Merge pull request #16346 from ClickHouse/sigaltstack

Provide diagnostics on stack overflow

programs/server/Server.cpp

@@ -388,7 +388,7 @@ int Server::main(const std::vector<std::string> & /*args*/)
     LOG_WARNING(log, "Server was built in debug mode. It will work slowly.");
 #endif
 
-#if defined(ADDRESS_SANITIZER) || defined(THREAD_SANITIZER) || defined(MEMORY_SANITIZER)
+#if defined(SANITIZER)
     LOG_WARNING(log, "Server was built with sanitizer. It will work slowly.");
 #endif
 

src/Common/ThreadStatus.cpp

@@ -2,11 +2,14 @@
 #include <Common/ThreadProfileEvents.h>
 #include <Common/QueryProfiler.h>
 #include <Common/ThreadStatus.h>
+#include <common/errnoToString.h>
 #include <Interpreters/OpenTelemetrySpanLog.h>
 
 #include <Poco/Logger.h>
 #include <common/getThreadId.h>
 
+#include <signal.h>
+
 
 namespace DB
 {
@@ -21,6 +24,11 @@ namespace ErrorCodes
 thread_local ThreadStatus * current_thread = nullptr;
 thread_local ThreadStatus * main_thread = nullptr;
 
+#if !defined(SANITIZER) && !defined(ARCADIA_BUILD)
+    alignas(4096) static thread_local char alt_stack[4096];
+    static thread_local bool has_alt_stack = false;
+#endif
+
 
 ThreadStatus::ThreadStatus()
     : thread_id{getThreadId()}
@@ -34,6 +42,46 @@ ThreadStatus::ThreadStatus()
 
     /// NOTE: It is important not to do any non-trivial actions (like updating ProfileEvents or logging) before ThreadStatus is created
     /// Otherwise it could lead to SIGSEGV due to current_thread dereferencing
+
+    /// Will set alternative signal stack to provide diagnostics for stack overflow errors.
+    /// If not already installed for current thread.
+    /// Sanitizer makes larger stack usage and also it's incompatible with alternative stack by default (it sets up and relies on its own).
+#if !defined(SANITIZER) && !defined(ARCADIA_BUILD)
+    if (!has_alt_stack)
+    {
+        /// Don't repeat tries even if not installed successfully.
+        has_alt_stack = true;
+
+        /// We have to call 'sigaltstack' before first 'sigaction'. (It does not work other way, for unknown reason).
+        stack_t altstack_description{};
+        altstack_description.ss_sp = alt_stack;
+        altstack_description.ss_flags = 0;
+        altstack_description.ss_size = sizeof(alt_stack);
+
+        if (0 != sigaltstack(&altstack_description, nullptr))
+        {
+            LOG_WARNING(log, "Cannot set alternative signal stack for thread, {}", errnoToString(errno));
+        }
+        else
+        {
+            /// Obtain existing sigaction and modify it by adding a flag.
+            struct sigaction action{};
+            if (0 != sigaction(SIGSEGV, nullptr, &action))
+            {
+                LOG_WARNING(log, "Cannot obtain previous signal action to set alternative signal stack for thread, {}", errnoToString(errno));
+            }
+            else if (!(action.sa_flags & SA_ONSTACK))
+            {
+                action.sa_flags |= SA_ONSTACK;
+
+                if (0 != sigaction(SIGSEGV, &action, nullptr))
+                {
+                    LOG_WARNING(log, "Cannot set action with alternative signal stack for thread, {}", errnoToString(errno));
+                }
+            }
+        }
+    }
+#endif
 }
 
 ThreadStatus::~ThreadStatus()

src/Functions/trap.cpp

@@ -61,9 +61,10 @@ public:
         return std::make_shared<DataTypeUInt8>();
     }
 
-    [[clang::optnone]] void executeImpl(Block & columns, const ColumnNumbers & arguments, size_t result, size_t input_rows_count) const override
+    [[clang::optnone]]
+    ColumnPtr executeImpl(const ColumnsWithTypeAndName & block, const DataTypePtr & result_type, size_t input_rows_count) const override
     {
-        if (const ColumnConst * column = checkAndGetColumnConst<ColumnString>(columns[arguments[0]].column.get()))
+        if (const ColumnConst * column = checkAndGetColumnConst<ColumnString>(block[0].column.get()))
         {
             String mode = column->getValue<String>();
 
@@ -135,6 +136,10 @@ public:
             {
                 (void)context.getCurrentQueryId();
             }
+            else if (mode == "stack overflow")
+            {
+                executeImpl(block, result_type, input_rows_count);
+            }
             else if (mode == "mmap many")
             {
                 std::vector<void *> maps;
@@ -160,7 +165,7 @@ public:
         else
             throw Exception("The only argument for function " + getName() + " must be constant String", ErrorCodes::ILLEGAL_COLUMN);
 
-        columns[result].column = columns[result].type->createColumnConst(input_rows_count, 0ULL);
+        return result_type->createColumnConst(input_rows_count, 0ULL);
     }
 };