Allow third party sigsegv handler

For example from sanitizers.

3 files changed, 13 insertions, 2 deletions

diff --git a/CRT.c b/CRT.c
index 7776c4e7..3aea895e 100644
--- a/CRT.c
+++ b/CRT.c
@@ -552,6 +552,8 @@ void CRT_restorePrivileges() {
 
 // TODO: pass an instance of Settings instead.
 
+struct sigaction old_sigsegv_handler;
+
 void CRT_init(int delay, int colorScheme, bool allowUnicode) {
    initscr();
    noecho();
@@ -605,7 +607,11 @@ void CRT_init(int delay, int colorScheme, bool allowUnicode) {
       }
    }
 #ifndef DEBUG
-   signal(11, CRT_handleSIGSEGV);
+   struct sigaction act;
+   sigemptyset (&act.sa_mask);
+   act.sa_flags = (int)SA_RESETHAND;
+   act.sa_handler = CRT_handleSIGSEGV;
+   sigaction (SIGSEGV, &act, &old_sigsegv_handler);
 #endif
    signal(SIGTERM, CRT_handleSIGTERM);
    signal(SIGQUIT, CRT_handleSIGTERM);
diff --git a/CRT.h b/CRT.h
index 8a5d6ac6..32992e41 100644
--- a/CRT.h
+++ b/CRT.h
@@ -108,6 +108,7 @@ typedef enum ColorElements_ {
 
 void CRT_fatalError(const char* note) __attribute__ ((noreturn));
 
+extern struct sigaction old_sigsegv_handler;
 void CRT_handleSIGSEGV(int sgn);
 
 #define KEY_ALT(x) (KEY_F(64 - 26) + (x - 'A'))
diff --git a/linux/LinuxCRT.c b/linux/LinuxCRT.c
index c65b7822..dbfad27f 100644
--- a/linux/LinuxCRT.c
+++ b/linux/LinuxCRT.c
@@ -7,6 +7,8 @@ in the source distribution for its full text.
 
 #include "config.h"
 #include "CRT.h"
+
+#include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #ifdef HAVE_EXECINFO_H
@@ -32,5 +34,7 @@ void CRT_handleSIGSEGV(int sgn) {
    fprintf(stderr, "\nUnfortunately, you seem to be using an unsupported platform!");
    fprintf(stderr, "\nPlease contact your platform package maintainer!\n\n");
    #endif
-   abort();
+
+   /* Call old sigsegv handler; may be default exit or third party one (e.g. ASAN) */
+   sigaction (SIGSEGV, &old_sigsegv_handler, NULL);
 }