#include <libkern/OSAtomic.h>
#include <sys/sdt.h>
+#include <sys/codesign.h>
/*
* Missing prototypes that Mach should export
extern thread_t port_name_to_thread(mach_port_name_t port_name);
extern kern_return_t get_signalact(task_t , thread_t *, int);
extern unsigned int get_useraddr(void);
-extern kern_return_t task_suspend_internal(task_t);
-extern kern_return_t task_resume_internal(task_t);
/*
* ---
static void stop(proc_t, proc_t);
int cansignal(proc_t, kauth_cred_t, proc_t, int, int);
int killpg1(proc_t, int, int, int, int);
-int setsigvec(proc_t, thread_t, int, struct __kern_sigaction *, boolean_t in_sigstart);
static void psignal_uthread(thread_t, int);
+static void psignal_try_thread(proc_t, thread_t, int signum);
kern_return_t do_bsdexception(int, int, int);
void __posix_sem_syscall_return(kern_return_t);
+char *proc_name_address(void *p);
/* implementations in osfmk/kern/sync_sema.c. We do not want port.h in this scope, so void * them */
kern_return_t semaphore_timedwait_signal_trap_internal(mach_port_name_t, mach_port_name_t, unsigned int, clock_res_t, void (*)(kern_return_t));
static int filt_sigattach(struct knote *kn);
static void filt_sigdetach(struct knote *kn);
static int filt_signal(struct knote *kn, long hint);
-static void filt_signaltouch(struct knote *kn, struct kevent64_s *kev,
+static void filt_signaltouch(struct knote *kn, struct kevent_internal_s *kev,
long type);
struct filterops sig_filtops = {
#define PSIG_LOCKED 0x1
#define PSIG_VFORK 0x2
#define PSIG_THREAD 0x4
+#define PSIG_TRY_THREAD 0x8
static void psignal_internal(proc_t p, task_t task, thread_t thread, int flavor, int signum);
if (p == q)
return(1);
+ /* you can't send launchd SIGKILL, even if root */
+ if (signum == SIGKILL && q == initproc)
+ return(0);
+
if (!suser(uc, NULL))
return (1); /* root can always signal */
return (0);
}
+/*
+ * <rdar://problem/21952708> Some signals can be restricted from being handled,
+ * forcing the default action for that signal. This behavior applies only to
+ * non-root (EUID != 0) processes, and is configured with the "sigrestrict=x"
+ * bootarg:
+ *
+ * 0 (default): Disallow use of restricted signals. Trying to register a handler
+ * returns ENOTSUP, which userspace may use to take special action (e.g. abort).
+ * 1: As above, but return EINVAL. Restricted signals behave similarly to SIGKILL.
+ * 2: Usual POSIX semantics.
+ */
+unsigned sigrestrict_arg = 0;
+
+#if PLATFORM_WatchOS || PLATFORM_AppleTVOS
+static int
+sigrestrictmask(void)
+{
+ if (kauth_getuid() != 0 && sigrestrict_arg != 2) {
+ return SIGRESTRICTMASK;
+ }
+ return 0;
+}
+
+static int
+signal_is_restricted(proc_t p, int signum)
+{
+ if (sigmask(signum) & sigrestrictmask()) {
+ if (sigrestrict_arg == 0 &&
+ task_get_apptype(p->task) == TASK_APPTYPE_APP_DEFAULT) {
+ return ENOTSUP;
+ } else {
+ return EINVAL;
+ }
+ }
+ return 0;
+}
+
+#else
+
+static inline int
+signal_is_restricted(proc_t p, int signum)
+{
+ (void)p;
+ (void)signum;
+ return 0;
+}
+#endif /* !(PLATFORM_WatchOS || PLATFORM_AppleTVOS) */
/*
* Returns: 0 Success
signum = uap->signum;
if (signum <= 0 || signum >= NSIG ||
- signum == SIGKILL || signum == SIGSTOP)
+ signum == SIGKILL || signum == SIGSTOP)
return (EINVAL);
+ if ((error = signal_is_restricted(p, signum))) {
+ if (error == ENOTSUP) {
+ printf("%s(%d): denied attempt to register action for signal %d\n",
+ proc_name_address(p), proc_pid(p), signum);
+ }
+ return error;
+ }
+
if (uap->osa) {
sa->sa_handler = ps->ps_sigact[signum];
sa->sa_mask = ps->ps_catchmask[signum];
thread_t sig_thread;
struct task * sig_task = p->task;
kern_return_t kret;
-
+
*thr = THREAD_NULL;
if ((p->p_lflag & P_LINVFORK) && p->p_vforkact) {
return(KERN_SUCCESS);
}else
return(KERN_FAILURE);
- }
+ }
proc_lock(p);
+
TAILQ_FOREACH(uth, &p->p_uthlist, uu_list) {
if(((uth->uu_flag & UT_NO_SIGMASK)== 0) &&
(((uth->uu_sigmask & mask) == 0) || (uth->uu_sigwait & mask))) {
}
#endif /* SIGNAL_DEBUG */
+ /* catch unexpected initproc kills early for easier debuggging */
+ if (signum == SIGKILL && p == initproc)
+ panic_plain("unexpected SIGKILL of %s %s",
+ (p->p_name[0] != '\0' ? p->p_name : "initproc"),
+ ((p->p_csflags & CS_KILLED) ? "(CS_KILLED)" : ""));
+
/*
* We will need the task pointer later. Grab it now to
* check for a zombie process. Also don't send signals
sig_task = get_threadtask(thread);
sig_thread = thread;
sig_proc = (proc_t)get_bsdtask_info(sig_task);
+ } else if (flavor & PSIG_TRY_THREAD) {
+ sig_task = p->task;
+ sig_thread = thread;
+ sig_proc = p;
} else {
sig_task = p->task;
sig_thread = (struct thread *)0;
* the corresponding task data structures around too. This
* reference is released by thread_deallocate.
