Fix sigsetjmp/siglongjmp to save/restore RT signals on arm/x86 too.

Our arm and x86 ABIs shipped with a 32-bit `sigset_t`, so we need to
use sigprocmask64 to save/restore the RT signals too. (This is important
because several are in use by the system, and the behavior of our 32-bit
`sigset_t` is to clear the RT signals.)

Bug: http://b/72493232
Test: ran tests
Change-Id: Idff91f8b2849276e5a3073d07eccd84e02a34410
diff --git a/tests/setjmp_test.cpp b/tests/setjmp_test.cpp
index bb01601..4f5e60c 100644
--- a/tests/setjmp_test.cpp
+++ b/tests/setjmp_test.cpp
@@ -19,6 +19,8 @@
 #include <setjmp.h>
 #include <stdlib.h>
 
+#include "ScopedSignalHandler.h"
+
 TEST(setjmp, setjmp_smoke) {
   int value;
   jmp_buf jb;
@@ -63,61 +65,59 @@
   }
 }
 
-// Two distinct signal sets, pipu
+// Two distinct signal sets.
 struct SigSets {
   SigSets() : one(MakeSigSet(0)), two(MakeSigSet(1)) {
   }
 
-  static sigset_t MakeSigSet(int offset) {
-    sigset_t ss;
-    sigemptyset(&ss);
-    sigaddset(&ss, SIGUSR1 + offset);
-#if defined(__LP64__)
-    // For arm and x86, sigset_t was too small for the RT signals.
-    // For mips, sigset_t was large enough but jmp_buf wasn't.
-    sigaddset(&ss, SIGRTMIN + offset);
-#endif
+  static sigset64_t MakeSigSet(int offset) {
+    sigset64_t ss;
+    sigemptyset64(&ss);
+    sigaddset64(&ss, SIGUSR1 + offset);
+    sigaddset64(&ss, SIGRTMIN + offset);
     return ss;
   }
 
-  sigset_t one;
-  sigset_t two;
-  sigset_t original;
+  sigset64_t one;
+  sigset64_t two;
 };
 
-void AssertSigmaskEquals(const sigset_t& expected) {
-  sigset_t actual;
-  sigprocmask(0 /* ignored */, NULL, &actual);
-  size_t end = sizeof(sigset_t) * 8;
+void AssertSigmaskEquals(const sigset64_t& expected) {
+  sigset64_t actual;
+  sigprocmask64(SIG_SETMASK, NULL, &actual);
+  size_t end = sizeof(expected) * 8;
   for (size_t i = 1; i <= end; ++i) {
-    EXPECT_EQ(sigismember(&expected, i), sigismember(&actual, i)) << i;
+    EXPECT_EQ(sigismember64(&expected, i), sigismember64(&actual, i)) << i;
   }
 }
 
 TEST(setjmp, _setjmp_signal_mask) {
+  SignalMaskRestorer smr;
+
   // _setjmp/_longjmp do not save/restore the signal mask.
   SigSets ss;
-  sigprocmask(SIG_SETMASK, &ss.one, &ss.original);
+  sigprocmask64(SIG_SETMASK, &ss.one, nullptr);
   jmp_buf jb;
   if (_setjmp(jb) == 0) {
-    sigprocmask(SIG_SETMASK, &ss.two, NULL);
+    sigprocmask64(SIG_SETMASK, &ss.two, NULL);
     _longjmp(jb, 1);
     FAIL(); // Unreachable.
   } else {
     AssertSigmaskEquals(ss.two);
   }
-  sigprocmask(SIG_SETMASK, &ss.original, NULL);
 }
 
 TEST(setjmp, setjmp_signal_mask) {
+  SignalMaskRestorer smr;
+
   // setjmp/longjmp do save/restore the signal mask on bionic, but not on glibc.
   // This is a BSD versus System V historical accident. POSIX leaves the
   // behavior unspecified, so any code that cares needs to use sigsetjmp.
   SigSets ss;
-  sigprocmask(SIG_SETMASK, &ss.one, &ss.original);
+  sigprocmask64(SIG_SETMASK, &ss.one, nullptr);
   jmp_buf jb;
   if (setjmp(jb) == 0) {
-    sigprocmask(SIG_SETMASK, &ss.two, NULL);
+    sigprocmask64(SIG_SETMASK, &ss.two, NULL);
     longjmp(jb, 1);
     FAIL(); // Unreachable.
   } else {
@@ -129,37 +129,38 @@
     AssertSigmaskEquals(ss.two);
 #endif
   }
-  sigprocmask(SIG_SETMASK, &ss.original, NULL);
 }
 
 TEST(setjmp, sigsetjmp_0_signal_mask) {
+  SignalMaskRestorer smr;
+
   // sigsetjmp(0)/siglongjmp do not save/restore the signal mask.
   SigSets ss;
-  sigprocmask(SIG_SETMASK, &ss.one, &ss.original);
+  sigprocmask64(SIG_SETMASK, &ss.one, nullptr);
   sigjmp_buf sjb;
   if (sigsetjmp(sjb, 0) == 0) {
-    sigprocmask(SIG_SETMASK, &ss.two, NULL);
+    sigprocmask64(SIG_SETMASK, &ss.two, NULL);
     siglongjmp(sjb, 1);
     FAIL(); // Unreachable.
   } else {
     AssertSigmaskEquals(ss.two);
   }
-  sigprocmask(SIG_SETMASK, &ss.original, NULL);
 }
 
 TEST(setjmp, sigsetjmp_1_signal_mask) {
+  SignalMaskRestorer smr;
+
   // sigsetjmp(1)/siglongjmp does save/restore the signal mask.
   SigSets ss;
-  sigprocmask(SIG_SETMASK, &ss.one, &ss.original);
+  sigprocmask64(SIG_SETMASK, &ss.one, nullptr);
   sigjmp_buf sjb;
   if (sigsetjmp(sjb, 1) == 0) {
-    sigprocmask(SIG_SETMASK, &ss.two, NULL);
+    sigprocmask64(SIG_SETMASK, &ss.two, NULL);
     siglongjmp(sjb, 1);
     FAIL(); // Unreachable.
   } else {
     AssertSigmaskEquals(ss.one);
   }
-  sigprocmask(SIG_SETMASK, &ss.original, NULL);
 }
 
 #if defined(__aarch64__)
@@ -218,7 +219,7 @@
 #elif defined(__aarch64__)
 #define __JB_SIGFLAG 0
 #elif defined(__i386__)
-#define __JB_SIGFLAG 7
+#define __JB_SIGFLAG 8
 #elif defined(__x86_64)
 #define __JB_SIGFLAG 8
 #elif defined(__mips__) && defined(__LP64__)