[RFC PATCH] linux-user: trap internal SIGABRT's

[Alex Bennée]

linux-user wants to trap all signals in case they are related to the
guest. This however results in less than helpful core dumps when the
error is internal to QEMU. We can detect when an assert failure is in
progress by examining __glib_assert_msg and fall through to
cpu_abort() which will pretty print something before restoring the
default SIGABRT behaviour and dumping core.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
 linux-user/signal.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/linux-user/signal.c b/linux-user/signal.c
index 32854bb375..8ecc1215f7 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -809,6 +809,8 @@ static inline void rewind_if_in_safe_syscall(void *puc)
     }
 }
 
+GLIB_VAR char *__glib_assert_msg;
+
 static void host_signal_handler(int host_sig, siginfo_t *info, void *puc)
 {
     CPUArchState *env = thread_cpu->env_ptr;
@@ -821,6 +823,10 @@ static void host_signal_handler(int host_sig, siginfo_t 
*info, void *puc)
     uintptr_t pc = 0;
     bool sync_sig = false;
 
+    if (__glib_assert_msg) {
+        cpu_abort(cpu, "internal QEMU error, aborting...");
+    }
+
     /*
      * Non-spoofed SIGSEGV and SIGBUS are synchronous, and need special
      * handling wrt signal blocking and unwinding.
-- 
2.30.2