Fix sigaction(3) for 64-bit.

Also clean up <signal.h> and revert the hacks that were necessary
for 64-bit in linker/debugger.cpp until now.

Change-Id: I3b0554ca8a49ee1c97cda086ce2c1954ebc11892
diff --git a/libc/bionic/sigaction.cpp b/libc/bionic/sigaction.cpp
new file mode 100644
index 0000000..6468b2d
--- /dev/null
+++ b/libc/bionic/sigaction.cpp
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <signal.h>
+
+#if __LP64__
+extern "C" void __rt_sigreturn(void);
+extern "C" int __rt_sigaction(int, const struct __kernel_sigaction*, struct __kernel_sigaction*, size_t);
+#else
+extern "C" int __sigaction(int, const struct sigaction*, struct sigaction*);
+#endif
+
+int sigaction(int signal, const struct sigaction* bionic_new_action, struct sigaction* bionic_old_action) {
+#if __LP64__
+  __kernel_sigaction kernel_new_action;
+  if (bionic_new_action != NULL) {
+    kernel_new_action.sa_flags = bionic_new_action->sa_flags;
+    kernel_new_action.sa_handler = bionic_new_action->sa_handler;
+    kernel_new_action.sa_mask = bionic_new_action->sa_mask;
+    kernel_new_action.sa_restorer = bionic_new_action->sa_restorer;
+
+    if (!(kernel_new_action.sa_flags & SA_RESTORER)) {
+      kernel_new_action.sa_flags |= SA_RESTORER;
+      kernel_new_action.sa_restorer = &__rt_sigreturn;
+    }
+  }
+
+  __kernel_sigaction kernel_old_action;
+  int result = __rt_sigaction(signal,
+                              (bionic_new_action != NULL) ? &kernel_new_action : NULL,
+                              (bionic_old_action != NULL) ? &kernel_old_action : NULL,
+                              sizeof(sigset_t));
+
+  if (bionic_old_action != NULL) {
+    bionic_old_action->sa_flags = kernel_old_action.sa_flags;
+    bionic_old_action->sa_handler = kernel_old_action.sa_handler;
+    bionic_old_action->sa_mask = kernel_old_action.sa_mask;
+    bionic_old_action->sa_restorer = kernel_old_action.sa_restorer;
+
+    if (bionic_old_action->sa_restorer == &__rt_sigreturn) {
+      bionic_old_action->sa_flags &= ~SA_RESTORER;
+    }
+  }
+
+  return result;
+#else
+  // The 32-bit ABI is broken. struct sigaction includes a too-small sigset_t.
+  // TODO: if we also had correct struct sigaction definitions available, we could copy in and out.
+  return __sigaction(signal, bionic_new_action, bionic_old_action);
+#endif
+}
diff --git a/libc/bionic/signal.c b/libc/bionic/sigaddset.cpp
similarity index 70%
copy from libc/bionic/signal.c
copy to libc/bionic/sigaddset.cpp
index 949db13..33ec6f8 100644
--- a/libc/bionic/signal.c
+++ b/libc/bionic/sigaddset.cpp
@@ -25,33 +25,16 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
+
 #include <signal.h>
 
-
-static __sighandler_t
-_signal(int  signum, __sighandler_t  handler, int  flags)
-{
-    struct sigaction  sa;
-    __sighandler_t    result = SIG_ERR;
-
-    sigemptyset( &sa.sa_mask );
-
-    sa.sa_handler = handler;
-    sa.sa_flags   = flags;
-
-    if ( !sigaction( signum, &sa, &sa ) )
-        result = (__sighandler_t) sa.sa_handler;
-
-    return result;
-}
-
-
-__sighandler_t bsd_signal(int signum, __sighandler_t handler)
-{
-  return _signal(signum, handler, SA_RESTART);
-}
-
-__sighandler_t sysv_signal(int signum, __sighandler_t handler)
-{
-  return _signal(signum, handler, SA_RESETHAND);
+int sigaddset(sigset_t* set, int signum) {
+  int bit = signum - 1; // Signal numbers start at 1, but bit positions start at 0.
+  unsigned long* local_set = (unsigned long*) set;
+  if (set == NULL || bit < 0 || bit >= (int) (8*sizeof(sigset_t))) {
+    errno = EINVAL;
+    return -1;
+  }
+  local_set[bit / LONG_BIT] |= 1UL << (bit % LONG_BIT);
+  return 0;
 }
diff --git a/libc/bionic/signal.c b/libc/bionic/sigdelset.cpp
similarity index 70%
copy from libc/bionic/signal.c
copy to libc/bionic/sigdelset.cpp
index 949db13..9eea250 100644
--- a/libc/bionic/signal.c
+++ b/libc/bionic/sigdelset.cpp
@@ -25,33 +25,16 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
+
 #include <signal.h>
 
