From 15e5fc96a151fa7175479152dd47c80a0d008bfc Mon Sep 17 00:00:00 2001
From: Alexey Milovidov <milovidov@clickhouse.com>
Date: Sun, 18 Sep 2022 02:24:56 +0200
Subject: [PATCH] Add a trap

---
 src/Functions/trap.cpp | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/Functions/trap.cpp b/src/Functions/trap.cpp
index 5bb0ed210de..16fada0f67d 100644
--- a/src/Functions/trap.cpp
+++ b/src/Functions/trap.cpp
@@ -14,6 +14,7 @@
 #include <cstdlib>
 #include <unistd.h>
 #include <sys/mman.h>
+#include <dlfcn.h>
 
 
 namespace DB
@@ -25,6 +26,7 @@ namespace ErrorCodes
     extern const int ILLEGAL_TYPE_OF_ARGUMENT;
     extern const int BAD_ARGUMENTS;
     extern const int CANNOT_ALLOCATE_MEMORY;
+    extern const int CANNOT_DLOPEN;
 }
 
 
@@ -136,7 +138,7 @@ public:
             }
             else if (mode == "access context")
             {
-                (void)context.getCurrentQueryId();
+                (void)context->getCurrentQueryId();
             }
             else if (mode == "stack overflow")
             {
@@ -166,6 +168,12 @@ public:
                     maps.push_back(map);
                 }
             }
+            else if (mode == "dlopen")
+            {
+                void * handle = dlopen("libc.so.6", RTLD_NOW);
+                if (!handle)
+                    throw Exception(ErrorCodes::CANNOT_DLOPEN, "Cannot dlopen: ({})", dlerror()); // NOLINT(concurrency-mt-unsafe) // MT-Safe on Linux, see man dlerror
+            }
             else
                 throw Exception("Unknown trap mode", ErrorCodes::BAD_ARGUMENTS);
         }