[msan] Extract signal_impl and sigaction_impl

[vitalybuka]

Summary

Preparation for using interceptor from sanitizer_common.

[vitalybuka]

less moving

[vitalybuka]

undo some changes

[vitalybuka]

Undo more changes

[eugenis]

compiler-rt/lib/msan/msan_interceptors.cc

1009

why forward declarations? Just move the interceptors below the _impl definitions.

[eugenis]

Ah ok I see your other change.

[vitalybuka]

update

compiler-rt/lib/msan/msan_interceptors.cc

static void read_sigaction(const __sanitizer_sigaction *act) {
   CHECK_UNPOISONED(&act->sa_flags, sizeof(act->sa_flags));
   if (act->sa_flags & __sanitizer::sa_siginfo)
     CHECK_UNPOISONED(&act->sigaction, sizeof(act->sigaction));
   else
     CHECK_UNPOISONED(&act->handler, sizeof(act->handler));
   CHECK_UNPOISONED(&act->sa_mask, sizeof(act->sa_mask));
 }
 
+static int sigaction_impl(int signo, const __sanitizer_sigaction *act,
+                          __sanitizer_sigaction *oldact);
+static uptr signal_impl(int signo, uptr cb);
+
 INTERCEPTOR(int, sigaction, int signo, const __sanitizer_sigaction *act,
             __sanitizer_sigaction *oldact) {
+  return sigaction_impl(signo, act, oldact);
+}
+
+INTERCEPTOR(int, signal, int signo, uptr cb) {
+  cb = signal_impl(signo, cb);
+  return REAL(signal)(signo, cb);
+}
+
+static int sigaction_impl(int signo, const __sanitizer_sigaction *act,
+                          __sanitizer_sigaction *oldact) {
   ENSURE_MSAN_INITED();
   if (act) read_sigaction(act);
   int res;
   if (flags()->wrap_signals) {
     SpinMutexLock lock(&sigactions_mu);
     CHECK_LT(signo, kMaxSignals);
     uptr old_cb = atomic_load(&sigactions[signo], memory_order_relaxed);
     __sanitizer_sigaction new_act;
static int sigaction_impl(int signo, const __sanitizer_sigaction *act,
   }
 
   if (res == 0 && oldact) {
     __msan_unpoison(oldact, sizeof(__sanitizer_sigaction));
   }
   return res;
 }
 
-INTERCEPTOR(int, signal, int signo, uptr cb) {
+static uptr signal_impl(int signo, uptr cb) {
   ENSURE_MSAN_INITED();
   if (flags()->wrap_signals) {
     CHECK_LT(signo, kMaxSignals);
     SpinMutexLock lock(&sigactions_mu);
     if (cb != __sanitizer::sig_ign && cb != __sanitizer::sig_dfl) {
       atomic_store(&sigactions[signo], cb, memory_order_relaxed);
-      cb = (uptr) SignalHandler;
+      cb = (uptr)&SignalHandler;
     }
-    return REAL(signal)(signo, cb);
-  } else {
-    return REAL(signal)(signo, cb);
   }
+  return cb;
 }
 
 extern "C" int pthread_attr_init(void *attr);
 extern "C" int pthread_attr_destroy(void *attr);
 
 static void *MsanThreadStartFunc(void *arg) {
   MsanThread *t = (MsanThread *)arg;
   SetCurrentThread(t);