Check if a fatal signal is from kernel

nobu · nobu · commit f928e60d4131 · 2024-04-03T23:14:52.000+09:00
On Linux, `siginfo_t` uses a union for each `si_code`, and the field corresponding to `si_pid` does not belong to the `_sigfault` field for SIGSEGV. It actually overlaps the `si_addr` field, which is usually non-zero on stack overflow. #10201 (comment)
diff --git a/signal.c b/signal.c
@@ -867,16 +867,19 @@ check_stack_overflow(int sig, const void *addr)
     }
 }
 # endif
+
 # ifdef _WIN32
 #   define CHECK_STACK_OVERFLOW() check_stack_overflow(sig, 0)
 # else
 #   define FAULT_ADDRESS info->si_addr
 #   ifdef USE_UCONTEXT_REG
-#     define CHECK_STACK_OVERFLOW() (info->si_pid ? (void)0 : check_stack_overflow(sig, (uintptr_t)FAULT_ADDRESS, ctx))
+#     define CHECK_STACK_OVERFLOW_() check_stack_overflow(sig, (uintptr_t)FAULT_ADDRESS, ctx)
 #   else
-#     define CHECK_STACK_OVERFLOW() (info->si_pid ? (void)0 : check_stack_overflow(sig, FAULT_ADDRESS))
+#     define CHECK_STACK_OVERFLOW_() check_stack_overflow(sig, FAULT_ADDRESS)
 #   endif
 #   define MESSAGE_FAULT_ADDRESS " at %p", FAULT_ADDRESS
+#   define SIGNAL_FROM_USER_P() ((info)->si_code == SI_USER)
+#   define CHECK_STACK_OVERFLOW() (SIGNAL_FROM_USER_P() ? (void)0 : CHECK_STACK_OVERFLOW_())
 # endif
 #else
 # define CHECK_STACK_OVERFLOW() (void)0
