From a55bbf15dd5fba2926012383758cbf7fb8414cba Mon Sep 17 00:00:00 2001
From: lingsheng <lingsheng@huawei.com>
Date: Wed, 11 Aug 2021 11:14:11 +0800
Subject: [PATCH] Fix build error with Glibc 2.34

---
 asmrun/signals_asm.c   | 23 ++++++++++++++++-------
 byterun/caml/signals.h |  1 +
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/asmrun/signals_asm.c b/asmrun/signals_asm.c
index 3895d75..bc911da 100644
--- a/asmrun/signals_asm.c
+++ b/asmrun/signals_asm.c
@@ -182,7 +182,6 @@ DECLARE_SIGNAL_HANDLER(trap_handler)
 #ifdef HAS_STACK_OVERFLOW_DETECTION
 
 static char * system_stack_top;
-static char sig_alt_stack[SIGSTKSZ];
 
 #if defined(SYS_linux)
 /* PR#4746: recent Linux kernels with support for stack randomization
@@ -272,17 +271,27 @@ void caml_init_signals(void)
 
   /* Stack overflow handling */
 #ifdef HAS_STACK_OVERFLOW_DETECTION
-  {
-    stack_t stk;
+  if (caml_setup_stack_overflow_detection() != -1) {
     struct sigaction act;
-    stk.ss_sp = sig_alt_stack;
-    stk.ss_size = SIGSTKSZ;
-    stk.ss_flags = 0;
     SET_SIGACT(act, segv_handler);
     act.sa_flags |= SA_ONSTACK | SA_NODEFER;
     sigemptyset(&act.sa_mask);
     system_stack_top = (char *) &act;
-    if (sigaltstack(&stk, NULL) == 0) { sigaction(SIGSEGV, &act, NULL); }
+    sigaction(SIGSEGV, &act, NULL);
   }
 #endif
 }
+
+int caml_setup_stack_overflow_detection(void)
+{
+#ifdef HAS_STACK_OVERFLOW_DETECTION
+  stack_t stk;
+  stk.ss_sp = malloc(SIGSTKSZ);
+  if (stk.ss_sp == NULL) return -1;
+  stk.ss_size = SIGSTKSZ;
+  stk.ss_flags = 0;
+  return sigaltstack(&stk, NULL);
+#else
+  return 0;
+#endif
+}
diff --git a/byterun/caml/signals.h b/byterun/caml/signals.h
index 99924e4..33fba31 100644
--- a/byterun/caml/signals.h
+++ b/byterun/caml/signals.h
@@ -42,6 +42,7 @@ void caml_record_signal(int signal_number);
 void caml_process_pending_signals(void);
 void caml_process_event(void);
 int caml_set_signal_action(int signo, int action);
+int caml_setup_stack_overflow_detection(void);
 
 CAMLextern void (*caml_enter_blocking_section_hook)(void);
 CAMLextern void (*caml_leave_blocking_section_hook)(void);
-- 
2.23.0