-
-static __sighandler_t
-_signal(int  signum, __sighandler_t  handler, int  flags)
-{
-    struct sigaction  sa;
-    __sighandler_t    result = SIG_ERR;
-
-    sigemptyset( &sa.sa_mask );
-
-    sa.sa_handler = handler;
-    sa.sa_flags   = flags;
-
-    if ( !sigaction( signum, &sa, &sa ) )
-        result = (__sighandler_t) sa.sa_handler;
-
-    return result;
-}
-
-
-__sighandler_t bsd_signal(int signum, __sighandler_t handler)
-{
-  return _signal(signum, handler, SA_RESTART);
-}
-
-__sighandler_t sysv_signal(int signum, __sighandler_t handler)
-{
-  return _signal(signum, handler, SA_RESETHAND);
+int sigdelset(sigset_t* set, int signum) {
+  int bit = signum - 1; // Signal numbers start at 1, but bit positions start at 0.
+  unsigned long* local_set = (unsigned long*) set;
+  if (set == NULL || bit < 0 || bit >= (int) (8*sizeof(sigset_t))) {
+    errno = EINVAL;
+    return -1;
+  }
+  local_set[bit / LONG_BIT] &= ~(1UL << (bit % LONG_BIT));
+  return 0;
 }
diff --git a/libc/bionic/signal.c b/libc/bionic/sigemptyset.cpp
similarity index 70%
copy from libc/bionic/signal.c
copy to libc/bionic/sigemptyset.cpp
index 949db13..2993169 100644
--- a/libc/bionic/signal.c
+++ b/libc/bionic/sigemptyset.cpp
@@ -25,33 +25,14 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
+
 #include <signal.h>
 
-
-static __sighandler_t
-_signal(int  signum, __sighandler_t  handler, int  flags)
-{
-    struct sigaction  sa;
-    __sighandler_t    result = SIG_ERR;
-
-    sigemptyset( &sa.sa_mask );
-
-    sa.sa_handler = handler;
-    sa.sa_flags   = flags;
-
-    if ( !sigaction( signum, &sa, &sa ) )
-        result = (__sighandler_t) sa.sa_handler;
-
-    return result;
-}
-
-
-__sighandler_t bsd_signal(int signum, __sighandler_t handler)
-{
-  return _signal(signum, handler, SA_RESTART);
-}
-
-__sighandler_t sysv_signal(int signum, __sighandler_t handler)
-{
-  return _signal(signum, handler, SA_RESETHAND);
+int sigemptyset(sigset_t* set) {
+  if (set == NULL) {
+    errno = EINVAL;
+    return -1;
+  }
+  memset(set, 0, sizeof(sigset_t));
+  return 0;
 }
diff --git a/libc/bionic/signal.c b/libc/bionic/sigfillset.cpp
similarity index 70%
copy from libc/bionic/signal.c
copy to libc/bionic/sigfillset.cpp
index 949db13..7b7cbb8 100644
--- a/libc/bionic/signal.c
+++ b/libc/bionic/sigfillset.cpp
@@ -25,33 +25,14 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
+
 #include <signal.h>
 
