nuke all other threads in the group.
*/
goto out_unlock;
}
pcred = __task_cred(p);
- if ((info == SEND_SIG_NOINFO ||
- (!is_si_special(info) && SI_FROMUSER(info))) &&
+ if (si_fromuser(info) &&
euid != pcred->suid && euid != pcred->uid &&
uid != pcred->suid && uid != pcred->uid) {
ret = -EPERM;
for (;;) {
struct k_sigaction *ka;
-
- if (unlikely(signal->group_stop_count > 0) &&
- do_signal_stop(0))
- goto relock;
-
/*
* Tracing can induce an artifical signal and choose sigaction.
* The return value in @signr determines the default action,
if (unlikely(signr != 0))
ka = return_ka;
else {
+ if (unlikely(signal->group_stop_count > 0) &&
+ do_signal_stop(0))
+ goto relock;
+
signr = dequeue_signal(current, ¤t->blocked,
info);