user-exec.c: fix build on NetBSD/sparc64 and NetBSD/arm

A couple of #ifdef changes necessary to use NetBSD's ucontext
structs on sparc64 and arm.
Signed-off-by: NTobias Nygren <tnn@NetBSD.org>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: 1425591461-17550-1-git-send-email-tnn@NetBSD.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

user-exec.c

@@ -404,6 +404,10 @@ int cpu_signal_handler(int host_signum, void *pinfo,
     struct sigcontext *uc = puc;
     unsigned long pc = uc->sc_pc;
     void *sigmask = (void *)(long)uc->sc_mask;
+#elif defined(__NetBSD__)
+    ucontext_t *uc = puc;
+    unsigned long pc = _UC_MACHINE_PC(uc);
+    void *sigmask = (void *)&uc->uc_sigmask;
 #endif
 #endif
 
@@ -441,15 +445,25 @@ int cpu_signal_handler(int host_signum, void *pinfo,
 
 #elif defined(__arm__)
 
+#if defined(__NetBSD__)
+#include <ucontext.h>
+#endif
+
 int cpu_signal_handler(int host_signum, void *pinfo,
                        void *puc)
 {
     siginfo_t *info = pinfo;
+#if defined(__NetBSD__)
+    ucontext_t *uc = puc;
+#else
     struct ucontext *uc = puc;
+#endif
     unsigned long pc;
     int is_write;
 
-#if defined(__GLIBC__) && (__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ <= 3))
+#if defined(__NetBSD__)
+    pc = uc->uc_mcontext.__gregs[_REG_R15];
+#elif defined(__GLIBC__) && (__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ <= 3))
     pc = uc->uc_mcontext.gregs[R15];
 #else
     pc = uc->uc_mcontext.arm_pc;