-
-static __sighandler_t
-_signal(int  signum, __sighandler_t  handler, int  flags)
-{
-    struct sigaction  sa;
-    __sighandler_t    result = SIG_ERR;
-
-    sigemptyset( &sa.sa_mask );
-
-    sa.sa_handler = handler;
-    sa.sa_flags   = flags;
-
-    if ( !sigaction( signum, &sa, &sa ) )
-        result = (__sighandler_t) sa.sa_handler;
-
-    return result;
-}
-
-
-__sighandler_t bsd_signal(int signum, __sighandler_t handler)
-{
-  return _signal(signum, handler, SA_RESTART);
-}
-
-__sighandler_t sysv_signal(int signum, __sighandler_t handler)
-{
-  return _signal(signum, handler, SA_RESETHAND);
+int sigfillset(sigset_t* set) {
+  if (set == NULL) {
+    errno = EINVAL;
+    return -1;
+  }
+  memset(set, ~0, sizeof(sigset_t));
+  return 0;
 }
diff --git a/libc/bionic/signal.c b/libc/bionic/sigismember.cpp
similarity index 70%
copy from libc/bionic/signal.c
copy to libc/bionic/sigismember.cpp
index 949db13..0dc73ac 100644
--- a/libc/bionic/signal.c
+++ b/libc/bionic/sigismember.cpp
@@ -25,33 +25,15 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
+
 #include <signal.h>
 
-
-static __sighandler_t
-_signal(int  signum, __sighandler_t  handler, int  flags)
-{
-    struct sigaction  sa;
-    __sighandler_t    result = SIG_ERR;
-
-    sigemptyset( &sa.sa_mask );
-
-    sa.sa_handler = handler;
-    sa.sa_flags   = flags;
-
-    if ( !sigaction( signum, &sa, &sa ) )
-        result = (__sighandler_t) sa.sa_handler;
-
-    return result;
-}
-
-
-__sighandler_t bsd_signal(int signum, __sighandler_t handler)
-{
-  return _signal(signum, handler, SA_RESTART);
-}
-
-__sighandler_t sysv_signal(int signum, __sighandler_t handler)
-{
-  return _signal(signum, handler, SA_RESETHAND);
+int sigismember(const sigset_t* set, int signum) {
+  int bit = signum - 1; // Signal numbers start at 1, but bit positions start at 0.
+  const unsigned long* local_set = (const unsigned long*) set;
+  if (set == NULL || bit < 0 || bit >= (int) (8*sizeof(sigset_t))) {
+    errno = EINVAL;
+    return -1;
+  }
+  return (int) ((local_set[bit / LONG_BIT] >> (bit % LONG_BIT)) & 1);
 }
diff --git a/libc/bionic/signal.c b/libc/bionic/signal.cpp
similarity index 75%
rename from libc/bionic/signal.c
rename to libc/bionic/signal.cpp
index 949db13..48b2e72 100644
--- a/libc/bionic/signal.c
+++ b/libc/bionic/signal.cpp
@@ -25,33 +25,30 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
+
 #include <signal.h>
 
+static sighandler_t _signal(int signum, sighandler_t handler, int flags) {
+  struct sigaction sa;
+  sigemptyset(&sa.sa_mask);
+  sa.sa_handler = handler;
+  sa.sa_flags = flags;
 
-static __sighandler_t
-_signal(int  signum, __sighandler_t  handler, int  flags)
-{
-    struct sigaction  sa;
-    __sighandler_t    result = SIG_ERR;
+  if (sigaction(signum, &sa, &sa) == -1) {
+    return SIG_ERR;
+  }
 
-    sigemptyset( &sa.sa_mask );
-
-    sa.sa_handler = handler;
-    sa.sa_flags   = flags;
-
-    if ( !sigaction( signum, &sa, &sa ) )
-        result = (__sighandler_t) sa.sa_handler;
-
-    return result;
+  return (sighandler_t) sa.sa_handler;
 }
 
-
-__sighandler_t bsd_signal(int signum, __sighandler_t handler)
-{
+sighandler_t bsd_signal(int signum, sighandler_t handler) {
   return _signal(signum, handler, SA_RESTART);
 }
 
-__sighandler_t sysv_signal(int signum, __sighandler_t handler)
-{
+sighandler_t sysv_signal(int signum, sighandler_t handler) {
   return _signal(signum, handler, SA_RESETHAND);
 }
+
+sighandler_t signal(int signum, sighandler_t handler) {
+  return bsd_signal(signum, handler);
+}