[sanitizer] Simplify sigaction and sigset_t handling.

llvm-svn: 189338

4 files changed, 54 insertions, 37 deletions

diff --git a/compiler-rt/lib/msan/msan_interceptors.cc b/compiler-rt/lib/msan/msan_interceptors.cc
index 5215674e7ce..6d5111791bb 100644
--- a/compiler-rt/lib/msan/msan_interceptors.cc
+++ b/compiler-rt/lib/msan/msan_interceptors.cc
@@ -909,7 +909,7 @@ static void SignalHandler(int signo) {
 
 static void SignalAction(int signo, void *si, void *uc) {
   UnpoisonParam(3);
-  __msan_unpoison(si, __sanitizer::struct_sigaction_sz);
+  __msan_unpoison(si, sizeof(__sanitizer_sigaction));
   __msan_unpoison(uc, __sanitizer::ucontext_t_sz);
 
   typedef void (*sigaction_cb)(int, void *, void *);
@@ -930,21 +930,21 @@ INTERCEPTOR(int, sigaction, int signo, const __sanitizer_sigaction *act,
     __sanitizer_sigaction new_act;
     __sanitizer_sigaction *pnew_act = act ? &new_act : 0;
     if (act) {
-      internal_memcpy(pnew_act, act, __sanitizer::struct_sigaction_sz);
-      uptr cb = __sanitizer::__sanitizer_get_sigaction_sa_sigaction(pnew_act);
-      uptr new_cb =
-          __sanitizer::__sanitizer_get_sigaction_sa_siginfo(pnew_act) ?
-          (uptr)SignalAction : (uptr)SignalHandler;
+      internal_memcpy(pnew_act, act, sizeof(__sanitizer_sigaction));
+      uptr cb = (uptr)pnew_act->sa_sigaction;
+      uptr new_cb = (pnew_act->sa_flags & __sanitizer::sa_siginfo)
+                        ? (uptr)SignalAction
+                        : (uptr)SignalHandler;
       if (cb != __sanitizer::sig_ign && cb != __sanitizer::sig_dfl) {
         sigactions[signo] = cb;
-        __sanitizer::__sanitizer_set_sigaction_sa_sigaction(pnew_act, new_cb);
+        pnew_act->sa_sigaction = (void (*)(int, void *, void *))new_cb;
       }
     }
     res = REAL(sigaction)(signo, pnew_act, oldact);
     if (res == 0 && oldact) {
-      uptr cb = __sanitizer::__sanitizer_get_sigaction_sa_sigaction(oldact);
+      uptr cb = (uptr)oldact->sa_sigaction;
       if (cb != __sanitizer::sig_ign && cb != __sanitizer::sig_dfl) {
-        __sanitizer::__sanitizer_set_sigaction_sa_sigaction(oldact, old_cb);
+        oldact->sa_sigaction = (void (*)(int, void *, void *))old_cb;
       }
     }
   } else {
@@ -952,7 +952,7 @@ INTERCEPTOR(int, sigaction, int signo, const __sanitizer_sigaction *act,
   }
 
   if (res == 0 && oldact) {
-    __msan_unpoison(oldact, __sanitizer::struct_sigaction_sz);
+    __msan_unpoison(oldact, sizeof(__sanitizer_sigaction));
   }
   return res;
 }
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
index 436a34dc26b..49982584edc 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -1976,13 +1976,13 @@ INTERCEPTOR(int, poll, __sanitizer_pollfd *fds, __sanitizer_nfds_t nfds,
 
 #if SANITIZER_INTERCEPT_PPOLL
 INTERCEPTOR(int, ppoll, __sanitizer_pollfd *fds, __sanitizer_nfds_t nfds,
-            void *timeout_ts, void *sigmask) {
+            void *timeout_ts, __sanitizer_sigset_t *sigmask) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, ppoll, fds, nfds, timeout_ts, sigmask);
   if (fds && nfds) read_pollfd(ctx, fds, nfds);
   if (timeout_ts)
     COMMON_INTERCEPTOR_READ_RANGE(ctx, timeout_ts, struct_timespec_sz);
-  if (sigmask) COMMON_INTERCEPTOR_READ_RANGE(ctx, timeout_ts, sigset_t_sz);
+  // FIXME: read sigmask when all of sigemptyset, etc are intercepted.
   int res =
       COMMON_INTERCEPTOR_BLOCK_REAL(ppoll)(fds, nfds, timeout_ts, sigmask);
   if (fds && nfds) write_pollfd(ctx, fds, nfds);
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.cc b/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.cc
index edd579bdae5..c8584ea1fcc 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.cc
@@ -136,26 +136,12 @@ namespace __sanitizer {
 
   uptr sig_ign = (uptr)SIG_IGN;
   uptr sig_dfl = (uptr)SIG_DFL;
+  uptr sa_siginfo = (uptr)SA_SIGINFO;
 