*/
-
+
if (((flavor & PSIG_VFORK) == 0) && ((sig_proc->p_lflag & P_LTRACED) == 0) && (sig_proc->p_sigignore & mask)) {
DTRACE_PROC3(signal__discard, thread_t, sig_thread, proc_t, sig_proc, int, signum);
action = SIG_DFL;
act_set_astbsd(sig_thread);
kret = KERN_SUCCESS;
+ } else if (flavor & PSIG_TRY_THREAD) {
+ uth = get_bsdthread_info(sig_thread);
+ if (((uth->uu_flag & UT_NO_SIGMASK) == 0) &&
+ (((uth->uu_sigmask & mask) == 0) || (uth->uu_sigwait & mask)) &&
+ ((kret = check_actforsig(sig_proc->task, sig_thread, 1)) == KERN_SUCCESS)) {
+ /* deliver to specified thread */
+ } else {
+ /* deliver to any willing thread */
+ kret = get_signalthread(sig_proc, signum, &sig_thread);
+ }
} else if (flavor & PSIG_THREAD) {
/* If successful return with ast set */
kret = check_actforsig(sig_task, sig_thread, 1);
goto psigout;
}
-
uth = get_bsdthread_info(sig_thread);
/*
}
}
-
proc_lock(sig_proc);
if (sig_proc->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
psignal_internal(PROC_NULL, TASK_NULL, thread, PSIG_THREAD, signum);
}
+/* same as psignal(), but prefer delivery to 'thread' if possible */
+static void
+psignal_try_thread(proc_t p, thread_t thread, int signum)
+{
+ psignal_internal(p, NULL, thread, PSIG_TRY_THREAD, signum);
+}
/*
* If the current process has received a signal (should be caught or cause
switch ((long)p->p_sigacts->ps_sigact[signum]) {
case (long)SIG_DFL:
- /*
- * Don't take default actions on system processes.
- */
- if (p->p_ppid == 0) {
-#if DIAGNOSTIC
- /*
- * Are you sure you want to ignore SIGSEGV
- * in init? XXX
- */
- printf("Process (pid %d) got signal %d\n",
- p->p_pid, signum);
-#endif
- break; /* == ignore */
- }
-
/*
* If there is a pending stop signal to process
* with default action, stop here,
switch ((long)p->p_sigacts->ps_sigact[signum]) {
case (long)SIG_DFL:
- /*
- * Don't take default actions on system processes.
- */
- if (p->p_ppid == 0) {
-#if DIAGNOSTIC
- /*
- * Are you sure you want to ignore SIGSEGV
- * in init? XXX
- */
- printf("Process (pid %d) got signal %d\n",
- p->p_pid, signum);
-#endif
- break; /* == ignore */
- }
-
/*
* If there is a pending stop signal to process
* with default action, stop here,
}
static void
-filt_signaltouch(struct knote *kn, struct kevent64_s *kev, long type)
+filt_signaltouch(struct knote *kn, struct kevent_internal_s *kev, long type)
{
proc_klist_lock();
switch (type) {
}
break;
default:
- panic("filt_machporttouch() - invalid type (%ld)", type);
+ panic("filt_signaltouch() - invalid type (%ld)", type);
break;
}
proc_klist_unlock();
else
task_vtimer_clear(p->task, TASK_VTIMER_USER);
- psignal(p, SIGVTALRM);
+ psignal_try_thread(p, thread, SIGVTALRM);
}
}
else
task_vtimer_clear(p->task, TASK_VTIMER_PROF);
- psignal(p, SIGPROF);
+ psignal_try_thread(p, thread, SIGPROF);
}
}
task_vtimer_clear(p->task, TASK_VTIMER_RLIM);
- psignal(p, SIGXCPU);
+ psignal_try_thread(p, thread, SIGXCPU);
}
}
projects / apple / xnu.git / blobdiff