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-rw-r--r--erts/emulator/sys/unix/erl_unix_sys.h26
-rw-r--r--erts/emulator/sys/unix/sys.c31
2 files changed, 56 insertions, 1 deletions
diff --git a/erts/emulator/sys/unix/erl_unix_sys.h b/erts/emulator/sys/unix/erl_unix_sys.h
index bc55fab8fb..1932e97742 100644
--- a/erts/emulator/sys/unix/erl_unix_sys.h
+++ b/erts/emulator/sys/unix/erl_unix_sys.h
@@ -45,7 +45,7 @@
#include <fcntl.h>
#include "erl_errno.h"
#include <signal.h>
-
+#include <setjmp.h>
#if HAVE_SYS_SOCKETIO_H
# include <sys/socketio.h>
@@ -349,4 +349,28 @@ extern int exit_async(void);
#define ERTS_EXIT_AFTER_DUMP _exit
+#if !defined(__APPLE__) && !defined(__MACH__)
+/* Some OS X versions do not allow (ab)using signal handlers like this */
+#define ERTS_HAVE_TRY_CATCH 1
+
+/* We try to simulate a try catch in C with the help of signal handlers.
+ * Only use this as a very last resort, as it is not very portable and
+ * quite unstable. It is also not thread safe, so make sure that only
+ * one thread can call this at a time!
+ */
+extern void erts_sys_sigsegv_handler(int);
+extern jmp_buf erts_sys_sigsegv_jmp;
+#define ERTS_SYS_TRY_CATCH(EXPR,CATCH) \
+ do { \
+ SIGFUNC prev_handler = sys_signal(SIGSEGV, \
+ erts_sys_sigsegv_handler); \
+ if (!setjmp(erts_sys_sigsegv_jmp)) { \
+ EXPR; \
+ } else { \
+ CATCH; \
+ } \
+ sys_signal(SIGSEGV,prev_handler); \
+ } while(0)
+#endif
+
#endif /* #ifndef _ERL_UNIX_SYS_H */
diff --git a/erts/emulator/sys/unix/sys.c b/erts/emulator/sys/unix/sys.c
index 74d67cbd57..57f9fbef53 100644
--- a/erts/emulator/sys/unix/sys.c
+++ b/erts/emulator/sys/unix/sys.c
@@ -223,6 +223,8 @@ static int sig_suspend_fds[2] = {-1, -1};
static int async_fd[2];
#endif
+jmp_buf erts_sys_sigsegv_jmp;
+
#if CHLDWTHR || defined(ERTS_SMP)
erts_mtx_t chld_stat_mtx;
#endif
@@ -683,6 +685,35 @@ void sys_sigrelease(int sig)
sigprocmask(SIG_UNBLOCK, &mask, (sigset_t *)NULL);
}
+void erts_sys_sigsegv_handler(int signo) {
+ if (signo == SIGSEGV) {
+ longjmp(erts_sys_sigsegv_jmp, 1);
+ }
+}
+
+/*
+ * Function returns 1 if we can read from all values in between
+ * start and stop.
+ */
+int
+erts_sys_is_area_readable(char *start, char *stop) {
+ int fds[2];
+ if (!pipe(fds)) {
+ /* We let write try to figure out if the pointers are readable */
+ int res = write(fds[1], start, (char*)stop - (char*)start);
+ if (res == -1) {
+ close(fds[0]);
+ close(fds[1]);
+ return 0;
+ }
+ close(fds[0]);
+ close(fds[1]);
+ return 1;
+ }
+ return 0;
+
+}
+
static ERTS_INLINE int
prepare_crash_dump(int secs)
{