 #if SANITIZER_LINUX
   int e_tabsz = (int)E_TABSZ;
 #endif
 
-  uptr __sanitizer_get_sigaction_sa_sigaction(void *act) {
-    struct sigaction *a = (struct sigaction *)act;
-    // Check that sa_sigaction and sa_handler are the same.
-    CHECK((void *)&(a->sa_sigaction) == (void *)&(a->sa_handler));
-    return (uptr) a->sa_sigaction;
-  }
-  void __sanitizer_set_sigaction_sa_sigaction(void *act, uptr cb) {
-    struct sigaction *a = (struct sigaction *)act;
-    a->sa_sigaction = (void (*)(int, siginfo_t *, void *))cb;
-  }
-  bool __sanitizer_get_sigaction_sa_siginfo(void *act) {
-    struct sigaction *a = (struct sigaction *)act;
-    return a->sa_flags & SA_SIGINFO;
-  }
-
   int af_inet = (int)AF_INET;
   int af_inet6 = (int)AF_INET6;
 
@@ -730,9 +716,15 @@ namespace __sanitizer {
   COMPILER_CHECK(offsetof(__sanitizer_##CLASS, MEMBER) ==          \
                  offsetof(CLASS, MEMBER))
 
+// For sigaction, which is a function and struct at the same time,
+// and thus requires explicit "struct" in sizeof() expression.
+#define CHECK_STRUCT_SIZE_AND_OFFSET(CLASS, MEMBER)                       \
+  COMPILER_CHECK(sizeof(((struct __sanitizer_##CLASS *) NULL)->MEMBER) == \
+                 sizeof(((struct CLASS *) NULL)->MEMBER));                \
+  COMPILER_CHECK(offsetof(struct __sanitizer_##CLASS, MEMBER) ==          \
+                 offsetof(struct CLASS, MEMBER))
+
 COMPILER_CHECK(sizeof(__sanitizer_pthread_attr_t) >= sizeof(pthread_attr_t));
-COMPILER_CHECK(sizeof(__sanitizer::struct_sigaction_max_sz) >=
-                   sizeof(__sanitizer::struct_sigaction_sz));
 
 COMPILER_CHECK(sizeof(socklen_t) == sizeof(unsigned));
 CHECK_TYPE_SIZE(pthread_key_t);
@@ -821,7 +813,19 @@ CHECK_TYPE_SIZE(pollfd);
 CHECK_SIZE_AND_OFFSET(pollfd, fd);
 CHECK_SIZE_AND_OFFSET(pollfd, events);
 CHECK_SIZE_AND_OFFSET(pollfd, revents);
+
 CHECK_TYPE_SIZE(nfds_t);
 
+CHECK_TYPE_SIZE(sigset_t);
+
+COMPILER_CHECK(sizeof(__sanitizer_sigaction) == sizeof(struct sigaction));
+// Can't write checks for sa_handler and sa_sigaction due to them being
+// preprocessor macros.
+CHECK_STRUCT_SIZE_AND_OFFSET(sigaction, sa_mask);
+CHECK_STRUCT_SIZE_AND_OFFSET(sigaction, sa_flags);
+#if SANITIZER_LINUX
+CHECK_STRUCT_SIZE_AND_OFFSET(sigaction, sa_restorer);
+#endif
+
 #endif  // SANITIZER_LINUX || SANITIZER_MAC
 
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.h b/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.h
index 1ccdb30a480..a602bfe0b40 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.h
@@ -25,7 +25,6 @@ namespace __sanitizer {
   extern unsigned struct_tm_sz;
   extern unsigned struct_passwd_sz;
   extern unsigned struct_group_sz;
-  extern unsigned struct_sigaction_sz;
   extern unsigned siginfo_t_sz;
   extern unsigned struct_itimerval_sz;
   extern unsigned pthread_t_sz;
@@ -33,7 +32,6 @@ namespace __sanitizer {
   extern unsigned timeval_sz;
   extern unsigned uid_t_sz;
   extern unsigned mbstate_t_sz;
-  extern unsigned sigset_t_sz;
 
 #if !SANITIZER_ANDROID
   extern unsigned ucontext_t_sz;
@@ -135,17 +133,32 @@ namespace __sanitizer {
     void *align;
   };
 
-  uptr __sanitizer_get_sigaction_sa_sigaction(void *act);
-  void __sanitizer_set_sigaction_sa_sigaction(void *act, uptr cb);
-  bool __sanitizer_get_sigaction_sa_siginfo(void *act);
+#if SANITIZER_ANDROID
+  typedef unsigned long __sanitizer_sigset_t;
+#elif SANITIZER_MAC
+  typedef unsigned __sanitizer_sigset_t;
+#elif SANITIZER_LINUX
+  struct __sanitizer_sigset_t {
+    // The size is determined by looking at sizeof of real sigset_t on linux.
+    uptr val[128 / sizeof(uptr)];
+  };
+#endif
 
-  const unsigned struct_sigaction_max_sz = 256;
-  union __sanitizer_sigaction {
-    char size[struct_sigaction_max_sz]; // NOLINT
+  struct __sanitizer_sigaction {
+    union {
+      void (*sa_handler)(int sig);
+      void (*sa_sigaction)(int sig, void *siginfo, void *uctx);
+    };
+    __sanitizer_sigset_t sa_mask;
+    int sa_flags;
+#if SANITIZER_LINUX
+    void (*sa_restorer)();
+#endif
   };
 
   extern uptr sig_ign;
   extern uptr sig_dfl;
+  extern uptr sa_siginfo;
 
 #if SANITIZER_LINUX
   extern int e_tabsz;